Reporting renal biopsies from Cyprus: a systematic approach

Background: The etiology of renal disease varies in different parts of the world. In the Middle East, half of all patients reaching end-stage are categorised as either unknown etiology or hypertension-related nephropathy. Objectives: To report a renal biopsy series, in a reproducible format and manner, so that data can be compared directly among other series. Patients and Methods: Biopsies of native kidneys were performed in a 10-year period, at a tertiary referral hospital that provides the entire nephrology service for north Cyprus. Data are reported from 153 patients older than 17 years, who were either Turkish-Cypriot or from the Turkish mainland. Results: Mean biopsy rate was 48 per million population (pmp) per year. Mean age was 45.7 years (range 18-78). Overall, the sex distribution was similar (male 51%). The most common histopathological categories were primary glomerulonephritis (GN) (56%), secondary GN (27%), and tubulo-interstitial disease (14%). Of those with primary GN, 29% had secondary (2o) focal and segmental glomerulosclerosis (FSGS) (29%), followed by IgA nephropathy (24 %), membranous 18% and a further 11 patients with 1o FSGS (12%). The incidence of IgA nephropathy was 6.3 per pmp/year. When expressed as a percentage of the annual biopsy rate, 14% of all biopsies showed IgA nephropathy. Conclusions: To compare data among centres, they must be expressed in terms of the population (incidence pmp/year) and the biopsy rate. In our population, secondary FSGS is common and uncharacterised and we believe many will be caused by monogenic disease