OKB7 recognizes antigen on T-cell malignancies

This article describes the pattern of OKB7 positivity in 49 cases of lymphoid malignancies (31 ALL, 17 chronic lymphocytic leukemia (CLL), 1 HCL). The authors have observed that it reacted with 4 out of 5 cases of T-ALL and 8 out of 17 cases of B-CLL. Incidentally all cases of OKB7+ T-ALL were also CALLA+. One case of HCL and 26 cases of non-T-ALL did not react with this antibody. The authors suggest that OKB7 is not specific for B-lineage and many cases of T-ALL may cross-react with it. However, it may be useful for identification of peculiar T-ALL phenotypes (T+, OKB7+, and CALLA+).