What is new in therapy of glomerulonephritis in 2003/2004.

The article reviews reports and opinions dealing with management of human glomerulonephritis that have appeared in the years 2003/2004. The following glomerulopathies have been covered: primary focal and segmental glomerulosclerosis, IgA nephropathy, membranous nephropathy, lupus nephritis, ANCA positive vasculitis and HCV-positive membranoproliferative cryoglobulinemic glomerulopathy. Aside from original studies, expert opinions and recommendations have been cited.

Mechanism of antinephritic effect of proteinase inhibitors in experimental anti-GBM glomerulopathy.

We have previously documented amelioration of rat autologous anti-GBM nephritis with the antiproteolytic drugs epsilon-aminocaproic acid (EACA) and aprotinin, given from the day of induction or later in the course of disease. In the present study we investigated potential mechanisms of this effect by assessing interactions of the drugs with proteinase-dependent generation of superoxide anion in glomeruli, and their influence on both GBM degradation in vitro and activity of glomerular proteolytic enzymes. Release of O2- by enzymatically disrupted glomeruli, isolated from nephritic control or EACA/aprotinin-treated rats, was measured with the ferricytochrome reduction method and its activity was correlated with proteinuria and glomerular cellularity at the early phase of the disease. The hydroxyproline release assay was used to quantitate degradation of rat GBM in vitro by leukocyte proteinases stimulated by phorbol myristate acetate (PMA), in the presence or absence of EACA and aprotinin. Finally, the activities of elastase, cathepsins B and L, and plasmin, together with collagenase-like activity, were assessed fluorimetrically in homogenates of glomeruli isolated from control and antiproteolytic-drug-treated nephritic rats. EACA and aprotinin notably inhibited production of superoxide by nephritic glomeruli (by 47% and 66%, respectively), and this effect was not significantly correlated with proteinuria or glomerular hypercellularity at the early stage of disease. On the other hand, generation of O2- by glomeruli of untreated nephritic rats was notably correlated with total glomerular cell counts and numbers of macrophages infiltrating glomeruli. PMA-stimulated neutrophils and macrophages caused degradation of isolated rat GBM in vitro, markedly attenuated in the presence of EACA (P<0.0005) and, to a lesser extent, by addition of aprotinin (P<0.01). The activity of elastase was significantly reduced in glomeruli of nephritic rats treated with EACA or aprotinin (both P<0.001), while activities of remaining proteinases were not appreciably affected. The beneficial influence of proteinase inhibitors on rat anti-GBM disease may be due, at least in part, to abrogation of superoxide generation in nephritic glomeruli. EACA and aprotinin also have potential to interfere with digestion of GBM, and both these effects may be related to suppression of glomerular elastase.

The importance of tubulointerstitial injury in the early phase of primary glomerular disease.

OBJECTIVES: As tubulointerstitial damage is regarded secondary to glomerular injury in primary glomerulopathies, we assessed lesions to renal tubulointerstitium in recently diagnosed primary glomerular diseases and evaluated their impact on progression of the disease during the first 2 years after diagnosis. DESIGN: A nonrandomized prospective study assessing tubulointerstitial morphometry at diagnosis, markers of tubular function within the next 6 months and progression of the disease (creatinine clearance) during 24 months' follow-up. SETTING: Single tertiary referral centre. SUBJECTS: Forty-six patients with primary glomerular disease, the diagnostic oligobiopsy performed within 2 months of the onset of clinical symptoms. INTERVENTIONS: All patients were subjected to antiinflammatory/immunosuppressive treatment. MAIN OUTCOME MEASURES: Alterations in results of tubulointerstitial morphometry and tubular function tests, correlations between these variables and parameters of nephrosis/renal function, selection of the most accurate predictor of disease progression within 24 months after diagnostic biopsy. RESULTS: Function of proximal tubules, markedly deteriorated at the time of diagnosis, significantly improved 6 months later (urinary beta2-microglobulin: P < 0.0025), along with reduction in proteinuria (P < 0.00125). No appreciable alterations in function of distal tubules were noted. Morphometric indices revealing interstitial expansion and tubular atrophy significantly correlated with creatinine clearance at 6 months (P = 0.032) and were the best predictors of deteriorating renal function at 24 months. Excretion of beta2-microglobulin at the time of diagnosis was the best marker for impairment of glomerular filtration 6 months later. CONCLUSIONS: Significant damage to cortical tubulointerstitium occurs concurrently with glomerular injury in primary glomerulopathies and may predict the clinical course of the disease already in its initial phase.

