Pregnancy-induced Alloimmunization against Platelet Antigens. HLA and Human Platelet Antigens (HPA).

Serologic analysis of three cases of neonatal alloimmune thrombocytopenia associated with HLA antibodies

“…Enomoto and colleagues 39 reported that 9.4 percent (384 of 4069) of pregnant Japanese women were positive for the presence of HLA antibodies 39 . Our local data discovered levels of said antibodies at 17.6 percent (984 of 5578).…”

Neonatal alloimmune thrombocytopenia associated with fetomaternal hemorrhage

“…Indeed, a single episode of pregnancy has been reported to increase the positivity rate of anti-HLA by 5%. 5 In summary, we reported a case of severe FMH associated with NAIT. Multipara may already possess anti-HLA antibodies.…”

“…Accordingly, repeat pregnancies would increase the possibility of carrying antibodies against fetal antigens. Indeed, a single episode of pregnancy has been reported to increase the positivity rate of anti‐HLA by 5% 5 …”

Double-Filtration Plasmapheresis and High-Dose Intravenous Immunoglobulin Therapy in a Case of Anti-M Alloimmunization

“…The patient tested positive for anti-HPA-4b antiplatelet antibodies, the most common type of anti-HPA antibody in Japanese individuals. 11 Anti-HPA antibodies are observed in 0.6 to 0.8% of pregnancies and may manifest as NAIT in 10% of these cases, 12 which is why DFPP and IVIG were continued while monitoring the fetal status. As uterine contractions are a potential cause of fetomaternal transfusion and further sensitization by increased fetal blood inflow to the mother's bloodstream, the increased production of anti-M antibodies was a concern.…”