MYELOPATHY AMONG BRAZILIANS COINFECTED WITH HUMAN T-CELL LYMPHOTROPICVIRUS TYPE-I AND HIV

Objective: To determine whether subjects coinfected with HTLV-I and HI V have a higher frequency of myelopathy than subjects singly infected with HIV. Design: A prospective, nested case-control study of HTLV-I a nd HIV coinfected (cases) and HIV singly infected adults (controls) pa rticipating in a prospective HIV cohort study at a university hospital outpatient HIV clinic in Rio de Janeiro, Brazil. Measurements: Subjec ts were evaluated for evidence of myelopathy by a neurologist unaware of their HTLV serologic status. Patients with at least two pyramidal s igns, such as paresis, hypertonicity or spasticity, hyperreflexia, clo nus, diminished or absent superficial reflexes, or the presence of pat hologic reflexes (e.g., Babinski or Hoffmann), were defined as having myelopathy. Myelopathy severity was quantified using the Kurtzke Funct ional Disability Scale (FDS); patients with FDS scores greater than or equal to 4 were considered to have significant myelopathy. Selected p atients with myelopathy underwent lumbar puncture for the evaluation o f intrathecal synthesis of HTLV-I antibodies. Results: Of 15 coinfecte d subjects, 11 (73%) had evidence of myelopathy versus 10 of 62 subjec ts (16%) with HIV single infection (adjusted odds ratio [OR] = 13.0, p = 0.00002). When only myelopathy patients with FDS scores of greater than or equal to 2 or greater than or equal to 4 were included, the as sociation between coinfection and the presence of myelopathy remained (OR = 7.3, p = 0.0003 for scores greater than or equal to 2; and OR = 8.9 for scores greater than or equal to 4, p = 0.04). In addition, a h igher proportion of coinfected subjects had peripheral neuropathy (40% ) than controls (16%) (OR = 3.5, p = 0.07). Conclusion: Coinfection wi th HTLV-I was strongly associated with myelopathy among subjects infec ted with HIV. The relative contribution of HTLV-I versus HN in the pat hogenesis of coinfection-associated myelopathy is not known. Coinfecti on may also be associated with peripheral neuropathy. Further studies are needed to elucidate the mechanisms of coinfection-associated neuro logic conditions.