Purification of antilymphocyte antibody (ALA) from patients with systemic lupus erythematosus (SLE)-immunoabsorption and elution.

Purification of antilymphocyte antibody (ALA) from patients with systemic lupus erythematosus (SLE) was achieved by immunoabsorption and elution. Human tonsil cells or thymocytes were used as absorbents. Complement dependent microcytotoxicity tests showed that, in comparison to the parent sera, the eluate from tonsil cells was eight times, and that from thymocytes four times, more active. Antinuclear activity was eliminated by elution. The ALA was almost entirely IgM, IgG being involved in only a few cases. IgA lacked cytotoxic activity. ALA was directed at both T- and B-cell surface determinants, which suggests that, in SLE, it has a heterogeneous biological composition.