Isohemagglutinin Titer

Determine the titer of isohemagglutinins (anti-A and/or anti-B) in serum; the absence of expected isohemagglutinins may suggest an immunological deficiency. This test is not recommended for the determination of immunodeficiency. Dependent upon a variety of factors, normal titers are >1:8.

The presence of cold agglutinins other than anti-A and anti-B may interfere with test interpretation. Newborns, infants younger than six months of age, and patients who have undergone immunosuppressive therapy may not demonstrate expected ABO isohemagglutinins.

Issitt PD, Anstee DJ. Applied Blood Group Serology. 4th ed. 1998.