15. Trends of primary diagnoses in renal biopsies

Many renal diseases can be diagnosed relatively safely and defini-tively by renal biopsies. This study investigates diagnoses made from renal biopsies on the Pacific Laboratory Medicine Services (PaLMS) database, the pathology provider for the Northern Sydney Area Health Service, comparing all reports from 2000 and 2010–11. A retrospective analysis of the renal biopsy reports was performed, and a principle diagnosis obtained from each. Diagnoses were then also classified into glomerular, tubulointerstitial, systemic and ‘other’ categories. The majority of diagnoses from both time periods were of the glomerular category (41%). Within the glomerular category, IgA nephropathy was the most common principle diagnosis (14.1%). The tubulointerstitial disease category consisted mainly of acute tubular necrosis (12.3%). Chronic hypertension, SLE and diabetic nephropathy were the most common diagnoses in the systemic category (4–7%). The ‘other’ category included renal transplant rejection (7.4%) and chronic kidney disease NOS (4.9%). The findings were largely consistent with other renal biopsy studies both from Australia and overseas. Although overall the patterns of diagnoses remained largely unchanged, between 2000 and 2010/11 there was an increase in the relative incidence of acute tubular necrosis possibly due to increased numbers of transplant biopsies, and a relative decrease of IgA nephropathy possibly due to an increase in clinical threshold before biopsy.