Demographic and clinicopathologic features of membranous glomerulonephritis

Objective: To determine the frequency of membranous glomerulonephritis(MGN) in the renal biopsy specimens. To observe the presenting features and the demographics to determine association, if any, between MGN and hepatitis B in these patients. Design: Descriptive study. Place and Duration of Study: The section of histopathology, The Aga Khan University Hospital, Karachi over a period of three years (May 1999-April 2002). Subjects and Methods: All consecutive percutaneous renal biopsy specimens received during the study period were included. A total of 1590 renal biopsy specimens were evaluated. All cases where a definitive diagnosis of MGN (stage II to IV) was made on light and/or immunofluorescence studies were included in the results. Twenty-eight cases were excluded owing to inadequate material. Cases with a presumptive diagnosis and those in stage I of MGN were also excluded. Laboratory investigations carried out include urine examination, blood urea nitrogen. (BUN), serum creatinine, 24 hours urinary protein, Hepatitis B sAg, serological tests for hepatitis C virus, ANA, dsDNA, etc. Clinical features and results of laboratory analysis were recorded along with light microscopic features and statistical analysis was carried out. Results: Out of 1562 renal biopsy specimens, 835(53.4%) cases showed primary glomerular pathology. 741(47.4% of the total) cases presented with nephrotic syndrome. Out of these in 176 cases (23.75%), findings were those of membranous glomerulonephritis followed by amyloidosis and focal segmental glomerulosclerosis. Among the cases with MGN, 23(13%) cases were those of secondary MGN whereas 87% were grouped under primary MGN. The male to female ratio was 2.2:1. Mean age at presentation was 29 years, median 29 years and a mode of 30 years. Nineteen cases (1.07%) were seen in children of 14 years old or less. Conclusion: The frequency of MGN was much higher in our study subjects as compared to most other regional studies. No significant association with hepatitis B was seen with only 4 out of 89 cases showing positivity for HBsAg. The pattern of disease corresponds more to that seen in the west.