Rare Anti-Cw antibody: Two case reports with review of literature

Abstract

Introduction: Anti-Cw is a low-frequency antibody against Cw (Rh8) antigen, a low incidence antigen of the Rh system. Anti-Cw antibody may cause mild to moderate hemolytic disease of the fetus and newborn (HDFN) and mild to severe immediate or delayed hemolytic transfusion reactions (HTR). The antigenic frequency of Cw in the Indian population is 1.25%. Two cases of Anti-Cw antibody are being reported which were detected during routine antibody screening, one an oncology patient and the other a healthy blood donor. Case 1: A 30-year-old male, known case of acute myeloid leukemia, with previous history of induction chemotherapy and blood transfusion was admitted for further management and chemotherapy. When three cell antibody screening was performed using an automated platform, the screen was positive with +2 reactions. Antibody identification using 14 cells suggested the presence of an Anti-Cw antibody. On further testing, the patient red blood cell (RBCs) were negative for Cw antigen. Case 2: A 20-year-old male, first-time, voluntary blood donor, with no history of blood transfusion donated whole blood. On performing three cell antibody screening using automated platform, screen was found to be positive with +3 reactions. Antibody identification performed using 14 cell panel suggested the presence of Anti-Cw antibody. On further testing, the donor RBCs were negative for Cw antigen. Conclusion: Antibody screening and identification is recommended in pretransfusion testing, especially in multi-transfused patients and patients belonging to the reproductive age group, so that antibody to low-frequency antigen can be detected and its potential to cause HTR and HDFN can be assessed.