Impact of Uniform Methods on Interlaboratory Antibody Titration Variability: Antibody Titration and Uniform Methods.
BACKGROUND
-Substantial variability between different antibody titration methods prompted development and introduction of uniform methods in 2008.


OBJECTIVE
-To determine whether uniform methods consistently decrease interlaboratory variation in proficiency testing.


METHODS
-Proficiency testing data for antibody titration between 2009 and 2013 were obtained from the College of American Pathologists. Each laboratory was supplied plasma and red cells to determine anti-A and anti-D antibody titers by their standard method: gel or tube by uniform or other methods at different testing phases (immediate spin and/or room temperature [anti-A], and/or anti-human globulin [AHG: anti-A and anti-D]) with different additives. Interlaboratory variations were compared by analyzing the distribution of titer results by method and phase.


RESULTS
-A median of 574 and 1100 responses were reported for anti-A and anti-D antibody titers, respectively, during a 5-year period. The 3 most frequent (median) methods performed for anti-A antibody were uniform tube room temperature (147.5; range, 119-159), uniform tube AHG (143.5; range, 134-150), and other tube AHG (97; range, 82-116); for anti-D antibody, the methods were other tube (451; range, 431-465), uniform tube (404; range, 382-462), and uniform gel (137; range, 121-153). Of the larger reported methods, uniform gel AHG phase for anti-A and anti-D antibodies had the most participants with the same result (mode). For anti-A antibody, 0 of 8 (uniform versus other tube room temperature) and 1 of 8 (uniform versus other tube AHG), and for anti-D antibody, 0 of 8 (uniform versus other tube) and 0 of 8 (uniform versus other gel) proficiency tests showed significant titer variability reduction.


CONCLUSIONS
-Uniform methods harmonize laboratory techniques but rarely reduce interlaboratory titer variance in comparison with other methods.
Lohith S
LS
Bachegowda
Yan H
YH
Cheng
Thomas
T
Long
From the Department of Transfusion Medicine (Drs Bachegowda, Cheng, and Shaz), New York Blood Center, New York, New York; and Biostatistics, College of American Pathologists, Northfield, Illinois (Mr Long).
Beth H
BH
Shaz
D000017:ABO Blood-Group System / Q000276:immunology; D000574:American Medical Association; D000906:Antibodies / Q000032:analysis* / Q000097:blood / Q000276:immunology; D019411:Clinical Laboratory Techniques / Q000379:methods / Q000592:standards* / Q000706:statistics & numerical data; D003625:Data Collection / Q000379:methods / Q000706:statistics & numerical data; D004912:Erythrocytes / Q000276:immunology; D006405:Hematology / Q000379:methods / Q000592:standards; D006801:Humans; D007753:Laboratories / Q000592:standards* / Q000706:statistics & numerical data; D059021:Laboratory Proficiency Testing / Q000592:standards*; D000072142:Pathologists; D010338:Pathology, Clinical / Q000379:methods / Q000458:organization & administration / Q000592:standards; D012015:Reference Standards; D012204:Rh-Hr Blood-Group System / Q000276:immunology; D018029:Rho(D) Immune Globulin / Q000032:analysis / Q000097:blood / Q000276:immunology; D014481:United States
D000017:ABO Blood-Group System; D000906:Antibodies; C061961:RHO(D) antibody; D012204:Rh-Hr Blood-Group System; D018029:Rho(D) Immune Globulin