ABSTRACT
BACKGROUND: The healthcare burden due to chronic kidney disease has increased worldwide in the past decade. Elucidating the aetiology of chronic kidney disease may help in identifying strategies for prevention, both in the population and the Individual patient. Only a clinicopathological study can define the exact spectrum of chronic kidney disease since epidemiological studies have not shown a consistent aetiological profile. The histological evidence used to support the diagnosis varies with the degree to which renal biopsy is done. Renal biopsy is the gold standard in making an aetiological diagnosis in renal failure, but as a diagnostic tool in chronic kidney disease it is underutilized. METHODS: This prospective study done at Christian Medical College, Vellore in southern India from 1998 to 2003 aimed to determine the aetiological profile of severe chronic kidney disease by analysing renal biopsies. The value of pre-renal biopsy clinical Judgement in predicting the histological diagnosis was also assessed. Patients with diabetic nephropathy were excluded from the study. RESULTS: Four hundred and fifty-seven patients had evidence of chronic kidney disease as evidenced on biopsy as well as on clinical parameters. Three hundred and twenty-two of these patients (70.5%) had glomerulonephritis as the histological diagnosis. Fifty-five (12%) had Interstitial nephritis, 30 (6.6%) had hypertensive arteriosclerosis and 28 (6.1%) had metabolic nephropathies. The positive predictive value of a pre-biopsy clinical diagnosis in predicting interstitial nephritis was very low (33%). A large number of patients clinically diagnosed to have chronic interstitial nephritis had other aetiologies of chronic kidney disease. CONCLUSION: Glomerulonephritis was the most common cause of chronic kidney disease, not including diabetic nephropathy, followed by interstitial disease and benign arterionephrosclerosis. In patients with unidentified severe chronic kidney disease, renal biopsy provided an aetiological diagnosis.