Spectrum of Morphologic Features of Lupus Nephritis According to Nephrology/Renal Pathology Society (ISN/RPS) Classification

Introduction Lupus nephritis is one of the most important secondary glomerulopathy and a significant cause of chronic renal failure. Early diagnosis is key to improved prognosis. The International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification stratifies renal biopsy evaluation in different classes that correlates with clinical renal outcome. In the current study, we aimed to evaluate the proportion of patients in each class of lupus nephritis in our population. Methods We evaluated renal biopsies of 128 patients that fulfilled the clinical and serologic criteria of lupus nephritis. The histologic classification was done according to the ISN/RPS classification, and immunofluorescence studies were performed. Active and chronic lesions were assessed on renal biopsy, and association of different histopatholgic parameters with lupus classes was done. Results The mean age was 28.85±12.24 years. Most of the patients were from age group ≤25 years (48.4%). Active lesions were seen in 66 (51.6%) patients, with endocapillary hypercellularity being the most common active lesion type, i.e. 81.8%. Chronic lesions were noted in 42 (32.8%) patients, with glomerular sclerosis being the most common chronic lesion type, i.e. 69%. Majority of the patients belonged to class IV (46.9%). Females were more likely to present at advanced lupus stage compared to males, and older patients (>50 years) had a higher chance to present at a late stage (class IV and higher). Active lesions were significantly found more frequently in classes III and IV, while chronic lesions were more likely to present in classes III to V. Conclusion We found that a significant proportion of patients of lupus nephritis in our population presents at an advanced stage as more than 60% patients were of class IV or higher. This signifies lack of appropriate clinical surveillance of patients and assessment of renal functions early in disease course. This also necessitates revision of our locoregional protocols to manage lupus nephritis patients and a need to perform a renal biopsy early in disease course.