Clinical features of adult patients with acute lymphocytic leukemia according to immunological phenotypes of lymphoblasts

An immunological classification of adult acute lymphocytic leukemia (ALL) to three main subgroups appears to be of important value since some evaluation has been established between a phenotype of leukemic cells and clinical features. We investigated the immunological phenotypes on bone marrow and/or peripheral blood lymphoblasts for 27 adult patients with ALL. Spontaneous rosette formation with sheep erythrocytes (E-rosettes) was identified as T cell and the presence of complement receptor for C3 (EAC-rosettes) identified as B cell. The median age of patients with T-cell (5 cases), B-cell (5 cases) and null-cell ALL (17 cases) was 48, 18 and 31 years, respectively. Morphologically, leukemic cells from T-cell ALL patients very often revealed indented, folded nucleus characteristic of adult T-cell leukemia proposed by Uchiyama et al.. With respect to their clinical features, there were differences noted in the number of patients with organomegaly and high peripheral white blood cell counts. Very commonly, patients with T-cell and B-cell ALL had massive leukemic infiltration, compared with those with null-cell ALL. Of interest is the correlation between this immunological classification and the prognosis, since T-cell and B-cell ALL were associated with a poorer prognosis than null-cell ALL, in terms of the median length of first complete remission and median survival. This poorer prognosis in adult patients with T-cell and B-cell ALL would provide useful information for selecting differing forms of therapy.