Objective: Urine cystatin C (CC) is considered as a marker of renal affection, e. g. tubulopathy – estimation of diagnostic efficacy of urine CC measurement. Material and Methods: 3 groups were tested: 1st group: 71 patients with primary or secondary glomerulopathy, 2nd group: 24 probands with hypertension and organ complications (II–III WHO grading), 3rd group: 50 patients with suspicion for nefropathy NS. In all of them CC in urine was assayed (immunoturbidimetry; in 3rd group CC immunoturbidimetry and ELISA test were performed). Urine albumin, α1-microglobulin, GMT, creatinine and osmolality and serum osmolality, cystatin C and creatinine were determined additionally. Results: Diagnostic efficacy of urine cystatin C was sufficient only in 1st subgroup (AUC 0.76). Urine CC measurement with ELISA did not increase diagnostic efficacy. Conclusion: Urine cystatin C measurement did not prove useful for the diagnosis of mild renal function affection even if the sensitive ELISA method was used. Urine cystatin C is not usually detecable in individuals with incipient nefropathy even after positive findings of other urine pathological markers.

        Key words: cystatin C, tubulopathy.