Current epidemiological overview of glomerulonephritis in Latin America: a systematic literature review.

Background: Glomerulonephritis (GN) is a group of kidney disorders marked by glomerular damage, leading to proteinuria, hematuria, hypertension, and impaired kidney function. Despite advancements in diagnostics, kidney biopsy remains the gold standard for diagnosis. The prevalence of GN varies globally, with Latin America showing a significant increase in incidence rates.

Methods: This systematic review adhered to PRISMA guidelines and included observational studies from PubMed, Embase, Cochrane, and SciELO databases. Studies were selected based on their focus on the prevalence of GN and its subtypes in Latin America from 2000 onward. The quality of the studies was assessed using the Newcastle-Ottawa Scale adapted for cross-sectional studies.

Results: Following the search, a total of 4336 articles were screened. Of these, 49 underwent full-text review, and 35 met the inclusion criteria, encompassing 61,979 kidney biopsies analyzed across studies conducted in Latin America. The studies spanned a time frame of 1-35 years, with a mean age at biopsy ranging from 28 to 57 years. Focal Segmental Glomerulosclerosis (FSGS) and Lupus Nephrtis were the most frequent primary and secondary glomerulopathies. Nephrotic syndrome was the leading indication for biopsy, and electron microscopy was only reported in 17 studies. Few studies reported data on estimated glomerular filtration rate (eGFR), interstitial fibrosis, and tubular atrophy. Furthermore, subclassification of FSGS into primary and secondary forms was performed in only four studies. Most countries in Latin America reported kidney biopsy rates below 50 per million population per year (pmp/yr), substantially lower than those observed in high-income countries, where rates commonly exceed 100-200 pmp/yr.

Conclusions: The epidemiology of glomerulonephritis in Latin America is heterogeneous, with marked regional differences and predominance of FSGS as the leading primary GN; however, data on primary FSGS (pFSGS) are lacking. Compared to high-income countries, most Latin American countries report significantly lower rates of kidney biopsies per million population, which, combined with limited diagnostic resources, may contribute to the underdiagnosis and potential misclassification of glomerular diseases.