Transforming growth factor-beta levels in human allograft chronic fibrosis correlate with rate of decline in renal function.

BACKGROUND: Long-term renal transplant function is limited primarily by a progressive scarring process loosely termed "chronic rejection, chronic allograft nephropathy, or allograft fibrosis." Although the etiology of transplant fibrosis is uncertain, several possible factors including chronic cyclosporin A (CsA) exposure may contribute to its pathogenesis. CsA stimulates renal fibrosis perhaps through the induction of the potent pro-sclerotic growth factor, transforming growth factor beta (TGFbeta). Previously, we demonstrated that, in human transplant biopsies, acute CsA toxicity but not acute tubular necrosis is associated with elevated levels of renal TGFbeta protein. We now examine whether long-term CsA treatment (>1 year) is associated with elevated levels of intra-allograft TGFbeta and whether heightened expression of TGFbeta is clinically significant. METHODS: Using immunohistochemical techniques, we determined the relative level of expression of intrarenal TGFbeta protein in transplant biopsies. We studied biopsies obtained from 40 CsA-treated patients that were diagnosed as having chronic allograft fibrosis. Biopsies were scored as having minimal or high levels of TGFbeta. RESULTS: Seventy-two percent of patients expressed high levels of intra-allograft TGFbeta. This group of patients lost renal function at an average rate of -19.5+/-17.3 ml/min/year. In contrast, patients with minimal or no TGFbeta expression experienced a decline of only -6.2+/-4.1 ml/min/year (P=0.01). CONCLUSIONS: These results suggest that the majority of CsA-treated patients with biopsy proven chronic fibrosis have elevated levels of intra-graft TGFbeta that correlates with an increased rate of decline in renal function.

Increased renal tubular expression of transforming growth factor beta in human allografts correlates with cyclosporine toxicity.

Cyclosporine A (CsA) is a potent immunosuppressive drug that inhibits the transcription of several proinflammatory cytokines including interleukin-2. In contrast, CsA stimulates transcription of the pleuripotent cytokine, transforming growth factor-beta (TGF beta). Since the effect of CsA in transplant recipients is unpredictable, we examined whether tissue levels of TGF beta protein in renal allografts correlate with in vivo CsA responsiveness. Intra-allograft TGF beta protein content was assessed in renal biopsies by immunohistochemical means using the mouse anti-TGF beta monoclonal antibody (Mab), 1D11. We studied 68 specimens: 21 with acute CsA toxicity (ACT), 11 with acute tubular necrosis (ATN) and 36 with acute cellular rejection (ACR). Intensity of TGF beta immunostaining was evaluated in a blinded fashion using a scale from 0 to 3+. In biopsies with histological evidence of CsA toxicity, 77% demonstrated intense (2 to 3+) TGF beta immunostaining. TGF beta protein was detected in both proximal and distal tubules but was either absent or present in low levels within glomeruli and interstitium. In contrast, only one of the 11 biopsies with ATN had minimal staining (1+) for TGF beta. The remaining 10 biopsies with ATN were negative for TGF beta immunostaining. In biopsies with ACR, the levels of renal TGF beta were more variable with 36% showing intense (2 to 3+) staining and 64% having minimal or no (0 to 1+) tubular TGF beta. Within the first 18 months post-transplantation, patients with intense TGF beta staining and ACR underwent an average of 4.1 +/- 1.8 allograft biopsies and suffered 33% graft losses. During the same period of time, the patients with ACR and absent or low (0 to 1+) TGF beta levels underwent only 2.1 +/- 1.2 biopsies, maintained better late renal function and suffered 4% graft losses. In conclusion, we demonstrate that TGF beta protein levels in renal allografts correlate with CsA effect and differentiate ACT from ATN. In CsA treated patients who develop ACR, TGF beta levels predict the subsequent clinical course and graft function. Therefore, evaluating tissue levels of TGF beta may offer unique diagnostic and prognostic benefits in the care of patients receiving CsA based immunosuppression.

