IDENTIFICATION AND PROGNOSTIC SIGNIFICANCE OF SURFACE MEMBRANE DETERMINANTS ON CHILDHOOD ACUTE LYMPHOCYTIC LEUKEMIA (ALL) CELLS: IMMUNOGLOBULIN (SIg), Fc PORTION OF IMMUNOGLOBULIN (Fc) AND COMPLEMENT (C3) RECEPTORS

Abstract

Most reports have now described two populations of childhood. ALL patients (pts.); those with T cell (thymic dependent) receptors and those lacking receptors on their neoplastic cells. Assays for surface receptors of the T and thymic independent (B) system were used to study 47 pts. with ALL whose bone marrow contained a mean of 85% leukemlc cells. Two pts. had T cell disease and 36 were non-T, non-B. Nine pts. were identified whose leuke-mic cells had B receptors. The pts. with B cell receptors had SIg (2), Fc (3), and C3 (3) on their leukemic cells. Both T and B receptors were found on the ninth pt.' cells. The same surface characteristics were found on leukemic cells from these pts.' bone marrow, blood, and pleural and cerebrospinal fluid. Studies showed that the leukemic cells were not of monocytic or granulocytic origin. Although a remission was obtained in each patient the relapse rate of the B cell group was worse than a similarly treated group of 36 non-T, non-B ALL pts. (p<.001). Initial total leukocyte counts (TLC) of the B cell group were greater (p<.05) but when the pts. in both groups with TLC >25,000/mm3 were compared, the relapse rate of the B cell pts. was significantly worse (p<.025). The results show that B cell leukemia variants comprise a significant proportion of ALL and the presence of these receptors on leukemic cells have an ominous significance.