A case of membranous nephropathy with ANCA-associated necrotizing glomerulonephritis during oral administration of PTU for Graves' disease

We experienced a coincidental case of two types of glomerulopathy associated with Graves' disease. A 64-year-old man, who had been treated with propylthiouracil(PTU) for Graves' disease for 15 years, was admitted to our hospital for macroscopic hematuria and rapidly progressive deterioration of renal function. Although his thyroid function had been within the normal range during treatment, the level of thyrotropin receptor antibody(TRAb) gradually increased from a year before admission. Serological tests revealed that he was positive for myeloperoxidase-antineutrophil cytoplasmic antibody(MPO-ANCA). The renal biopsy specimen showed necrotizing and crescentic glomerulonephritis(GN) superimposed on membranous nephropathy(MN). This is a rare case of MN complicated with ANCA associated crescentic GN in a Graves' disease patient. Association of these two renal alterations was not clearly defined. MN involved with Graves' disease also has been rarely reported. Some reports demonstrated deposition of thyroglobulin and other thyroid related antigens in the glomeruli. In the present case, long-term impairment of Graves' disease and elevation of TRAb might have been responsible for the formation and deposition of thyroid-associated immune complex in the glomeruli. As for crescentic GN, PTU might have induced ANCA-associated GN independently of MN. This case is instructive for considering the relation between Graves' disease and renal injury.     

Apoptosis, proliferation and inflammatory infiltration in ANCA-positive glomerulonephritis

AIMS: Antineutrophil cytoplasmic antibodies (ANCA) are detected in most patients with crescentic glomerulonephritis and necrotizing small vessel vasculitis. ANCA cause renal inflammation and proliferation. Apoptosis is necessary for resolution of inflammation. We studied apoptosis, apoptosis-regulating proteins, proliferation and infiltration with ANCA target antigen containing neutrophils and monocytes in renal biopsies from ANCA patients and disease controls. METHODS: Skin biopsies from patients with leukocytoclastic vasculitis (n=6) and renal biopsies from patients with ANCA vasculitis (n=10), ANCA-negative crescentic glomerulonephritis (CGN, n=7), mesangio-proliferative GN (n=6), post-streptococcal GN (PSGN, n=4), diabetic nephropathy (n=6) and minimal change nephropathy (MCNP, n=6) were evaluated by immunohistochemistry. Biopsies were stained for apoptosis (TdT-mediated UTP nick-end labeling, TUNEL), proliferation (Ki-67), neutrophils (NP 57), and monocytes (KP 1). We also evaluated Fas and Bcl-2 expression. RESULTS: Apoptosis was common in leukocytoclastic vasculitis skin biopsies, but was rare in renal biopsies. ANCA-positive NCGN showed the lowest apoptosis rate, similar to MCNP and diabetic nephropathy. The highest apoptosis rate was seen in PSGN. The highest glomerular Bcl-2 expression was present in ANCA-positive biopsies. The Bcl-2/TUNEL ratio was significantly increased in ANCA-positive necrotizing crescentic glomerulonephritis (NCGN) compared to ANCA-negative CGN and PSGN. When proliferation (Ki-67) and apoptosis were expressed as a ratio, we observed the highest index in biopsies from patients with ANCA-positive NCGN because of their low apoptosis rates. Finally, the glomerular inflammatory infiltrate in ANCA-positive NCGN showed a high percentage of neutrophils. CONCLUSIONS: These preliminary results suggest an imbalance between apoptosis and proliferation, favoring proliferation, in renal biopsies from ANCA-positive NCGN patients.     

Crescentic glomerulonephritis associated with infective endocarditis: renal recovery after immediate surgical intervention

