Identification of recipient Rh phenotype in a chronically transfused child by two-colour immunofluorescence

A child with hyporegenerative anaemia was chronically transfused with group 0 Rh-negative blood. As typing with anti-D showed a mixed-field pattern, the patient's red blood cells (RBC) were identified as D positive. Due to the transfused ccddee RBC, it was impossible to determine by simple agglutination whether c was present on the patient's RBC. To resolve this question, two-colour indirect immunofluorescence was performed using D as a marker of the patient's RBC. Likewise, Duffy and Kidd antigens could be determined on the patient's RBC despite multiple transfusions.