Gamma2, Gamma1A, and Gamma1M Antinuclear Factors in Human Sera*

Abstract

A modification of the indirect immunofluorescent technique was employed to detect antinuclear factors (ANF) of gamma2-, gamma1A-, or gamma1M-immunoglobulin classes. Gamma1A ANF in two cases appeared to sediment as 7 S globulins and be resistant to sulfhydryl (SH) treatment, whereas in other cases, they appeared to sediment faster than 7 S globulins and be inactivated by the SH treatment. ANF and rheumatoid factors (RF), although frequently found together in the same serum, behaved as separate serological entities, but evidence was found that in some RA sera RF may interact with gamma2 ANF on nuclei to give the appearance of gamma1M ANF. ANF of all three immunoglob-ulin classes was detected in sera from both rheumatoid arthritis (RA) and lupus erythematosis (LE) patients. Gamma2 ANF was found in higher titer in LE than in RA sera. Among the LE sera gamma2 and gamma1A ANF were found in higher titer, if the sera were from patients with disease for less than 1 year. LE patients with disease for more than 1 year, who generally were also in remission and on chloroquin or steroid therapy, had lower titers of gamma2 and gamma1A ANF. Among the RA sera only 27% had ANF by a less sensitive immunofluorescent test. Among these ANF was found in those patients who had severe disease with a median duration of 9 years. RA sera lacking ANF by a less sensitive test were from patients with less severe disease and disease of shorter duration, but of ten such patients selected for study, five with disease of somewhat longer duration proved to have low titer gamma1M ANF.