Helicobacter pylori in kidney allograft recipients: high prevalence of colonization and low incidence of active inflammatory lesions.

Since kidney transplant recipients are at enhanced risk for developing severe upper gastrointestinal disease and Helicobacter pylori (Hp) is an important pathogen in active gastritis and peptic ulcer, we performed gastroduodenoscopic examination, coupled with assessment of Hp colonization in 29 renal allograft recipients complaining of recurrent dyspepsia. Results were compared with those of 25 chronically hemodialyzed patients and 16 subjects free from renal disease, also suffering from upper gastrointestinal symptoms of similar severity. We found that while transplant recipients have had a high prevalence of Hp infection (62 vs. 34.6% in dialysis and 43.6% in control dyspeptic patients), active gastritis was clearly less frequently seen in these patients than in control subjects (transplant group: 6.9%, dialysis 3.8%, control 31.3%) and peptic ulceration was totally absent. Prevalence of Hp colonization was even higher in renal graft recipients on triple posttransplant immunosuppression (82%). In dyspeptic transplant and dialysis patients, colonization with Hp did not account for development of active inflammatory lesions, an association frequently seen in subjects free from renal disease and immunosuppressive therapy.

Cytotoxic effect of autocrine and macrophage-derived nitric oxide on cultured rat mesangial cells.

Expression of the inducible form of nitric oxide synthase (iNOS) has been found to be up-regulated in cytokine-stimulated mesangial cells (MC) and in experimental glomerulonephritis. Since direct toxicity of nitric oxide (NO) has been implicated in damage of bacteria, neoplastic and intact pancreatic cells, we investigated whether NO is cytotoxic to cultured MC, which may be relevant to pathogenesis of glomerular injury. MC isolated from rat glomeruli generated substantial amounts of nitrite, the stable NO end-product, when cells were stimulated with IL-1beta and tumour necrosis factor-alpha (TNF-alpha). Total DNA synthesis was significantly reduced in the presence of IL-1beta and TNF-alpha, and this effect was completely reversed by N(G)-monomethyl-L-arginine (L-NMMA), an inhibitor of iNOS. Stimulation of MC with IL-1beta and TNF-alpha caused remarkable toxicity to these cells, measured by the MTT test (3-(4,5-dimethylthiazol-2-yl)2,5-diphenyl tetrazolium bromide cleavage, specific cytotoxicity 41.5 +/- 20.3%), and much less prominent MC lysis (3H-thymidine release, specific cytolysis 11.5 +/- 5.3%). Toxic effects of cytokines were fully reversible by the iNOS inhibitor. Lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma), but not IL-1beta and TNF-alpha, induced rat peritoneal macrophages to produce large amounts of nitrite. In co-culture, such prestimulated macrophages had significantly cytotoxic (MTT test 62.9 +/- 19.9%) and cytolytic (3H-thymidine release 57.9 +/- 13.8%) effects on MC. Again, this toxicity was totally inhibited in the presence of L-NMMA. We conclude from these results that cytokine-stimulated generation of NO by MC or macrophages is directly toxic to MC, and may play a role in pathogenesis of glomerular injury involving mesangiolysis.

Effect of antiproteolytic drugs: epsilon-aminocaproic acid (EACA) and aprotinin on experimental anti-GBM nephritis.

