Synergistic effects of anti-gp330 and anti-dipeptidyl peptidase type IV antibodies in the induction of glomerular damage.

Passive Heymann nephritis (PHN) in the rat is induced by the administration of heterologous antibodies to renal tubular epithelium (RTE). The nephritogenic capacity of anti-RTE resides primarily in the antibody fraction directed against a 330-kD glycoprotein (gp330). However, monospecific anti-gp330 antibodies are less nephritogenic than anti-RTE antibodies. This discrepancy led us to study a possible synergizing role for different antibody specificities present within anti-RTE. The enzyme dipeptidyl peptidase type IV (DPP IV) is, like gp330, present in RTE as well as in the glomerulus. Anti-DPP IV antibodies have been shown to induce an acute, transient proteinuria. In this study, we investigated the nephritogenic effect of separate or simultaneous administration of heterologous anti-DPP IV and anti-gp330 antibodies. Injection of anti-DPP IV antibodies resulted in a short-lived glomerular binding, and in a dose-dependent polyuria, albuminuria or proteinuria. Binding of anti-gp330 antibodies was slower, but much more stable. Albuminuria could only be observed in the heterologous phase. Combined injection did not alter antibody-binding kinetics of either antibody nor the albuminuria induced by anti-gp330. However, in the presence of anti-gp330 antibodies, a lower dose of anti-DPP IV was capable to induce transient albuminuria as compared to anti-DPP IV alone. In conclusion, anti-DPP IV and anti-gp330 antibodies bind to different sites in the glomerulus with different kinetics. The presence of anti-gp330 deposits facilitated anti-DPP-IV-induced renal injury.

Redistribution of glomerular dipeptidyl peptidase type IV in experimental lupus nephritis. Demonstration of decreased enzyme activity at the ultrastructural level.

BACKGROUND: In murine chronic graft-versus-host disease, an experimental model for lupus nephritis, autoantibodies against renal tubular epithelium can be found. Part of these antibodies are directed against a constituent of renal tubular epithelium, the enzyme Dipeptidyl peptidase IV (DPP IV). DPP IV is present on the cell membrane of glomerular epithelial and endothelial cells, and plays an important role in cell-extracellular matrix interactions. In mice and rats, administration of heterologous anti-DPP IV antibodies can induce proteinuria and podocyte effacement. EXPERIMENTAL DESIGN: In this study, the glomerular DPP IV enzyme activity was investigated in the course of graft-versus-host disease in (C57BL/10 x DBA/2) F1 hybrids both by light- and electron microscopy using a DPP IV-specific substratum. RESULTS: Light microscopical examination revealed an overall reduction of DPP IV activity and an altered distribution pattern in glomeruli as early as 4 weeks after induction of graft-versus-host disease. Immunofluorescence studies using anti-DPP IV antibodies showed actual redistribution, excluding antibody-mediated enzyme inactivation. Enzyme electron microscopy revealed an irregular deposition of reaction product characterized by a patchy, "moth eaten" appearance of the endothelial and epithelial membranes. This process occurred simultaneously with the development of albuminuria and preceded the effacement of epithelial foot processes. In control mice, DPP IV showed a continuous distribution along endothelial and podocyte membranes. CONCLUSIONS: In view of these findings we postulate that impairment of the function of DPP IV as a non integrin adhesion molecule may be one of the causative factors underlying the structural and functional lesions observed in this model for lupus nephritis.

Gender-related influences on the development of chronic graft-versus-host disease-induced experimental lupus nephritis.

Autoimmune diseases are far more common in women than in men. In the incidence of systemic lupus erythematosus (SLE), the female-to-male ratio is as high as 10:1. This suggests that sex hormones may play a fundamental role in determining the susceptibility to these diseases. In order to investigate the sex-related differences in the inducibility of chronic graft-versus-host disease-related experimental lupus nephritis, lymphocytes from female DBA/2 donor mice were administered to either male or female (C57BL10 x DBA/2)F1 recipients. An additional group of male recipients received lymphocytes from male DBA/2 donors. After four cell transfers, female recipients developed a significantly higher albuminuria than both male groups. Serum concentrations of autoantibodies against glomerular basement membrane (GBM), collagen IV, and laminin were significantly higher in females 2-4 weeks after induction. Levels of circulating autoantibodies against renal tubular epithelial antigens (RTE) and nuclear antigens were not different between the sexes. In transfer studies, the necessity of the presence of anti-GBM and anti-RTE autoantibodies for the development of glomerulonephritis was confirmed. These findings indicate that: (i) in this model of lupus nephritis, susceptibility to glomerulonephritis is strongly influenced by sex-related genes; and (ii) among the variety of autoantibodies occurring in this model of SLE, both anti-GBM and anti-RTE autoantibodies play a key role in the pathogenesis of glomerulonephritis.

