engleski

Crystalluria Observed by Light Microscopy

The presence of a variety of crystal composition and habit in human urine (crystalluria) is a proof that a state of supersaturation exists or existed in times past in the urinary tract. Crystalluria can reflect the state of urine with the respect to factors such as inhibitors, aggregation and growth of crystals, which are important to the urinary calculi formation. In this work, the crystals that appear in urine of stone-forming patients and controls were observed by light microscopy. The crystalluria indicators were also compared with the morphology and composition of calculi crystals as well as the biochemical composition of urine. Figs. 1a and 1b show crystalluria observed in 3 and 24 hours aged first morning urine of a control. The crystals of uric acid in the beginning are small (Fig. 1a) but they grow and aggregate during the time (Fig. 1b). Composition of the urinary sediment was analysed by X-ray diffraction and was determined to be uric acid dihydrate (H_2U 2H_2O). Pathological biochemical parameters of this urine showed the existence of hypercalciuria, hiperoxaluria, hiperuricosuria and hipocitraturia. Figs. 1c-h show crystalluria in urine of patients with urolithiasis. In the morning urine of one of these patients with the recurrent calcium oxalate monohidrate (COM) stone, the platelets of COM crystals were observed (Fig. 1c) and a high concentration of Ca and Ox, as well as a low citrate concentration were determined. Bipyramidal crystals of calcium oxalate dihidrate (COD) and some small crystals of uric acid (Fig. 1d), were observed in urine of another patient. In this case, hypercalciuria, hiperoxaluria, hiperuricosuria and hipocitraturia were also determined. This patient already operated a stone composed of COM. Analyses of urine of the patient who had earlier had a stone of mixed composition (carbonate apatite (HCAP) and COM) showed the platelets of phosphate (Fig. 1e) and the elevated Ca concentration. In urine of a patient with the recurrent stone composed of COM and hydroxyapatite (HA), the platelets of phosphate and amorphous phosphate (Fig. 1f) were detected and a high Ca concentration determined. Fig. 1g shows the crystals of COD and amorphous phosphate in urine of a patient who had suffered of mixed stone composed of COM, COD and HA. The concentration of Ca and uric acid were found to be higher than normal. The crystals of COM, COD and uric acid as well as a mixed stone of uric acid and COM were spotted in urine of another patient (Fig. 1h). Elevated concentration of Ox and uric acid were determined. Both of the last two patients had hipocitraturia which often accompanies the formation of CaO_x stones. It can be concluded that a group of stone-forming patients creates larger and more aggregated crystals, as well as a greater number of crystals in their urines than the normal subjects. However, normal subjects (non-stone-formers) may exhibit marked crystalluria. The relevance of crystalluria in kidney stone formers remains controversial. It is not possible to identify the stone-forming individuals on the basis of crystalluria only.

crystalluria; light microscopy; urine; urinary calculi formation; stone forming patients

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