BACKGROUND: Given the evidence accrued by other authors on beneficial effect of protease inhibitors on experimental immune nephritis, and following our preliminary report on abrogation of immune glomerulopathy in the rat by antifibrinolytic and antiproteolytic drug, epsilon-aminocaproic acid (EACA), we investigated the effect of this drug on the rat autologous anti-GBM nephritis. Along with the EACA we evaluated another protease inhibitor, aprotinin, an antagonist of serine proteases. METHODS: EACA (0.3g/kg) or aprotinin (5000 kallkrein inhibition units, KIU/kg) was administered intraperitoneally (t.i.d.) from day 0 (preventive protocol) or day 3 (therapeutic protocol) of autologous anti-GBM nephritis induced in Wistar rats. Proteinuria, creatinine clearance and renal histopathology were assessed as markers of disease activity, while glomerular fibrin deposits (immunoperoxidase staining) and standard parameters of coagulation/fibrinolysis of peripheral blood enabled insight into local and systemic haemostatic mechanisms. Glomerular binding of anti-GBM antibodies (immunofluorescence) and serum titres of autologus nephrotoxic antibodies (haemagglutination assay) represented conditions of immune induction of glomerulopathy. RESULTS: Our experiments indicated that EACA, and to a lesser extent also aprotinin, are capable of preventing proteinuria (EACA, reduction by 57.6%; aprotinin, reduction by 26.8%, compared to untreated nephritic rats, day 3 post-induction) and glomerular histopathological changes, without affecting endogenous creatinine clearance, otherwise depressed in this model of glomerulonephritis. More importantly, both drugs significantly ameliorated glomerular lesions and proteinuria, even when the treatment was initiated on day 3 post-induction, after the injury has begun (EACA reduced proteinuria by 32.0%, and aprotinin reduced it by 20.9% day 7). Administration of EACA and aprotinin at doses reducing glomerular injury did not cause appreciable fibrin deposition in glomeruli of nephritic rats, nor did it modify parameters of systemic coagulation and fibrinolysis in these animals, EACA and aprotinin did not interfere with serum titres of nephrotoxic antibody, nor with the intensity of its binding to the glomerular basement membrane in vivo. CONCLUSIONS: Antiproteolytic drugs utilized in our studies exert their beneficial effect on autologous anti-GBM nephritis through interference with inflammatory phase of the disease, while sparing its immune induction and mechanisms of coagulation/fibrinolysis.

[Fulminant course of glomerulonephritis with acute renal failure in a 63-year old man]. / Burzliwy przebieg klebuszkowego zapalenia nerek z ich ostra niewydolnoscia u 63-letniego mezczyzny.

A 63-year old man presented with severe nephrotic syndrome and acute renal failure, accompanied by congestive circulatory insufficiency and hypertension. During the next four days, despite intense symptomatic treatment of nephrotic syndrome impairment of glomerular filtration continued to progress (serum creatinine rose from 6.5 mg/dl to 7.5 mg/dl) and 24-hour proteinuria reached 26.7 g, while proteinaemia was 43.7 g/l. After having excluded malignancy and systemic disease, patient was given two doses of methylprednisolone (750 mg every other day) along with haemodialyses on three consecutive days. On the fourth day dialyses were stopped due to development of poliuria. Patient's circulation parameters have improved and so did the renal function. Kidney biopsy revealed scarce glomerular proliferation and interstitial mononu: clear infiltrates. Steroids being continued (prednisone 50 mg on alternate days), patient's condition continued to improve, results of laboratory tests practically returned to normal and two subsequent hospital observations within monthly intervals confirmed stability of remission.

A case of severe anti-neutrophil cytoplasmic antibody (ANCA)-positive crescentic glomerulonephritis and asymptomatic gastric cancer.

A 64-year-old man presented with symptoms of systemic immune disease dominated by rapidly progressive glomerular injury with highly positive ANCA of cytoplasmic distribution. The clinical course was characterized by dependence upon the intensity of immunosuppression, which has finally led to development of fungal septicaemia and death. The post mortem examination revealed occult gastric cancer with regional lymphatic involvement and crescentic glomerulonephritis, while failing to substantiate clinical findings of systemic vasculitis. This is, to our knowledge, the first case of ANCA-positive glomerulonephritis accompanying visceral malignancy and as such raises the question of whether it results from a simple coincidence or a causal relationship.

High prevalence of antibodies to hepatitis C virus in three haemodialysis centres in south-western Poland.

