Evidence that Hy-RBCs express weak Jo(a) antigen
BACKGROUND: RBCs of the Hy- phenotype have, in the past, been typed as Gy(a+(w)), Hy-, Jo(a-), and RBCs with the Jo(a-) phenotype type Gy(a+), Hy-(w), and Jo(a-). Anti-Hy and anti-Jo(a) are difficult to identify mainly because appropriate reagent R6Cs are poorly characterized. Historically, anti-Jo(a) has not reacted with RBCs with either phenotype. This report describes a case of an anti-Jo(a) th