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• W2076356875 abstract "The phenotypic changes in parathyroid cells after successful renal transplantation remain to be elucidated. We compared 10 diffuse and 11 nodular hyperplastic parathyroid glands from five renal allograft recipients with persistent hyperparathyroidism, with five diffuse and 13 nodular hyperplasia from seven uremic patients on hemodialysis, and 13 normal glands. Comparisons included expressions of both vitamin D receptor (VDR) and calcium-sensing receptor (CaSR), proliferative activity (Ki67), and apoptosis (TUNEL). Immunoreactivity was assessed semiquantitatively and expressed as labeling index. The area/cell was also measured to assess cellular hypertrophy. The labeling indexes of VDR (587±71; mean±s.e.m.) and CaSR (45.0±2.8) in recipients’ diffuse hyperplasia were significantly higher than those in uremic diffuse hyperplasia (224±44, 29.3±2.3, respectively) (P<0.01, each). However, these expressions remained low in recipients’ nodular hyperplasia (42±8, 11.8±1.4, respectively). Ki67 labeling index in recipients’ nodular hyperplasia (7±1) was significantly smaller than in uremic patients (24±6, P<0.01). TUNEL labeling index in recipients’ diffuse hyperplasia (30±5) was the highest among the groups. The cell volume tended to be smaller in both patterns of hyperplasia in allograft recipients compared with uremic patients. Our results suggest that the phenotypic change in parathyroid cells after renal transplantation depends on the pattern of hyperplasia, where it is normalized only in diffuse hyperplastic glands in which the number of cells also regresses with significant induction of apoptosis. The phenotypic changes in parathyroid cells after successful renal transplantation remain to be elucidated. We compared 10 diffuse and 11 nodular hyperplastic parathyroid glands from five renal allograft recipients with persistent hyperparathyroidism, with five diffuse and 13 nodular hyperplasia from seven uremic patients on hemodialysis, and 13 normal glands. Comparisons included expressions of both vitamin D receptor (VDR) and calcium-sensing receptor (CaSR), proliferative activity (Ki67), and apoptosis (TUNEL). Immunoreactivity was assessed semiquantitatively and expressed as labeling index. The area/cell was also measured to assess cellular hypertrophy. The labeling indexes of VDR (587±71; mean±s.e.m.) and CaSR (45.0±2.8) in recipients’ diffuse hyperplasia were significantly higher than those in uremic diffuse hyperplasia (224±44, 29.3±2.3, respectively) (P<0.01, each). However, these expressions remained low in recipients’ nodular hyperplasia (42±8, 11.8±1.4, respectively). Ki67 labeling index in recipients’ nodular hyperplasia (7±1) was significantly smaller than in uremic patients (24±6, P<0.01). TUNEL labeling index in recipients’ diffuse hyperplasia (30±5) was the highest among the groups. The cell volume tended to be smaller in both patterns of hyperplasia in allograft recipients compared with uremic patients. Our results suggest that the phenotypic change in parathyroid cells after renal transplantation depends on the pattern of hyperplasia, where it is normalized only in diffuse hyperplastic glands in which the number of cells also regresses with significant induction of apoptosis. Secondary hyperparathyroidism is the major complication in patients with chronic renal disease, and the main pathogenic factors include the deficiency of active vitamin D production, hypocalcemia, and phosphorus retention. The sustained hyperfunction of the parathyroid gland is attributable to the progressive proliferation of parathyroid cells. Immunohistochemical analyses have revealed the downregulation of vitamin D receptor (VDR), calcium-sensing receptor (CaSR), and the cyclin-dependent kinase inhibitor, p21 and p27, and the upregulation of transforming growth factor-α in resected glands from animal models and hemodialysis patients.1.Brown A.J. Ritter C.S. Finch J.L. et al.Decreased calcium-sensing receptor expression in hyperplastic parathyroid glands of uremic rats: role of dietary phosphate.Kidney Int. 1999; 55: 1284-1292Abstract Full Text Full Text PDF PubMed Scopus (136) Google Scholar, 2.Kifor O. Moore Jr, F.D. Wang P. et al.Reduced immunostaining for the extracellular Ca2+-sensing receptor in primary and uremic secondary hyperparathyroidism.J Clin Endocrinol Metab. 1996; 81: 1589-1606Google Scholar, 3.Gogusev J. Duchambon P. Hory B. et al.Depressed expression of calcium receptor in parathyroid gland tissue of patients with hyperparathyroidism.Kidney Int. 1997; 51: 328-336Abstract Full Text PDF PubMed Scopus (435) Google Scholar, 4.Korkor A.B. Reduced binding of [3H]1,25-dihydroxyvitamin D3 in the parathyroid glands of patients with renal failure.N Engl J Med. 1987; 316: 1573-1577Crossref PubMed Scopus (253) Google Scholar, 5.Fukuda N. Tanaka H. Tominaga Y. et al.Decreased 1,25-dihydroxyvitamin D3 receptor density is associated with a more severe form of parathyroid hyperplasia in chronic uremic patients.J Clin Invest. 