Anti-Ds injection immunoglobulin (Anti-D Ig) prophylaxis prevents haemolytic disease of the fetus and newborn. Monoclonal IgG anti-Ds (mAb-Ds) would enable unlimited supplies but have differed in efficacyhttps://equinemedcare.com/ in FcγRIIIa-mediated ADCC assays and clinical trials. Structural variations of the oligosaccharide chains of mAb-Ds are hypothesised to be responsible. Quantitative data on 12 Fc-glycosylation features of 23 mAb-Ds (12 clones, 5 produced from multiple cell lines) and one blood donor-derived anti-D Ig were obtained by HPLC and mass spectrometry using 3 methods. Glycosylation of mAb-Ds from human B-lymphoblastoid cell lines (B) was similar to anti-D Ig although fucosylation varied, affecting ADCC activity. In vivo, two B mAb-Ds with 77–81% fucosylation cleared red cells and prevented D-immunisation but less effectively than anti-D Ig. High fucosylation (>89%) of mouse-human heterohybridoma (HH) and Chinese hamster ovary (CHO) mAb-Ds blocked ADCC and clearance. Rat YB2/0 mAb-Ds with <50% fucosylation mediated more efficient ADCC and clearance than anti-D Ig. Galactosylation of B mAb-Ds was 57–83% but 15–58% for rodent mAb-Ds. HH mAb-Ds had non-human sugars. These data reveal high galactosylation like anti-D Ig (>60%) together with lower fucosylation (<60%) as safe features of mAb-Ds for mediating rapid red cell clearance at low doses, to enable effective, inexpensive prophylaxis.
Anti-D immunoglobulin (anti-D Ig, RhIG) is a very safe and effective prophylactic therapy to prevent haemolytic disease of the fetus and newborn (HDFN). After its introduction 50 years ago, deaths are now rare, approximately 0.02 per thousand births, a reduction of about 98% since 1950 when mortality from HDFN was about 10% of perinatal deaths.Anti-Ds injection
However, in low- or middle-income countries HDFN still affects thousands of babies annually Worldwide estimates for 2010 were 141,000 fetal and neonatal deaths and 27,000 cases of kernicterus caused by bilirubin toxicity leading to a high risk of lifelong neurological dysfunction Many countries have insufficient, sporadic or no anti-D prophylaxis due to its unavailability, high cost or insufficient public healthcare organisation or resources
Anti-D Ig preparations consist of IgG fractionated from pooled plasma of hyperimmunised D-negative donors. These IgG preparations have multiple anti-D specificities and affinities. Relatively low doses of this poly-clonal anti-D (100–300 µg anti-D) are administered antenatally and/or postnatally to susceptible women, which are D-negative with a D-positive fetus or baby. Fetal blood may leak into maternal blood by fetomaternal haemorrhage (FMH) through the placenta, occasionally during pregnancy but more often after parturitionn the oligosaccharide chains attached to the Fc portion of IgG Human IgG has a h.Anti-Ds injection