Transfusion support with RBCs from an Mk homozygote in a case of autoimmune hemolytic anemia following diphtheria-pertussis-tetanus vaccination

BACKGROUND: Autoimmune hemolytic anemia (AIHA) in children, although unusual, is often associated with recent infection. Several reports have identified the diphtheria-pertussis-tetanus (DPT) vaccination as a possible trigger for AIHA. STUDY DESIGN AND METHODS: Life-threatening AIHA was diagnosed in a 6-week-old infant 5 days after receiving a DIPT vaccination, The patient required daily transfusion and/or exchange transfusion for 3 weeks. RBCs from an M-k homozygote were found compatible with the patient's autoantibody. Transfusion of RBCs from an Mk homozygote and later RBCs from an individual (K.T.) with a variant glycophorin, Mi.VII, were required to sustain the patient's Hb level until autoantibody production ceased, as evidenced by a fall in antibody titer and the patient's Hct returning to normal. RESULTS: The DAT was positive (3+) with only anti-C3 on presentation. An IgM cold reactive autoantibody with probable anti-Pr specificity and high thermal amplitude (37degreesC) was identified in the serum. The DAT was no longer positive after transfusion with compatible blood. CONCLUSION: This case represents life-threatening AIHA in an infant, temporally related to a DPT injection and responsive to a combination of immunosuppression and transfusion of rare compatible blood.