Influence of the interview on the evaluation of applicants to medical school.

PURPOSE: To determine whether medical school admission interviewers change their evaluations and impressions of applicants as a direct result of the interview. METHOD: In 1991-92, 419 applicants to the University of Virginia School of Medicine were interviewed by members of the admission committee in two separate half-hour sessions. After reviewing each applicant's folder, interviewers rated the applicant before the interview on six objective scales. After the interview, ratings were again made on the same six scales, on the same form, below the ratings made before the interview. Data were examined using paired t-tests, Pearson correlations, and stepwise multiple-regression analysis. RESULTS: Of the six scales, only the ratings of Commitment to Serve Others were not significantly changed by the interview; the ratings of Familiarity with Issues in Medicine changed the most (p < .01 by paired t-test). The ratings of Overall Impression increased for accepted applicants and decreased for rejected applicants. CONCLUSION: The interview did influence interviewers' ratings made before the interview, and in the direction consistent with admission decisions, which supports the continued use of the interview. Although the magnitude of the changes was not large, the changes validate the conviction that the interview aids in the selection of individuals for medical school.

Membranoproliferative glomerulonephritis with primary Sjögren's syndrome.

Glomerular involvement in primary Sjögren's syndrome is rare and only five cases of membranoproliferative glomerulonephritis have been reported. We present a case of a 31-year-old white woman with primary Sjögren's syndrome who developed nephrotic syndrome. Evaluation showed no evidence of an associated connective tissue disease. Kidney biopsy was consistent with type I membranoproliferative glomerulonephritis. The patient's nephrotic syndrome resolved spontaneously, a course that has not been reported previously in this setting.

Study of EHS type IV collagen lacking Goodpasture's epitope in glomerulonephritis in rats.

The Goodpasture's epitope has been mapped to the alpha 3 non-collagenous chain (NC1) of type (IV) collagen [alpha 3col(IV)]. We have developed a model of experimental autoimmune glomerulonephritis (EAG) in rats immunized once with collagenase solubilized GBM (csGBM). Engelbreth-Holm-Swarm (EHS) tumor contains abundant col(IV) with little or no alpha 3col(IV). To test the hypothesis that antigens related to Goodpasture epitope are required to produce EAG in our model, we immunized rats once with 40 micrograms csEHS. Positive controls immunized with csGBM developed typical EAG with GBM bound antibody, proteinuria, and glomerulonephritis. EHS rats developed circulating and bound antibody to mesangium and tubular basement membrane with minimal GBM deposits, but did not develop proteinuria or glomerulonephritis. Although circulating antibody in EHS rats bound to csGBM by ELISA, there was no binding in ELISA to M2 antigen containing the Goodpasture epitope while EAG rat's serum did bind. By Western blot with antisera to Goodpasture epitope, EHS antigen was less complex than GBM in the monomer/dimer regions and appeared to lack NC1 corresponding to alpha 3col(IV). Blotting with sera from EHS rats demonstrated reactivity to various components of GBM but not to alpha 3col(IV). EAG sera and renal eluates bound to alpha 3col(IV). EAG rats evidenced cell mediated immunity while EHS rats did not (stimulation index EHS 1.1, EAG rats 8.0).(ABSTRACT TRUNCATED AT 250 WORDS)

Juxtaglomerular body abnormalities in youth-onset diabetic subjects.

