Normal Renal Tissue Specimens Research Articles

The Role of Renal Macrophage, AIM, and TGF-β1 Expression in Renal Fibrosis Progression in IgAN Patients.

ObjectiveTo analyze the expression of macrophages, AIM, TGF-β1 in the kidney of IgAN patients, and to explore the role of macrophages, AIM, TGF-β1 in the progression of renal fibrosis in IgAN patients.MethodsThe paraffin specimens of renal tissue from 40 IgAN patients were selected as the observation group. At the same time, paraffin specimens of normal renal tissue from 11 patients treated by nephrectomy were selected as the normal control group. We observed the distribution of macrophages, the expression of AIM and TGF-β1 by immunohistochemical staining and/or immunofluorescence.ResultThe number of M0, M1, M2 macrophages could be found increased in IgAN patients. M0 macrophages are mainly polarized towards M2 macrophages. The expression of AIM and TGF-β1 were significantly higher in IgAN patients than in NC. M2 macrophage, AIM and TGF-β1 were positively correlated with serum creatinine and 24-hour proteinuria, but negatively correlated with eGFR. M2 macrophages, AIM, TGF-β1 were positively correlated with fibrotic area.ConclusionM2 macrophages, AIM and TGF-β1 play important roles in the process of IgAN fibrosis, and the three influence each other.

P0674DCR2,AS A SENESCENCE MARKER,IS ASSOCIATED WITH DISEASE SEVERITY AND PROGRESSION IN IGA NEPHROPATHY PATIENTS

Abstract Background and Aims Accelerated senescence of renal tubular epithelial cells (RTECs) may contribute to the progression of IgA Nephropathy (IgAN). Our previous studies demonstrated that DcR2 may reflect senescence of RTECs in experimental models and patients with diabetic nephropathy. The objective of this study was to investigate the association of DCR2 with disease severity and progression in IgAN. Method We included a retrospective cohort of 105 patients with biopsy proven IgAN. 15 normal renal tissue specimens displaying insignificant alterations biopsied from patients with renal carcinoma were recruited as controls. Renal biopsies from all patients were scored according to Oxford classification (MEST-C score). We analysed the degree of expression and localization of DCR2 in biopsies from kidneys with IgAN, and correlated their immunostaining levels with various clinical and histological parameters at baseline. Cox regression was performed for the composite renal outcome defined as 30% reduction in initial estimated glomerular filtration rate (eGFR) and/or end-stage renal disease (ESRD), and for the individual components during a follow-up for 60 or more months. Results DCR2 was overexpressed in the cytoplasm of RTECs obtained from kidneys of patients with IgAN [male: 60.9%, age:39.5±13.0 years, mean arterial pressure (MAP): 95.2±18.0 mmHg, proteinuria: 1.9 (0.7, 3.7)g/day, Initial eGFR:89.8±37.2 ml/min/1.73 m2], and were elevated with the increasing T scores. At baseline, DCR2 protein levels in the RTECs was inversely correlated with eGFR (R=−0.597, P=0.000) and positively associated with 24h-proteinuria (R=0.379, P=0.000) and the T score (R=0.632, P = 0.000). During a median follow-up of 80 (60, 125) months, patients with ≥25% tubular DCR2 positive showed worse eGFR slopes (the rate of eGFR decline) than those<25% DCR2 positive group [4.35 (2.17, 5.53) versus 0.36 (-0.96, 1.19) ml/min per 1.73 m2 per year; P=0.000)]. Kaplan–Meier survival analysis revealed that renal survival for the composite outcome was significantly lower in the ≥25% DCR2 positive group than in the<25% DCR2 positive group (P=0.000). In Cox regression models, ≥25% tubular DCR2 positive expression independently associated with poor renal outcome (HR=2.02, P=0.001) after adjustment for multiple known risk factors for IgAN progression, including baseline proteinuria, hypertension, eGFR, Oxford scores, and steroids/immunosuppressive therapy. Moreover, tubular DCR2 expression showed the highest sensitivity and specificity (80.8% and 87.3%, respectively) at a cut-off value of 25.5% DCR2 positive expression over proteinuria and eGFR for the composite outcome. The area under the receiver operating characteristic curve (AUROC) of tubular DCR2 expression was 0.880. Conclusion DCR2 is associated with disease severity and prognosis in IgAN patients and may have additional prognostic value besides established risk markers.

