The incidence of primary glomerulonephritis worldwide: a systematic review of the literature

Background. Little is known about the worldwide variation in incidence of primary glomerulonephritis (GN). The objective of this review was to critically appraise studies of incidence published in 1980-2010 so that an overall view of trends of these diseases can be found. This would provide important information for determining changes in rates and understanding variations between countries. Methods. All relevant papers found through searches of Medline, Embase and ScienceDirect were critically appraised and an assessment was made of the reliability of the reported incidence data. Results. This review includes 40 studies of incidence of primary GN from Europe, North and South America, Canada, Australasia and the Middle East. Rates for the individual types of disease were found to be in adults, 0.2/100 000/year for membrano-proliferative GN, 0.2/100 000/year for mesangio-proliferative GN, 0.6/100 000/year for minimal change disease, 0.8/100 000/year for focal segmental glomerulosclerosis, 1.2/100 000/year for membranous nephropathy and 2.5/100 000/year for IgA nephropathy. Rates were lower in children at around 0.1/100 000/year with the exception of minimal change disease where incidence was reported to be 2.0/100 000/year in Caucasian children with higher rates in Arabian children (9.2/100 000/year) and Asian children (6.2-15.6/100 000/year). Conclusions. This study found that incidence rates of primary GN vary between 0.2/100 000/year and 2.5/100 000/ year. The incidence of IgA nephropathy is at least 2.5/100 000/year in adults; this disease can exist subclinically and is therefore only detected by chance in some patients. In addition, referral policies for diagnostic biopsy vary between countries. This will affect the incidence rates found.