Unveiling the masked native blood group following thalidomide therapy in a thalassemia patient: A 5 WHY analysis approach.

Blood grouping discrepancy in patients with hematological disorders can occur due to red cell sensitization following transfusion, transplantation, and pregnancy or pre-analytical errors. Prompt initiation of root cause analysis is vital to avoid complications of wrong blood transfusion. We present an unusual case of Rh mismatched grouping report of 24 year old female thalassemia patient being managed in our hospital since 2015. Her current type and screen were observed as O Rh D negative with negative antibody screen while the historical blood group was O Rh D positive. The pre-analytical errors were ruled out and blood grouping performed from fresh sample also demonstrated as O Rh D negative despite antigen enhancement techniques and had no recent transfusion history. We sought to reason out the possibilities for discordant Rh grouping report, historical and present group through "Funnel based problem solving 5 WHY analysis" approach. The review of the past clinical history revealed that the patient had undergone Rh mismatch bone marrow transplant (Rh D positive donor and Rh D negative recipient) at 5 years of age which soon resulted in graft failure. Yet, she continued to receive Rh D positive blood thereafter with no development of anti-D which explains the historical blood group. Recently the patient was started on thalidomide, the Hb F inducer drug, which helped in maintaining her hemoglobin level between 9 and 10 g/dl without transfusion support for two months. This allowed unmasking of native Rh D negative blood and the review of clinical history played a significant role in resolution of grouping discrepancy.