Objectives: To identify the trends in the diagnostic frequency of glomerular disease subtypes by renal biopsy in children in Saudi Arabia over the last 20 years. Methods: In this retrospective observational study, we identified all patients aged <18 years for whom native kidney biopsy was performed between 1998 and 2017. The period during which biopsy was performed (1998-2004, 2005-2011, and 2012-2017) and the demographic information and their association with the prevalence of various glomerular disease subtypes were our primary outcomes. Results: A total of 326 cases with renal biopsy were analyzed; the mean age of participants being 11 years and 45.4% of them were girls. Unexpectedly, secondary glomerulonephritis accounted for 42.3% of the cases, and lupus nephritis was the most common cause noted in 20.7% of the cases. The minimal change and focal segmental glomerulosclerosis were the most common glomerulonephritis in 59% of the cases. The frequency of membranoproliferative glomerulonephritis and mesangioproliferative glomerulonephritis significantly decreased from 15% and 17% in the period prior to 2004 to 3.3% ( p =0.003) and 1.7% in 2012-2017 ( p <0.001). Conclusions: We found a considerable shift in the frequency of many glomerular disease subtypes in 1998-2017, which make clinical predication of the underlying etiology challenging for clinician. Renal biopsy still remains a critical diagnostic procedure for managing a considerable proportion of renal diseases.

Introduction: Glomerular diseases in the elderly population are a challenging clinical dilemma, and kidney biopsy is of paramount importance to clarify the morphological changes. The aim of this study was to evaluate the prevalence of major glomerulopathies that affect older adults.Methods: This retrospective study included 70 adults aged >65 years and was performed at four tertiary centres in Saudi Arabia between January 2001 and December 2017.Results: There were 74 native kidney biopsies, which accounted for 7.2% of all native renal biopsies that were performed in the 16-year period. Furthermore, 64% of the native biopsied patients were men. The most common clinical presentations were nephrotic syndrome (40%) and acute kidney injury (20%).In older adults with primary glomerular diseases, IgA nephropathy was the most frequent pathological type (36.4%), whereas diabetes mellitus was the most frequent etiology (37.5%) for secondary glomerular diseases. Women were more likely to develop diabetic nephropathy. Conclusion:The prevalence of IgA is progressively increasing and is currently the most frequent type of primary glomerular disease diagnosed in senior adult. Diabetes has become the leading cause of secondary glomerular disease. Renal biopsy is therefore of paramount importance because an accurate diagnosis will help clinicians establish the diagnosis and guide therapy for both younger and older adults.