Uptake and degradation of soluble aggregates of IgG by monocytes of patients with rheumatoid arthritis: relation to disease activity

Article Abstract:

In the body's secondary line of defense against bacteria and other foreign substances, proteins produced by B cells and known as immunoglobulins, or antibodies, react with the antigens (specific molecules on the surface of the foreign substance) to form immune complexes, which are then normally cleared from the bloodstream. Immune complexes, or aggregated antibodies, of the subclass G (IgG) circulating throughout the body are thought to be related to symptoms of rheumatoid arthritis such as vasculitis (inflammation of blood vessels). Immune complexes (IC) become more concentrated in the blood when synthesis of IgG is increased or their degradation is decreased. Monocytes are the blood cells that give rise to phagocytic cells, whose function is to clear immune complexes from the circulation. This phagocytic system is diminished in diseases such as RA. To evaluate the relationship between monocyte degradation of immune complexes and clinical and laboratory signs of RA disease activity, 79 patients with RA and rheumatoid vasculitis were studied over 16 months. Active joint inflammation and high levels of IC correlated significantly with decreased degradation by monocytes. Symptoms unrelated to joint function and drug therapy did not correlate to monocyte activity. The relationship between types of receptors (cell-surface molecules) on monocytes and disease activity was studied. All patients had significantly more receptors recognizing Fc (the protein structure common to all antibodies) and significantly fewer receptors for two complement proteins (blood proteins that destroy bacteria and other cells) than healthy subjects. Levels of Fc receptors on monocytes were higher in patients with active RA or those with rheumatoid vasculitis than those with inactive disease, and they also had significantly fewer complement receptors. The study suggests that RA disease activity is linked to immune complex degradation by monocytes and by receptor levels on the monocytes. (Consumer Summary produced by Reliance Medical Information, Inc.)

Monocytes, Immune complexes

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Oral contraception and its possible protection against rheumatoid arthritis

Article Abstract:

Rheumatoid arthritis (RA) is a disease that causes inflammation and tissue damage in the joints. The disease is more common in women than in men, and in most cases is less severe during pregnancy. These findings, along with the suggestion that female hormones may somehow be related to RA, provided the basis for examining the relationship between the use of oral contraceptives and RA. Many different studies have attempted to determine whether or not oral contraceptives have a protective effect against RA. After 12 years of research, there is still no clear answer to this question. Five studies concluded that oral contraceptives have no protective effect against RA, while seven other studies reported that the use of oral contraceptives can reduce the incidence of RA by about 50 percent. Recently, a workshop was held to address this issue and to try to reach a conclusion. The results from the workshop indicate that the use of oral contraceptives is probably associated in some way with RA. When the results from all of the previous studies were analyzed based on geographic location, it was concluded that there is a greater protective effect against RA in oral contraceptive users in Europe than in the United States. However, this finding may reflect differences in the way that the studies were performed and differences in the severity of the RA in the people studied. Previous studies have indicated that the use of oral contraceptives is associated with smoking, alcohol consumption, sexual behavior and recurrent genital tract infections. The relationship between these factors and RA is not known. The majority of the recent studies have just added confusion as to whether oral contraceptives protect against RA. Further studies are needed before a definite conclusion can be reached. (Consumer Summary produced by Reliance Medical Information, Inc.)

Complications and side effects, Autoimmune diseases, Oral contraceptives

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Lifestyle and the risk of rheumatoid arthritis: cigarette smoking and alcohol consumption

Article Abstract:

Studies on the relationship between the use of oral contraceptives and the onset of rheumatoid arthritis (RA) have arrived at conflicting conclusions. In studies that focused on oral contraceptive use among patients with RA, researchers noted that other behaviors, such as smoking, were not the same in patients and controls. Smoking is known to affect various systemic functions. The effects of smoking and another related behavior, alcohol consumption, on the occurrence of rheumatoid arthritis were studied in 135 young women with RA and 378 control patients with osteoarthritis or soft tissue rheumatism. Patients with RA tended to have used oral contraceptives less often before RA symptoms developed, and were less frequent users of alcohol or tobacco. Thirty-three percent of RA patients were current cigarette smokers, while 48 percent of other subjects smoked cigarettes. The risk of RA in women who smoked at least one cigarette per day was about one-half that of those who did not smoke. This effect was independent of oral contraceptive use. A similar decreased risk was found among RA patients who used alcohol, and this was also independent of cigarette smoking and oral contraceptive use. The study suggests that alcohol consumption is reduced among RA patients; this may be due to the fear of adverse drug reactions and because joint pain increases strikingly after drinking alcohol. The results also suggests that cigarette smoking may affect the occurrence of RA due to its effects on female and male hormones and on cellular and immune functions. (Consumer Summary produced by Reliance Medical Information, Inc.)

Health aspects, Drinking of alcoholic beverages, Drinking (Alcoholic beverages), Smoking and women, Women smokers

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