Patterns of biopsy-proven renal disease in Cape Town, South Africa, from 1995 to 2017
Thesis (MMed)--Stellenbosch University, 2019.
Introduction: The causes, prevalence and outcomes of renal disease in developing countries may differ compared to developed countries. In most African countries, little data on the topic is available because of the lack of renal biopsy and chronic kidney disease (CKD)/end stage renal disease (ESRD) registries. In view of the limited African data on the spectrum of renal disease, we have described the causes of biopsy-proven renal disease encountered at Tygerberg Hospital (TBH), in Cape Town, over a 23-year period and examined whether patterns have changed over this period. Methods: This retrospective study included all patients who underwent renal biopsies at TBH from January 1995 to December 2017. Cases were identified from the records of the Division of Anatomical Pathology, where biopsy records are stored in paper files. From these files, we created an electronic database using REDCap™, to digitize this archive. Results: This report is based on a total of 2564 native kidney biopsies, which were the first biopsies for each patient. Slightly more biopsies were performed on females (53%). The majority of the patients were between the ages of 20-39 (48.5%), while patients over 60 years and under 20 years accounted for 6.6% and 13.3% respectively. The most common indication for biopsy was nephrotic syndrome (42.4%). Overall, the most common pattern of kidney disease observed was glomerulonephritis. Lupus nephritis (LN) was the most common glomerular disease (20.9%), followed by mesangiocapillary glomerulonephritis (MCGN, 16.4%), Focal segmental glomerulosclerosis (FSGS, 10.8%) and membranous nephropathy (MGN, 7.9%). The number of cases of primary and secondary glomerular diseases were similar. Among the primary glomerular disease, MCGN (32.2%) was the most common, followed by FSGS (21.2%), MGN (15.4%) and mesangioproliferative GN (14.5%). Among the secondary glomerular diseases, LN was the most common (42.4%), followed by Human immunodeficiency virus associated nephropathy (HIVAN, 20.1%), diabetic nephropathy (DN, 13.7%) and Post infectious glomerulonephritis (PIGN, 13.3%). IgA nephropathy was uncommon, accounting for only 2.4% of all glomerular disease. The number of HIV-positive patients biopsied increased steadily over the study period, from only 2 in 1995 to 40 patients in 2017. Of the total of 519 HIV-positive patients, 44.1% had HIVAN. Of 218 patients identified as diabetics, diabetic nephropathy was identified in 68.3% and another renal disease was diagnosed in 32%. Hypertensive renal disease was diagnosed in only 2.7% of all our biopsies. Myeloma kidney and amyloidosis were the most prevalent among the less common causes of renal disease, accounting for 1.5% and 1.1% of total biopsies, respectively. Conclusion: An electronic renal registry was successfully established which will serve to facilitate good patient management and further research. Valuable new information has been generated regarding the patterns of renal disease in the Western Cape over the last two decades.