AUTOANTIBODIES IN HIV-INFECTED PATIENTS THAT MODULATE THE CHOLINERGICACTIVITY OF HEART AND GUT TISSUE

In human immune deficiency virus (HIV) disease, direct infection of he art tissue with HIV and repeated intestinal infections with opportunis tic pathogens are thought to be the main cause of cardiac disease and diarrhoea respectively. A role for autoimmune phenomena may also be in volved in the pathogeny of HIV disease. In this study, we demonstrate that immunoglobulins from the A and G classes from HIV positive patien ts are able to interfere with the function of the muscarinic cholinerg ic receptors from heart and gut. Both IgA and IgG HIV+ preparations de creased the tension of isolated atria and increased the tension of iso lated ileum. The mechanical effect of carbachol was inhibited in both atria and ileum preparations, when they were preincubated with either IgA or IgG HIV+ fractions. An inhibitor of muscarinic cholinergic rece ptors (atropine) impaired the negative inotropic action of HIV+ immuno globulins (Ig) on the heart and prevented the positive inotropic effec t of HIV+ Igs on ileum. HIV+ IgA fraction was approximately ten fold m ore potent to interfere with the cholinergic function as compared to t he IgG fraction. These results suggest that antibodies present in HIV serum may also modulate muscle's cholinergic activity in the heart an d ileum from HIV+ patients.