1993; 92: 1436-1443Crossref PubMed Scopus (559) Google Scholar, 6.Brown A.J. Dusso A. Lopez-Hilker S. et al.1,25-(OH)2D3 receptors are decreased in parathyroid glands from chronically uremic dogs.Kidney Int. 1989; 35: 19-23Abstract Full Text PDF PubMed Scopus (135) Google Scholar, 7.Tokumoto M. Tsuruya K. Fukuda K. et al.Reduced p21, p27 and vitamin D receptor in the nodular hyperplasia in patients with advanced secondary hyperparathyroidism.Kidney Int. 2002; 62: 1196-1207Abstract Full Text Full Text PDF PubMed Scopus (0) Google Scholar, 8.Dusso A.S. Pavlopoulos T. Naumovich L. et al.p21WAF1 and transforming growth factor-α mediate dietary phosphate regulation of parathyroid cell growth.Kidney Int. 2001; 59: 855-865Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar, 9.Cozzolino M. Lu Y. Finch J. et al.p21WAF1 and TGF-α mediate parathyroid growth arrest by vitamin D and high calcium.Kidney Int. 2001; 60: 2109-2117Abstract Full Text Full Text PDF PubMed Scopus (159) Google Scholar These phenotypic alterations of parathyroid cells develop during the earlier course of chronic renal disease,1.Brown A.J. Ritter C.S. Finch J.L. et al.Decreased calcium-sensing receptor expression in hyperplastic parathyroid glands of uremic rats: role of dietary phosphate.Kidney Int. 1999; 55: 1284-1292Abstract Full Text Full Text PDF PubMed Scopus (136) Google Scholar, 8.Dusso A.S. Pavlopoulos T. Naumovich L. et al.p21WAF1 and transforming growth factor-α mediate dietary phosphate regulation of parathyroid cell growth.Kidney Int. 2001; 59: 855-865Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar, 9.Cozzolino M. Lu Y. Finch J. et al.p21WAF1 and TGF-α mediate parathyroid growth arrest by vitamin D and high calcium.Kidney Int. 2001; 60: 2109-2117Abstract Full Text Full Text PDF PubMed Scopus (159) Google Scholar and parathyroid hyperplasia changes its pattern from diffuse to nodular one.5.Fukuda N. Tanaka H. Tominaga Y. et al.Decreased 1,25-dihydroxyvitamin D3 receptor density is associated with a more severe form of parathyroid hyperplasia in chronic uremic patients.J Clin Invest. 1993; 92: 1436-1443Crossref PubMed Scopus (559) Google Scholar In most cases, the biochemical disorders normalize within the first month after successful renal transplantation, in association with the normalization of parathyroid function within 12 months.10.Alsina J. Gonzalez M.T. Bonnin R. et al.Long-term evolution of renal osteodystrophy after renal transplantation.Transplant Proc. 1989; 21: 2151-2158PubMed Google Scholar, 11.Saha H.H. Salmela K.T. Ahonen P.J. et al.Sequential changes in vitamin D and calcium metabolism after successful renal transplantation.Scand J Urol Nephrol. 1994; 28: 21-27Crossref PubMed Scopus (52) Google Scholar, 12.Claesson K. Hellman P. Frödin L. et al.Prospective study of calcium homeostasis after renal transplantation.World J Surg. 1998; 22: 635-642Crossref PubMed Scopus (19) Google Scholar, 13.Bonarek H. Merville P. Bonarek M. et al.Reduced parathyroid functional mass after successful kidney transplantation.Kidney Int. 1999; 56: 642-649Abstract Full Text Full Text PDF PubMed Scopus (83) Google Scholar, 14.Messa P. Sindici C. Cannella G. et al.Persistent secondary hyperparathyroidism after renal transplantation.Kidney Int. 1998; 54: 1704-1713Abstract Full Text Full Text PDF PubMed Scopus (168) Google Scholar However, even with achievement of normal renal function, persistent hyperparathyroidism can still be recognized in some allograft recipients, requiring parathyroidectomy.14.Messa P. Sindici C. Cannella G. et al.Persistent secondary hyperparathyroidism after renal transplantation.Kidney Int. 1998; 54: 1704-1713Abstract Full Text Full Text PDF PubMed Scopus (168) Google Scholar, 15.Schmid T. Muller P. Spelsberg F. Parathyroidectomy after renal transplantation: a retrospective analysis of long-term outcome.Nephrol Dial Transplant. 1997; 12: 2393-2396Crossref PubMed Scopus (58) Google Scholar, 16.Mourad M. Malaise J. Chautems R.C. et al.Early posttransplant calcemia as a predictive indicator for parathyroidectomy in kidney allograft recipients with tertiary hyperparathyroidism.Transplant Proc. 2000; 32: 437-440Abstract Full Text Full Text PDF PubMed Scopus (13) Google Scholar, 17.Kinnaert P. Nagy N. Decoster-Gervy C. et al.Persistent hyperparathyroidism requiring surgical treatment after kidney transplantation.World J Surg. 2000; 24: 1391-1395Crossref PubMed Scopus (35) Google Scholar, 18.Kligo M. Pirsch J.D. Warner T.F. et al.Tertiary hyperparathyroidism after renal transplantation: surgical strategy.Surgery. 