Background: Differences in epidemiology of kidney disease across the Middle East may arise from variations in indication for biopsy, environmental exposure and socio-economic status. The Lebanese population is composed of different ethnicities, with distinct ancestry and religion, enabling comparison of their effect on the prevalence of kidney disease within a confined geographic setting and uniform practices. Here we report 5 years' detailed epidemiology of renal diseases, based on histological diagnosis, in a sample from three large pathology centres in Lebanon.
Methods: Records of renal biopsies analysed at the American University of Beirut Medical Center, Hotel Dieu de France Hospital and the Institut National de Pathologie from January 2003 till December 2007 were retrospectively examined. We recorded the following data for each patient: age, gender, indication for renal biopsy and histopathological diagnosis. Religious affiliation and parents' consanguinity were recorded when feasible.
Results: The mean age at renal biopsy was 36.76 ± 20 years (range 1-84). The most common diagnosis was mesangioproliferative glomerulonephritis (GN; 20%), followed by focal segmental glomerulosclerosis (13.2%). While there were no differences in age, gender or indications for biopsy among different religious affiliations, mesangioproliferative GN was significantly more frequent among Muslims (P = 0.039) and offspring of consanguineous unions (P = 0.036). On the other hand, focal segmental glomerulosclerosis was most prevalent in Christians (P < 0.001).
Conclusions: Variation in the distribution of diagnoses between Muslim and Christian groups likely reflects differences in population structure and ancestry. In particular, the increased prevalence of mesangioproliferative GN among offspring of consanguineous unions in Muslims suggests a recessive genetic component to this disease which may be identified via homozygosity mapping. These findings have important implications for formulating renal health policies and designing research studies in this population.