Monoclonal antibodies to CALLA do not alter polymorphonuclear functions.

The common acute lymphoblastic leukemia antigen (CALLA) is present on the malignant cells of most patients with acute lymphoblastic leukemia (ALL). Monoclonal antibodies (MoAbs) to CALLA have been useful for differentiating lymphoblastic from nonlymphoblastic leukemias as well as for serotherapy in ALL. Since this MoAb also reacts with polymorphonuclear (PMN) leukocytes, it was of interest to determine whether or not MoAbs to CALLA affected PMN function. We therefore evaluated four MoAbs to CALLA for their effect on PMN function. Two of the MoAbs were IgG and two were IgM. Chemotaxis was studied using Micro-Boyden chambers. Intraleukocyte bacterial killing was studied using Staph:PMN of 2:1 and 10:1, and metabolic activation was evaluated by hexose monophosphate shunt activity. The results showed that these MoAbs to CALLA did not impair the parameters of PMN function studied. These findings have relevance to the usefulness of MoAbs to CALLA for serotherapy and also as a probe for understanding the surface molecule properties that have a bearing on PMN host defense functions.