Non-invasive detection of prenatal fetal ABO and/Rh(D)blood groups by flow cytometry(FCM) / 中国输血杂志

Objective To establish the FCM method of non invasive detection of fetal ABO and Rh(D) blood groups in maternal blood.Methods Using absorption and elution method, we obtained the IgG anti A and anti B from human sera. The IgG anti A, B, D were used as the first antibody to react with RBCs in maternal peripheral blood.The goat anti human IgG F(ab')2 FITC was used as the second antibody to conjugate anti A, B, D antibodies, Meanwhile anti i PE was used to mark fetal RBCs in maternal peripheral blood.The fluorescence dot plot diagrams of maternal and fetal cells acquired by FCM were used to detect fetal ABO and Rh(D) blood groups.Results Peripheral blood from 69 pregnant women between 8 and 39 weeks of gestation were studied.Fetal cells could not be found in 13 samples.Of the remaining 56 samples,fetal red cells were identified successfully with ABO/Rh(D) blood types identical to those tested after the birth of the baby.Conclusion In women with fetomaternal hemorrhage(FMH) during pregnancy,the FCM method established by the author can accurately and non invasively detect the blood groups of fetuses.This method can possibly be used for diagnosis of hemolytic disease of the newborn.

Studies on the prenatal chromosomal analysis and the changes of maternal serum alpha-fetoprotein following chorionic villus sampling

Transcervical chorionic villus sampling (CVS) was performed in 174 patients between 7 & 12 menstrual weeks of pregnancy opting for prenatal diagnosis. Advanced maternal age was the most common indication for CVS (39.7%). The sampling success rate was 95.4% (166/174), representing 88.9% at 7 to 8 weeks, 98.9% at 9 to 10 weeks & 92.7% at 11 to 12 weeks gestation. In 139 of 174 patients (80%), successful sampling was accomplished in one or two catheter passages only. Four spontaneous fetal losses (2.3%) occurred. The cytogenetic analysis routinely used was the direct overnight & long-term culture methods which revealed 4 abnormalities (2.4%). To date, 90 of the women have been delivered & all infants are doing well and the remaining 65 pregnancies are continuing uneventually. Maternal serum alphafetoprotein (MSAFP) concentration was determined in 72 patients immediately before & after CVS. A significant increase of 20% or more, comparable to pre CVS levels, was noted immediately after sampling in 56 of 72 patients (77.8%). The increase in MSAFP concentration correlated with the amount of villi sampled (r = 0.498, p less than 0.001) & with the number of sampling attempts (p less than 0.05). Estimated CVS related fetomaternal hemorrhage (FMH) ranged from 0.005 to 0.1552 ml and in 5 of 72 patients (6.90%) 0.06 ml or more of FMH was noted. Two of the 5 patients had FMH of 0.1 ml or more.

A study on immuno-state and RHD gene of a rare D~(VI) type Ⅲ pregnant woman / 中国输血杂志

Objective Study on fetomaternal immuno state and RHD type of a pregnant woman of weak D phenotype.MethodsThrough polymerase chain reaction (PCR)、direct genomic DNA sequencing and flow cytometry.ResultsIn both sequence specific promer (SSP) PCR and the sequencing PCR tests, the sample was detected negative in exons 3 6 of the RHD gene, whereas all other exons (exons 1 2,7 10) were tested positive. And the sequence of detected exons (exons 1 2,7 10) are the same with normal RHD in GenBank (accession no. AJ299020 1 and AJ299026 9). Serologically and genetically, the sample can be designated as D category VI type Ⅲ. Through a duce tube PCR method, the RhD zygosity of this individual was typed CD VI e/cde。In flow cytometry, a few fetal erythrocytes were detected in peripheral blood of the mother. However there were no anti D detected in sera and hemolytic disease of the newborn(HDN) observed at all.ConclusionSevere cases of HDN have occurred in D positive babies born to partial D mother with anti D, although HDN don't take place in this case. We may still consider D VI phenotype individuals as D positive donors and D negative receiptions in our transfusion practice and in clinical anti D allo immune prophylaxis and monitoring.