Abnormal microalbuminuria in insulin-dependent diabetic subjects (IDDS) is significantly associated with pre-clinical nephropathy. In youth-onset IDDS declining plasma renin activity is significantly associated with improved albumin excretion, while persistently elevated renin activity is associated with continued abnormal microalbuminuria. To determine if these changes are reflected in changes in cell count in the juxtaglomerular body and if biopsy findings correlate with abnormal microalbuminuria, renal tissue of 20 IDDS (Study IDDS) ages 16 to 31 years, evaluated concurrently for plasma renin activity and microalbuminuria, were examined by light microscopy. Biopsy or autopsy specimens from 21 normal subjects and 32 IDDS (Non-Study IDDS), ages 2 to 25, were also examined. Specimens from the majority of prepubertal and all pubertal and postpubertal Non-Study IDDS and all Study IDDS independently of status of microalbuminuria had morphologic abnormalities. Normal or mesangially expanded glomeruli were found in association with expanded juxta-glomerular bodies and increased cell number, or with sclerotic bodies and decreased cell number. Sclerosis of juxtaglomerular bodies occurred independently of glomerular sclerosis. The highest percentage of glomeruli with expanded juxtaglomerular bodies and high cell count was present in specimens of Study IDDS with the most abnormal levels of microalbuminuria. T lymphocytes, noted within juxtaglomerular bodies, were present in specimens of 62% of the 52 Study and Non-Study IDDS. Abnormalities of the juxtaglomerular body are distinctive features of renal pathology in IDDS. T lymphocytes in the endocrine juxtaglomerular body suggest the presence of an autoimmune process. Confirmatory studies are necessary.

Proliferative autoimmune glomerulonephritis in rats: a model for autoimmune glomerulonephritis in humans.

Some forms of glomerulonephritis (GN) in humans appear consequent to autoimmunity. Experimental autoimmune GN (EAG) has been described in sheep, but attempts to develop EAG in other mammals have resulted only in antibody and proteinuria but no GN. We have developed a model of EAG in an inbred mammalian species to further study pathogenetic mechanisms. We immunized Brown Norway (BN) and Wistar-Kyoto (WKY) rats with glomerular basement membrane (GBM) or collagenase solubilized GBM (csGBM). Circulating and bound anti-GBM antibody developed in all rats. Only interstitial nephritis occurred in BN rats despite amounts of glomerular and serum anti GBM antibodies similar to WKY animals. One hundred percent of WKY rats immunized with csGBM/acid developed reproducible severe GN at two to three weeks with proteinuria and decreased kidney function which progressed to glomerulosclerosis and interstitial fibrosis. Antigen in acid was a requisite for induction of EAG. EAG rats had positive tests for delayed type hypersensitivity, their T cells underwent antigen specific transformation, and T cells and macrophages were present histologically. Passive transfer of EAG serum to naive rats resulted in fixation to recipient GBM but no proteinuria or GN. This new model of EAG in rats appears dependent on genetic factors, may involve cellular immunity in pathogenesis, requires exposure of the nephritogenic antigen, and is highly similar to rapidly progressive GN in humans.

Long-term oral or intravenous aluminum administration in rabbits. I. Renal and hepatic changes.

Long-term aluminum (Al) administration was studied in rabbits using intravenous (I.V.) injections of aluminum maltol or oral aluminum citrate in drinking water along with calcium. In the intravenous study, renal and liver tissue Al levels increased and were associated with proximal renal tubular pathology and with hepatic periportal Al-positive multinucleated cells. After oral Al, renal Al levels were increased in the Al-hard water group, while hepatic Al levels were not significantly increased over controls. However, cirrhosis was found in five orally-loaded animals which received Al and/or low dietary calcium or soft water. Collectively, these findings suggest that renal accumulation of Al is causally related to nephrotoxicity; that the lack of renal changes after oral loading is due to low absorption from normal adult gastrointestinal tract and normal functioning of mature kidneys; and that the elevated liver Al levels, achieved after I.V. administration, are related to the presence of hepatic Al-containing giant cells.

Distribution of renin mRNA and its protein in the developing kidney.

