Prevalence and trend of biopsy-proven IgA nephropathy in China: a systematic review

BACKGROUND: IgA nephropathy (IgAN) is one of the most common primary glomerulonephritis worldwide, and its distribution varies significantly in different regions. The prevalence and trend of its changes in different regions of China are still unclear. Therefore, this study aims to analyze kidney biopsy data to summarize the prevalence and trend of IgAN in different regions in China. METHODS: Through a systematic electronic search of PubMed, Embase, China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database (SinoMed), Cochrane Library, and Wanfang databases from inception to March 1, 2023. Kidney biopsy data from the different provinces, municipalities and autonomous regions were recorded and analyzed. RESULTS: Data concerning a total of 143,176 patients with primary glomerulonephritis in 34 provinces of China were extracted from the reported kidney biopsy data and included in the final analysis set, of which 39.73% were IgAN (56,886 cases). The proportions of male and female patients were 58.67% and 41.33%, respectively. The prevalence of IgAN patients was higher in economically developed provinces and municipalities. The weighted average prevalence before 2010 and after 2010 was 40.45% and 37.97%, respectively. CONCLUSIONS: IgAN remains the most common biopsy-proven primary glomerulonephritis in China. The prevalence of IgAN was 39.73% in China, and it was higher in developed provinces and municipalities than in other areas. The weighted average prevalence of IgAN in China decreased slightly after 2010.