1998; 124: 677-684Abstract Full Text Full Text PDF PubMed Scopus (62) Google Scholar, 19.Kerby J.D. Rue L.W. Blair H. et al.Operative treatment of tertiary hyperparathyroidism. A single-center experience.Ann Surg. 1998; 227: 878-886Crossref PubMed Scopus (80) Google Scholar In these patients, excessive parathyroid hormone (PTH) secretion continues, which enhances calcium (Ca) re-absorption and phosphorus (Pi) excretion via the transplanted kidney, leading to hypercalcemia and hypophosphatemia. The restoration of active vitamin D synthesis and improvement of skeletal resistance to PTH may also accelerate hypercalcemia. It has been reported that renal allograft recipients with persistent secondary hyperparathyroidism tend to have a history of longer duration of hemodialysis and a higher level of PTH at the time of renal transplantation,10.Alsina J. Gonzalez M.T. Bonnin R. et al.Long-term evolution of renal osteodystrophy after renal transplantation.Transplant Proc. 1989; 21: 2151-2158PubMed Google Scholar, 20.Christensen M.S. Nielsen H.E. Parathyroid function after renal transplantation: interrelationships between renal function, serum calcium and serum parathyroid hormone in normocalcemic long-term survivors.Clin Nephrol. 1977; 8: 472-476PubMed Google Scholar suggesting that persistent hyperparathyroidism is largely dependent on parathyroid gland volume, that is, the pattern of hyperplasia.21.McCarron D.A. Muther R.S. Lenfesty B. et al.Parathyroid function in persistent hyperparathyroidism: relationship to gland size.Kidney Int. 1982; 22: 662-670Abstract Full Text PDF PubMed Scopus (100) Google Scholar, 22.Harach H.R. Jasani B. Parathyroid hyperplasia in tertiary hyperparathyroidism: a pathological and immunohistochemical reappraisal.Histopathology. 1992; 21: 513-519Crossref PubMed Scopus (36) Google Scholar There is still uncertainty about regression of parathyroid hyperplasia after successful renal transplantation. Lewin et al.23.Lewin E. Wang W. Olgaard K. Reversibility of experimental secondary hyperparathyroidism.Kidney Int. 1997; 52: 1232-1241Abstract Full Text PDF PubMed Scopus (49) Google Scholar suggested that in spite of the rapid reversibility of parathyroid function after renal transplantation in uremic rats, parathyroid gland regression does not contribute to this reversibility, although no histological data were presented to prove this. On the other hand, Bonarek et al.13.Bonarek H. Merville P. Bonarek M. et al.Reduced parathyroid functional mass after successful kidney transplantation.Kidney Int. 1999; 56: 642-649Abstract Full Text Full Text PDF PubMed Scopus (83) Google Scholar reported a significant decrease in the mean maximal PTH levels at 6 months after renal transplantation, suggesting that the improvement of parathyroid function was mainly owing to reduction of its functional mass. Normal parathyroid cells are known to show an extremely low turnover, their mean lifespan being approximately 2 years in adult rats24.Wang Q. Palnitkar S. Parfitt A.M. Parathyroid cell proliferation in the rat: effect of age and of phosphate administration and recovery.Endocrinology. 1996; 137: 4558-4562Crossref PubMed Scopus (64) Google Scholar and 20 years in humans.25.Wang Q. Palnitkar S. Parfitt A.M. The basal rate of cell proliferation in normal human parathyroid tissue: implications for the pathogenesis of hyperparathyroidism.Clin Endocrinol. 1997; 46: 343-349Crossref PubMed Scopus (51) Google Scholar Interestingly, the rate of proliferation of hyperplastic parathyroid tissue of uremic patients is reported to be higher than that of apoptosis.26.Drüeke T.B. Cell biology of parathyroid gland hyperplasia in chronic renal failure.J Am Soc Nephrol. 2000; 11: 1141-1152PubMed Google Scholar, 27.Zhang P. Duchambon P. Gogusev J. et al.Apoptosis in parathyroid hyperplasia of patients with primary or secondary uremic hyperparathyroidism.Kidney Int. 2000; 57: 437-445Abstract Full Text Full Text PDF PubMed Scopus (36) Google Scholar Thus, Parfitt28.Parfitt A.M. The hyperparathyroidism of chronic renal failure: a disorder of growth.Kidney Int. 1997; 52: 3-9Abstract Full Text PDF PubMed Scopus (180) Google Scholar expected that the regression after kidney transplantation must be an extremely slow process, and if it occurs, apoptosis may be involved. However, there are no data on changes in parathyroid cell number and cell hypertrophy after successful renal transplantation. The present study was designed to determine the mechanism of persistent hyperparathyroidism in renal allograft recipients. For this purpose, we examined the phenotypic changes of parathyroid cells, in terms of expressions of VDR and CaSR, in the resected glands from renal allograft recipients who have had more than one hyperplastic nodules and finally underwent parathyroidectomy owing to severe persistent hyperparathyroidism. The second aim of the study was to assess the balance between cell proliferation and apoptosis in these resected glands. As depicted in Table 1, the preoperative level of corrected serum Ca was significantly highest in allograft recipients with persistent hyperparathyroidism, followed by those in uremic patients and the control subjects. Serum Pi was high in hemodialysis patients, followed by control subjects, and was lowest in allograft recipients. Serum alkaline phosphatase and intact PTH were higher in the recipients than those of other groups. Among five recipients, endogenous 1,25-dihydroxyvitamin D3 was measured in only one recipient, which was 53 pg/ml (within normal range).Table 1Clinical featuresNormalHemodialysis patientsRenal allograft recipientsP-valuen1585—Age (years)55±359±348±2NSDuration of hemodialysis (months)NA190±46139±22NSRenal disease (CGN/DM/unknown)NA4/2/23/0/2—Time between renal transplantation and parathyroidectomy (months)NANA12±3—Serum corrected calcium (mg/dl)9.1±0.110.7±0.212.3±0.5<0.01Serum phosphate (mg/dl)3.7±0.15.5±0.32.5±0.2<0.01Serum alkaline phosphatase (U/l)219±15704±102506±99<0.05Serum intact PTH (pg/ml)NA1007±120187±30<0.01CGN, chronic glomerulonephritis; DM, diabetes mellitus; n, number of specimens; NA, not available; PTH, parathyroid hormone.Data are expressed as mean±s.e.m. Open table in a new tab CGN, chronic glomerulonephritis; DM, diabetes mellitus; n, number of specimens; NA, not available; PTH, parathyroid hormone. Data are expressed as mean±s.e.m. The gland weight was heavier in uremic nodular hyperplasia and recipients with nodular hyperplasia, followed by those with diffuse hyperplasia of both groups (Table 2). Histopathological examination revealed that all the renal allograft recipients who underwent parathyroidectomy had at least more than one nodular hyperplastic glands.Table 2Parathyroid gland weight, labeling indices of VDR, CaSR, Ki67 antigen expression and TUNEL, and cell size index in five parathyroid tissues obtained from each groupGroupnParathyroid gland weight (g)VDR labeling index (/1000 cells)CaSR labeling index (%)Ki67 labeling index (/1000 cells)TUNEL labeling index (/1000 cells)Cell size index (μm2/cell)Normal glands13NA639±20350.3±2.94±12±1123±6Hemodialysis patientsDiffuse hyperplasia50.23±0.10224±44*29.3±2.3*5±23±1131±6Nodular hyperplasia131.32±0.36#42±8*,#11.8±1.4*,#24±6*,#7±2200±17*,#Renal allograft recipientsDiffuse hyperplasia100.09±0.06558±71#45.0±2.8#5±330±5*,#125±5Nodular hyperplasia110.44±0.14§§103±45*17.7±3.5*7±1§8±3155±7§§CaSR, calcium-sensing receptor; NA, not available; TUNEL, TdT-mediated dUTP nick end labeling; VDR, vitamin D receptor.Data are expressed as the mean±s.e.m.*P<0.01 vs normal glands, #P<0.01 vs uremic diffuse hyperplasia, §P<0.01, §§P<0.05 vs uremic nodular hyperplasia. Open table in a new tab CaSR, calcium-sensing receptor; NA, not available; TUNEL, TdT-mediated dUTP nick end labeling; VDR, vitamin D receptor. Data are expressed as the mean±s.e.m. *P<0.01 vs normal glands, #P<0.01 vs uremic diffuse hyperplasia, §P<0.01, §§P<0.05 vs uremic nodular hyperplasia. Immunohistochemical staining of VDR protein revealed nuclear localization and that of CaSR protein revealed mainly cytoplasmic localization. Representative figures are shown in Figure 1. The labeling indices of the expressions of VDR and CaSR protein in both uremic nodular hyperplasia and recipients with nodular hyperplasia were significantly reduced compared with those of normal glands (P<0.01, each). On the other hand, the expression levels in recipients with diffuse hyperplasia were significantly higher than those in uremic diffuse hyperplasia (P<0.01, each), being comparable with those of the control (Table 2). Ki67 antigen expression showed mainly nuclear localization (Figure 2). Semiquantitative analysis demonstrated a significantly higher Ki67 labeling index in uremic nodular hyperplasia than in normal glands (P<0.01). On the other hand, that of recipients with nodular hyperplasia was comparable with that of the normal control, and was significantly lower than that of patients with uremic nodular hyperplasia (P<0.01). Analysis of parathyroid tissue by TdT-mediated dUTP nick end labeling (TUNEL) technique revealed a distinct pattern of nuclear staining in positive cells and negative cells (Figure 1). Figure 1c, f, and i shows representative features in normal glands and uremic diffuse and nodular hyperplasia, respectively. A few apoptotic cells per high-power field (× 400 magnification) were noted. Figure 1l shows typical features of a recipient with diffuse hyperplasia, demonstrating the presence of large numbers of TUNEL-positive cells. In recipients with nodular hyperplasia, only few TUNEL-positive cells were encountered (Figure 1o). Table 2 lists the average number of apoptotic cells per 1000 parathyroid cells (labeling index) for each tissue group. The TUNEL labeling index in recipients with diffuse hyperplasia was extremely and significantly higher compared with other tissue groups (P<0.01, each). The differences in the labeling indices of Ki67 and TUNEL were assessed in the five groups (Figure 3). The Ki67 labeling index was equal to that of TUNEL in normal control, and was higher than that of TUNEL in uremic nodular hyperplasia. In recipients with diffuse hyperplasia, the TUNEL labeling index was extremely higher than the Ki67 labeling index. Parathyroid cell volume in each tissue group was measured by calculating the cell profile area divided by the cell number, expressed as cell size index (Table 2). Representative hematoxylin–eosin-stained sections are shown in Figure 4. The cell profile area of patients with uremic nodular hyperplasia was significantly larger than that of normal glands and uremic patients with diffuse hyperplasia (P<0.01, each). The cell size index of recipients with nodular hyperplasia