Analysis of multiple loci can increase reliability of detection of fetal Y-chromosome DNA in maternal plasma.

OBJECTIVE: Aiming to develop more reliable methods for determination of fetal gender from maternal plasma we compared three different systems of polymerase chain reaction (PCR) detection of Y-chromosome DNA. METHODS: Cell-free DNA was isolated from 96 samples of maternal plasma and (1) amplified using AmpFLSTR-Identifiler (15 autosomal STR loci and amelogenin) or AmpFLSTR-Yfiler (16 Y-chromosome STR loci) kits and subsequently analyzed on ABI-PRISM 310 Genetic Analyzer, or (2) analyzed using Quantifiler-Y DNA-Quantification kit. Gender of fetuses was confirmed by cytogenetic analysis or phenotypically at birth. RESULTS AND CONCLUSIONS: AmpFLSTR-Identifiler and Quantifiler-Y Human-Quantification kits were rather reliable in determining fetal gender (92.5 and 98.1%, respectively), but false negatives were still present in both systems. AmpFLSTR-Yfiler was found to be fully reliable as it amplified Y-chromosome in all cases of male fetuses, and was thus 100% correct in determining fetal gender. In addition, it enabled comparison of polymorphic Y-chromosome loci between father and a child, thus further supporting specificity of obtained results.

Effects of rHuEPO treatment on red blood cell osmotic resistance.

Red blood cell osmotic resistance (RBCOR) is defined as resistance to osmotic changes in cell integrity after their exposure to hypotonic saline solution. The investigation examined the effect of rHuEPO on RBCOR in hemodialysed patients. The study included 58 patients aged 49 +/- 14 years, treated by hemodialysis for 59 +/- 43 months on average. Half of the patients received rHuEPO for anemia correction. RBCOR was determined in all patients as 3 values: hemolysis start point (HSP), hemolysis end point (HEP) and middle osmotic resistance (MOR). The patients underwent laboratory checkup for parameters characteristically changed in the uremic syndrome. In the control group of healthy subjects (n = 16) RBCOR was only determined. No differences were found in the average values of HSP, HEP and MOR between the rHuEPO treated group of patinets and the untreated group. Compared to healthy individuals, the hemodialysed patients displayed significantly higher values of HSP, HEP and MOR. The only one significant correlation of RBCOR and routine laboratory features was found between MOR and predialytic serum concentrations of calcium (r = 0.28, p < 0.05) and hydrogen ions (r = 0.37, p < 0.05). Our results suggest that the administration of rHuEPO does not affect RBCOR in hemodialysed patients, that RBCOR is not always reduced in this population and that it correlates with a small number of laboratory parameters characteristic for the uremic syndrome.