A patient's serum weakly reacts with 16 group O panel cells. What is the most likely antibody causing these results?

When a patient's serum weakly reacts with multiple group O panel cells, it’s important to consider antibodies that are known to cause such weak reactivity. The most likely antibody responsible in this scenario is anti-Ch.

Anti-Ch is a naturally occurring antibody that targets the Chido/Rogers blood group system. The Chido and Rogers antigens are often found on the red blood cells of group O individuals. Since the patient’s serum shows weak reactivity with many panel cells, it suggests the presence of an antibody like anti-Ch, which can exhibit weaker antigen-antibody interactions, particularly at lower temperatures or under specific conditions.

In contrast, the other options represent antibodies that would typically cause stronger reactions or specific patterns that do not align with weak reactivity observed in this case. Anti-k and anti-e are specific antibodies associated with the Kell and Rh systems, respectively, which might show stronger or more defined reactivity patterns. Anti-Js^b reacts with cells from individuals who carry the Jka antigen, which would not be uniformly present in all group O cells, making it less likely to be the cause of weak, broad reactivity across all tested samples.

Thus, the characteristics of anti-Ch make it the most plausible cause for the observed weak re