Three shades of black - secondary thrombotic microangiopathy.

Thrombotic microangiopathy is a group of disorders characterized by microangiopathic hemolytic anemia, thrombocytopenia and organ damage. Wide age distribution and the heterogeneity in presentation demand a deeper understanding into the pathogenesis of TMA. Primary TMA is distinct from TMA associated with secondary causes and remains clinically occult till a precipitating factor aggravates it. The extent and severity of renal damage caused by each of them is also distinct. The first alerting signal could be the presence of schistiocytes on peripheral smear and arteriolar thrombi on light microscopy. Thus in secondary TMA, identification of the underlying disorder is indispensible for targeted management.

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.