Miroslava Beňovská

Evaluation of FUS-2000 urine analyzer: analytical properties and particle recognition

Abstract This study evaluates the performance of microscopic part of a hybrid analyzer FUS-2000 (Dirui Industrial Co., Changchun, China), its analytical properties and particle recognition. The evaluation of trueness, repeatability, detection limit, carry-over, linearity range and analytical stability was performed according to Dirui protocol guidelines designed by Dirui Company to guarantee the quality of the instrument. Trueness for low, medium and high-value concentrations was calculated with bias of 15.5, 4.7 and −6.6%, respectively. Detection limit of 5 Ery/μl was confirmed. Coefficient of variation of 11.0, 5.2 and 3.8% was measured for within-run repeatability of low, medium and high concentration. Between-run repeatability for daily quality control had coefficient of variation of 3.0%. Carry-over did not exceed 0.05%. Linearity was confirmed for range of 0–16,000 particles/μl (R2 = 0.9997). The analytical stability had coefficient of variation of 4.3%. Out of 1258 analyzed urine samples, 362 positive were subjected to light microscopy urine sediment analysis and compared to the analyzer results. Cohen’s kappa coefficients were calculated to express the concordance. Squared kappa coefficient was 0.927 (red blood cells), 0.888 (white blood cells), 0.908 (squamous epithelia), 0.634 (transitional epithelia), 0.628 (hyaline casts), 0.843 (granular casts) and 0.623 (bacteria). Single kappa coefficients were 0.885 (yeasts) and 0.756 (crystals), respectively. Aforementioned results show good analytical performance of the analyzer and tight agreement with light microscopy of urine sediment.

The New Possibilities in Early Diagnosis of Preeclampsia by Soluble fms-Like Tyrosine Kinase-1 and Placental Growth Factor in 16–20 Weeks Gestation

Background Soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) are used in diagnosing preeclampsia (PE), but their potential in early prediction in pregnant women at 16 to 20 weeks gestation (WG) has remained unexplored. Methods We retrospectively measured serum levels of sFlt-1 and PlGF in 120 pregnant women at 16 to 20 WG. Among these women, 16 had early-onset PE and 23 had late-onset PE. Results Compared with normal pregnancy values, in the serum of women in whom PE later developed, sFlt-1 values increased (P <.001), values of PlGF decreased (P = .001), and the sFlt-1/PlGF ratio increased (P <.001) as early as 16 to 20 WG. Receiver operating characteristic (ROC) curve analysis for the sFlt-1/PlGF ratio at 16 to 20 WG showed an area under the curve (AUC) value of 0.863 (95% confidence interval [CI], 0.788-0.918), P <.001, sensitivity of 74.4%, and specificity of 86.6% for PE in general; and AUC of 0.970 (95% CI, 0.913-0.994), P <.001, sensitivity of 100%, and specificity of 81.5% for early-onset PE only. Also, we determined the 5th and 95th percentiles for sFlt-1, PlGF, and sFlt-1/PlGF ratio values of healthy pregnant women. Conclusion sFlt-1 and PlGF and, in particular, the sFlt-1/PlGF ratio can detect PE as early as 16 to 20 WG-as long as 10 to 15 weeks before PE onset.