Human immunodeficiency virus and multiple sclerosis: a review of the literature

Multiple sclerosis (MS) and human immunodeficiency virus (HIV) infection are frequent and well-studied nosological entities. Yet, comorbidity of MS and HIV has only been rarely reported in the medical literature. We conducted a literature search using the databases PubMed, Ovid and Google Scholar, with the aim of identifying published studies and reports concerning HIV and MS. Recent epidemiological studies indicated a negative association between MS and HIV in terms of a reduced risk of developing MS in HIV positive patients. Accumulating clinical evidence additionally suggests a possibly reduced relapse rate of MS in HIV patients. Nevertheless, it remains currently unclear whether this observed inverse correlation could be due to the HIV infection itself, HIV treatment or the combination of both. Among the limited cases of MS in HIV infected patients, MS occurrence was mainly reported during acute HIV infection or during HIV seroconversion. This finding is in line with reports of HIV-related autoimmune disorders, which also occur in early phases of HIV disease. Beneficial effects of antiretroviral therapy on MS activity were reported in few clinical cases. Yet, the single phase II clinical trial (INSPIRE), which investigated the effects of antiretroviral medication (using the integrase inhibitor raltegravir) in patients with relapsing-remitting MS, failed to corroborate any beneficial effects at group level. Nevertheless, recently published experimental evidence suggests that HIV treatments may hold therapeutic potential for MS treatment. Thus, further studies are warranted to firstly, delineate the immunological mechanisms underlying possible efficacy of HIV treatments in MS, and to secondly, assess whether repurposing of HIV drugs for MS could be a worthwhile future research objective.