CONTRIBUTION A L’ETUDE DES HYPERCALCIURIES

Abstract

Hypercalciuria (Hca) is a multifactorial pathology that can present as a quantitative polygenic trait or a monogenic trait, either autosomal dominant in most cases, autosomal recessive or X-linked recessive. The objective of this work was the study of Hca in western Algeria, the determination of its prevalence and the exploration of analyzes allowing its diagnosis. We measured calcium in the urine (calciuria) and in the blood (calcemia). All samples revealed that the patients had hypercalcemia or hypercalciuria. The study of urinary stones and crystals in lithiasis patients was carried out at the “Urinary Lithiasis” laboratory (UMAB University, Mostaganem). We also determined, through a retrospective survey (2023/2024), some epidemiological characteristics of stone patients with CAH. The prevalence of Hca among lithiasis patients was 3.62%, but this figure should be verified by other studies, because the sample analyzed was small. The morpho-constitutional analysis of the stones was first carried out using a stereomicroscope, to determine their morphology (type). Secondly, the calculations are analyzed by infrared spectrophotometry, in order to determine their composition. The types whose etiology is Hca are: type II (calcium oxalate dihydrate), and types IVa and IVd. The study of crystalluria using a polarization optical microscope made it possible to observe weddellite crystals, characteristic of Hca, in lithiasis patients. The retrospective study identified 59 patients with hypercalciuria, of whom 39.1% had permanent or major Hca (group I), and 60% had moderate or intermittent Hca (group II). The average age of the patients was 44 years, there was a female predominance in group I, and a male predominance in group II. There was more family history of lithiasis in group I, but consanguinity was lower in this group, recurrence was high (66% and 72% in groups I and II respectively). It would be interesting to continue this work with a larger sample of patients and to be able to analyze serum calcium and calciuria in all subjects. This will make it possible to better characterize Hca, and thus help practitioners in the management of this pathology.