A unique cell surface antigen identifying lymphoid malignancies of B cell origin.

TLDR

A monoclonal anti‑B1 antibody targeting a unique B‑cell surface differentiation antigen was employed to characterize malignant cells from leukemias and lymphomas. B‑cell lymphomas and chronic lymphocytic leukemias uniformly expressed the B1 antigen, whereas T‑cell and myeloid leukemias did not; roughly half of non‑T acute lymphoblastic leukemias and chronic myelogenous leukemia in blast crisis were B1 reactive, and 75 % of CALLA‑positive ALL cases were B1 positive, suggesting a shared B‑cell lineage for most B‑cell tumors.

Abstract

A monoclonal antibody (anti-B1) specific for a unique B cell surface differentiation antigen was used to characterize the malignant cells from patients with leukemias or lymphomas. All tumor cells from patients with lymphomas or chronic lymphocytic leukemias, bearing either monoclonal kappa lambda light chain, expressed the B1 antigen. In contrast, tumor cells from T cell leukemias and lymphomas or acute myeloblastic leukemia were unreactive. Approximately 50% of acute lymphoblastic leukemias (ALL) of non-T origin and 50% of chronic myelocytic leukemia in blast crisis were also anti-B1 reactive. Moreover, 21 of 28 patients with the common ALL antigen (CALLA) positive form of ALL were anti-B1 positive, whereas 0 of 13 patients with CALLA negative ALL were reactive. These observations demonstrate that an antigen present on normal B cells is expressed on the vast majority of B cell lymphomas and on approximately 75% of CALLA positive ALL, suggesting that these tumors may share a common B cell lineage.