title: The manual Polybrene test has limited sensitivities for detecting the Kidd blood group system.
abstract: OBJECTIVE
  The Kidd system antibodies, if undetected, can cause immediate or delayed hemolytic transfusion reactions as well as hemolytic disease of the newborn. There have been anecdotal reports about the inefficiency of the manual Polybrene test in detecting these antibodies. Here, we sought to determine the sensitivity of the manual Polybrene test in detecting anti-Jk(a) and anti-Jk(b) antibodies and Jk(a) and Jk(b) antigens.
  
  
  METHODS
  Ten archived anti-Jk(a)/Jk(b) antibody positive human sera were examined by both the manual Polybrene test and the indirect antiglobulin test using polyspecific antibodies, monospecific anti-IgG antibodies and anti-C3 antibodies. Furthermore, 40 randomly selected donor blood samples were collected and phenotyped for the frequencies of Jk(a) and Jk(b) antigens using the manual Polybrene test and the indirect antiglobulin test. The results from these tests were further confirmed by saline tube tests.
  
  
  RESULTS
  The manual Polybrene test displayed an overall sensitivity of 60% in detecting anti-Jk(a) and anti-Jk(b) antibody. Specifically, it had a sensitivity of 57.14% for anti-Jk(a) antibody and a sensitivity of 66.7% for anti-Jk(b) antibody. Furthermore, the manual Polybrene test exhibited a sensitivity of 46.15% for Jk(a) antigen and a sensitivity of 77.42% for Jk(b) antigen.
  
  
  CONCLUSIONS
  The manual Polybrene test has a very low sensitivity in detecting anti-Jk(a) and anti-Jk(b) antibody, especially anti-Jk(a) antibody. It is also a very insensitive test for detecting Jk(a) antigen.
authors.affiliation: Department of Anatomy, Zhongshan Medical School of Sun Yat-sen University, Guangzhou, Guangdong. jingchun21@yahoo.com
authors.forename: Jing-Chun
authors.initials: JC
authors.lastname: Liu
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Fu-Ping
authors.initials: FP
authors.lastname: Liu
authors.forename: Yun-Shao
authors.initials: YS
authors.lastname: He
mesh_terms: D000906:Antibodies / Q000276:immunology; D001803:Blood Transfusion; D006403:Hematologic Tests / Q000379:methods*; D006461:Hemolysis; D006583:Hexadimethrine Bromide / Q000378:metabolism*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D007667:Kidd Blood-Group System / Q000032:analysis* / Q000276:immunology; D012680:Sensitivity and Specificity
chemical_list: D000906:Antibodies; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007667:Kidd Blood-Group System; D006583:Hexadimethrine Bromide