Case series investigation on the Lewis system antibodies encountered during a routine screening in a tertiary care hospital-based blood center.

Background: Anti-Lewis antibodies, usually do not react at 37°C, hence are clinically insignificant. However, on rare occasions, these antibodies have been reported as the cause for hemolytic transfusion reaction (HTR).

Aim: We report our experience on the 6 cases of anti-Lewis antibodies that reacted at room temperature (RT) and at 37°C.

Materials And Methods: Standard serological methods were employed in detection and identification of antibodies. Demographic and clinical details were obtained from the records on the subjects under study.

Results: These were found among the patients and the blood donors of varied age groups and gender (21 to 65 years). Also, they were found among the patients with varied clinical diagnosis. The 2 patients in second trimester had anti-Le a or anti-Le b and other 2 male patients had anti-Le ab or anti-Le b with wide thermal amplitude were found during the course of pre- transfusion compatibility tests including antibody screening and cross-matching. Two male donors typed Le (a-b-) had anti-Le ab with wide thermal amplitude. Lewis antigen negative RBC units were provided for transfusion in the situation.

Conclusion: Although antibodies to Lewis blood group antigens often react at lower temperatures and therefore remain clinically insignificant, some of them, on rare circumstances, may react at higher temperature of 37°C and may produce hemolytic episode or at least yield reduce survival of incompatible red cells in transfusion recipients. On safer side, the antigen-negative unit may be used in transfusion. The donors' registry with detailed phenotype profile may go a long way to provide blood for transfusion in emergency situations.