Diagnostic yield of kidney biopsies performed in a suburban, satellite hospital

Kidney biopsy is indicated to confirm the clinical diagnosis or to evaluate prognosis of a renal problem. It is a reliable and safe procedure, especially with real-time ultrasound guidance. This is a single-center, retrospective review of the biopsies performed in Hospital Tengku Ampuan Afzan, Pahang from 2000 to 2010. The demographic data, clinical parameters, and histological reports were extracted from clinic records and analyzed to determine the diagnostic adequacy of biopsy samples for both lupus and non-lupus patients. A total of 219 biopsies were performed throughout the period and only 74 were included in this review. Their mean age was 22.5 ± 10.5 years. 59.5% of the biopsies were performed on female patients. Malays comprised 79.7% (n = 59) of them, followed by Chinese (18.9%, n=14) and Indian (1.4%, n=1). About one-third of the biopsies(n = 25) were performed on patients with lupus nephritis and two-thirds (n = 49) on non-lupus nephritis patients. At the time of biopsy, their serum creatinine values were normal, serum albumin 28.4 ± 10 g/L and total cholesterol 8.9 ± 4.6 mmol/L (mean ± SD). The urine dipstick was 3+ for both proteinuria and hematuria and daily protein excretion was 3.6 ± 3.2 g. Sixty-seven specimens were considered adequate and only six (8%) were inadequate for histological interpretations. The mean number of glomeruli in the biopsy specimens was 16 ± 9.9 (range: 0-47 glomeruli). In non-lupus patients, focal segmental glomerulosclerosis was the commonest histological diagnosis (n = 15, 30.6%), followed by minimal change disease (n = 13, 26.5%) and mesangial proliferative glomerulonephritis (n = 7, 14.3%). Membranous nephropathy was diagnosed in four (8.2%) and membranoproliferative glomerulonephritis in two (4.1%) specimens. Both post-infectious glomerulonephritis and advanced glomerulosclerosis were found in one specimen each. Among the lupus nephritis patients (n = 25), 88% of them were females (P <0.05) and lupus nephritis WHO class IV was the commonest variant (n = 12, 48%) followed by WHO class III (n = 7, 28%). Membranous glomerulopathy or lupus nephritis WHO class V was found in three (12%), and two (8%) had lupus nephritis WHO class II. Serum albumin, urinalysis findings, and daily urinary protein excretion were comparable for both lupus and non-lupus patients. In conclusion, renal biopsy in our center is adequate and sufficient for histological interpretations and management of patients with renal problems.