Imaging of Mycobacterium avium-intracellulare infection in AIDS patients on highly active antiretroviral therapy: Reversal syndrome

OBJECTIVE. We recently encountered six patients with AIDS and an unusual co mplication of disseminated infection with Mycobacterium avium-intracellular e, which developed after the initiation of highly active antiretroviral the rapy, including protease inhibitors and two new nucleoside analogues. Each patient had a febrile illness after the initiation of therapy and then deve loped mass lesions containing mycobacterial organisms in various organ syst ems, including bone, skin, and mesenteric and mediastinal nodes. All these patients suddenly experienced improvement in immunologic status as evidence d by decreasing viral loads and increasing CD4 cell counts. We chose to cal l this reaction "M. avium-intracellulare reversal syndrome." We describe th e radiologic appearance of this unusual manifestation of infection with M. avium-intracellulare in patients with AIDS. CONCLUSION. New or enlarging lymphadenopathy or unusual musculoskeletal and cutaneous infections in patients with AIDS who are receiving highly active antiretroviral therapy may represent a response of the recovering immune s ystem to a new or previously subclinical infection with M. avium-intracellu lare.