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.