Epitope specificity of anti-gp330 autoantibodies determines the development of proteinuria in active Heymann nephritis.

In active Heymann nephritis, an experimental autoimmune disease in the rat, gp330 is regarded as the main antigenic target. Immunization with detergent-solubilized renal tubular epithelium (RTE-DOC) has been shown to be less nephritogenic than immunization with crude RTE. In this study immunization with either crude RTE or affinity-purified gp330 did, but immunization with RTE-DOC did not induce proteinuria. Both a possible aberrant subclass distribution of anti-gp330 autoantibodies and the involvement of additional nephritogenic autoantigens such as DPP IV (gp90) or laminin could be excluded. Circulating anti-gp330 autoantibody titers were significantly higher in RTE-DOC-immunized rats than in RTE-immunized animals. In contrast, significantly more antibodies were shown to bind in the glomeruli in the latter group. The time of onset of abnormal proteinuria was shown to be related to the recognition of a particular V8 protease-induced 250 kD fragment of gp330 in Western blots. This study shows that a particular fragment-specific subset of autoantibodies against gp330 is involved in the glomerular damage in Heymann nephritis.

T-cell receptors and ICAM-1 expression in renal allografts during rejection.

Sixty-two biopsies taken from 38 kidney grafts were studied for 15 histological and 10 immunohistological parameters. The biopsies were divided into three groups, according to the clinical diagnosis at the time they were performed: group 1, rejection (n = 43); group 2, other causes of dysfunction (n = 10); and group 3, stable function (n = 9). Histological signs of acute rejection included diffuse interstitial infiltrate, tubular basement membrane damage, mononuclear leukocyte infiltration, and congestion of the peritubular capillaries. Immunoperoxidase staining with monoclonal antibodies to ten markers showed a statistically significant association between detection of T-cell receptor subunits alpha-beta (TcR2) and gamma-delta (TcR1) on infiltrating lymphocytes and of intercellular adhesion molecule-1 (ICAM-1) in tubular cells and acute rejection. These results suggest that T-cell receptors and ICAM-1 may be useful markers to differentiate acute rejection from renal graft dysfunctions due to other abnormalities.

Expression of HLA-DQ antigens in the small-intestinal mucosa of patients with coeliac disease.

Studies at the DNA and product level of B-cell lines of coeliac patients have shown a strong association between coeliac disease and the HLA-DQ alpha 2.3 and HLA-DQ beta 2.7 alleles. The monoclonal antisera SFR20-DQ alpha 5 and XIII-358.4, which specifically react with HLA-DQ alpha 2.3 and with HLA-DQ beta 2.3 and -DQ beta 2.7, respectively, have been used to detect the expression of these specificities in the small-intestinal mucosa of 7 coeliac patients and 11 non-coeliac persons. An immunoperoxidase technique on frozen tissue sections of jejunal biopsy specimens was used. Positive specimens showed immunoperoxidase staining of lymphocytes and histiocytes in the lamina propria. The epithelial cells showed no immunoperoxidase staining. Positive results at the intestinal level correlated with the HLA typing of the patients and controls. The distribution found for the HLA-DQ alleles in the intestinal mucosa makes the role of a HLA-DQ alpha/beta dimer as gliadin receptor at the epithelial cell less probable, but it is compatible with the hypothesis that these DQ molecules are involved in the regulation of the intestinal immune response to gluten.

Helicobacter pylori infection of gastric mucin cell metaplasia: the duodenum revisited.

The histological material of 158 Billroth II gastrectomy specimens, used for a former study that established a relationship between duodenal ulcers and the presence of gastric metaplastic epithelium in the duodenal bulb, was reinvestigated for the presence of Helicobacter pylori. The results show that in all duodenal ulcer patients with gastric mucin cell metaplasia H. pylori colonized the metaplastic epithelium accompanied by an inflammatory response. The intestinal mucosa was always negative for H. pylori. H. pylori-positive patients also had the micro-organism in their gastric antrum. The results further support the hypothesis that infection of gastric mucosa in the bulb by H. pylori underlies duodenal ulcer disease.

