Renal histology in pauci-immune rapidly progressive glomerulonephritis: 8-year retrospective study.

Context: The need to perform reporting of renal biopsies of antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitides in a more uniform manner required relook at our eight-year data. Aims: To document detailed renal histopathology of pauci-immune rapidly progressive glomerulonephritis (RPGN) and also to seek any significant differences in renal histology of C-ANCA-positive, P-ANCA-positive, and ANCA-negative patients. Materials and Methods: A detailed analysis of the histopathologic features of renal biopsies of 48 patients in whom a diagnosis of pauci-immune glomerulonephritis was concluded on renal biopsy and who presented clinically as rapidly progressive renal failure was done. Statistical Analysis Used: One-way ANOVA and Pearson Chi square tests. Results: Compared with ANCA +ve patients, the ANCA -ve patients were much younger (46.85 ± 16.12 years vs 34.28±15.94 years). No significant differences were found between renal lesions of C-ANCA, P-ANCA, and ANCA-negative patients, except for diffuse tubular atrophy which was more severe and more frequently present with P-ANCA positivity (P value=0.013). Conclusions: Pauci-immune RPGN (irrespective of ANCA status) is a relatively rare disorder in patients who are undergoing the renal biopsy at our institute, constituting 2% of all renal biopsies submitted. It is mandatory to have ANCA serology status during reporting of a kidney biopsy showing pauci-immune crescentic or necrotizing glomerulonephritis. Also, if a uniform reporting strategy is followed throughout the country, the studies from this vast country will be comparable.

A decade long experience of anti-neutrophil cytoplasmic antibody testing in a tertiary care referral center in North India: Perspective from a developing country.

Background: In a developing, tropical country like India, discontinuous power supply, high temperatures during summer, and lack of consistent cold chain and funds provide a challenging atmosphere for anti-neutrophil cytoplasmic antibody (ANCA) testing and reporting. However, a simple in-house test and testing algorithm are described here, which have been developed and tested over time. Materials and Methods: An analysis of a decade of testing and reporting of ANCA in the Department of Immunopathology in a tertiary referral health care center was performed to highlight the importance of testing for ANCA in proposed 1999 guideline recommended indications. Results: A total of 4195 ANCA tests were conducted from 2000 to 2009. Overall, 2060 (49%) requests had indications which met the 1999 guidelines, while the remaining 2135 (51%) fell outside the guidelines. A total of 350 samples (8.3%) were positive for ANCA on indirect immunofluorescence (IIF), out of which 212 were guideline recommended and 138 (3.2%) were non-guideline recommended ANCA requests; thus, 3.2% of non-small vessel ANCA associated vasculitis (non-SVAAV) conditions showed false positive results when the population was otherwise unselected. Maximum requests (1432) were for rapidly progressive renal failure/acute renal failure. Conclusions: The audit shows that compliance with guidelines for ANCA testing would decrease the number of false positive results. In-house screening for ANCA by IIF is cost-effective and must be performed at least twice on two different samples from the same patient or on two different sets of ANCA preparations in all the cases who requested ANCA testing with a proposed 1999 guideline recommended indication.