What is the primary mechanism by which ABO incompatibility leads to hemolysis in transfusion reactions?

A Complement-mediated lysis ✓
B Antibody-dependent cellular cytotoxicity
C Activation of coagulation cascade
D Release of inflammatory cytokines

Explanation

ABO incompatibility leads to the binding of pre-formed antibodies to the corresponding antigens on red blood cells, activating the complement system and resulting in cell lysis.

Source

Robbins and Cotran Pathologic Basis of Disease
Hematology Hematology: Blood Grouping and Crossmatching Hematology: Blood Grouping and Crossmatching Medium MEDICAL Confidence: high