AN OVERVIEW OF BIOPSY-PROVEN GLOMERULAR DISEASES IN MALAYSIA: 18-YEAR DATA FROM THE NATIONAL POPULATION-BASED REGISTRY

The Malaysian Registry of Renal Biopsy (MRRB) was established in 2005 to define the national burden and epidemiological patterns of glomerular diseases. Over a period of 18 years, the registry evolved into a comprehensive, population-based database encompassing 58 participating centres across Malaysia. To date, 8 reports have been published. This paper presents an overview of the biopsy-proven glomerular diseases recorded between 1 January 2005 to 31 December 2022.

All patients undergoing native or allograft kidney biopsies at participating centres were prospectively enrolled in the MRRB. Data were submitted via the MRRB web-based application, which captured detailed demographic, clinical and laboratory information at presentation and/or at the time of biopsy. Long-term outcomes were ascertained through data linkage with the National Registration Department (for patient mortality) and the Malaysian Dialysis and Transplant Registry (for renal outcomes).

Biopsy Activity

A total of 25,376 native and 3,919 allograft kidney biopsies were reported. The annual number of biopsies showed a steady upward trend throughout the registry period.

Paediatric Population

Children (<15 years) comprised 9.8% of all native kidney biopsies. Among them, minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS) accounted for 44.9% of diagnoses, followed by lupus nephritis (LN, 25.1%).

Adult Primary Glomerular Diseases

A total of 8,944 biopsies were reported as primary glomerular diseases. A notable temporal shift was observed, in which MCD was the predominant diagnosis between 2005-2014. However, between 2015-2022, FSGS emerged as the most common entity (29.2%), followed by MCD (26.7%), IgA nephropathy (IgAN, 25.5%) and membranous nephropathy (MN, 10.7%). Notably, IgAN demonstrated a progressive rise over the years, becoming the most common primary glomerular disease in 2022 (33.7%). Among adult IgAN patients, 21.2% presented with nephrotic syndrome and 49.3% were hypertensive. Their 5-year and 10-year renal survival rates were 75.1% and 63.9%, respectively.

Adult Secondary Glomerular Diseases

A total of 9,436 cases of biopsy-proven secondary glomerular diseases were reported.

Lupus nephritis (LN) was the leading cause (78.7%) with a median age of 29.1 years. The most frequent histopathological classes were Class IV/IV+V (51.9%), followed by Class III/III+V (27.6%). The prevalence of hypertension and reduced kidney function correlated strongly with histological severity: reduced eGFR (<60 mL/min/1.73 m²) occurred most commonly in Class VI (55.0%), Class IV/IV+V (39.1%), and Class III/III+V (16.6%). Renal survival for LN was 87% at 5 years and 80% at 10 years.

Diabetic nephropathy (DN) was the second most common biopsy-proven secondary glomerular disease (15%), despite being the leading cause of end-stage kidney disease (ESKD) nationally and globally. The proportion of biopsy-confirmed DN rose markedly from 10.1% (2005–2009) to 25.2% in 2022, reflecting increased biopsy yield and disease burden. 

MRRB provides invaluable, long-term, population-based epidemiological data on glomerular diseases in Malaysia. Over 18 years, the registry has documented evolving patterns of disease, with an increasing recognition of IgAN and DN, while LN continues to dominate among secondary causes. These insights are essential for strategic healthcare planning, early intervention, and guiding future clinical and translational research in glomerular diseases.