Background
Glomerulonephritis is a relatively rare disease with numerous subtypes and limited numbers of patients with each. Comprehensive epidemiological surveys are therefore difficult to undertake and there are few data on the spectrum of renal disease, especially in Iran. The aim was to determine the pattern of glomerulonephritis in Iran.
Material and Method
Following a retrospective study on 400 candidates for renal biopsy whose renal specimens were evaluated at the pathology department of Tehran's referral hospital during 2006 and 2007, 393 cases were registered. The biopsy specimens were processed for light and electron microscopy and one renal pathologist confirmed these diagnoses using standard diagnostic criteria.
Results
The mean +/-SD patient age was 31.9+/-15.9 (range: 3-78 years). Primary glomerulonephritis included 276 (70.2%) patients and 81(20.6%) had secondary glomerulonephritis. Of the 393 cases, 54.7% were male, 15.0% were children, and 3.8% were elderly. The most common glomerulonephritis was FSGS (37.1%) followed by MGN (16.5%) and lupus nephritis (13.4%). Furthermore, FSGS was the most common glomerulonephritis in the males (34.4%) and in all age groups.
Conclusions
These data make a small contribution to the epidemiology of glomerulonephritis in Iran, showing an epidemiological difference from a previous study in Iran and other Middle East countries, particularly an increasing prevalence of focal and segmental glomerulosclerosis. A multi-center study with a larger sample size should be performed to create an Iranian registry of renal biopsies.

Keywords: Kidney - pathology, Iran - epidemiology, Glomerulonephritis - physiopathology, Child, Preschool, Child, Biopsy, Adolescent, young adult