The intrarenal distribution of renin changes markedly during maturation. To determine whether renin gene expression changes along the developing renal vasculature, renin mRNA distribution was assessed using in situ hybridization histochemistry. Fetal, newborn, and adult kidney tissue sections from Wistar-Kyoto rats were hybridized with an oligonucleotide complementary to rat renin mRNA. In fetal kidneys, renin mRNA was found in the vascular pole of juxtamedullary glomeruli and along afferent, interlobular, and arcuate arteries. In kidneys from newborn rats, renin mRNA localized throughout the whole length of afferent arterioles, but was not detected in interlobular or arcuate arteries. In adult kidneys, hybridization signals were less intense and confined to the juxtaglomerular apparatus. Immunolocalization of renin with a polyclonal anti-rat renin antibody paralleled closely the mRNA distribution. Northern blot analyses demonstrated that renin mRNA levels were higher in fetal and newborn (20- and 10-fold, respectively) than in adult kidneys. We conclude the following. 1) The fetal kidney expresses the renin gene. 2) Expression of the renin gene is subjected to developmental changes. 3) As maturation progresses, localization of renin synthesis and storage shifts from large intrarenal arteries to a restricted, classical juxtaglomerular site in the afferent arteriole.

Disparate urinary catecholamine patterns in secondary hypertension due to unique sequential development of pheochromocytoma and neuroblastoma.

A 43-year-old white woman had a pheochromocytoma removed from her left adrenal gland, and one year later she developed a new left upper abdominal mass that was found to be a neuroblastoma. On both occasions, urinary vanillylmandelic acid level was elevated. However, urinary norepinephrine and epinephrine levels were increased only during the pheochromocytoma episode, while the urinary homovanillic acid level was elevated only when neuroblastoma developed. Despite a high suspicion of pheochromocytoma recurrence, the urinary catecholamine profile was suggestive of neuroblastoma, which was revealed by histopathologic analysis of the tumor tissue.

A long-term intravenous model of aluminum maltol toxicity in rabbits: tissue distribution, hepatic, renal, and neuronal cytoskeletal changes associated with systemic exposure.

We studied the toxicity of an intravenously injected, water-soluble aluminum complex (aluminum maltol) in 20 young adult male New Zealand white rabbits over a period of 8 to 30 weeks. Sixteen rabbits injected with aluminum-free maltol and 15 untreated rabbits served as controls. Rabbits were injected three times per week with 75 mumol of aluminum maltol per injection, or a molar equivalent amount of maltol alone, through an indwelling jugular catheter. Liver contained the highest concentrations of aluminum among the aluminum maltol-treated rabbits, and aluminum accumulation was correlated with the appearance of periportal multinucleated giant cells in 13 of 20 rabbits. These cells stained positively for aluminum when a fluorescent (Morin) stain was applied to tissue from rabbits with a high concentration of aluminum in the liver. Proximal renal tubular necrosis or atrophy was found in 15 of 20 aluminum maltol-treated rabbits but not in maltol-treated and untreated controls. Renal tubules in rabbits with acute proximal renal necrosis stained positively for aluminum. Neurofibrillary tangles, immunoreactive with a monoclonal antibody to the 200-kDa subunit of neurofibrillary protein, were observed in the oculomotor nucleus of 3 aluminum maltol-treated rabbits (treated for 12, 20, and 29 weeks), but in none of the two groups of controls. These tangles were present in 3 of 10 aluminum-treated rabbits in which the nucleus was located. None of the 17 animals in both control groups in which the nucleus was found demonstrated tangles. A slight increase in brain tissue aluminum concentration was confirmed by an electrothermal atomic absorption spectrophotometric method. There were no specific findings in heart or lung tissue from aluminum-treated rabbits, although the aluminum content of these tissues was 10 to 20 times greater than control values. This model should be useful for investigating the effects of systemic exposure to high concentrations of solubilized aluminum.

Methylprednisolone therapy for acute crescentic rapidly progressive glomerulonephritis.

