Fibrillary glomerulonephritis with prevalent IgA deposition associated with undifferentiated connective tissue disease: A case report.

We described a 41-year-old female patient, who presented with proteinuria occurring 5 years after the onset of an undifferentiated connective tissue disease (UCTD). At renal biopsy, a pattern of focal necrotizing glomerulonephritis with mesangial and parietal deposition of the IgA, C3 and K chains was observed. Electron microscopy showed organized fibrillary deposits in mesangial, subendothelial, intramembranous and subepithelial sites. Fibrils were randomly arranged, had no hollow core and had a diameter ranging between 10 and 23 nm. This case showed a rare combination of fibrillary glomerulonephritis and prevalent IgA deposition, in the clinical context of UCTD.

Multicenter study on hepatitis C virus-related cryoglobulinemic glomerulonephritis.

BACKGROUND: Mixed cryoglobulinemia is a multisystem disorder associated strongly with hepatitis C virus (HCV) infection. The kidney frequently is involved, and glomerulonephritis represents the key factor affecting prognosis. METHODS: Clinical, serological, immunogenetic, and morphological data were collected retrospectively from medical records of 146 patients with cryoglobulinemic glomerulonephritis who underwent biopsies in 25 Italian centers and 34 cryoglobulinemic controls without renal involvement. RESULTS: Eighty-seven percent of patients were infected with HCV; genotype 1b was more frequent than genotype 2 (55% versus 43%). Diffuse membranoproliferative glomerulonephritis was the most prevalent histological pattern (83%). Type II cryoglobulin (immunoglobulin Mkappa [IgMkappa]/IgG) was detected in 74.4% of cases. The remainder had type III (polyclonal IgM/IgG) cryoglobulins. A multivariate Cox proportional hazard model showed that age, serum creatinine level, and proteinuria at the onset of renal disease were associated independently with risk for developing severe renal failure at follow-up. Overall survival at 10 years was about 80%. Kaplan-Meier survival curves were worsened by a basal creatinine value greater than 1.5 mg/dL (>133 mumol/L), but were unaffected by sex and HCV infection. Cardiovascular disease was the cause of death in more than 60% of patients. CONCLUSION: Data confirm the close association between mixed cryoglobulinemia and HCV infection and between glomerulonephritis and type II cryoglobulin. Survival profiles are better than previously reported in the literature, probably because of improvement in therapeutic regimens. Causes of death reflect this improvement in survival, with an increased prevalence of cardiovascular events compared with infectious complications and hepatic failure, which were predominant in the past.

Virus-related glomerular diseases: histological and clinical aspects.

Viral infections can be the causative agent in many glomerular diseases, and diagnostic criteria include clinical and laboratory data and tissue molecular analysis. Hepatitis B virus (HBV) is a well known cause of membranous glomerulonephritis (MGN), membranoproliferative GN (MPGN) and IgA nephropathy (IgAN), frequently in Asian populations. Hepatitis C virus (HCV), besides cryoglobulinemia-mediated glomerulonephritis (GN), is reported to cause other forms of GN. Human immunodeficiency virus (HIV) infection is closely related to a collapsing focal segmental glomerulosclerosis (FSGS), a distinct disease that affects mainly Africans and African-Americans. In the course of HIV infection other immune complex (IC) GN can occur, most frequently in whites. Nephrotic syndrome and progression to renal insufficiency are the main clinical manifestations. HIV-HCV co-infection is related to an IC glomerular disease, sometimes with immunotactoid deposits. Recent reports emphasize the role of parvovirus B19 (PV B19) for "idiopathic" collapsing FSGS and ICGN, and of Coxsackie B virus for IgAN. Renal biopsy is useful for defining virus-related glomerular lesions and a guide for prognostic and therapeutic evaluation.