Mortality caused by stomach cancer after remote partial gastrectomy for benign conditions: 40 years of follow up of an Amsterdam cohort of 2633 postgastrectomy patients.

Mortality caused by stomach cancer was analysed in a cohort of 2633 postgastrectomy patients who underwent surgery for benign conditions in the academic medical centre of the University of Amsterdam between 1931-1960. In comparison with mortality from gastric cancer in the general Dutch population, the observed versus expected ratio in the postgastrectomy group was significantly increased among women, after a postoperative latency of more than 15 years (O/E: 4.77; p = 0.011) and among men after a postoperative latency of more than 25 years (O/E: 3.13; p = 0.005). The analysis confirms that the discrepancies in risk appraisal which seem to exist between reports published in Europe and the USA may be explained by the differences in length of follow up in these studies.

Gastric, pancreatic, and colorectal carcinogenesis following remote peptic ulcer surgery. Review of the literature with the emphasis on risk assessment and underlying mechanism.

Based upon literature data, a 2-fold risk for gastric and colorectal cancer and a 2- to 5-fold risk for pancreatic cancer are predicted after remote peptic ulcer surgery. The association between previous ulcer surgery and subsequent gastric cancer appears firm; the linkage between colorectal and pancreatic cancer is more tenuous. Increased formation of carcinogens in the hypochlorhydric stomach following gastric surgery may be incriminated. Other conditions have features in common with the operated stomach and are also thought to be a suitable microenvironment for the subsequent development of cancers. Viewed in that light, further research of the putative relationship between peptic ulcer surgery and carcinogenesis and their underlying mechanism is highly desirable. Molecular cancer epidemiology and environmental pathology are proposed as useful tools for such studies. In the long run, the hypochlorhydric stomach might be a condition suitable for the chemoprevention of cancer.

Epidemiology of Crohn's disease in Regio Leiden, The Netherlands. A population study from 1979 to 1983.

An epidemiologic study of inflammatory bowel disease was conducted in Regio Leiden, the Netherlands, between 1979 and 1983. Archives of endoscopy, radiology, pathology, and specialist letters were reviewed for suspected patients with inflammatory bowel disease, together with a survey of all general practitioners to verify completeness of data. One thousand forty patients were identified and each diagnosis was reviewed. Two hundred ten patients had Crohn's disease and 257 had ulcerative colitis. Of the other 573 patients, the largest proportion (21%) had incomplete data for disease classification. Others had irritable bowel syndrome, diverticulitis, or ischemic or irradiation colitis; some were nonresident patients with inflammatory bowel disease treated within the region and others were out of the period for inclusion in this investigation. The incidence of Crohn's disease was 3.9 per 10(5) per year and the period prevalence was 48 per 10(5). The sex-specific incidence was similar, although the disease was significantly more common in women aged 20-29 yr. The prevalence in the city municipalities of Leiden and Alphen on the Rijn (63 per 10(5)) was similar but significantly greater than in suburban (39 per 10(5)) or agarian areas (40 per 10(5)). This may be partially due to urban density but not to differences in water supply. The lack of cases in the migrant population almost reaches significant levels, but studies in locations with a higher migrant population may clarify the issue.

Monoclonal antibody G 250 recognizes a determinant present in renal-cell carcinoma and absent from normal kidney.

This report describes a monoclonal antibody designated G 250, subclass IgGl, that recognizes an antigen preferentially expressed on cell membranes of renal-cell carcinoma cells (RCC) and not expressed in normal proximal tubular epithelium. G 250 antibody reacted with 46 of 47 primary RCC, with 7 of 8 RCC metastases and with a few other malignant tumors. The staining pattern of G 250 differs from that of other RCC-related antibodies described. Preliminary experiments show that this antibody can be used to visualize RCC xenografts in nude mice by immunoscintigraphy.

Acute glomerulonephritis after intravenous injection of monoclonal anti-thymocyte antibodies in the rat.

Female Wistar rats were injected with (mouse) monoclonal antibodies (Moabs) of different IgG subclasses directed to rat thymocytes or rat tumor cells. Following intravenous injection of antithymocyte Moabs, glomerular binding of mouse IgG was observed during the first 4 days along the GBM and in the mesangium. No staining for mouse IgG was detected in anti-tumor Moab injected rats. Animals injected with IgG 2a anti-thymocyte Moab developed glomerulonephritis and a massive proteinuria in contrast to rats injected with IgG 1 Moab which is non-complement fixing. The glomerulonephritis lesion consisted of microaneurysms and focal and segmental proliferation. Deposits of complement and fibrin could be detected exclusively in rats injected with IgG 2a anti-thymocyte Moab during the whole observation period of 14 days. This is the first demonstration of overt glomerulonephritis lesions on the injection of monoclonal antibodies.

