Non-invasive prenatal diagnosis of foetal gender through maternal circulation in first trimester of pregnancy
JOURNAL OF OBSTETRICS AND GYNAECOLOGY
Authors: Mandavi, Saeed; Karami, Fatemeh; Sabbaghi, Saeed
Abstract
Owing to the lack of perfect accuracy and sufficient sample size in previously performed studies on cell-free foetal DNA (cffDNA) for detection of foetal gender through maternal plasma, this study aimed to investigate the efficiency of using two Y-chromosome specific probes in foetal sex determination during first trimester of pregnancy. Five millilitres of whole blood was drawn from 192 pregnant women (10-12 weeks) and was subjected to isolate cffDNA following separation of plasma. TaqMan Real-time PCR was performed on isolated cffDNA using primer pairs and probes specific for SRY, ZFY and beta-globin genes. Co-amplification of ZFY and SRY genes was detected in 103 samples confirmed after the birth. Sensitivity and specificity of the test were calculated to be 100%. Further study on larger sample size is required to confirm the reproducibility of the present test in early and non-invasive determination of foetal sex.IMPACT STATEMENT What is already known on this subject? Foetal gender analysis through maternal plasma has been investigated in some cell-free foetal DNA (cffDNA) analysis. However, the detection rate and method of cffDNA analysis were different among various studies. What do the results of this study add? This study introduced a modified simple probe based real time analysis with perfect detection rate.
Passively transferred IgG enhances humoral immunity to a red blood cell alloantigen in mice
BLOOD ADVANCES
Authors: Gruber, David R.; Richards, Amanda L.; Howie, Heather L.; Hay, Ariel M.; Lebedev, Jenna N.; Wang, Xiaohong; Zimring, James C.; Hudson, Krystalyn E.
Abstract
Antibodies are typically thought of as the endpoint of humoral immunity that occur as the result of an adaptive immune response. However, affinity-matured antibodies can be present at the initiation of a new immune response, most commonly because of passive administration as a medical therapy. The current paradigm is that immunoglobulin M (IgM), IgA, and IgE enhance subsequent humoral immunity. In contrast, IgG has a "dual effect" in which it enhances responses to soluble antigens but suppresses responses to antigens on red blood cells (RBCs) (eg, immunoprophylaxis with anti-RhD). Here, we report a system in which passive antibody to an RBC antigen promotes a robust cellular immune response leading to endogenous CD4(+) T-cell activation, germinal center formation, antibody secretion, and immunological memory. The mechanism requires ligation of Fc gamma receptors on a specific subset of dendritic cells that results in CD4(-) T-cell activation and expansion. Moreover, antibodies cross-enhance responses to a third-party antigen, but only if it is expressed on the same RBC as the antigen recognized by the antibody. Importantly, these observations were IgG subtype specific. Thus, these findings demonstrate that antibodies to RBC alloantigens can enhance humoral immunity in an IgG subtype-specific fashion and provide mechanistic elucidation of the enhancing effects.