In the last 10 years we have evaluated 63 patients with acute crescentic rapidly progressive glomerulonephritis (AC-RPGN), 46 of whom received pulse methylprednisolone (PM). The groups consisted of patients with no immune deposits, immune complexes, vasculitis, and antiglomerular basement membrane (anti-GBM) disease. Seventy-nine percent of non-anti-GBM patients improved versus 25% of unpulsed, p less than 0.005; 70% stopped dialysis (D) versus none of unpulsed, p less than 0.009; creatinine decreased from 8.6 before to 2.7 mg/dl after PM, p less than 0.05. Percent crescents and oligoanuria did not influence PM results, but did with conventional therapy (prednisone, cytotoxics, anticoagulants, supportive treatment). Seventeen percent of anti-GBM patients improved, none stopped D. In anti-GBM patients, serum creatinine less than 6 mg/dl was associated with a favorable response to PM, p = 0.045. Twenty-one percent of responding patients lost function at 19.8 months. The long-term response for non-anti-GBM patients was 62%. Patients with low chronicity on biopsy had shorter duration of disease (p = 0.006) and 92% initial, 85% long-term improvement; those with high chronicity had an immediate 71%, and 36% long-term response rate, p less than 0.02. Thus, PM is effective and appears superior to conventional therapy in treatment of non-anti-GBM AC-RPGN.

Transfer of experimental glomerulonephritis in chickens by mononuclear cells.

We have produced experimental autoimmune glomerulonephritis (EAG) in histocompatible SC chickens by immunization with different types of glomerular antigen. The development of EAG was time, but not antigen, dependent. Transfer of mononuclear cells from spleens and kidneys of nephritic animals resulted in EAG in naive recipients. Transferred EAG developed earlier than in immunized donors and was not associated with circulating or bound anti-GBM antibodies. Control recipients did not develop disease from control cells alone, soluble antigen, or antigen plus control cells. The cells which transferred EAG appeared morphologically by light and electron microscopy to be lymphocytes, sedimented as lymphocytes, were positive with anti-serum to thymocytes but negative with anti-bursa anti-serum, stained as T-cells with monoclonal antibodies and underwent blast transformation in response to mitogen and GBM antigen. Other organ specific diseases have been transferred by cells alone; to our knowledge this is the first description of glomerulonephritis transferred by cells alone. This new pathogenetic process may play an important role in the development of glomerulonephritis in other animal models as well as in humans.

Clinical identification of nondiabetic renal disease in diabetic patients with type I and type II disease presenting with renal dysfunction.

A retrospective study was done on 109 diabetic patients who had renal biopsies during 1974-1984 to determine factors identifying nondiabetic renal disease in patients with diabetes mellitus presenting with renal dysfunction. Six of 49 (12%) patients with type I and 17 of 60 (28%) with type II diabetes mellitus had other renal diseases, with or without diabetic glomerulosclerosis. Multivariate predictors of other renal disease in type I diabetes mellitus were duration less than 5 years (p less than 0.001), absence of proteinuria (p less than 0.001), and absence of neuropathy (p less than 0.05). In type II diabetes mellitus these were late age of onset (p less than 0.001), absence of neuropathy (p less than 0.05), and Caucasian race (p less than 0.005). Some patients with other diseases appeared to respond to therapy directed at their nondiabetic glomerulosclerosis disease. We emphasize the need to distinguish between the subgroup of diabetic patients with nondiabetic renal disease from the majority who have diabetic glomerulosclerosis alone. The latter group should be spared the discomforts, risks, and costs of a renal biopsy.

T-cells and macrophages in rapidly progressive glomerulonephritis: clinicopathologic correlations.