was comparably larger than that of the normal control, but significantly smaller than that of patients with uremic nodular hyperplasia (P<0.05). The index was comparable between uremic and recipient patients with diffuse hyperplasia. The present study revealed that the diffuse hyperplastic parathyroid glands of renal allograft recipient patients with persistent secondary hyperparathyroidism show restoration of VDR and CaSR expression, together with significant apoptosis. Histopathological examination revealed that these patients had at least more than one nodular hyperplastic glands, considered as the causative nodules for the persistent hyperparathyroidism. These results were compatible with the previous reports, demonstrating that glands of patients with persistent hyperparathyroidism after renal transplantation contained more than one nodular hyperplasia.14.Messa P. Sindici C. Cannella G. et al.Persistent secondary hyperparathyroidism after renal transplantation.Kidney Int. 1998; 54: 1704-1713Abstract Full Text Full Text PDF PubMed Scopus (168) Google Scholar, 22.Harach H.R. Jasani B. Parathyroid hyperplasia in tertiary hyperparathyroidism: a pathological and immunohistochemical reappraisal.Histopathology. 1992; 21: 513-519Crossref PubMed Scopus (36) Google Scholar Restoration of these sensing receptors was obvious only in diffuse hyperplasia. It is well known that active vitamin D itself is a strong factor for upregulation of VDR and CaSR expression,29.Denda M. Finch J. Brown A.J. et al.1,25-dihydroxyvitamin D3 and 22-oxacalcitriol prevent the decrease in vitamin D receptor content in the parathyroid glands of uremic rats.Kidney Int. 1996; 50: 34-39Abstract Full Text PDF PubMed Scopus (87) Google Scholar, 30.Brown A.J. Zhong M. Finch J. et al.Rat calcium-sensing receptor is regulated by vitamin D but not by calcium.Am J Physiol. 1996; 270: F454-F460PubMed Google Scholar via vitamin D responsive element upstream of CaSR gene.31.Canaff L. Hendy G.N. Human calcium-sensing receptor gene. Vitamin D response elements in promoters P1 and P2 confer transcriptional responsiveness to 1,25-dihydroxyvitamin D.J Biol Chem. 2002; 277: 30337-30350Crossref PubMed Scopus (351) Google Scholar Thus, the recovery of active vitamin D production by the transplanted kidney is considered to play a major role in its process, and more importantly, the responsiveness of the diffuse type of hyperplasia to active vitamin D was intact, whereas it was lost in the nodular hyperplastic glands. Indeed, serum vitamin D level of one recipient recovered to normal level. It was also interesting to see that in spite of comparatively low PTH level, bone turnover as well as serum calcium levels increased in renal allograft recipients with persistent hyperparathyroidism. These results suggest that the skeletal resistance to PTH may recover after successful renal transplantation. Another important finding of the present study was the reduced proliferative activity, as assessed by the expression of Ki67 protein, in both types of hyperplasia in allograft recipients. Ki67 expression in recipients with nodular hyperplasia was also lower than in uremic nodular hyperplasia, being compatible with that in normal glands. Parfitt28.Parfitt A.M. The hyperparathyroidism of chronic renal failure: a disorder of growth.Kidney Int. 1997; 52: 3-9Abstract Full Text PDF PubMed Scopus (180) Google Scholar postulated that renal functional recovery after renal transplantation might arrest further growth of parathyroid glands. We demonstrated previously that the suppression of cyclin-dependent kinase inhibitors, p21 and p27, in a vitamin D-dependent manner was the main stream to parathyroid gland hyperplasia.7.Tokumoto M. Tsuruya K. Fukuda K. et al.Reduced p21, p27 and vitamin D receptor in the nodular hyperplasia in patients with advanced secondary hyperparathyroidism.Kidney Int. 2002; 62: 1196-1207Abstract Full Text Full Text PDF PubMed Scopus (0) Google Scholar In diffuse hyperplasia, it is easily understood that restoration of VDR improves the sensing mechanism of active vitamin D, with a resultant inhibition of cell cycle progression. In nodular hyperplasia, it means no further glandular growth. However, the mechanism by which Ki67 expression was reduced in nodular hyperplasia could not be elucidated in the present study. It is speculated that normalization of uremic milieu might play a role in suppression of cell proliferation. Furthermore, the weight of parathyroid glands of recipients with nodular hyperplasia was lower than that of uremic patients with nodular hyperplasia. Indeed, the cell volume expressed as cell size index was significantly lower in this type of hyperplasia compared with uremic nodular hyperplasia. These results suggest that the former was less hypertrophic compared with the latter. Nagano et al.32.Nagano N. Miyata S. Abe M. et al.Sevelamer hydrochloride reverses parathyroid gland enlargement via regression of cell hypertrophy but not apoptosis in rats with chronic renal insufficiency.Nephrol Dial Transplant. 