The Incidence of Evanescent Antibodies to Red Blood Cell Antigens in a Tertiary Care Hospital in Northern India.

Background and Objectives: The anti-A and anti-B are naturally occurring antibodies in the human body but alloantibodies may be formed in individuals who lacks that corresponding red cell antigen after any sensitising event like blood transfusion or pregnancy. The aim of this study was to find the incidence of evanescenct RBC alloantibodies that may not be detectable at the time of pre-transfusion screening. Methods: This was a retrospective observational study from January 2017 to May 2019 in a tertiary care centre from North India. The data on antibody screening and identification retrieved from the departmental records. The patients were screened for red blood cell antibody and those with a positive screening test were further investigated for antibody identification. Antibody screening was performed by solid phase method using Immucor Capture-R Ready Screen (4 cell). Confirmed positive samples were investigated with advance methods of Antibody ID using Reagent panel Red Blood Cells Capture-R Ready ID (16 Cell) in Automated Analyzer Iris or Neo (Immucor Inc. Nocross, GA, USA). As and when required other advance techniques of adsorption and elution, etc were also performed too. Results: The total number of patient screened during this period were 8071. Amongst them 312 were positive for antibody screening (3.8%), of those 216 (62.9%) cases had alloantibodies and 96 (30.7%) cases had autoantibodies. Among the 216 cases of alloantibody, 147 (68.1%) cases had single alloantibody and 69 (31.9%) cases had multiple alloantibodies. Amongst the patients having single alloantibody, the prevalence was highest for Anti-D 54 (36.7%), followed by Anti-E 27 (18.3%), Anti-C 8 (5.4%), Anti-c 7 (4.7%), Anti-K 9 (6.1%), Anti-Fyb 11 (7.4%), Anti-M 18 (12.2%), Anti-N 4 (2.7%), Anti-Fyb 3 (2%), Anti-Lea 3 (2%), Anti-Cw 2 (1.3%) and Anti-Mia 1 (0.6%). Of the 96 patients with autoantibody 72 had warm autoantibody, 10 had cold autoantibody and there were 8 cases of mixed warm and cold autoantibodies. There were 6 patients with warm autoantibody with underlying alloantibody. Conclusion: In conclusion, the high prevalence of Anti-Rh (Anti-D, E), Anti-M, Anti-Fyb antibodies in patient requiring transfusion reiterates the importance of stringent antibody screening and identification as an essential step in preventing delayed hemolytic transfusion reaction. [ABSTRACT FROM AUTHOR]