Leprosy revealed with HIV treatment
By Carol Kemper, MD, FACP
Dr. Kemper reports no financial relationships relevant to this field of study. This article originally appeared in the May 2005 issue of Infectious Disease Alert. It was peer reviewed by Connie Price, MD and edited by Stan Deresinski, MD. Infectious Disease Alert's Physician Editor, Stan Deresinski, MD, FACP, serves on the speaker's bureau of Merck, Pharmacia, GlaxoSmithKline, Pfizer, Bayer, and Wyeth, and does research for Merck. Peer reviewer Connie Price, MD, reports no consultant, stockholder, speaker's bureau, research, or other financial relationship with any company related to this field of study.
Source: A ProMED-mail post, October 25, 2006; promed@promedmail.org
Hiv/aids specialists in britain and the U.S. caring for HIV+ persons from developing countries are reporting a new phenomenon - exacerbations of previously unrecognized leprosy in HIV+ persons receiving highly active antiretroviral therapy (HAART). As patients initiate HAART, and with improvement in their immune systems, their leprosy appears to "wake up." Patients have developed painful nodules around the nerves of the neck and face, with numb fingers and toes. The diagnosis of leprosy may not be immediately obvious, and the granulomatous response seen in nodules may be misleading. The clinical and histopathological presentation appears similar to a Type 1 reversal reaction, where activated CD4 cells migrate into infected lesions and produce cytokines. As such, it seems analogous to other HIV-related infections, with paradoxical worsening with immune reconstitution.
There are an estimated 300,000 new cases of leprosy diagnosed annually around the world, mostly in Brazil, India, Africa, and the Caribbean, although I have cases in my clinic from Central America, China and the Philippines. Initial concerns that HIV infection may lead to thousands of new cases of leprosy in the developing world have not been born out. Some assume this may be a function of patients dying of their HIV before developing clinically apparent leprosy, which typically incubates for up to 8 to 13 years. It is estimated that perhaps 2% of leprosy patients in places like Brazil may be co-infected with HIV. Interestingly, even in HIV+ patients with leprosy, the histology on biopsy maybe similar to that seen in non-HIV-infected persons. Even patients with advanced HIV disease appear able to mount a granulomatous response to M. leprae, in contrast to those infected with M. tuberculosis. Type 1 reversal reactions, associated with T cell activation to M. leprae have been described in 2 HIV+ patients who did not receive ART.
Clinicians caring for HIV+ patients from developing countries should be alert to the possibility of asymptomatic leprosy being unmasked by antiretroviral therapy.