High expression of P53-induced Ring-h2 protein is associated with poor prognosis in clear cell renal cell carcinoma

PurposeThis study was carried out to examine P53-induced Ring-h2 protein (Pirh2) expression and investigate its clinical and prognostic significance in patients with clear cell renal cell carcinoma (ccRCC). MethodsPirh2 mRNA and protein expressions were detected by quantitative reverse-transcription polymerase chain reaction (Q-RT PCR) and Western blotting in 35 frozen renal cancer tissue specimens and 35 adjacent normal renal tissue specimens of the same patients. Pirh2 protein expression was assessed by immunohistochemical analysis in 92 paraffin-embedded specimens of human ccRCC and 30 specimens of adjacent normal renal tissue. Correlations between Pirh2 and clinicopathologic features and prognosis were analyzed statistically. ResultsPirh2 mRNA and protein levels in ccRCC samples were increased significantly as compared with the adjacent normal renal tissues (P < 0.001). Pirh2 mRNA overexpression correlated with high stage and grade of the renal cancer (P < 0.001 and P < 0.001 respectively). Pirh2 protein expression was negative in most normal renal tissue specimens (23/30) but positive in 52.2% (48/92) of ccRCC specimens (P = 0.006). Pirh2 protein expression correlated with tumor grade and stage (P < 0.001 and P < 0.001 respectively). The median follow-up interval was 42.0 months. Overexpression of Pirh2 protein in ccRCC was significantly associated with shorter overall survival and recurrence-free survival (P = 0.001 and P = 0.003, respectively). Multivariate analysis showed that Pirh2 expression was an independent prognostic factor for ccRCC patients (P = 0.037). ConclusionsPirh2 was up-regulated in ccRCC at both transcriptional and translational levels compared with normal renal tissues, suggesting that Pirh2 may be a potential prognostic marker for ccRCC.

Expression of MMP-2 and TIMP-1 in Renal Tissue of Patients with Chronic Active Antibody-mediated Renal Graft Rejection

ObjectiveTo investigate the expression of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metallopropteinase-1 (TIMP-1) in the renal allografts of patients with chronic active antibody-mediated rejection (AMR), and to explore their role in the pathogenesis of AMR.MethodsImmunohistochemistry assay and computer-assisted image analysis were used to detect the expression of MMP-2 and TIMP-1 in the renal allografts with interstitial fibrosis and tubular atrophy (IF/TA) in 46 transplant recipients and 15 normal renal tissue specimens as the controls. The association of the expression level of either MMP-2 or TIMP-1 with the pathological grade of IF/TA in AMR was analyzed.ResultsThe expression of either MMP-2 or TIMP-1 was significantly increased in the renal allografts of the recipients as compared with the normal renal tissue (P < 0.05). MMP-2 expression tended to decrease, while TIMP-1 and serum creatinine increased along with the increase of pathological grade of IF/TA (P < 0.05). In IF/TA groups, the expression of TIMP-1 was positively correlated to serum creatinine level (r = 0.718, P < 0.05).ConclusionsIt is suggested by the results that abnormal expressions of MMP-2 and TIMP-1 might play roles in the development of renal fibrosis in chronic AMR.Virtual SlidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1128474926172838

Reverse-phase protein array marker evaluation of protein expression patterns related to anti-angiogenesis treatment in renal cell carcinoma