A 57-year-old man was referred to our hospital because of acute cardiac failure and acute renal insufficiency. Laboratory data showed elevation of serum immune complex levels and antineutrophil cytoplasmic antibody (ANCA) titers, with cytoplasmic pattern (C-ANCA) on indirect immunofluorescence (IIF), and proteinase 3 specificity (PR3-ANCA) on solid-phase enzyme-linked immunosorbent assay (ELISA). Hemodialysis therapy was initiated, and this relieved the symptoms of cardiac failure. Echocardiography revealed three-grade aortic insufficiency and two large floating vegetations on the aortic valve. Considering the risk of embolism, we immediately performed aortic valve replacement and surgically removed the vegetations, subsequently giving antibiotic therapy. Six weeks after the operation, the patient's renal function showed marked improvement and the serological abnormalities, except for ANCA titers, had normalized, resulting in no need for dialysis. A renal biopsy specimen revealed diffuse proliferative glomerulonephritis (GN) with crescents including more than 50% of glomeruli, and granular deposits of IgM, C3, and C1q on immunofluorescence. ANCA titers remained high, but the patient's renal function has been stable, indicating a discrepancy between ANCA titers and his clinical course. In this patient, treatment by immediate surgical intervention, performed during the acute phase with active GN and highly reduced renal function, led to dramatic renal recovery. This case suggests that surgical removal of vegetations in the early stage of crescentic GN may result in a good renal outcome in patients with rapidly progressive GN associated with endocarditis. Although it has been suggested that ANCA may have some relationship to GN in endocarditis, in this patient, its pathogenetic significance is questionable. Received: March 10, 2000 / Accepted: May 23, 2000     

Clinical and pathologic characteristics of pauci-immune anti-myeloperoxidase antibody associated glomerulonephritis with nephrotic range proteinuria

Background: Heavy proteinuria in antineutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis (GN) is usually considered to be associated with immune deposits in renal biopsy. Nephrotic ANCA GN without immune deposits (pauci-immune) is rare and has not been studied specially. In this study characteristics of these patients are to be investigated.

Methods: Clinical and pathological characteristics from 20 kidney biopsy-proven pauci-immune anti-myeloperoxidase antibody-associated GN patients with nephrotic proteinuria were analyzed and were compared with ANCA GN patients without nephrotic proteinuria.

Results: Acute kidney injury (AKI) and gross hematuria were much prevalent but extra-renal involvement was less prevalent in pauci-immune ANCA GN with nephrotic proteinuria than in pauci-immune ANCA GN without nephrotic proteinuria. No more severe hypoalbuminemia, hypercoagulability, hyperlipidemia or higher thrombosis incidence were found between two groups. Compared with patients without nephrotic proteinuria, patients with nephrotic proteinuria had more prevalent crescentic category in histopathology. Proteinuria decreased quickly after treatment but much poorer renal prognosis was found in pauci-immune ANCA GN with nephrotic proteinuria. The results of urinary albumin to total protein ratio and urinary protein electrophoresis showed pauci-immune ANCA GN with nephrotic proteinuria had obvious non-selective proteinuria.

Conclusions: Pauci-immune ANCA GN with nephrotic proteinuria do not have more severe hypoalbuminemia, hypercoagulability or hyperlipidemia than patients without nephrotic proteinuria. Non-selective proteinuria might be the reason. However, pauci-immune ANCA GN with nephrotic proteinuria have more prevalent crescentic category in histopathology, higher incidence of AKI, gross hematuria and poorer renal prognosis despite of good sensitivity to therapy of proteinuria.     

Antigen-specific radioimmunoassays for anti-neutrophil cytoplasmic antibodies in the diagnosis of rapidly progressive glomerulonephritis.

Circulating anti-neutrophil cytoplasmic antibodies (ANCA) have been described in most patients with "pauci-immune" necrotizing and crescentic glomerulonephritis. A 29-kDa serine protease (p29 or proteinase 3) and myeloperoxidase are the two best characterized antigens recognized by ANCA. The study presented here was conducted to define the diagnostic value of assays for antibodies against these two antigens in rapidly progressive glomerulonephritis. Radioimmunoassays were developed for anti-p29 and anti-myeloperoxidase antibodies, with purified antigens, and the results of the radioimmunoassays were compared with those obtained by immunofluorescence tests for ANCA. We performed assays on serum samples from 123 patients with the syndrome of rapidly progressive glomerulonephritis, as well as from 200 blood bank donors and from 717 additional control patients. Without knowledge of the results of ANCA tests, the renal pathologic findings in the 123 patients with rapidly progressive glomerulonephritis were analyzed, and 42 were classified as pauci-immune necrotizing and crescentic glomerulonephritis, 18 were classified as anti-glomerular basement membrane nephritis and 63 were classified as other forms of renal disease. We found radioimmunoassays to be more reliable in the diagnosis of pauci-immune necrotizing and crescentic glomerulonephritis than immunofluorescence testing. By radioimmunoassay, ANCA were found in 40 of 42 patients (95% sensitivity) with pauci-immune necrotizing and crescentic glomerulonephritis (14 with anti-p29 and 26 with anti-myeloperoxidase antibodies). The tests for antibodies to p29 and myeloperoxidase were 99.9 and 99.5% specific for pauci-immune necrotizing and crescentic glomerulonephritis, respectively. In the setting of rapidly progressive glomerulonephritis, a positive radioimmunoassay for anti-p29 or anti-myeloperoxidase antibodies (together with a negative test for anti-GBM antibodies) gives a probability of pauci-immune necrotizing and crescentic glomerulonephritis of over 99%.     

