Reducing the variation in performance of antibody titrations.

Abstract

Abstract Background.—Antibody titration is difficult to standardize. We investigated whether a detailed, uniform procedure for antibody titration would reduce variation in both tube-based and gel card titres in an international study. Methods.—Laboratories (n = 35) tested proficiency testing material provided by the College of American Pathologists each according to (i) their routine method; (ii) a detailed, uniform method; and (iii) the uniform method titrating the serum sample against a red cell of specified phenotype (D+ C− c+ E+ e− for anti-D; A1 for anti-A) instead of the red cell of the same phenotype provided in the proficiency testing kit. Uniform method results were reported with 1+ and w+ end-points. Paired statistical analyses of variance were conducted using the F-test. Results.—The variance between laboratories was not significantly reduced with the uniform method using a 1+ end-point. However, a statistically significant reduction in the variance of anti-D and anti-A titres by the tube-based...