2006; 21: 634-643Crossref PubMed Scopus (11) Google Scholar reported that regression of cell hypertrophy was the mechanism of regression of parathyroid growth by sevelamer hydrochloride administration. Our results suggest that serum Pi concentration might be related to the mechanism of parathyroid cell hypertrophy. In the present study, the low Pi levels in renal allograft recipients were concordant with the above study.32.Nagano N. Miyata S. Abe M. et al.Sevelamer hydrochloride reverses parathyroid gland enlargement via regression of cell hypertrophy but not apoptosis in rats with chronic renal insufficiency.Nephrol Dial Transplant. 2006; 21: 634-643Crossref PubMed Scopus (11) Google Scholar Abundant apoptotic cells were found in diffuse hyperplastic glands, promising future regression of hyperplastic nodules. In the human parathyroid gland, Zhang et al.27.Zhang P. Duchambon P. Gogusev J. et al.Apoptosis in parathyroid hyperplasia of patients with primary or secondary uremic hyperparathyroidism.Kidney Int. 2000; 57: 437-445Abstract Full Text Full Text PDF PubMed Scopus (36) Google Scholar revealed that the number of apoptotic cells in secondary parathyroid hyperplasia was significantly higher than in normal parathyroid gland by using the TUNEL technique. Our present results showed that the number of apoptotic cells in nodular hyperplasia was not different from that of normal glands, whereas it was extremely increased in diffuse hyperplasia. Drüeke's group27.Zhang P. Duchambon P. Gogusev J. et al.Apoptosis in parathyroid hyperplasia of patients with primary or secondary uremic hyperparathyroidism.Kidney Int. 2000; 57: 437-445Abstract Full Text Full Text PDF PubMed Scopus (36) Google Scholar, 33.Drüeke T.B. Zhang P. Gogusev J. Apoptosis: background and possible role in secondary hyperparathyroidism.Nephrol Dial Transplant. 1997; 12: 2228-2233Crossref PubMed Scopus (15) Google Scholar examined the degree of apoptosis and cell proliferation in human parathyroid gland. Based on their data, they claimed that the rate of parathyroid cell proliferation would be theoretically higher than that of apoptosis in parathyroid hyperplasia of secondary hyperparathyroidism.26.Drüeke T.B. Cell biology of parathyroid gland hyperplasia in chronic renal failure.J Am Soc Nephrol. 2000; 11: 1141-1152PubMed Google Scholar According to this hypothesis, if regression of hyperplastic glands really occurs, the rate of apoptosis should have prevailed the rate of proliferation. We compared directly the value of both TUNEL and Ki67 labeling indices to assess the tendency of proliferation or regression (Figure 3). TUNEL labeling index was significantly higher than Ki67 labeling index in recipients’ diffuse hyperplasia in the present study. Thus, the hyperplastic parathyroid glands in uremic patients could regress in certain conditions like after successful renal transplantation. Fukagawa et al.34.Fukagawa M. Okazaki R. Takano K. et al.Regression of parathyroid hyperplasia by calcitriol-pulse therapy in patients on long-term dialysis.N Engl J Med. 1990; 323: 421-422Crossref PubMed Scopus (135) Google Scholar, 35.Fukagawa M. Kitaoka M. Yi H. et al.Serial evaluation of parathyroid size by ultrasonography is another useful marker for the long-term prognosis of calcitriol pulse therapy in chronic dialysis patients.Nephron. 1994; 68: 221-228Crossref PubMed Scopus (155) Google Scholar suggested regression of hyperplastic glands in response to oral pulse therapy with active vitamin D in small-sized nodules, that is, diffuse type of hyperplasia. These results suggest that parathyroid hyperplasia of diffuse type may potentially regress by inducing apoptosis. However, the exact factor that might induce apoptosis could not be identified. Recently, in VDR-expressing prostate cancer cell lines, it was revealed that active vitamin D inhibited the expression of antiapoptotic proteins, such as Bcl-2 and Bcl-XL, leading to activation of mitochondrial pathway that ultimately results in causing apoptosis, whereas, in VDR-deficient prostate cell lines, apoptosis was not induced.36.Guzey M. Kitada S. Reed J.C. Apoptosis induction by 1alpha, 25-dihydroxyvitamin D3 in prostate cancer.Mol Cancer Ther. 2002; 9: 667-677Google Scholar Based on this report, normalization of active vitamin D–VDR system may be involved in the induction of apoptosis in diffuse hyperplasia of parathyroid glands. Considered together, these results suggest that nodular hyperplasia does not show significant level of apoptosis because its VDR expression remained low, having little chance to regress. In the renal allograft recipients with more than one nodular hyperplasia, PTH oversecretion would continue owing to reduced sensing receptor and increased parathyroid cell number, in spite of the recovery of cell hypertrophy. As reported in this study, renal allograft recipients with severe persistent hyperparathyroidism are considered to have more than one nodular parathyroid hyperplasia accompanied by diminished expression of CaSR and/or VDR. Tominaga et al.37.Tominaga Y. Tanaka Y. Sato K. et al.Histopathology, pathophysiology, and indications for surgical treatment of renal hyperparathyroidism.Semin Surg Oncol. 