An unusual endocarditis-induced crescentic glomerulonephritis treated by plasmapheresis

A 58-year-old man presented with fever and a rapidly progressive glomerulonephritis. An infective endocarditis due to Streptococcus parasanguis was diagnosed. A renal biopsy revealed type III pauci-immune crescentic glomerulonephritis. As first-line therapy, antibiotics were administered alone. Faced to the unsuccessful anti-infective approach, corticosteroid therapy was added as a second-line therapy. Finally, plasmapheresis introduced as the third-line therapy, significantly improved renal function. This case is an original type III rapidly progressive glomerulonephritis, since ANCA were repeatedly found negative. In very few cases, plasmapheresis was successfully used for the treatment of infective endocarditis-induced crescentic glomerulonephritis. The pathophysiology and the potential efficiency of plasmapheresis are discussed.     

A case of relapse of C-ANCA-associated glomerulonephritis in post-transplant patients

We experienced a case of relapse of proteinase 3-specific antineutrophil cytoplasmic autoantibody (C-ANCA)-associated rapid progressive glomerulonephritis (RPGN) in a patient after renal transplantation. A 19-yr-old man, who underwent a living donor kidney transplantation, presented a rapid renal function deterioration along with a sign of infection. Initially he was treated as acute rejection, but renal function did not improve. Renal biopsy revealed crescentic glomerulonephritis, and C-ANCA titer was 12 EU/mL, resulting in the diagnosis of C-ANCA-associated RPGN. He was treated with three consecutive methylprednisolone pulses twice in addition to the basal immunosuppressive medications (cyclosporine A and mizoribine), then his renal function improved to normal. Bearing the possibility of recurrence of glomerulonephritis in mind, we re-evaluated the nature and disease course of renal failure of original kidney. He experienced a rapid deterioration of renal function in 1992, and eventually CAPD was started in 1992. His serum in 1992 revealed high titer of C-ANCA (24 EU/mL), and renal biopsy performed in 1992 showed a crescentic glomerulonephritis. Taken together, we diagnosed this event as a relapse of C-ANCA-associated GN. Lessons from our experience are: 1) steroid pulse and high-dose corticosteroid therapy may be useful for the treatment of relapse of C-ANCA-associated GN patients after renal transplantation; 2) the possibility of a relapse of C-ANCA-associated GN following renal transplantation has to be kept in mind, especially when infection precedes the deterioration of allograft kidney function.     

Post-reperfusion rapidly progressive glomerulonephritis in post-transplant IgA nephropathy

Rapidly progressive glomerulonephritis (RPGN) is a rare occurrence in IgA nephropathy (IgAN) in renal transplant patients on immunosuppressive therapy. RPGN post ischemia-reperfusion has not been previously reported. We report a 62 year old male patient on azathioprine therapy, 9 years after left cadaveric renal transplantation due to end stage renal disease of unknown etiology, who presented with progressive deterioration in renal function and hematuria. Renal biopsy was consistent with IgAN. Duplex and CT scan demonstrated a decreased renal graft perfusion, due to severe atherosclerosis and stenosis of iliac arteries. The patient underwent left axilo-femoral bypass graft surgery with improvement in kidney graft perfusion and function. However, few weeks later, patient presented with pulmonary edema and advanced renal failure and he was initiated on hemodialysis. Repeated renal biopsy demonstrated crescentic GN. To the best of our knowledge, this is the first report of RPGN following reversal of ischemia and reperfusion. There was no evidence for atherembolic disease which is not uncommon after vascular surgery and it has been reported to be rarely associated to crescentic GN. Theoretical explanations for exacerbation of IgAN to crescentic GN, following successful reperfusion, could be enhancement of capillary damage, inflammation and oxidative stress. Putative mechanisms for these phenomena may be interaction of reperfusion-induced hyperfiltration, high intraglomerular capillary pressure, oxidative stress, increased polymorphonucler cells infiltration and inflammation; the presence of IgA immune deposits and azathioprine metabolites, both can also be associated to enhancement of oxidative stress.     