We phenotyped with monoclonal antibodies (MAb) the cellular infiltrates in kidneys of patients with rapidly progressive glomerulonephritis (RPGN) responsive (R) or nonresponsive (NR) to pulse methylprednisolone therapy (PM)-eight anti-GBM, six no immune deposits, three immune complex, two vasculitis, and one proliferative GN. There were glomerular, periglomerular, crescentic, and interstitial T and T-cell subsets. Few interstitial and no glomerular B and NK cells were observed. TH cells were much more common than TS. Phenotypes were quantitatively evaluated in 221 nephritic and 32 control glomeruli. T and/or TH cells were positively correlated with M phi, r = 0.30 to 0.74, P less than 0.05 to 0.0005. Although differences in phenotypes were observed, these differences were insufficient to distinguish between subtypes. Analysis of R and NR revealed no relationship to percent crescents, entry serum creatinine, oliguria, or need for dialysis. NR was related to presence of anti-GBM disease, P = 0.001, as was ability to stop dialysis, 0 of 7 GBM versus 9 of 10 other, P less than 0.001. Mild infiltrates of lymphocytes and M phi correlated with R, P less than or equal to 0.02. R had fewer numbers of TH and M phi in glomeruli, P = 0.0001, in crescents, P less than 0.02, and total TH and M phi compared to NR, P less than 0.001. Crescentic and total TH/S ratios were lower in NR than R, P less than 0.05. These findings demonstrate that components of the cell-mediated immune (CMI) system are present by MAb analysis, that subtypes cannot be differentiated by CMI constitution, and R to PM is related to intensity and composition of CMI involvement. Independence of the CMI system relative to anti-GBM disease remains to be clarified.

Fetal expression of muscle-specific isoactins in multiple organs of the Wistar-Kyoto rat.

Actin, a cytoskeletal and contractile protein, is expressed in six different isoforms that exhibit striking specificity. No studies have considered the muscle-specific actin expression in multiple organ systems in the intact fetus. Using a monoclonal antibody (B4) which reacts specifically with the isoactins of the smooth and skeletal muscle our immunohistochemical study examined whole fetal body sections to follow the development of actin expression throughout the last third of gestation in the Wistar-Kyoto rat. B4 staining was exclusively localized to muscle, confirming its high specificity and its usefulness for studying the ontogeny of muscle-specific isoactins. At 15 days of gestation, B4 staining was detected in the heart, the thoracic aorta and the skeletal muscle of the chest wall. The distribution and intensity of staining in the heart were initially higher than in the aorta or skeletal muscle and remained unchanged throughout the remainder of gestation, suggesting that the maturation of cardiac actin expression is well developed, although not fully completed before birth. Expression of muscle-specific actins in skeletal muscle was age-dependent and correlated with the maturational changes of muscle cell precursors. B4 staining in the fetal kidney was not apparent until day 20 of gestation and was localized to the inner cortical vessels. in association with the most mature nephrons, suggesting a centrifugal maturation of the intrarenal vasculature. The intensity of B4 staining in most tissues including bronchi, bowel, diaphragm, chest wall muscle and peripheral and pulmonary arteries increased by the end of gestation.

Morphologic correlates of renal growth arrest in neonatal partial ureteral obstruction.

To investigate the morphologic correlates of decreased renal blood flow and growth arrest resulting from chronic partial ureteral obstruction in the neonate, guinea pigs were subjected to unilateral ureteral constriction within the first 2 days of life and were studied at 3 and 8 wk of age. Severity of histologic changes in the obstructed and intact contralateral kidney was assessed by light microscopy. Morphometric glomerular measurements were made using a computerized tracing device. Since contralateral nephrectomy or administration of angiotensin converting enzyme inhibitor (enalapril) result in increased blood flow to the obstructed kidney, morphologic changes were also examined in separate groups of animals subjected to these maneuvers, and were compared to appropriate controls. Ipsilateral chronic partial ureteral obstruction resulted in decreased glomerular volume (p less than 0.0001) and increased glomerular crowding associated with tubular dilatation and progressive glomerular sclerosis, tubular atrophy, and interstitial fibrosis. The intact contralateral kidney underwent hypertrophy with increase in glomerular volume (p less than 0.0001) and decreased glomerular density. Contralateral nephrectomy prevented the decrease in glomerular volume in the obstructed kidney and resulted in decreased glomerular density and reduced tubular atrophy at 3 wk of age. Enalapril prevented the decrease in glomerular volume at 3 wk of age, but glomerular and tubular changes progressed and were unaffected by enalapril at 8 wk. Left kidney glomerular volume was directly related to renal blood flow (r = 0.71, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)