Differential prognosis detected by immunophenotyping in acute lymphoblastic leukemia of childhood with poor prognostic factors.

Immunological phenotypes of leukemic blasts from 50 children with acute lymphoblastic leukemia (ALL) have been examined with a panel of monoclonal antibodies to evaluate their prognostic significance. Thirty-seven of them were common-ALL positive for CD10 "common-ALL antigen (CALLA)" (NL-1), CD19(B4) and HLA-DR. One was pre-B ALL negative for CALLA and another null-ALL which expressed HLA-DR alone. Six of the remaining 11 cases were traditional T-ALL positive for CD2(9.6), and the other five tentative pre-T ALL positive for CD7(Tp40) but negative for CD2. Twenty-one out of 39 patients with non-T ALL were treated with the standard regimen. The 18 children with non-T ALL having poor prognostic factors, five with pre-T ALL and six with T-ALL were treated with the more intensive regimen. The median follow-up period was 36 (range 4 to 74) months. Their disease-free survival probabilities were compared. It was found that the disease-free survival of non-T ALL patients with poor prognostic factors was comparable to that of the patients without such factors as a result of the more intensive chemotherapy. Among the patients with poor prognostic factors, those with pre-T ALL as well as those with T-ALL, which were positive for CD7 antigen, were found to have significantly short disease-free survival times (P less than 0.03). CD7 antibody is most useful for detecting ALL patients with poor prognoses.