Prevalence of different types of glomerulonephritis based on renal biopsy reports in Iran and the world: A systematic review

Background and aims: This epidemiological study reviews studies evaluating renal biopsy results in Iran and the world, and provides crucial material for clinical practice, future regional protocols, preventive approaches and further researches. Methods: In January 2017, we searched and reviewed studies on frequency of native renal biopsy disorders in Iran and the world. Bibliographic databases including PubMed, Google Scholar, and Iranian databases including Scientific Information Database, Iran Medex, and Magiran were searched to select relevant studies. Reference lists of potentially relevant articles were also hand-searched to identify additional articles. We categorized countries to the six regions defined by World Health Organization (WHO): Africa, the Americas, South-East Asia, Europe, the Eastern Mediterranean, and the Western Pacific. Data regarding year, number of cases, gender predominance, mean and range of age, and number of centers was gathered. Those articles that fulfilled the following criteria were included in our study: 1) presenting an estimation of glomerulonephritis prevalence, 2) including a population of > 1000 cases, and 3) published in full manuscript form. Studiesconducted in highly selective populations (e.g. a certain age group or a certain type of renal disease) were excluded. Results: In three out of seven previous studies conducted in Iran (Table 1), the most prevalent pathological diagnosis was MGN (with a prevalence of 21.5% to 26.8%), in two others MCD predominates (25.2% to 30.4%), and in the other study FSGS had the highest prevalence (37.1%). One study performed by the authors in Isfahan, Iran, also showed a high prevalence for FSGS (24.8%). Three of the studies were performed in Tehran, capital of Iran, while three others were conducted in Hamadan and Kermanshah, two cities located in Western Iran. In Europe and Western PacificRegion, IgAN was by far the most prevalent glomerulonephritis, while studies in other parts of the world show conflicting results (Table 2). Conclusion: As reported in our study, results from different parts of the world vary, which can be possibly explained by the differences in socioeconomic status and genetic and environmental factors. It has been realized that having a national registry in Iran is crucial to determine current status, better planning and management of renal disorders.

کلیدواژه ها:

Epidemiology ، glomerulonephritis ، renal biopsy ، systematic review