RESUMO
BACKGROUND/AIMS: There is disagreement regarding the performance of conventional optical microscopy to assess the origin of hematuria. The aim of this study was to determine the optimal cutoff point for dysmorphic cells in order to detect glomerular hematuria by optical and phase-contrast microscopy. METHODS: In total, 131 urine samples (66 from patients with glomerulopathies and 65 from nephrolithiasis patients) were evaluated in a blinded fashion. The percentages of doughnut cells and acanthocytes were verified by optical and phase-contrast microscopy. A total of 131 patients were randomly allocated to the derivation (n = 73) and validation (n = 58) groups. Receiver-operating characteristic (ROC) curves were plotted to check the discriminatory power of each group and the best cutoff points were determined by the Youden index in the derivation group and subsequently tested in the validation group. RESULTS: All areas under the ROC curve (AUCs) were statistically significant using both methods (conventional optical and phase-contrast microscopy) and both groups (derivation and validation). AUCs did not differ between different glomerulopathies. The best cutoff point to determine the glomerular origin of hematuria by total dysmorphic cells was 22% using an optical conventional microscope and 40% by phase-contrast microscopy. CONCLUSION: We determined the best cutoff points to interpret erythrocyte dysmorphism and demonstrated that it is possible to discriminate the origin of hematuria by evaluating erythrocyte dysmorphism in urinalysis using either an optical or a phase-contrast microscope.
Assuntos
Eritrócitos Anormais , Hematúria/etiologia , Hematúria/urina , Nefropatias/complicações , Nefropatias/urina , Adulto , Feminino , Humanos , Nefropatias/diagnóstico , Masculino , Microscopia de Contraste de Fase , Pessoa de Meia-Idade , Método Simples-Cego , Urinálise/métodosRESUMO
BACKGROUND: Elevated sodium excretion in urine resulting from excessive sodium intake can lead to hypercalciuria and contribute to the formation of urinary stones. The aim of this study was to evaluate salt intake in patients with urinary lithiasis and idiopathic hypercalciuria (IH). METHODS: Between August 2007 and June 2008, 105 lithiasic patients were distributed into 2 groups: Group 1 (n = 55): patients with IH (urinary calcium excretion > 250 mg in women and 300 mg in men with normal serum calcium); Group 2 (n = 50): normocalciuric patients (NC). Inclusion criteria were: age over 18 years, normal renal function (creatinine clearance ≥ 60 ml/min), absent proteinuria and negative urinary culture. Pregnant women, patients with intestinal pathologies, chronic diarrhea or using corticoids were excluded. The protocol of metabolic investigation was based on non-consecutive collection of two 24-hour samples for dosages of: calcium, sodium, uric acid, citrate, oxalate, magnesium and urinary volume. Food intake was evaluated by the three-day dietary record quantitative method, and the Body Mass Index (BMI) was calculated and classified according to the World Health Organization (WHO). Sodium intake was evaluated based on 24-hour urinary sodium excretion. RESULTS: The distribution in both groups as regards mean age (42.11 ± 10.61 vs. 46.14 ± 11.52), weight (77.14 ± 16.03 vs. 75.99 ± 15.80), height (1.64 ± 0.10 vs. 1.64 ± plusorminus 0.08) and BMI (28.78 ± 5.81 vs. 28.07 ± 5.27) was homogeneous. Urinary excretion of calcium (433.33 ± 141.92 vs. 188.93 ± 53.09), sodium (280.08 ± 100.94 vs. 200.44.93 ± 65.81), uric acid (880.63 ± 281.50 vs. 646.74 ± 182.76) and magnesium (88.78 ± 37.53 vs. 64.34 ± 31.84) was significantly higher in the IH group (p < 0.05). There was no statistical difference in calcium intake between the groups, and there was significantly higher salt intake in patients with IH than in NC. CONCLUSIONS: This study showed that salt intake was higher in patients with IH as compared to NC.