[AIDS: a model for the study of atopy?].

The drug intolerance and allergic manifestations linked to infection with the Human Immunodeficiency Virus (HIV) are often misunderstood. However, in the light of recent advances in immunopathology, these manifestations perhaps give an indication as to more general mechanisms of allergy. Drug intolerance is frequent during the course of AIDS, and is largely due to sulphamides; more rarely to pentamidine or amoxycillin associated with clavulanic acid. Other allergic manifestations are frequent in subjects suffering from AIDS, and occur all the more so in those subjects who are atopic before their immunodepression occurred. Metabolic anomalies occurring during the course of the disease perhaps partially explain certain aspects of drug intolerance. However, it seems that it is particularly the immunological changes which are at the origin of allergic manifestations to these diseases. AIDS is characterised by polyclonal activation of B-lymphocytes which leads to hyper-gammaglobulinaemia. This excess of antibody confronted with an excess of antigen in association with the administration of high doses of long-term antibiotics would favour the formation of antigen antibody complexes which may be responsible for the manifestations of a type of "serum sickness". Besides, there is a specific dysregulation of IgE synthesis as evident by a rise of serum IgE in subjects suffering from AIDS. That would explain the progressive increase in the expression of interleukine-4 and interleukine-10 during the course of the disease at the expense of the expression of interleukine-2 and interferon gamma. The shift from a Th1 cytokine secretion profile to that of a Th2 profile could be a consequence of decreased IL12 production by HIV infected monocyte/macrophages.(ABSTRACT TRUNCATED AT 250 WORDS)