Peri-operative red cell transfusion management in a rare H-deficient (Para-Bombay) blood group variant
A 51-year-old male with coronary artery disease (CAD)/triple vessel disease (TVD) was admitted to the hospital for CABG procedure. He was a known diabetic, hypertensive, and hypothyroid patient. His chief complaint was chest pain with class-III angina, class-III New York Heart Association (NYHA). His haemoglobin was 14 g/dl and biochemical investigations were unremarkable. Coronary angiogram demonstrated TVD.\nABO, Rh typing, and antibody screening was done by both tube and gel column haemagglutination methods. This patient showed “O” cell group, but weak positive and delayed reaction was observed with anti-H lectin []. However, cell grouping with anti-H usually shows strong positive reaction with “O” group individuals and completely absent reaction with Bombay blood group people. In addition, the serum grouping showed extra antibody or unexpected antibody reacting with pooled “O” cells (control), which was considered as anti-H antibody []. This was further confirmed by incubation at 4°C and elution of antibody at 50°C. The weak antigen in Para-Bombay phenotype was identified by virtue of the cells giving weak reactions with anti-H and by successful elutions of antibodies.\nBased on the strong positive (4+) reaction with O cells, and weak and delayed reactivity with lectin Ulex europaeus (anti-H), the diagnosis of Para-Bombay blood group was considered. In view of the non-availability of compatible blood for this patient, his siblings were tested for blood grouping and typing. Three out of four siblings showed similar blood group phenotype. Red cell compatibility was confirmed with these siblings and considered for transfusion.\nIn the operation theatre, the patient received bolus dose of tranexamic acid (10 mg/kg) followed by continuous infusion before skin incision to reduce blood loss. Sternotomy was performed and two units of autologous blood were collected with acute normovolemic haemodilution technique before heparinisation and the haemoglobin dropped to 10 g/dl. After cannulation, CPB was started, and after aortic cross clamp, the coronary artery bypass was done with left internal mammary artery grafted to left anterior descending artery, sequential radial artery graft to obtuse marginal obtuse marginal II and I. CABG procedure with three grafts was uneventful. After successful completion of the procedure, the heparin was reversed with protamine sulphate and gradually the patient was weaned off the bypass machine.\nIntraoperative blood loss was about 1000 ml and one unit of autologous blood was transfused intraoperatively. Postoperatively, the patient received two units of blood, one autologous and the other from his brother with similar blood group. Patient had good recovery and was discharged home on eighth postoperative day. He was advised follow-up for 1 month and to have an identity card with his blood group and donor list for emergency.