We assessed the prevalence of anti-hepatitis C virus (anti-HCV) antibodies and markers of hepatitis B virus (HBV) infection in patients of three haemodialysis centres before initiating anti-HBV vaccinations. Of the 94 patients, 39 (41.5%) were anti-HCV positive (+) and 81 (86.2%) were anti-hepatitis B core antigen (HBc) positive. There was a high rate of anti-HBc positivity among anti-HCV (+) patients (92.3%), although the presence of anti-HCV and anti-HBc antibodies were not significantly related to each other. Multiple blood transfusions (> 5 units) was a risk factor for development of HCV infection (P < 0.02), while none of our patients admitted intravenous drug abuse. Although 53.8% of anti-HCV (+) patients have had moderate serum alanine aminotransferase (ALT) elevations during the study period, none has had considerable liver disease, nor did the increased ALT correlate with the presence of anti-HCV. Only two of 17 staff members participating in the survey were anti-HCV (+), though almost every one gave a history of accidental needlestick exposure. All the study subjects were human immunodeficiency virus (HIV) negative. Our results, obtained with the second-generation, highly specific enzyme immunoassay and verified by the immunoblot assay for anti-HCV antibodies, support a recent suggestion that earlier reports might have underestimated the true prevalence of anti-HCV antibodies in haemodialysis patients.

[The importance of inflammatory mediators in immune injury of renal glomeruli]. / Znaczenie mediatorów reakcji zapalnej w uszkodzeniu klebuszków nerkowych o podlozu immunologicznym.

The article reviews contemporary state of knowledge pertaining to the pathogenesis of immune glomerular injury with particular emphasis on mediation of the inflammatory phase of glomerulonephritis. Distinct classes of humoral and cellular mediators are analysed with regard to their participation in experimental and human glomerulonephritis.

The variety of clinical and histopathologic presentations of glomerulonephritis associated with latent syphilis.

Glomerulonephritis is a well established but rather uncommon complication of latent secondary syphilis. We present three cases of glomerulopathies associated with luetic infection, observed and managed in our institutions in the past three years. They illustrate a variety of clinicopathologic presentations of this nephropathy, from acute nephrotic syndrome through membranous glomerulopathy up to rapidly progressive glomerulonephritis. Regardless of the clinical course and histologic type, they were all characterized by strongly positive results of serologic tests for syphilis. Our observations suggest the necessity of eliminating luetic infection in aetiologic considerations of each newly diagnosed case of nephrotic syndrome.

Antiserum against tumor necrosis factor-alpha and a protease inhibitor reduce immune glomerular injury.

Previous studies in this laboratory have documented tumor necrosis factor alpha (TNF) release by macrophage laden glomeruli in the accelerated autologous form of nephrotoxic serum nephritis (AA-NTSN). We now report that the administration of anti-TNF antiserum to rats with the AA-NTSN reduces albuminuria in a dose related manner (day 8 postinduction) and limits glomerular necrosis (P less than 0.05) without affecting the endogenous creatinine clearance (CCr). Protease inhibitors block cytolytic activity of TNF in vitro and reduce glomerular necrosis in experimental nephritis in vivo. The combined administration of anti-TNF antiserum and an amidine-type protease inhibitor (BABIM) to rats with the AA-NTSN caused a greater diminution of albuminuria and histopathology than observed in rats treated with either agent alone, and also prevented the fall in CCr otherwise observed in this model system. Since, in our studies, BABIM did not inhibit cytolytic TNF activity in vitro, we conclude that the effects of combined administration of these two agents are mediated by independent mechanisms. Our results highlight the pathogenic significance of local TNF release in immune renal disease accompanied by prominent glomerular macrophage accumulation.

Spontaneous release of tumor necrosis factor alpha by isolated renal glomeruli and cultured glomerular mesangial cells.

Although mononuclear phagocytes were once considered the sole source of tumor necrosis factor alpha (TNF), it is now understood that other cell types, including T and B lymphocytes, may be stimulated to produce this factor. Herein we describe the release of a cytotoxic activity in vitro by isolated rat glomeruli and cultured glomerular mesangial cells. Immunoperoxidase staining with monoclonal antibodies against Ia and leukocyte common antigen-documented cultured mesangial cell populations were free of mononuclear phagocytes. Cytotoxic activities generated by isolated glomeruli and mesangial cell cultures eluted on gel chromatography in two peaks corresponding to molecular weights of 17 and 40 kDa and were fully inhibitable by anti-recombinant murine TNF antiserum. These data strongly suggest that intrinsic glomerular mesangial cells contribute to TNF release by intact glomeruli. Intraglomerular generation of TNF and perhaps other cell types may bear upon the pathogenesis of immune glomerular injury.