Azurocidin-specific-ANCA-related idiopathic necrotizing crescentic glomerulonephritis

An 80-year-old woman who had rapidly progressive glomerulonephritis unaccompanied by systemic vasculitis is described. On renal biopsy, she showed necrotizing crescentic glomerulonephritis by light microscopy and pauci-immune glomerular lesions by immunofluorescent study. No dense deposits were present on electronmicroscopic study. On serum examination, indirect immunofluorescent study showed perinuclear pattern antineutrophil cytoplasmic antibody (ANCA), but myeloperoxidase-ANCA and proteinase 3-ANCA were both negative. Her serum reacted only to azurocidin excluding other ANCA antigens: bactericidal permeability-increasing protein, cathepsin G, elastase, lactoferrin, or lysozyme. Serum creatinine level decreased, and C-reactive protein turned negative after steroid therapy. Azurocidin-ANCA also turned negative. It is suggested that azurocidin-ANCA might have been related to the inflammatory process of pauci-immune necrotizing crescentic glomerulonephritis in this patient.     

CC Chemokine Ligand 18 in ANCA-Associated Crescentic GN

ANCA-associated vasculitis is the most frequent cause of crescentic GN. To define new molecular and/or cellular biomarkers of this disease in the kidney, we performed microarray analyses of renal biopsy samples from patients with ANCA-associated crescentic GN. Expression profiles were correlated with clinical data in a prospective study of patients with renal ANCA disease. CC chemokine ligand 18 (CCL18), acting through CC chemokine receptor 8 (CCR8) on mononuclear cells, was identified as the most upregulated chemotactic cytokine in patients with newly diagnosed ANCA-associated crescentic GN. Macrophages and myeloid dendritic cells in the kidney were detected as CCL18-producing cells. The density of CCL18⁺ cells correlated with crescent formation, interstitial inflammation, and impairment of renal function. CCL18 protein levels were higher in sera of patients with renal ANCA disease compared with those in sera of patients with other forms of crescentic GN. CCL18 serum levels were higher in patients who suffered from ANCA-associated renal relapses compared with those in patients who remained in remission. Using a murine model of crescentic GN, we explored the effects of the CCL18 murine functional analog CCL8 and its receptor CCR8 on kidney function and morphology. Compared with wild-type mice, Ccr8^−/− mice had significantly less infiltration of pathogenic mononuclear phagocytes. Furthermore, Ccr8^−/− mice maintained renal function better and had reduced renal tissue injury. In summary, our data indicate that CCL18 drives renal inflammation through CCR8-expressing cells and could serve as a biomarker for disease activity and renal relapse in ANCA-associated crescentic GN.     

Crescentic glomerulonephritis in Beh?et's syndrome--results of therapy and review of the literature

The syndrome initially described by Beh?et in 1937 comprised the triad of ocular inflammation, oral and genital ulcers. The described manifestations have gradually expanded to include most tissues; renal involvement has been described but is usually mild. Although crescentic glomerulonephritis (GN) has been reported, it is extremely rare. We report two patients presenting with Beh?et's syndrome complicated by an active crescentic GN. Their course, following the initiation of therapy with prednisone and cyclophosphamide is described. Both patients evolved to a sclerosed glomerulopathy documented by follow-up renal biopsy in spite of a dramatic clinical improvement in one patient and a stabilization of renal function in the other. Both developed nephrotic range proteinuria without amyloidosis.     

