Antigen--antibody complexes related to the baboon endogenous virus in humans with acute lymphoblastic leukemia--hand mirror variant (ALL-HMC).

Hand mirror cells are a morphological configuration that are seen in immunologically stimulated lymphocytes and can be induced by antigen--antibody complexes. Therefore, the bone marrow and peripheral blood plasma of two patients with acute lymphoblastic leukemia--hand mirror variant were evaluated for the presence of antigen--antibody complexes. Both patients had antigen--antibody complexes in the bone marrow plasma and not in the peripheral blood plasma as determined by double counter-current immunoelectrophoresis. The antigen moiety of these complexes appears immunologically related to components of the baboon endogenous virus (BaEV), and the antibody moiety also appears related to structural components of the BaEV. Bone marrow plasmas from patients without leukemia were evaluated for the presence of antigen--antibody complexes and found to be negative. The antigen--antibody complexes may account for the presence of hand mirror cells in the bone marrow of patients with acute lymphoblastic leukemia--hand mirror variant.