IgM-immune complex glomerulonephritis associated with sarcoidosis

Hydralazine use can be associated with IgM-dominated immune complex-mediated glomerulonephritis

CONTEXT

IgM-dominant immune complex-mediated glomerulonephritis (IgM-dominant ICMGN) is a rare renal entity, characterized by a membranoproliferative pattern by light microscopy, dominant IgM staining by immunofluorescent staining, and subendothelial deposits by electron microscopy. This study was to investigate if some of IgM-ICMGN were associated with autoimmune disorders induced by hydralazine.

DESIGN

Seven IgM-dominant ICMGN cases were identified over 8 years. Their pathologic phenotypes and clinical scenarios were analyzed in detail.

RESULTS

Patients' ages ranged from 47 to 87 years old with 5 women and two men. Six of seven patients had drug-induced autoimmune phenomenon (hydralazine-induced positive ANCA and ANA). All of them had renal dysfunction and some proteinuria. Most pathologic features showed a membranoproliferative pattern of glomerulonephritis with dominant IgM deposits at subendothelial spaces. IgM nephropathy (a variant of focal segmental glomerulosclerosis), chronic thrombotic microangiopathy, and cryoglobulinemic glomerulopathy were ruled out in the cases.

CONCLUSION

The hydralazine-induced autoimmune phenomenon can be seen in IgM-dominant ICMGN, which should be classified as a subtype of membranoproliferative glomerulonephritis.

A case of systemic sarcoidosis with mesangial proliferative glomerulonephritis showing predominant deposition of IgG in the mesangial region

A 37-year-old African-British man was referred to our hospital for detailed examination because of persistent fever, swelling and pain in both ankle joints, and blurred vision for two months. Inguinal lymph node biopsy showed a large number of epithelioid granulomas without necrosis. Granulomatous anterior uveitis, nephropathy, high serum angiotensin-converting enzyme activity, and high serum-soluble interleukin-2 receptor were observed, and the diagnosis of systemic sarcoidosis was made. His serum creatinine was 1.4 mg/dL and hematuria, leukocyturia, and urine protein were also seen. The renal biopsy finding was mesangial proliferative glomerulonephritis, with no findings of granuloma formation or tubular interstitial nephritis. Immunofluorescence staining showed deposition of IgG, C3, and C1q in the mesangial region. IgG3 was dominant in subclass staining. There was no monoclonality on kappa and lambda staining. Electron microscopy showed predominant deposition in the mesangial region with some subepithelial and endothelial deposition. His hematuria and leukocyturia disappeared with steroid therapy, suggesting sarcoidosis-related nephropathy. A case of systemic sarcoidosis with mesangial proliferative glomerulonephritis showing predominant deposition of IgG in the mesangial region is presented. No cases of such histological findings have been reported so far, and it is necessary to analyze further cases to clarify the pathogenic significance of the renal biopsy findings observed in this case.

Atypical sarcoidosis diagnosed by bone marrow biopsy during renal workup for possible multiple myeloma

Sarcoidosis is a multi-organ disease of unknown etiology characterized by non-caseating granulomas. Here we report the case of a 78-year-old white male with a past medical history of diabetes mellitus, hypertension, and chronic kidney disease stage III with a baseline serum creatinine of 2.5 mg/dl. The patient had a prior admission history for acute kidney injury (AKI) attributed to dehydration and medication-induced nephro-toxicities. He presented to the renal clinic for follow-up with acute worsening of chronic kidney failure with a serum creatinine level of 3.5 mg/dl. Examination revealed that he was anemic and mildly hypercalcemic with suppressed parathyroid hormone and had proteinuria of 1.3 g per day. The computed tomography scan of the abdomen revealed right renal pelvic non-obstructing calculi. Serum protein electrophoresis revealed gammopathy with two distinct monoclonal peaks consisting of immunoglobulin G (IgG) kappa and IgG lambda, respectively. The kappa/lambda ratio was within normal limits, and urine protein electrophoresis showed no evidence of a monoclonal peak or Bence Jones proteins. Further workup for multiple myeloma, including bone marrow (BM) biopsy, revealed polyclonal plasma cells and B cells with no clonality. No morphological and immune-phenotypic evidence of plasma cell dyscrasia was found, but BM biopsy did show numerous non-caseating granulomas consistent with sarcoidosis. Skin biopsy from non-scaly 6-mm skin colored papule also showed non-caseating granulomas. The patient had elevated angiotensin-converting enzyme levels (165 ug/l) and an erythrocyte sedimentation rate of 27 mm/h. Kidney biopsy did not show granulomas. The hypercalcemia, proteinuria, and AKI responded well after 2 weeks of 60 mg oral prednisone daily.

[Kidney involvement in sarcoidosis]

Sarcoidosis is a chronic multisystemic inflammatory disorder of unknown etiology, characterized by the presence of non-necrotizing epithelioid and giant cell granulomas. Various renal manifestations have been reported in patients with sarcoidosis. Disorders of bone and mineral metabolism related to the overexpression of 25-hydroxyvitamin-D1α-hydroxylase by alveolar and granuloma macrophages are frequently associated with sarcoidosis. Hypercalcemia and hypercalciuria are a major cause of renal injury predisposing to pre renal azotemia, acute tubular necrosis, nephrolithiasis and nephrocalcinosis. Therapeutic management of hypercalcemia includes preventive measures (limited sunlight exposure, limited vitamin D and calcium intakes, and adequate hydration) and specific treatment in cases of severe hypercalcemia (corticosteroid therapy, chloroquine or ketoconazole). Granulomatous tubulointerstitial nephritis is the most common renal lesion associated with sarcoidosis leading to end stage renal disease in some patients. In these cases, interstitial fibrosis seems to appear early in the course of sarcoidosis and is a major prognostic factor requiring rapid corticosteroid therapy to reduce the risk of severe renal impairment. Membranous nephropathy seems to be the most frequent glomerular disease that may occur in association with sarcoidosis. Among kidney allograft recipients, the risk of recurrence of granulomatous tubulointerstitial nephritis is high and may have a negative impact on the graft survival.

Renal granuloma and immunoglobulin M-complex glomerulonephritis: a case of common variable immunodeficiency?

Common variable immunodeficiency (CVID) is characterized by reduced serum immunoglobulin levels and recurrent bacterial infections. Granulomatous infiltrations are occasionally found in the lymphoid or solid organs of affected patients, but renal involvement is rare. We present a case of possible CVID with interstitial noncaseating granuloma and immunoglobulin (IgM)-complex glomerulonephritis with a membranoproliferative pattern and with a favorable response to corticosteroids, intravenously administered immunoglobulins (IVIGs) and rituximab. CVID must be included in the differential diagnosis of renal granuloma and should be differentiated from sarcoidosis to ensure appropriate therapy.