16016 Background: Renal carcinoma patients treated with anti-VEGF therapy (bevacizumab) typically exhibit 10–15% partial responses with detectable primary tumor shrinkage in 70% of the cases (Rini B.I., Clin Cancer Res, 2007). It is not well known which factors determine response or are modulated by therapy. In this study, primary tumors from patients treated with bevacizumab-erlotinib were screened for protein expression of markers representing a broad spectrum of signaling pathways, including AKT, MAPK, angiogenesis, cell growth and apoptosis pathways. Methods: 32 patients with metastatic clear-cell renal carcinoma received bevacizumab 10mg/kg IV Q14 days for a total of 4 infusions plus erlotinib 150mg PO daily for 8 weeks. Nephrectomies were performed 2 weeks after last dose of erlotinib, 4 weeks after last dose of bevacizumab. Tumor and matched normal renal tissue specimens were histologically confirmed and subjected to protein extraction. Lysates were serially diluted and spotted on protein array slides. The arrays were stained with 47 specific antibodies for protein detection. Data were normalized and analyzed according to unsupervised hierarchical clustering approaches, for detecting patterns of protein expression across samples. VHL status (deletions and mutations) was also assessed for each tumor. Results: The protein array method clearly separated normal renal tissue from tumor samples according to their protein expression patterns, as demonstrated by unsupervised hierarchical clustering. Furthermore, duplicate and replicate preparations clustered tightly with their tumor specimen of origin, demonstrating marked reproducibility of the technique, and limited intra-tumor heterogeneity of the biomarkers being analyzed. Treated primary tumors with more than or equal to 10% shrinkage grouped into a distinct protein expression cluster. This cluster was driven mainly by 8 factors (p<0.001) with PTEN being the most prominent (increased expression in the ≥10% shrinkage cluster, p<1.3*10-7). This response group correlated with VHL copy loss (p<0.02). Conclusions: Bevacizumab-erlotinib treated renal tumors reveal distinct protein expression signatures according to the degree of primary tumor response. No significant financial relationships to disclose.

Expression of hypoxia inducible factor-1alpha and glucose transporter protein 1 in renal and bladder cancers and the clinical significance thereof

To investigate the protein expression of hypoxia inducible factor-1alpha (HIF-1alpha) and glucose transporter protein 1 (Glut-1) in renal cancer and bladder cancers and the clinical significance thereof. TransAMTMELISA was used to detect the protein expression of HIF-1alpha in the tissue sections from 25 patients with bladder transitional cell carcinoma (TCC) and 16 patients with renal clear cell carcinoma resected during operation and small amounts of normal renal and bladder tissues far from the cancer tissue resected simultaneously. Immunohistochemistry was used to detect the protein expression of Glut-1 in tissue sections from 58 patients with bladder carcinoma transitional cell carcinoma and 38 patients with renal clear cell carcinoma resected during operation. 16 specimens of normal bladder and 16 specimens of normal renal tissue were obtained from the patients with other diseases who underwent operation during the same period to be used as controls. Follow-up was conducted for more than 2 years for all patients. The protein expression of HIF-1alpha in the tissue of renal clear cell carcinoma was 3.38 +/- 1.71 microg/well, significantly higher than that in the tissue near the cancer (2.23 +/- 1.07 microg/well, P < 0.01). The protein expression of HIF-1alpha in the bladder TCC tissue was 2.69 +/- 1.34 microg/well, not significantly different from that in the tissue near the cancer (248 +/- 1.28 microg/well, P = 0.60). Protein expression of Glut-1 was not detected in the normal renal and bladder tissues, however, was significantly higher in the bladder TCC and renal clear cell carcinoma tissues. The positive rate of Glut-1 in the bladder TCC tissue was 77.90% (45/58). The positive rates of Glut-1 in the tissues of bladder TCC tissue, grades G1, G2, and G3 were 66.7%, 89.1%, and 53.3%. (P = 0.29), showing the correlation of Glut-1 expression with the grading of cancer. The positive rate of Glut-1 in the superficial TCC was 83.9%, not significantly different from that of the invasive TVV (70.4%, P = 0.90), showing that the Glut-1 is not correlated with the cancer staging. Nineteen of the 31 cases of superficial TCC showed recurrence within 2 years, however, the protein expression of Glut-1 rate was not significantly different between those with recurrence and those without recurrence (P = 0.90), showing that the protein expression of Glut-1 is not correlated with the recurrence of TCC. The protein expression of Glut-1 in the renal clear cell carcinoma was at a rate of 86.9% (33/38), however, it was not correlated with the grade and stage of the cancer. The protein expression of HIF-1alpha is strongly associated with the neoplastic progression of renal clear cell carcinoma, but its role in the development of bladder TCC is not clear yet. The protein expression of Glut-1 is strongly associated with the neoplastic progression of bladder TCC and renal clear cell carcinoma.

