Crescents in Kidney Biopsy – What Do They Imply? A Clinicopathologic Study of 40 Cases in a Tertiary Care Center

INTRODUCTION: Crescents in glomeruli mean proliferation of parietal epithelium of Bowman's capsule with the presence of macrophages, lymphocytes, neutrophils, fibrin, and collagen. When crescents are present in >50% of nonfibrosed glomeruli, it is called crescentic glomerulonephritis (CGN). The presence of crescents is indicative of poorer prognosis. CGN can be pauci immune (PI), immune complex mediated (ICM), and anti-glomerular basement membrane (anti-GBM) disease. AIM: The aim was to study the clinicopathological spectrum of CGN over a period of 10 years in our center. MATERIALS AND METHODS: Forty kidney biopsies with the presence of crescents over a period of 5 years were retrieved retrospectively from the histopathology records of the department of pathology. The clinical history, laboratory parameters, histopathology report, and the direct immunofluorescence (DIF) findings were analyzed. RESULTS: Totally 40 cases had crescents on light microscopy. Out of these, 17 cases qualified for CGN. The mean age of the patients was 20 years. Nephritic syndrome was the most common presentation in these 17 cases. The mean creatinine level was 3.55 mg/dL. PI (7/17, 41.1%) was the most common category, followed by ICM (6/17, 35.2%) and anti-GBM (4/17, 23.5%). Out of the ICM, two cases were of IgA nephropathy with crescents and one of lupus with crescents. CONCLUSION: PI is the most common type of CGN. DIF examination is essential for exact categorization of CGN. Kidney biopsy in these cases can guide management and benefit patients with timely initiation of aggressive therapy.