ASCP Blood Banking Specialist Practice Exam – Complete Test Prep 2025

The most likely antibody detected in a patient's pretransfusion specimen following a positive antibody screen and an incompatible crossmatch is indeed associated with the frequent blood group systems involved in transfusion reactions.

Anti-Ch is an antibody that can cause complications during transfusions due to its association with the Chido/Rogers blood group system, which can lead to positive antibody screens and incompatible crossmatches. This antibody is clinically significant and can react with cells that express the corresponding antigens, thus presenting a potential issue in transfusion medicine.

While others mentioned might be significant, the selection of Anti-Ch highlights its more common occurrence in patients who have undergone recent transfusions or pregnancies, thus enhancing its likelihood of detection in this specific situation. The presence of this antibody may lead to a serious transfusion reaction if not properly identified, which is why it is crucial for blood banking professionals to be aware of its implications.

In contrast, antibodies like Anti-K, Anti-Fyb, and Anti-IH also play important roles but are less commonly associated with the scenarios of positive antibody screens leading to incompatible crossmatches compared to Anti-Ch.