1997; 13: 78-86Crossref PubMed Scopus (168) Google Scholar revealed that 90% of parathyroid glands weighing more than 500 mg exhibit nodular formation. According to this finding, if a recipient had at least one parathyroid gland with an estimated weight of 500 mg at renal transplantation, this gland would have no chance to regress and some interventional therapy will be needed for the persistent hyperparathyroidism. Vitamin D therapy is known to have an effect on secondary hyperparathyroidism, but it would not be suitable for persistent hyperparathyroidism because of the side effect of hypercalcemia. A calcimimetic compound might be useful for the treatment of this condition.38.Kruse A.E. Eisenberger U. Frey F.J. et al.The calcimimetic cinacalcet normalizes serum calcium in renal transplant patients with persistent hyperparathyroidism.Nephrol Dial Transplant. 2005; 20: 1311-1314Crossref PubMed Scopus (144) Google Scholar, 39.Serra A.L. Schwarz A.A. Wick F.H. et al.Successful treatment of hypercalcemia with cinacalcet in renal transplant recipients with persistent hyperparathyroidism.Nephrol Dial Transplant. 2005; 20: 1315-1319Crossref PubMed Scopus (145) Google Scholar However, when these therapies are ineffective, parathyroidectomy is recommended. In conclusion, the fate of hyperplastic glands in persistent secondary hyperparathyroidism after renal transplantation depends on its pattern of hyperplasia; the diffuse type of hyperplasia has a strong tendency for regression. The remaining large nodular hyperplasia indicates little possibility of reversibility, requiring interventional treatment. Thus, if conservative therapy (e.g. vitamin D or calcimimetics supplementation) is ineffective, parathyroidectomy should be considered in patients with hyperplastic glands weighing more than 500 m2 detected by ultrasonography, to prevent hypercalcemia-induced renal dysfunction and kidney calcification. The subjects of the present study were renal allograft recipients with uncontrollable hypercalcemia and markedly elevated PTH after achieving normal renal function. Clinical history and follow-up information were carefully investigated in each patient, including age, preoperative serum level of Ca, Pi, alkaline phosphatase, and intact PTH. Parathyroid gland weight was measured following surgical resection. All allograft recipients with persistent secondary hyperparathyroidism had a stable renal function (serum creatinine concentration <1.5 mg/dl), and were not treated with vitamin D sterol owing to severe hypercalcemia. One recipient was treated with alendronate for high bone turnover, but it was ineffective. The tissue samples of parathyroid glands were obtained at Kyushu University Hospital between 1995 and 2003 at the time of surgery from patients with renal allograft and persistent hyperparathyroidism, patients on hemodialysis with severe secondary hyperparathyroidism, and patients with Graves’ disease. The parathyroid glands that were obtained included 13 normal glands, and according to the pattern of hyperplasia, 18 glands were subdivided into diffuse and nodular ones in each patient category, with a total of five with diffuse hyperplasia and 13 with nodular hyperplasia from patients on hemodialysis, and 10 with diffuse hyperplasia and 11 with nodular hyperplasia from allograft recipients. All specimens were fixed in 10% formalin and routinely processed with paraffin. Formalin-fixed, paraffin-embedded tissue sections were serially cut at 3 μm thickness and mounted on aminopropyltriethoxysilane-coated glass slides. The sections were deparaffinized in xylene and dehydrated through a series of ethanol solution. Immunohistochemical staining was performed as described previously.7.Tokumoto M. Tsuruya K. Fukuda K. et al.Reduced p21, p27 and vitamin D receptor in the nodular hyperplasia in patients with advanced secondary hyperparathyroidism.Kidney Int. 2002; 62: 1196-1207Abstract Full Text Full Text PDF PubMed Scopus (0) Google Scholar The sections were treated with 10 mM citrate, pH 6.0, in a microwave oven for antigen retrieval before immunohistochemical staining. They were also pretreated with 5% skim milk at room temperature for 1 h to block nonspecific binding of the primary antibodies. The serial sections were then incubated overnight with the primary antibodies at 4°C. The used antibodies included anti-CaSR antibody (Affinity Bioreagents Inc., CO, USA) at 1/100 dilution, anti-VDR antibody (Biomeda Laboratories, CA, USA) at 1/500 dilution, and anti-Ki67 antibody (Novocastra Laboratories, Newcastle, UK) at a 1/100 dilution. Ki67 antigen is a nuclear protein expressed in proliferating cells and required for cell proliferation. Immunostaining was performed with the Elite avidin biotin peroxidase kit (Nichirei, Tokyo, Japan) according to the specifications provided by the manufacturer. Quantitative analysis was performed using immunohistochemically stained serial sections. Fragmented DNA was detected in cell nuclei using the method described