Chemiluminescence of neutrophils in patients with glomerulonephritis treated with methylprednisolone.

The effect of high dose methylprednisolone (Solu-Medrol, Up John) (1000 mg) on chemiluminescence (CL) of peripheral blood neutrophils in patients with various primary glomerulopathies was determined. Contrary to the well-established influence of corticosteroids on in vitro suppression of leukocytic chemiluminescence, our studies disclose a remarkable enhancement of neutrophil chemiluminescent activity in patients receiving pulse methylprednisolone infusion. Subsequent administrations of the drug did not result in any significant change of the analysed parameters. Increased chemiluminescence returned to the pretreatment values within approximately seven days. A possible explanation for the observed phenomenon is discussed.

Mechanisms of glomerular injury in experimental immune nephritis. I. Tumor necrosis factor is released by renal glomeruli of nephritic rats.

Cytotoxic activity expressed by renal glomeruli of LEW rats with the accelerated autologous form of nephrotoxic serum nephritis (AA-NTSN) was assessed using the lymphotoxin (LT) sensitive line aL929. Glomeruli isolated on day 3 following nephritis induction were much more cytotoxic for aL929 in coculture than glomeruli of unmodified LEW (p less than 0.0025). Such a cytolysis was due to a soluble factor eluted on gel chromatography in a single peak corresponding to molecular weight (MW) of 40-45 kDa. The cytotoxic activity, harvested in 24-hour culture supernatants of nephritic glomeruli (NGS) and the chromatographic peak were totally inhibitable by antiserum neutralizing recombinant murine tumor necrosis factor alpha (rMuTNF). An abundant glomerular macrophage accumulation on day 3 and reduction of cytotoxicity (42.3%, p less than 0.01) upon irradiation limiting the mononuclear phagocyte infiltrate suggest that macrophages are at least partly responsible for TNF production by nephritic glomeruli. This study provides the initial documentation on generation of TNF in glomerular inflammatory injury induced by immune reaction.

Mechanisms of glomerular injury in experimental immune nephritis. II. Effect of a platelet activating factor receptor antagonist in an autologous nephritis model.

The role of Platelet Activating Factor (PAF) in experimental immune glomerulonephritis was assessed by administering the specific PAF receptor antagonist CV-3988 to inbred LEW rats with the Accelerated Autologous Nephrotoxic Serum Nephritis (AA-NTSN). Intravenous administration of CV-3988 caused a marked and sustained reduction in albuminuria and renal histopathological changes. Conversely, although CV-3988 appeared to modulate the fall in glomerular filtration rate (GFR) in the AA-NTSN, this trend was not statistically significant. Renal glomeruli isolated on day 1 after nephritis induction spontaneously released 16.9 +/- 2.2 ng of PAF per 200 glomeruli, while in glomeruli of healthy rats this secretion was virtually undetectable. The administration of CV-3988 to rats with AA-NTSN did not affect the following: binding of intravenously injected sheep anti-rat glomerular basement membrane (GBM) antibody; levels of autologous antibody to sheep immunoglobulin G; the functional integrity of circulating neutrophils. We conclude that local PAF generation and release is intimately linked with the pathogenesis of glomerular injury in this form of immune disease.

Effects of tumor necrosis factor on glomerular mesangial and epithelial cells in culture.

We have previously documented the importance of tumor necrosis factor (TNF) alpha in the pathogenesis of nephrotoxic-serum nephritis in rats. In this study, we evaluated the possible relevance of the well-established cytocidal TNF activity to the mechanism of glomerular injury by assessing sensitivity of rat mesangial and epithelial cell populations to recombinant murine TNF alpha (rMuTNF). Radiolabelled confluent mesangial cell cultures that were incubated with rMuTNF released significantly more 3H-thymidine than control monolayers (maximum specific release was 11.4 +/- 4.9% at 1,000 pg/ml of rMuTNF). rMuTNF was, however, approximately 1,000-fold less cytolytic in mesangial cells than in the lymphotoxin-sensitive L929 cell line. Conversely, glomerular epithelial cells were not affected by exposure to rMuTNF under the same conditions. These results suggest that the cytolytic effect of TNF may contribute to glomerular injury in nephrotoxic-serum nephritis.