A tale of tripartite: An experience from a tertiary care center of Eastern India.

BACKGROUND: Crescentic glomerulonephritis (Cr GN) is pattern of glomerular injury resulting from wide range of diseases sharing a common pathogenesis. OBJECTIVES: The objective of our study was to analyze the clinicopathological spectrum and outcome of Cr GN with special reference to its immunopathological subtypes using a panel of immunofluorescence stains. MATERIALS AND METHODS: Native renal biopsies with crescentic pattern of injury were included. Detailed Clinical and laboratory variables were analyzed along with the treatment protocol and renal outcome, wherever available. Renal biopsy slides were evaluated for various glomerular and extraglomerular features. Both qualitative and quantitative data were analyzed. RESULTS: A total of 57 cases of Cr GN were included; majority (47.36%) of cases were pauci-immune in nature. Among clinical features, ranges of proteinuria and creatinine level were significantly different between subgroups. The various light microscopic parameters, including proportion of cellular crescents and capillary wall necrosis were different. Presence of arteriolar changes also showed association with unfavorable outcome. Three unusual associations, including IgA nephropathy, membranous glomerulonephritis and Hepatitis B infection were detected. Adequate follow-up information was available in 35 of the patients. Of these, 14 were dialysis-dependent at the last follow-up. CONCLUSIONS: Type III Cr GN (pauci-immune Cr GN) was the commonest cause of Cr GN in our population. Adult patients required renal replacement therapy more frequently than pediatric cases those are chiefly infection associated. Critical appraisal of clinical, histopathological and immunofluorescence finding help to identify individual subtypes as treatment and outcome varies accordingly.

A tale of monoclonal immunoglobulin: Clinicopathological analysis of proliferative glomerulonephritis with monoclonal immunoglobulin deposit.

BACKGROUND: Proliferative glomerulonephritis with monoclonal immunoglobulin deposit (PGNMID) is an entity with a variable clinical and histological spectrum, which mimics immune-complex mediated glomerulonephritis on light microscopy. In this article, we aim to describe the clinical and pathological features of six cases of PGNMID that we encountered during our routine practice. MATERIALS AND METHODS: The study was of the prospective type carried out from February 2018 to August 2019. The renal biopsies that we received in our department, were processed for light microscopy, immunofluorescence microscopy, and electron microscopy. Light microscopic findings were carefully re-evaluated by two experienced renal pathologists. Key diagnostic features were 1) Monoclonal staining of glomeruli for one immunoglobulin (Ig) subclass and single light chain, 2) Membranoproliferative glomerulonephritis (MPGN) pattern (rarely membranous or crescentic), 3) Subendothelial and mesangial (rarely subepithelial) deposits. RESULTS: : We diagnosed five cases of IgG PGNMID and one case of IgA PGNMID with a mean age 53 ± 10.33 years. The most common histological pattern, seen in three cases was MPGN. IgG3 deposits were identified in five cases out of which k light chain restriction was present in four cases and λ light chain restriction was present in one case. IgA deposits were identified in one case that had λ light chain restriction. One patient suffered from multiple myeloma. CONCLUSIONS: The renal biopsy especially immunofluorescence analysis is the key modality for diagnosis of PGNMID where it shows staining of the glomerulus for a single heavy-chain subclass and a single light-chain isotype. Electron microscopic evaluation is necessary to differentiate PGNMID from other renal diseases with monoclonal immunoglobulin deposits.

Tip variant of focal segmental glomerulosclerosis: is it truly a benign variant?

BACKGROUND: Even though frequently described as a benign entity, the outcomes of the tip variant of focal segmental glomerulosclerosis (FSGS) have proven to be unclear. METHODS: This retrospective study includes a cohort of tip variant cases who presented to us from 2009 to 2012 and the analysis of their presenting clinical, histopathological features and treatment outcomes in comparison to the not otherwise specified (NOS) variants from our center in East India. RESULTS: Of the 224 biopsies of primary FSGS, 30 cases were the tip variant (13.39%). The mean age of presentation was around 29 years, with 57% being males. A nephrotic presentation was seen in 87% of cases, with 20% showing a presentation at <18 years of age for the first time. Global sclerosis, interstitial fibrosis, tubular atrophy and arteriolar hyalinosis were seen more commonly in the NOS variant. Twenty five patients of tip variant received steroid therapy and eight received alternative immunosuppression. Around 87% of the tip variant cases achieved some form of remission in proteinuria and 13.3% had a doubling of creatinine at a median follow-up of 2 years in comparison to NOS group in which 80% achieved some form of remission and 20% had a doubling of creatinine. CONCLUSION: Though the histopathological features and treatment responsiveness of the tip variant appear to be better than the NOS variety, the prognostic outcome does not seem to be as favorable as implicated previously with an important percentage of patients showing progressive worsening of renal function within a relatively short time span (2 years) in our cohort.