previously27.Zhang P. Duchambon P. Gogusev J. et al.Apoptosis in parathyroid hyperplasia of patients with primary or secondary uremic hyperparathyroidism.Kidney Int. 2000; 57: 437-445Abstract Full Text Full Text PDF PubMed Scopus (36) Google Scholar with some modifications. Paraffin sections of parathyroid tissue were deparaffinized and dehydrated. Then, after blocking with 0.3% H2O2 in methanol for 30 min at room temperature, 50 μl of TUNEL reaction mixture (10 × Tdt 50 μl, 1 × nucleotide mixture 450 μl, in situ cell death detection kit, POD: Roche, Mannheim, Germany) was added to each section and incubated in a moist chamber at 37°C for 1 h. Subsequently, 50 μl of converter POD (anti-fluorescein antibody, Fab fragment from sheep, conjugated with horseradish peroxidase) was applied to each specimen, and the slides were incubated for 30 min at 37°C in a humidified chamber. After reaction with converter POD, the sites of horseradish peroxidase were visualized with 3,3-diaminobenzidine and H2O2. Slides were counterstained with methyl green for 2 min. The method used for quantitative analysis was described previously.7.Tokumoto M. Tsuruya K. Fukuda K. et al.Reduced p21, p27 and vitamin D receptor in the nodular hyperplasia in patients with advanced secondary hyperparathyroidism.Kidney Int. 2002; 62: 1196-1207Abstract Full Text Full Text PDF PubMed Scopus (0) Google Scholar Briefly, only clear immunostaining for CaSR, VDR, Ki67, and TUNEL was considered positive immunoreactivity. The distribution of immunoreactivity was analyzed by quantifying positive staining in randomly selected areas in each specimen without prior knowledge of either diagnosis or outcome. The numbers of VDR-, Ki67-, and TUNEL-expressing cells were determined by counting a minimum of 1000 cells per slide using NIH image analysis freeware. The brightness and contrast of each image were uniformly enhanced or subtracted by Photoshop version 5.0 (Adobe, San Jose, CA, USA) followed by analysis using NIH image freeware version 1.62. With regard to VDR, Ki67, and TUNEL staining, in order to avoid the influence of nonspecific positive staining, plots of less than 30 pixels were excluded. The percentage of positive immunoreactive area per total area (CaSR) and the number of positive immunoreactive nuclei per 1000 parenchymal cells (VDR, Ki67, and TUNEL) were expressed as the labeling index. CaSR, VDR, Ki67, and TUNEL immunoreactive cells were randomly counted over a minimum of five fields in more than three sections. Repeat recounts for CaSR, VDR, Ki67, and TUNEL in 10% of the parathyroid glands conducted in a blind fashion showed variability of labeling index of less than ±5% from the original counts. In order to assess the cell hypertrophy, the area of one cell was calculated in hematoxylin-stained sections and expressed as cell size index by using the following formula: cell size index (μm2/cell)=T (μm2)/N, where T is the total area of the visual field and N is the total number of parathyroid cells per visual field. Data are expressed as mean±s.e.m. All statistical analyses were conducted using the StatView program (Abacus Concepts, Berkeley, CA, USA). One-way analysis of variance was used followed by Student's t-test with Bonferroni correction when indicated for comparison of histological findings between two groups. A P-value less than 0.05 was considered statistically significant." @default.
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• W2076356875 title "Persistent hyperparathyroidism in renal allograft recipients: Vitamin D receptor, calcium-sensing receptor, and apoptosis" @default.
• W2076356875 cites W1951231368 @default.
• W2076356875 cites W1971931756 @default.
• W2076356875 cites W1975398760 @default.
• W2076356875 cites W1977864809 @default.
• W2076356875 cites W1980238406 @default.
• W2076356875 cites W1988725026 @default.
• W2076356875 cites W1989640819 @default.
• W2076356875 cites W1991041088 @default.
• W2076356875 cites W1992960376 @default.
• W2076356875 cites W1993884994 @default.
• W2076356875 cites W2002296959 @default.
• W2076356875 cites W2007280540 @default.
• W2076356875 cites W2007811985 @default.
• W2076356875 cites W2012401383 @default.
• W2076356875 cites W2017116965 @default.
• W2076356875 cites W2025386904 @default.
• W2076356875 cites W2025944409 @default.
• W2076356875 cites W2033811782 @default.
• W2076356875 cites W2037045934 @default.
• W2076356875 cites W2039386621 @default.
• W2076356875 cites W2050571641 @default.
• W2076356875 cites W2068332720 @default.
• W2076356875 cites W2078943709 @default.
• W2076356875 cites W2081227689 @default.
• W2076356875 cites W2086832511 @default.
• W2076356875 cites W2094334270 @default.
• W2076356875 cites W2097417649 @default.
• W2076356875 cites W2130542552 @default.
• W2076356875 cites W2131447586 @default.
• W2076356875 cites W2131520754 @default.
• W2076356875 cites W2146254175 @default.
• W2076356875 cites W2150677313 @default.
• W2076356875 cites W2336662282 @default.
• W2076356875 cites W2406615204 @default.
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