INTRODUCTION The crystalluria is the expression of an excessive supersaturation of the urine. It can be made profitable to detect certain genetic pathologies and to appreciate the lithogenous urinary anomalies among suffering patients of nephrolithiasis or susceptible to develop a lithiasis. In spite of that, the study of the crystalluria remains an examination can be used in practice daily because of the constraints and technical difficulties of its realization 1 . At a known lithiasic patient, the supervision of the crystalluria in certain conditions, seems as an excellent indicator of the effectiveness Biosciences, Biotechnology Research Asia Vol. 4(1), 49-54 (2007) Study of spontaneous crystalluria for the lithiasic patients before and after surgical treatment B. KACEM 1 , A. BELOUATEK 1 , A. BENAHMED 2 , A SEMMOUD 2 and A. ADDOU 1 ¹Laboratoire (STEVA), Faculté des sciences, Université de Mostaganem 27000 (Algérie) ²Laboratoire (LASIR), Université de Lille 1, Bt C5 59655 Villeneuve d’Ascq Cedex (France) (Received: May 17, 2007; Accepted: June 12, 2007) ABSTRACT The study of the crystalluria is badly codified examination since it does not emerge always clearly to the eyes of the clinicians because of its difficult interpretation linked most of the time, to the imperfectly conditions of its realization. To check most if the crystalluria could help to predict the composition of the stones, it at the same time we follow the patient to avoid the maximum attempt of stone recurrence, we have studied the urine of 147 lithiasic patients before and after the surgical treatment of their stones, the frequency and the nature of the crystals have been compared to those ones observed in the waking urine in the subject of healthy persons studied in the same conditions. 234 first waking urine of lithiasic subjects before and after surgical interventions were examined using polarization microscopy to look for and identify an eventual crystalluria. Patients were divided into two groups (before and after surgical treatment). The result are expressed in sort of majority crystalluria. The whole frequency of the positive crystalluria was 94% for the groups, (98.6% before the operation and 86.2 after the operation) about twice more than the one observed in normal subjects. The crystalluria of the nature oxalate of calcium was far away as far as concerns the one of crystalline sort 30.3% before surgical treatment and 25.3% after the treatment. The average pH of the urines of lithiasic subject occurs between 5.59 and 7.66 in the sum is inferior to 7. That means more acid than those of healthy subjects. The whole results show that the positive crystalluria of lithiasic patients has fall down after the surgical treatment than before the treatment of 98.6% to 86.2%. The crystalline sort of the type weddellite is more frequent for the two sexes before or after the medical treatment, we also notice the total elimination of frequency of urate precipitation for the two sexes after the surgical treatment than before the treatment. Key words: Lihiasic, crystalluria, treatment surgical, calcium oxalate, pH. of medical treatment or at the contrary like a prognostic marker of the risk of stone recurrence in a lithiasic patient 2 . WERNESS 3 has well showed that the abundance of the crystalluria were different in the pathologies like the primary hyper- parathyroidy with and without lithiasis, the primary hyperoxaluria or the stone recurrence idiopathic calcic lithiasis. Recently the clinical interest to determine crystalline volume was been brought in the follow-up of the patients cystinuric for the detection of the risk of stone recurrence 4 and it was shown in elsewhere for common calcic lithiasis, that the frequency of the crystals in the urine of the wake up was strongly correlate with the risk of stone