title: Prevalence of Principal Rh Blood Group Antigens in Blood Donors at the Blood Bank of a Tertiary Care Hospital in Southern India.
abstract: BACKGROUND
  Rhesus (Rh) antigen was discovered in 1940 by Karl Landsteiner and Wiener. Due to its immunogenicity along with A, B antigens, Rh D antigen testing was made mandatory in pre-transfusion testing. Presently there are more than 50 antigens in Rh blood group system but major ones are D, C, E, c, and e. Very few reports are available regarding their prevalence in India and no reports are available from Andhra Pradesh.
  
  
  OBJECTIVE
  To study the prevalence of principal Rh blood group antigens like D, C, E, c & e in the voluntary blood donors attending our blood bank.
  
  
  METHODS
  A prospective cross-sectional non interventional study was carried out on 1000 healthy blood donors from August 2013 to July 2014 at our blood bank. Donors were grouped and typed for ABO and Rh major antigens using monoclonal blood grouping reagents as per the manufacturer's instructions. Statistical analysis was carried out using SPSS version 16. Comparison of categorical data between antigen positive and negative individuals was done using Chi-square test. Descriptive statistics for the categorical variables were performed by computing the frequencies (percentages) in each category. Incidence was given in proportion with 95% confidence interval.
  
  
  RESULTS
  A total of 1000 blood samples from donors were phenotyped. Among Rh antigens, e was the most common antigen (98.4%), followed by D-94.1%, C-88%, c-54.9% and E-18.8% with DCe/DCe (R1R1) (43.4%) being the most common phenotype and the least common phenotype is r'r' (0.1%).
  
  
  CONCLUSIONS
  Database for antigen frequency to at least Rh blood group system in local donors helps to provide antigen negative blood to patients with multiple alloantibodies, minimize alloimmunization rate, and thereby improve blood safety.
authors.affiliation: Senior Resident, Department of Transfusion Medicine, SVIMS , Tirupati, Andhra Pradesh, India .
authors.forename: Deepthi Krishna
authors.initials: DK
authors.lastname: Gundrajukuppam
authors.affiliation: Associate Professor, Department of Transfusion Medicine, SVIMS , Tirupati, Andhra Pradesh, India .
authors.forename: Sreedhar Babu Kinnera
authors.initials: SB
authors.lastname: Vijaya
authors.affiliation: Assistant Professor, Department of Transfusion Medicine, SVIMS , Tirupati, Andhra Pradesh, India .
authors.forename: Arun
authors.initials: A
authors.lastname: Rajendran
authors.affiliation: Professor and Head, Department of Transfusion Medicine, SVIMS , Tirupati, Andhra Pradesh, India .
authors.forename: Jothibai Dorairaj
authors.initials: JD
authors.lastname: Sarella
keywords: Alloimmunization; Phenotype; Rh blood group antigens; Transfusion