Studies into the occurrence of soluble antigen‐antibody complexes in disease

The first assessment of 127 rheumatoid patients, previously reported, revealed that the rheumatoid biologically active factor (RBAF) correlated with a more advanced and widespread form of disease. The results of a second assessment are reported here, carried out after an interval of 9 months in 107 of the patients originally studied. The RBAF status of one-fourth patients was found to be changed at the second assessment; although overall distribution between positive and negative groups remained constant. Those patients who converted from RBAF-positive to RBAF-negative showed marked clinical improvement, while subjects who converted from RBAF-negative to RBAF-positive failed to improve or were worse in certain parameters. These findings indicated that there was a direct relationship between alterations in the RBAF and clinical status.