Effect of total lymphoid irradiation on levels of serum autoantibodies in systemic lupus erythematosus and in rheumatoid arthritis.

The effects of total lymphoid irradiation (TLI) on serum levels of autoantibodies, and of antibodies to diphtheria toxoid, tetanus toxoid, and pneumococcal polysaccharide in patients with lupus nephritis were compared with those previously observed in rheumatoid arthritis (RA) patients. Baseline levels of antibodies to diphtheria toxoid and tetanus toxoid decreased significantly after TLI in patients with lupus and RA, but antibody levels to pneumococcal polysaccharide remained unchanged. After TLI, the levels of antinuclear and anti-DNA antibodies were reduced significantly in lupus, but levels of rheumatoid factor, antinuclear, and antigranulocyte antibodies all tended to increase in RA.