Association of prior sensitizing events with anti-human leukocyte antigen antibodies: An analysis of renal transplant recipients in a tertiary care centre in South India.

Traditionally, sensitizing events such as previous pregnancies, previous transfusions and prior transplants result in the production of anti-Human Leukocyte Antigen (HLA) antibodies. However, it has been observed that, anti-HLA antibodies have been detected in many patients with no prior history of sensitizing events. This retrospective study analysed the most recent 100 consecutive Single Antigen Bead (SAB) assay results performed on 100 patients. The SAB assay is used routinely to detect anti-HLA antibodies in transplant recipients. Results of the SAB assay were analyzed and subsequently studied to see if a correlation existed between sensitizing events, the type of events and presence of antibody. Analysis showed that 77% (77/100) had anti-HLA antibodies. 61 out of 100 patients had prior sensitizing events while the remaining 39 had none. Both these groups showed an almost equal percent of patients with anti-HLA antibodies 77% (47/61) and 76.9% (30/39) respectively. A single sensitizing event was seen in 54.1% (33/61) patients including previous transfusions in 29.5% (18/61), pregnancies in 11.4% (7/61) and prior transplant in 13.1% (8/61). Our study suggests that irrespective of whether patients have prior sensitizing events or not, patients run the risks of alloimmunization, and therefore appropriate screening tests should be included in the pre-transplant compatibility algorithm.

Crescentic glomerulonephritis: what's different in South Asia? A single center observational cohort study.

Background: The spectrum and outcomes of crescentic glomerulonephritis (Cr.GN) in South Asia is vastly different from that reported worldwide and there is a paucity of information. The aim of the study was to study the demography, clinical presentation, histology and predictors of longitudinal outcomes of Cr.GN in this population. Methods: An observational cohort study of renal biopsies was performed in the largest tertiary center in South India over a period of 10 years (January 2006 to December 2015) with ≥50% crescents on renal histology indicating Cr.GN. Results: A total of 8645 kidney biopsies were done; 200 (2.31%) were Cr.GN. Patients were categorized into three etiological groups: anti-glomerular basement membrane (type I), immune complex (type II), and pauci-immune (type III). Type II was the most common (96, 46.5%), followed by type III (73, 38%) and type I (31, 15.5%). Female preponderance was seen across all types. About half of all patients presented with recent onset hypertension. Type II had the highest median proteinuria (4.2 (2.1-6) g/day, p=0.06) and the median estimated glomerular filtration rate was lowest in type I (5 (4-8) ml/min/1.73m 2, p<0.001). Among type III, anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis was seen only in ~50% of patients. Nearly one third of patients with type I were also positive for ANCA making them 'double positive'. Acute glomerular insults like tuft necrosis and chronic changes as evidenced by moderate to severe interstitial fibrosis, was a predominant feature of type I. Conclusions: ANCA-negative pauci-immune vasculitis, as well as double positive Cr.GN, are reported for the first time in South-Asia. Renal survival was significantly worse in type I/III compared to type II. Types I/III, moderate to severe interstitial fibrosis and tubular atrophy, presence of oliguria/anuria and increasing percentage of crescents in renal biopsy were significant predictors of end stage kidney disease in our cohort.