Anti-neutrophil cytoplasmic antibody-associated glomerulonephritis in children

Two cases of anti-neutrophil cytoplasmic antibody (ANCA)-associated necrotizing and crescentic glomerulonephritis are reported. A 12-year-old girl and a 10-year-old boy presented with polyarthritis, anaemia, haematuria, proteinuria, impaired renal function, anorexia, nausea, marked loss of weight and lethargy. The boy also had a vasculitic rash and anterior uveitis. Both children had diffuse cytoplasmic ANCA identified by indirect immunofluorescence and confirmed by specific enzyme-linked immunosorbent assay. Renal biopsies showed severe focal and segmental necrotizing glomerulonephritis with 100% crescents. They were treated with plasma exchange, prednisolone, cyclophosphamide and heparin. Within 1 month of commencing treatment, both had normal serum creatinine concentrations and ANCA was not detectable. Renal biopsies 6 weeks following commencement of treatment revealed quiescent disease, although up to 40% of glomeruli were sclerosed or had fibrous crescents. Following cessation of cyclophosphamide and heparin after 7 months and reduction in steroid dose, a biopsy at 10 months in the boy revealed quiescent disease, but the girl had recurrent disease associated with reappearance of a low titre of ANCA and small cellular crescents in 20% of the glomeruli. These cases reflect the potential usefulnes of ANCA determination for categorizing paediatric patients, helping in the selection of therapy and as a possible marker of disease activity, similar to the experience in adults.     

ANCA-positive crescentic glomerulonephritis associated with minocycline therapy

Minocycline is an oral antibiotic widely used for the long-term treatment of acne and rheumatoid arthritis. A few patients develop antineutrophil cytoplasmic antibodies (ANCAs) during minocycline therapy. In this report, the authors describe a case of severe pauci-immune crescentic and necrotizing glomerulonephritis associated with positive cytoplasmic ANCA (C-ANCA) titers and proteinase 3 (PR3) levels after minocycline therapy. Discontinuation of minocycline and initiation of immunosuppressive treatment resulted in improvement of renal function and decline in C-ANCA titers and PR3 levels. A high degree of suspicion, testing for ANCA titers, prompt discontinuation of the drug, and initiation of immunosuppressive treatment are crucial to the diagnosis and treatment of drug-induced ANCA-associated glomerulonephritis.     

Two cases of ANCA-associated vasculitis in post-transplant kidney: relapse and de novo

Abstract:  Two cases of anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis (ANCA-V) occurred in the transplanted kidney were reported. Case 1 was a 57 yr-old female whose original disease was MPO-ANCA-V. A relapse of necrotizing crescentic glomerulonephritis occurred one year after transplantation with positive serum reaction for MPO-ANCA. In spite of several immunosuppressive treatments, the disease progressed and she returned to hemodialysis treatment three yr and seven months after transplantation. Case 2 was a 34 yr-old female whose original disease was IgA nephropathy. She had a stable clinical condition during 13 yr after transplantation; however, de novo onset of necrotizing crescentic glomerulonephritis occurred at 14 yr 10 months after transplantation with positive serum reaction for MPO-ANCA. She returned to hemodialysis treatment five yr after the onset of ANCA-V. Urinary abnormities such as microhematuria and proteinuria were useful diagnostic findings but the titers of serum MPO-ANCA were relatively low in both patients. Concerning the treatment, steroid pulse therapy was effective in some extents but the disease progressed to graft failure in both cases. ANCA-V is a severe glomerulonephritis which can occur in kidney allograft in the manner of relapse and de novo . Detection of urinary abnormalities and positive serum ANCA combined with histological confirmation of necrotizing crescentic glomerulonephritis and/or vasculitis is required for early diagnosis and effective treatment of ANCA-V in renal transplant patients.     

100例新月体肾炎的免疫病理分型及临床病理分析

目的：了解新月体性肾炎的免疫病理分型及其临床病理特点。方法：对我科近10年来经肾活检确诊的100例新月体性肾炎进行回顾性分析,对患者血清进行抗中性粒细胞胞浆抗体（ANCA）和抗肾小球基底膜（GBM）抗体的检测。结果：100例患者中21％为抗GBM抗体型,其中6／21例同时合并ANCA阳性;47％为免疫复合物型,其中9／47型ANCA阳性;32％为少免疫沉积型,其中17／32例为ANCA阳性小血管炎。3种类型相比,抗GBM抗体型以青年男性为主,多有少尿或无尿（P＜0．05）,肾小球受累受为广泛（P＜0．001）,预后差（P＜0．001）。免疫复合物型以中青年为主,多表现为肾病综合征（P＜0．01）,强化免疫抑制治疗有效。少免疫沉积型以中老年为主,有多系统受累（P＜0．05）,治疗效果相对较好。结论：我国新月体肾炎中虽仍以免疫复合物型为主,但抗GBM抗体型和ANCA阳性小血管炎并不少见。肾活检免疫病理和血清自身抗体的联合应用对新月体肾炎进行分类更接近病因学诊断。     

Glomerular lesions in patients with Churg-Strauss syndrome and the anti-myeloperoxidase antibody.

