An approach to incompatible cross-matched red cells: Our experience in a major regional blood transfusion center at Kolkata, Eastern India.

INTRODUCTION: With the increased utilization of immunohematology (IH) analyzers in the transfusion medicine, type, and screen policy is the method of choice. Still, the importance of routine crossmatching could not be overruled. Here, we tried to understand the clinical conditions and safety of red cell transfusion and their outcomes.

MATERIALS AND METHODS: This prospective study was conducted by IH laboratory, Medical College Kolkata, Blood Bank from October 1, 2015 to March 31, 2016. A set of 3cc ethylenediaminetetraacetic acid and clotted blood samples of the patients were received according to sample acceptance criteria. Blood grouping by conventional tube technique followed by crossmatching was performed by column agglutination technology (CAT) in polyspecific (IgG + C3d) gel media. Any positive result was rechecked in duplicate with additional two group-specific donor units. The persistent incompatibility was further evaluated using direct anti-human globulin test, auto control, antibody screening, and antibody identification by CAT.

RESULTS: On the evaluation of 14,387 sets of patients' sample, only 100 were found to be incompatible (0.69%). Incompatibility rate is higher in females (59%). Eighty-five of these patients were repeatedly transfused. Only 38% of incompatible crossmatch were positive on indirect anti-human globulin test/antibody screening. Antibody could be identified in 16 of them. Seventeen of 100 incompatible samples (17%) presented with panagglutination, were managed with Rh, Kell phenotype/best-matched red cell units. In these 16 patients, 23 alloantibodies were identified; allo anti-E was the most common.

CONCLUSION: This study showed antibody against the Rh system as the most common cause of incompatibility.