Changing histologic spectrum of adult nephrotic syndrome over five decades in north India: A single center experience

Glomerular diseases are an important cause of chronic renal failure in developing countries. The spectrum of diseases causing nephrotic syndrome is changing globally in the last few decades. The aim of this prospective study was to look at this spectrum at a tertiary care center in North India and to analyze the changing trends over the last five decades. Patients in the age group 18-60 years with nephrotic syndrome were consecutively included in the study. Renal biopsies were performed in all patients and were subjected to light microscopy, immunofluorescence (IF) and electron microscopy (EM). While the IF was performed in 78% of cases, EM was available in one-fourth of cases. During 2002-2007, 364 patients (60.2% males) were included in the study. The mean age was 31.5 years. Primary glomerular diseases accounted for 89% of cases while lupus nephritis was the most common secondary glomerular disease. Focal segmental glomerulosclerosis (FSGS) accounted for 30.6% of primary glomerular diseases making it the most common cause of nephrotic syndrome. It was followed by membranous glomerulonephritis (MGN) in 24.4%, mesangiocapillary glomerulonephritis in 17.9% and minimal change disease in 14.8%. In the age group >40 years, MGN was the most common lesion (32.5%) followed by FSGS (27.7%). Over the last five decades, there was a nearly five-fold increase in the incidence of FSGS, 3-fold increase in MGN and a 10-fold reduction in diffuse proliferative glomerulonephritis while there was no major change in incidence of other diseases. The biopsy diagnosis of FSGS has increased considerably in last few decades and it is now the most common cause of nephrotic syndrome in adults in North India. MGN is the most common lesion in patients over 40 years of age.