Heterogeneous neurocytotoxic antibodies in systemic lupus erythematosus.

Sera from eighteen patients with systemic lupus erythematosus (SLE) were tested for cytotoxic antibody to three neuronal and two glial continuous cell lines of human origin. Eighty per cent (fifteen out of eighteen) of the sera were cytotoxic to at least one of the cell lines, but only seven sera were active against all five lines. Three sera had anti-neuronal but not anti-glial reactivity. No sera were gliocytotoxic without neurocytotoxicity. Three SLE sera with relatively strong cytotoxicity to all five cell lines were abosrbed with each of the cell lines separately and the absorbed sera were then tested for residual cytotoxicity to each of the cell lines. The absorptions uncovered at least six different antibody specificities directed at antigens expressed on some but not all of the neuronal and glial cell lines. Each patient's serum had its own profile of antibody specificities reactive with membrane antigens on nervous tissue-derived cells.