Sensitivity of routine blood bank methods for the detection of anti-D as determined during proficiency testing

A proficiency testing program in immunohematology, involving over 240 laboratories, was used to assess the detection of anti-D in six concentrations ranging from 11 to 8,500 ng/mL. Using the indirect antiglobulin test, more than 98% of laboratories reporting detected anti-D at all concentrations. Enzyme and albumin antiglobulin methods as routinely practiced did not clearly increase sensitivity, and the direct agglutination methods used were much less sensitive than indirect antiglobulin methods. If proficiency testing truly reflects performance in practice in Ontario, Canada, the sensitivity of manual indirect antiglobulin methods in routine use for the detection of anti-D appears to meet reasonable expectations of these technics.