The role of human T cell lymphotrophic virus type 1, hepatitis B virus and hepatitis C virus coinfections in leprosy

Leprosy spectrum and outcome is associated with the host immune response against Mycobacterium leprae. The role of coinfections in leprosy patients may be related to a depression of cellular immunity or amplification of inflammatory responses. Leprosy remains endemic in several regions where human T cell lymphotrophic virus type 1 (HTLV-1), hepatitis B virus (HBV) or hepatitis C virus (HCV) are also endemic. We have evaluated the evidence for the possible role of these viruses in the clinical manifestations and outcomes of leprosy. HTLV-1, HBV and HCV are associated with leprosy in some regions and institutionalization is an important risk factor for these viral coinfections. Some studies show a higher prevalence of viral coinfection in lepromatous cases. Although HBV and HCV coinfection were associated with reversal reaction in one study, there is a lack of information about the consequences of viral coinfections in leprosy. It is not known whether clinical outcomes associated with leprosy, such as development of reactions or relapses could be attributed to a specific viral coinfection. Furthermore, whether the leprosy subtype may influence the progression of the viral coinfection is unknown. All of these important and intriguing questions await prospective studies to definitively establish the actual relationship between these entities.

Recombinant adeno-associated virus mediated gene transfer in a mouse model for homocystinuria

Homocystinuria is a metabolic disorder caused by a deficiency of cystathionine b-synthase (CBS). The major clinical symptoms of this disease are mental retardation, lens dislocation, vascular disease with life-threatening thromboembolisms, and skeletal deformities. The major treatments for CBS deficiency include pharmacologic doses of pyridoxine or dietary restriction of methionine. There is currently no effective long-term treatment to lower the elevated plasma levels of homocysteine. However, gene therapy could be an effective novel approach for the treatment of homocystinuria. A recombinant adeno- associated virus vector carrying human CBS cDNA (rAAV-hCBS) was constructed and administered to CBS-/- mice by intramuscular (IM) and intraperitoneal (IP) injections. Serum homocysteine concentrations significantly decreased in treated mice compared with age-matched controls two weeks after treatment. The treated CBS-/- mice had life spans 3-7 days longer compared with untreated CBS-/- mice. In CBS-/- mice treated with rAAV-hCBS via IP injection, the vector was detected in all organs examined including liver, spleen, and kidney, and CBS gene expression was observed by immunohistochemical staining in the liver. These results indicate the efficacy of gene delivery and demonstrate the possibility of gene therapy mediated by AAV gene transfer in this mouse model of homocystinuria.

The influence of CD4+ T cells, HIV disease stage and zidovudine on HIV isolation in Bahia, Brazil

HIV-1 isolation was attempted on 72 individuals, including persons with known HIV infection and five without proven HIV infection but with indeterminate Western blot patterns, as well as on low-risk HIV seronegative persons. The ability to detect HIV-1 from culture supernatant by p24 antigen capture assay was evaluated by segregating patients by absolute CD4+ cell counts, clinical stage of disease, p24 antigenemia and zidovudine use. The likelihood of a p24 positive HIV culture was highest among patients with CD4+ T-cell counts below 200/ul and patients with advanced clinical disease. Use of zidovudine did not affect the rate of HIV positivity in cultures.