We report here 4 patients with Churg-Strauss syndrome (CSS) who had classic symptoms including a history of bronchial asthma, severe eosinophilia and necrotizing vasculitis. The antineutrophil antibody (ANCA) against myeloperoxidase (MPO) titers was elevated (44-877 ELISA units), but the ANCA against proteinase-3 (PR3) was negative in all patients. One case was complicated with systemic inflammatory response syndrome (SIRS) and required plasmapheresis and continuous hemodiafiltration. One other patient clinically showed rapidly progressive glomerulonephritis and had hemodialysis 24 times. Two of 4 patients showed good responses with corticosteroid therapy alone, while 2 patients required the addition of cyclophosphamide. Urinary abnormalities such as proteinuria or microscopic hematuria were found in all patients. Three patients had a decreased glomerular filtration rate (GFR) and renal biopsy specimens obtained from these patients showed crescentic glomerulonephritis. One patient had mild to moderate mesangial-proliferative glomerulonephritis with interstitial eosinophilic infiltration. These findings suggest that renal involvements in CSS may not be as uncommon a disorder as previously considered, especially when MPO-ANCA is positive. MPO-ANCA may be associated with the onset of glomerular disorders in CSS.     

PR3-ANCA-positive crescentic necrotizing glomerulonephritis accompanied by isolated pulmonic valve infective endocarditis, with reference to previous reports of renal pathology

Patients with infective endocarditis (IE) often have renal complications which may include infarcts, abscesses and glomerulonephritis (GN). Furthermore, it is generally accepted that there is an association between IE and anti-neutrophil cytoplasmic antibody (ANCA). Here, we report the case of a 24-year-old man who developed rapidly progressive GN in the course of IE due to infection with alpha-streptococcus. The initial clinical manifestation of the condition was severe sacroiliitis without fever. Sandwich ELISA showed that the patient was positive for PR3-ANCA at low titer, and the classical complement pathway was also activated. Renal biopsy demonstrated several lesions: focal embolic GN, GN with immune deposits and focal and segmental crescentic necrotizing GN. Treatment with antibiotics and steroids led to eradication of the infection, and resolution of the renal disease was accompanied by immediate disappearance of PR3-ANCA and hypocomplementemia. During a 4-year follow-up period, no recurrence was observed. There have only been 7 case reports of GN associated with IE and PR3-ANCA in which the renal pathology has been described, and the current report is the first to document renal pathology in a patient with isolated pulmonic valve IE and PR3-ANCA. Moreover, this report is the first to show a change in renal biopsy findings in response to treatment. A review of the 7 literature cases and that of our patient showed that none involved pauci-immune GN. Hence, further studies are needed to clarify the prevalence of pauci-immune GN in ANCA-positive IE patients.     

T cells in crescentic glomerulonephritis

Crescent formation in glomerulonephritis (GN) is a manifestation of severe glomerular injury that usually results in a poor clinical outcome. In humans, crescentic GN is frequently associated with evidence of either systemic or organ-specific autoimmunity. T cells play a major role in initiation of adaptive immune responses that lead to crescentic injury. In experimental models of crescentic GN, Th1 predominant immune responses have been shown to promote crescent formation. Perturbation of regulatory T cell function may contribute to development of autoimmune crescentic GN. The presence of T cells and macrophages in crescentic glomeruli, frequently in the absence of humoral mediators of immunity, suggest a dominant effector role for T cells in crescentic GN. The association of cellular immune mediators with local fibrin deposition implicates cell-mediated "delayed-type hypersensitivity-like" mechanisms in crescent formation. Intrinsic renal cells also contribute to T cell-driven effector mechanisms in crescentic GN, via expression of MHC II and co-stimulatory molecules and by production of chemokines and cytokines that amplify leukocyte recruitment and injury.     

Diabetes delaying the diagnosis of RPGN

The present case describes the unusual association of a crescentic glomerulonephritis (GN), diabetes mellitus and a monoclonal gammopathy. After an unexplained deterioration of renal function, a kidney biopsy was performed. The finding of crescentic glomerulonephritis was unexpected. This case illustrates the usefulness of kidney biopsy in diabetes to exclude concomittant disease.