Prognostic significance of the number of renal glomeruli in reflux nephropathy

To monitor the decrease in the number of glomeruli in reflux nephropathy (RN) and to investigate its association with glomerular hypertrophy or clinical data, as some cases of RN progress to end-stage renal failure, although the mechanism of progression remains unknown and is generally thought to depend on remnant normal renal tissue mass, i.e. the number of remnant renal glomeruli (functional nephrons). From 1987 onward, a renal biopsy was taken in 71 patients (mean age 8.08 years) in two institutions to estimate the prognosis of patients with RN. The number of glomeruli per unit area and glomerular size in grossly normal renal tissue specimens were determined to explore the potential association between these variables and the total renal scars, renal function (glomerular filtration rate, GFR), or daily urinary protein excretion. The number of glomeruli was closely correlated with the actual size of glomeruli (y = 14.783 - 0.052x, R = 0.782). To a lesser extent, the number of glomeruli was also closely correlated with the size of glomeruli expressed in sds (y = 6.264 - 0.832x, R = 0.630). There was a good correlation between the number of glomeruli and the extent of renal scarring, renal function, or daily urinary protein excretion, although its association with renal function (GFR) was least evident. There was an association between the decrease in the number of glomeruli and glomerular hypertrophy, decreased renal function, or increased proteinuria. A renal biopsy taken from radiographically and macroscopically normal regions can be useful for assessing RN, and the size and number of glomeruli in the specimens might provide an important measure for estimating the prognosis of RN.

Telomerase Activity in Malignant and Benign Renal Tumors

Objectives: An important characteristic of malignant cells is their unlimited replicative potential, their immortality. In conferring this immortality, the enzyme telomerase is believed to play a crucial role. The detection of telomerase activity provides new knowledge regarding the biologic growth behavior of tumors and offers new diagnostic and therapeutic tools. Methods: In the present study the sensitive TRAP assay (telomeric repeat amplification protocol) was used to examine 44 malignant renal tumors and 8 benign tumors of the kidney and 52 specimens of normal renal tissue for telomerase activity. Results: Telomerase activity was detected in 63% of tissue samples obtained from histologically confirmed renal cell carcinomas. In cases of renal cell carcinoma restricted to the kidney, telomerase activity was detected in 58%. In cases in which tumor growth has progressed beyond the limits of the organ, telomerase activity was found in 69%. This stage dependence, however, did not reach statistical significance. No correlation to tumor grading was observed. Telomerase activity was found less frequent in chromophobe renal cell carcinomas. Neither the 8 benign renal tumors (4 oncocytomas and 4 angiomyolipomas) nor the specimens of normal kidney showed any evidence of telomerase activity. Conclusions: The proportion of remarkable slow-growing renal cell carcinomas showing telomerase activity is less than in other malignancies and may correlate with biologic growth behavior. Possible explanations include the presence of an alternative pathway, called ALT (alternative lengthening of telomeres) and an association with the loss or presence of the telomerase suppressor on the short arm of chromosome 3. Prolonged follow-up will be of special interest to determine whether lack of telomerase activity predicts favorable outcome.

