Antibodies with alloimmune reactivity are likely to be present in the plasma of the multiparous women. It include antibodies to human neutrophil antigens (HNA) or to human leukocyte antigens (HLA) that could be detrimental to recipients who have the corresponding antigens, which is passively transferred during transfusion, as specified in the report of National Library of Medicine (2012). What is the likelihood of having blood transfusion related reactions from implicated donors, especially multiparous women?
Sachs, U. J., Link, E., Hofmann, C., Wasel, W., & Bein, G. (2008). Screening of multiparous women to avoid transfusion-related acute lung injury: a single centre experience. Transfusion medicine (Oxford, England), 18(6), 348–354. Retrieved from https://pubmed.ncbi.nlm.nih.gov/19140817/
In a study conducted by L. Thurn, et. al., entitled, "Incidence and risk factors of transfusion reactions in postpartum blood transfusions", the increase of HLA antibodies observed in most pregnancies, especially in multiparous women may increase the risk of transfusion reactions during pregnancy.
Another study, entitled, "Transfusion-related mortality: the ongoing risks of allogeneic blood transfusion and the available strategies for their prevention" by E. C. Vamvakas, et. al., suggests that in 65% to 90% of TRALI cases, WBC (including class I and II HLA or neutrophil-specific) antibodies have been identified in the plasma of the implicated donor and that most of these implicated donors have been multiparous women.
All in all, these studies suggest a high correlation between multiparous women and blood transfusion-related reactions.
Thurn, L., Wikman, A., Westgren, M., & Lindqvist, P. G. (2019). Incidence and risk factors of transfusion reactions in postpartum blood transfusions. Blood advances, 3(15), 2298–2306. https://doi.org/10.1182/bloodadvances.2019000074
Eleftherios C. Vamvakas, Morris A. Blajchman; Transfusion-related mortality: the ongoing risks of allogeneic blood transfusion and the available strategies for their prevention. Blood 2009; 113 (15): 3406–3417. doi: https://doi.org/10.1182/blood-2008-10-167643