Renal survival in hereditary urolithiasis: a monocentric cohort study from a Tunisian nephrology department.

Introduction: hereditary urolithiasis (HUL) is rare and often underdiagnosed. The genetic type contributes, with other factors, to the onset of renal failure and its progression to end-stage renal disease (ESRD). The aim of our study was to determine the incidence of progression to ESRD and to identify factors influencing renal survival. Methods: we conducted an analytical retrospective study in our department of nephrology for 31 years [1990-2021]. Records of patients with HUL who were not in ESRD at diagnosis were retained. We performed a Cox proportional hazards model. Results: we included 73 patients, of whom 60.3% (n=44) were males. The mean age at the onset of urolithiasis symptomatology was 19.15± 15.57 years. The causes were cystinuria, hereditary tubulopathies and primary hyperoxaluria (PH), in 31, 24 and 18 cases, respectively. The delay in the etiological diagnosis was over 5 years in 41.1% (n=30). After a follow-up of an average period of 16 years, the annual incidence of ESRD was 0.94% and the annual decline in glomerular filtration rate was 3.5 ml/min. The multivariate study retained only PH as an independent factor associated with the occurrence of ESRD with an adjusted hazard ratio of 10.52, 95% CI: 1.664-66.507; p= 0.012. Primary hyperoxaluria had the highest annual incidence of ESRD during follow-up (3.42% vs. 0.46% for tubulopathies). The annual decline in glomerular filtration rate in PH was 5.73 ml/min, vs 2.9 ml/min in cystinuria and 2.67 ml/min in tubulopathies. Conclusion: primary hyperoxaluria was the main determinant of ESRD, highlighting the need for early etiological and genetic diagnosis, especially in consanguineous populations.