Telomerase activity in renal cell carcinoma

Telomerase activity has been shown to be increased in numerous tumors and cell lines, although to the authors' knowledge there has been no previous assessment of telomerase activity in renal cell carcinoma (RCC). To examine whether telomerase activity could be used as a biochemical parameter for predicting the behavior of RCC, telomerase activity was quantified in RCC samples and correlated with clinicopathologic findings. Telomerase activity was quantified in 50 RCC samples and 21 samples of normal renal tissue using fluorescence-based telomeric repeat amplification. Telomerase activity was detected in 28 of 50 RCC samples (mean +/- standard deviation, 35.03 +/- 18.47 U/microg protein), whereas there was no telomerase activity in 21 normal renal tissue specimens. Telomerase activity in tumors classified as pT4 was significantly higher than in tumors classified as pT1 to pT3. Telomerase activity also correlated with patient age. Telomerase activity was increased in RCC samples compared with normal renal tissues. Although significant associations were observed between telomerase activity and clinicopathologic parameters, further study is required to determine whether telomerase activity affects the biologic and clinical behavior of RCC.

Electron microscopic study of capillary in the human renal cell carcinoma

In this study, we investigated the ultrastructure of the microvasculature in human renal cell carcinoma (RCC) specimens. RCC specimens from 30 patients were studied by light microscopy after hematoxylin and eosin staining and alpha-smooth muscle actin staining, and by electron microscopy after uranyl acetate lead nitrate staining or periodic acid thiosemicarbazide gelatin methenamine silver staining. In the light microscopy, the capillaries located adjacent to the renal medullary tubules in normal renal tissue specimen were in an orderly manner, while capillaries in the RCC specimens were found to be densely or sparsely distributed unconventionally. The pericytes encircling the capillary endothelial cells were positive for alpha-smooth muscle actin and formed aggregates in many of the RCC specimens, but did not form aggregates in the normal tissue specimens. In the electron microscopy, capillary endothelial cells in the normal renal tissue specimens were found to form well-developed membranous structure such as characterized by fenestrations and tight junctions. However, few pericytes were detected. On the other hand, the capillary endothelial cells in RCC specimens were found to be immature with poorly developed junctional complexes. Capillary pericytes with numerous cytoplasmic processes were found in many of the RCC specimens. In addition, the basement membranes of the capillary walls were structurally abnormal in that it was being multilayered. Based on the results of analysis of a total of 324 capillaries observed in all RCC specimens, capillaries could be classified as type I capillaries, associated with well-developed pericytes with numerous processes, or type II capillaries, associated with few pericytes with few processes. Type I capillaries predominated in cases which an angiographically hypervascularity was detected. Whereas, type II capillaries predominated in cases in which angiographically hypovascular pattern were detected. The fine structure of the pericytes seems to reflect the qualitative difference in capillary structure between normal renal tissue and RCC specimens. Therefore, the present findings may contribute to the recognition of intratumoral hemodynamics.

Glomerular FcαR expression and disease activity in IgA nephropathy

In this study, we examined the receptors for the Fc portion of immunoglobulin A (IgA) (FcαR) in the glomeruli as well as circulating polymorphonuclear leukocytes and monocytes at the mRNA level by reverse transcription—polymerase chain reaction (RT-PCR) assay and at the protein level by an immunohistochemistry/flow cytometry technique using a specific anti-FcαR monoclonal antibody (My 43). Glomeruli were isolated from biopsy specimens of renal tissues from IgA nephropathy (IgAn; 20 cases) and non-IgA mesangial proliferative glomerulonephritis (PGN; 13 cases) patients, and from normal renal tissue specimens obtained from kidneys removed because of malignancies (five cases) applying the microdissection method. There was a relative increase in FcαR in the circulating phagocytes from IgAN patients compared with those PGN and healthy controls. FcαR expression was present in approximately 40% of glomeruli samples from IgAN patients at the message levels. FcαR-positive specimens were also strongly positive for expression of tumor necrosis factor-α, interleukin-1, and interleukin-6 mRNA. Specimens from PGN patients and healthy controls did not show any detectable FcαR message. Serum IgA levels and severity of hematuria were significantly higher in patients with positive FcαR expression. A message for FcαR was detected in the tissues that were more damaged histologically. Our data suggest that there is some in vivo induction of glomerular FcαR expression, possibly mediated by a synergistic stimulus from IgA and inflammatory cytokines, and the expressed receptor is likely to be involved in the disease process of IgAN.

