Clinical immunotoxicity of antirheumatic drugs

Non-steroidal antiinflammatory drugs (NSAIDs), corticosteroids and disease modifying antirheumatic drugs are commonly used for the treatment of the inflammatory rheumatic diseases. In addition to their antiinflammatory effects, many of these drugs influence an otherwise impaired immune system, which may result clinically in decreased resistance to infection and/or increased incidence of malignancies, in stimulation of the immune response and autoimmune diseases, or in allergy or hypersensitivity. Only corticosteroids increase considerably the risk of infections, immunosuppressive agents-at the low doses used in rheumatology-do not have this effect. Although the data are conflicting, neoplasms, especially leukaemias and lymphomas seem to develop more frequently during immunosuppressive treatment. Methotrexate, most commonly used nowadays in the early stage of joint disease, does not seem to increase the risk of malignancies. Although several drugs may induce autoimmune diseases, d-penicillamine is the commonest inducer. NSAIDs have the greatest propensity to produce allergy or hypersensitivity, causing various cutaneous, renal, and bronchial symptoms, and rarely vasculitis. Methods for the measurement of their plasma concentrations are available for most of the drugs, although not routinely used. Clinical vigilance, regular check-ups and full knowledge of side effects are crucial in the diagnosis of drug-induced immunotoxicity, especially because the symptoms and signs of immunotoxicity may mimic the naturally occurring features of the underlying disease.