Toward individual prognosis of IgA nephropathy.

The individual prognosis of adult IgA nephropathy patients was studied using the proportional hazards model for the time from biopsy until endstage renal disease. After selection of the most relevant prognostic factors, the 75 patients were stratified with respect to hypertension and its treatment. In these strata, individual prognosis was based on the initial age-adjusted glomerular filtration rate, the initial proteinuria, the presence/absence of gross hematuria, and the presence/absence of microscopic hematuria. Using the scores of a patient on these variables, the probability of surviving any given period of time can be estimated either graphically or by calculation. Prediction is feasible up to about 10 years. Attention has been given to supply all relevant estimates with confidence limits. For each patient the estimated 5-year survival probability as predicted by the model was compared with the actual outcome.

Variations in histopathological evaluation of non-neoplastic colonic mucosal abnormalities; assessment and clinical significance.

The variation between three pathologists examining histological features seen in non-neoplastic colonic mucosa from 40 biopsies was analysed. Several procedures to express observer variation were used and compared, with emphasis on kappa statistics. Only five features, the presence of ulceration, villous surface, epithelioid granulomas, severe mucus depletion and crypt abscesses were sufficiently reproducible by the three pairs of pathologists. These findings suggest that other criteria used for the classification of inflammatory bowel disease are potentially unsatisfactory. When results from different studies on biopsies are being compared, influence of observer variation should be identified. Comparison of statistical techniques showed overall variation to be less useful than other statistical procedures. There was little difference between results from kappa statistics and other measures of agreement (overall agreement excluded).

Subentities within adult primary IgA-nephropathy.

Since its definition is purely descriptive, IgA-nephropathy (IGAN) may comprise more disease entities which share the (epi)phenomenon of mesangial IgA-depositions. IGAN patients with macroscopical hematuria (macro-H) differ from the other IGAN patients in 9 aspects: history, HLA-DR, Gm-allotypes, actuarial kidney survival, initial creatinine clearance, initial proteinuria, initial microhematuria, age at presentation and light microscopy of the renal biopsy. The difference in the last five parameters may either be explained by the existence of subentities or by earlier detection of patients with macro-H. The dissimilarity in the first four parameters can only be due to the former theory. Therefore, we conclude that IGAN probably comprises at least two disease entities.

Abnormal reticuloendothelial function in patients with active vasculitis and idiopathic membranous glomerulopathy. A study with 99mTc-labeled heat-damaged autologous red blood cells.

Reticuloendothelial function was assessed in 11 patients with systemic lupus erythematosus, 8 patients with Wegener's granulomatosus, and 20 patients with idiopathic membranous glomerulopathy by using autologous 99mTc-labeled heat-damaged red blood cells. With this method organ uptake could be measured by quantitative scintigraphy. There was no relation between the T1/2 of the blood disappearance curve and the T1/2 of the splenic uptake curve. The T1/2 of the blood disappearance curve was normal in all three patient groups. However, there was a significant shift from spleen to liver uptake in patients with active systemic lupus erythematosus, active Wegener's granulomatosus, and membranous glomerulopathy in comparison with a control group. There was no relation with age, level of circulating immune complexes, complement level, kidney function, or immunosuppressive treatment. We conclude that an increase of the liver component of reticulo-endothelial function may compensate abnormalities in splenic function. This stresses the importance of quantitative scanning to detect such abnormalities. The study provides evidence for disease related hyposplenism in patients with active systemic lupus erythematosus, active Wegener's granulomatosus, and membranous glomerulopathy.

A sensitive method to measure PHA-induced cytotoxicity to adherent target cells using [3H]uridine as a terminal label.

This paper describes a modification of the PHA-induced cytotoxicity test of human peripheral blood lymphocytes against a tumour-derived adherent cell line (HeLa), in which the surviving target cells are labelled with [3H]uridine at the end of the assay. There is a direct correlation between [3H]uridine incorporation and the number of adherent target cells. The test proves to be very sensitive at low effector; target cell ratios. Frozen stored cells can be used in this system, a particular advantage because of the possibility of increasing the reproducibility of the assay by using the same batch of cryopreserved lymphocytes as a reference standard in each experiment. PHA-induced cytotoxicity was mainly found in the T cell enriched fraction.