Nephrotic tunnels in glomerular basement membrane as revealed by a new electron microscopic method.

To clarify the ultrastructure in situ of the normal human glomerular basement membrane and ultrastructural changes of the glomerular basement membrane in patients with nephrotic syndrome, specimens of normal renal tissue and specimens from patients with membranous nephropathy, lupus nephritis, minimal change nephrotic syndrome, diabetic nephropathy, and Alport's syndrome were obtained. Specimens were examined by transmission electron microscopy by the newly devised "tissue negative staining method." Normal glomerular basement membrane showed a three-dimensional lattice-like meshwork of fibrils measuring 1.9 +/- 0.4 nm in diameter that formed numerous uniform, round, oval, or polygonal pores 2.5 +/- 0.4 nm in short diameter and 2.8 +/- 0.5 nm in long dimension. The nephrotic glomerular basement membrane revealed varying degrees of ultrastructural defects, the most prominent being tunnels and cavities. Tortuous tunnels measuring approximately 15 to 50 nm in diameter penetrated the entire glomerular basement membrane. Cavities of various shapes measuring 15 to 200 nm in diameter were diffusely scattered in the glomerular basement membrane and occasionally aggregated to form a honeycomb structure that occupied the whole thickness of the glomerular basement membrane. These defects appeared to be the pathway for protein leakage.

Immunohistochemical studies on the expression of HLA class I antigens in renal cell carcinoma: comparison of primary and metastatic tumor tissue.

HLA class I expression was studied in 43 specimens of normal renal tissue, 48 primary renal cell carcinomas (RCCs), and 12 metastases by immunofluorescence, using two different monoclonal antibodies (MoAbs; IOT2c, W6/32). Homogenous staining of all normal renal tissues was observed, as expected. From the panel of 48 renal tumors, 40 had a strong expression of HLA class I antigens when tested with both MoAbs, 7 tumors had only weak expression of HLA class I and were regarded as 'HLA class I negative', and 1 tumor showed homogenous staining when tested with one MoAb (IOT2c) but was negative when the other was used (W6/32). This was the only case in which different results with the two MoAbs were found. Reduced expression of HLA class I antigens was observed in 5/12 metastases, and in 1 metastasis no expression of HLA class I could be seen. The staining chartacteristics of 10 metastases in comparison with the respective primary tumors were as follows: same HLA class I score 7/10; loss of HLA class I 3/10; gain of HLA class I 0/10. In RCC, a complete loss of HLA class I expression is a rare phenomena, which was observed in 0/48 primary tumors and in 1/12 metastases. Reduced expression of HLA class I antigens occurs in about 15% of primary tumors but is more frequent (50%) in metastases; however, if this is relevant for cytotoxicity by T lymphocytes is unknown.

Analysis of solid renal dysplasia by flow cytometry: malignant potential?

Renal nodular blastema/nephroblastomatosis is a recognized precursor of Wilms tumor. It also has been shown that nodular renal blastemata are seen in association with dysplastic renal parenchyma secondary to obstructive uropathy (i.e., ureteroceles or ectopic ureters). In an attempt to improve our understanding of the critical relationship between renal dysplasia and neoplasia, we performed flow cytometric evaluation on 16 paraffinembedded specimens of dysplastic kidneys removed during the period 1984–1989. All nephrectomy specimens were associated with obstruction, either duplex collecting systems (10), ectopic ureters (2) or posterior urethral valves (2), or vesicoureteral reflux (2). One specimen was found to contain nodular renal blastema. No evidence of malignancy was found in any specimen. A specimen of normal kidney and two of Wilms tumor (favorable histology) were studied for comparison. Nuclear deoxyribonucleic acid (DNA) ploidy studies were performed on single dissociated nuclei after deparaffinization and staining with propidium iodide. All dysplastic specimens, including the specimen with nodular renal blastema, demonstrated a diploid pattern of DNA as did the specimens of normal renal tissue. The Wilms tumor specimens demonstrated a diploid and a tetraploid pattern. In view of the fact that Wilms tumor may demonstrate diploid DNA patterns on flow cytometry, the findings of diploid patterns on all specimens of solid dysplasia militate against but do not eliminate the possibility of malignant degeneration.

