Kimmo Aho

Anticardiolipin response in acute infections

Paired serum specimens from 149 patients with six different infections verified by a significant rise in the specific antibody level were tested for anticardiolipin antibodies using enzyme-linked immunosorbent assay. Significantly raised levels, at least in one immunoglobulin class, were detected in 32% of the cases, and significant changes in the level indicating an ongoing process, in 26%. Taken as a whole, the response involved the immunoglobulins IgG, IgM, and IgA, although in patients with mumps the significantly raised levels were virtually confined to the IgA class. The binding of syphilitic antibodies to solid-phase cardiolipin was readily inhibited by cardiolipin liposomes, whereas this pattern of reactivity was noted in only one of four nonsyphilitic sera. It was concluded that anticardiolipin antibodies occur very frequently in a wide variety of uncomplicated infections.

Rheumatoid factors and rheumatoid arthritis.

Rheumatoid factors (RFs) are autoantibodies which bind the Fc region of IgG (1, 2). They can be induced in experimental animals by B cell mitogens and by immunization with a variety of different antigens. Induction by the antigen-driven route has been accomplished only in secondary but not in primary immunization, suggesting that RFs arise as a response occasioned by antigenlantibody-complex rather than the antigen alone.

IgG-rheumatoid factor in seronegative rheumatoid arthritis

The occurrence of IgG-rheumatoid factor (RF) reacting with rabbit IgG was studied in the sera of:a) 1105 elderly (55-74 years) males from rural areas of Finland, which were obtained in connection with a cohort study of atherosclerotic cardiovascular diseases (population series); and ofb) 201 adult patients with definite or probable rheumatoid arthritis or non-definite arthritis, which were taken in connection with a follow-up (6-9 years) examination of a patient cohort with recent inflammatory joint disease (patient series).IgG-RF was measured with an enzyme-linked immunosorbent assay (ELISA) adopting a Δ-value (absorbance to antigen/antibody complex minus absorbance to antigen alone) for use. The Waaler-Rose test was positive in 28 cases (2.5 %) of the population series. Raised levels of IgG-RF (a Δ-value of ≥ 0.200) were found in 12 sera. Nine of these were positive in the Waaler-Rose test, and two further sera contained raised levels of IgM-RF as measured by latex test or by IgM-RF ELISA. The IgG-RF ac...