Laminin, Fibronectin, and Goodpasture Antigen Detection in Patients with Alport's Syndrome

Indirect immunofluorescence study with laminin and fibronectin monoclonal antibodies on paraffin sections, as well as with serum from a patient with Goodpasture's syndrome with high titer of autoantibodies that recognize the antigenic determinants in human glomerular and tubular basement membrane, was performed on 14 patients with Alport's syndrome and 5 specimens of normal renal tissue obtained from donors in cases of renal transplantation (control group). We found no binding of Goodpasture antigen to glomerular and distal tubular basement membranes in renal biopsy tissue from all 14 patients with Alport's syndrome. In contrast, there was bright linear fluorescence of Goodpasture antigen on glomerular and tubular basement membranes of normal renal material. There was no difference in laminin and fibronectin binding in patients with Alport's syndrome and controls. In all the cases binding was strongly positive. These results suggest an abnormality or absence of immunoreactive autoantigen in the glomerular and distal tubular basement membrane in patients with Alport's syndrome. Therefore, Goodpasture antigen detection could be an important diagnostic method in early stages of Alport's syndrome when characteristic morphological changes are not yet developed.

Tissue-type plasminogen activator and its inhibitor in human glomerulonephritis.

We carried out an immunohistochemical study of tissue-type plasminogen activator (PA) and urokinase-type PA, and their inhibitors, PA inhibitor-1 and PA inhibitor-2, using renal biopsy specimens obtained from 86 patients with various forms of glomerulonephritis. The controls were four normal renal tissue specimens. On immunofluorescent observation, granular staining for tissue-type PA was found to be distributed along the glomerular capillary walls. The fluorescence was weak in the normal renal tissue and occasionally intense in the tissues of patients with IgA nephritis, minimal change nephrotic syndrome, and lupus nephritis. PA inhibitor-1 was abundant in the glomerular epithelial cells and scarce in the mesangial area and glomerular capillary lumens of the normal renal tissues. This was confirmed by immunoelectron microscopy using gold staining. The fluorescence of PA inhibitor-1 was weaker in some specimens of nephritic tissues than in the normal renal tissues. Urokinase-type PA and PA inhibitor-2 were negative within the glomeruli in all the specimens. In the glomerulonephritic tissues which were fibrin deposition-positive, tissue-type PA expression in the glomeruli tended to be strong. An association between fibrin deposition and PA inhibitor-1 staining was not clear. These data suggest that expression of tissue-type PA in the glomeruli increases in association with fibrin deposition.

The immunohistopathology of glomerular antigens. The glomerular basement membrane, collagen, and actomyosin antigens in normal and diseased kidneys.

The immunofluorescent localization of antisera to human glomerular basement membrane (GBM), collagen, and smooth muscle actomyosin was examined in 15 specimens of normal renal tissue and 98 specimens from patients with renal disease. The anti-GBM and anticollagen antisera normally localize to GBM, while antiactomyosin localizes to the mesangium. Diabetic nephropathy revealed a striking expansion of mesangial material reacting with antiactomyosin. In contrast, the expanded mesangium in membranoproliferative glomerulonephritis did not react with antiactomyosin, and the GBM localization of anti-GBM and anticollagen sera was similarly lost. The thickened GBM in diabetes mellitus and membranous nephropathy reacted with anti-GBM and anticollagen, but with accentuation of staining on the inner aspect of the GBM. In proliferative glomerulonephritis there was a moderate increase in the distribution of actomyosin. Glomerular sclerosis and hyalinization in all diseases studied was accompanied by a loss of immunofluorescent staining for all glomerular antigens, including collagen.