Human monoclonal antibodies to neutralize all dengue virus serotypes using lymphocytes from patients at acute phase of the secondary infection.

The global spread of the four dengue virus serotypes (DENV-1 to -4) has made this virus a major and growing public health concern. Generally, pre-existing neutralizing antibodies derived from primary infection play a significant role in protecting against subsequent infection with the same serotype. By contrast, these pre-existing antibodies are believed to mediate a non-protective response to subsequent heterotypic DENV infections, leading to the onset of dengue illness. In this study, we prepared hybridomas producing human monoclonal antibodies (HuMAbs) against DENV using peripheral blood mononuclear cells (PBMCs) from patients in the acute phase (around 1 week after the onset of illness) or the convalescent phase (around 2weeks after the onset of illness) of secondary infection. Interestingly, a larger number of hybridoma clones was obtained from patients in the acute phase than from those in the convalescent phase. Most HuMAbs from acute-phase infections were cross-reactive with all four DENV serotypes and showed significant neutralization activity to all four DENV serotypes. Thus, secondary DENV infection plays a significant role in stimulating memory cells to transiently increase the number of antibody-secreting plasma cells in patients in the early phase after the secondary infection. These HuMAbs will enable us to better understand the protective and pathogenic effects of DENV infection, which could vary greatly among secondarily-infected individuals.

Outcomes in HIV-infected patients on antiretroviral therapy with tuberculosis.

HIV-infected patients with active tuberculosis (TB) having CD4 counts < 100/mm3 and who were antiretroviral therapy (ART) naïve were reviewed retrospectively to determine the outcomes of their tuberculosis infection. All patients received ART at or after receiving anti-TB treatment. Clinical manifestations, treatment regimens and outcomes were analyzed. Of 101 patients, 62 (61.4%) completed TB treatment. Of these, 53.2% were treated with a 6-month standard TB regimen, while the rest were treated with prolonged TB regimens. The median interval between anti-TB treatment and ART was 68 days (range: 0-381). Among the clinically cured patients 66.1% received rifampin concomitantly with nevirapine, and 32.3% received rifampin concomitantly with efavirenz. The treatment success rate was 75.6%, with a mortality rate of 6.1%. The risk factors for death were resistant TB (p = 0.03) and poor compliance (p < 0.05). Seven point nine percent had multi-drug resistant TB. Possible or probable immune reconstitution inflammatory syndrome (IRIS) was seen in 15 cases (14.9%). No life-threatening IRIS was reported, and it did not affect disease outcome (p = 0.5). A shorter time between anti-TB treatment and ART onset was associated with the occurrence of IRIS (31 days vs 90 days; p < 0.05). Regarding adverse drug effects, 44.6% had side effects due either to anti-TB drugs or ART. Sixty-six point one percent of them occurred within the first 2 months of TB treatment, and 43 (76.8%) had to stop or change either anti-TB treatment or ART. The mortality rate with TB and HIV on ART was low and the occurrence of IRIS did not carry any additional mortality.

Travelers' malaria among foreigners at the Hospital for Tropical Diseases, Bangkok, Thailand - a 6-year review (2000-2005).

We retrospectively examined the charts of travelers admitted to the Hospital for Tropical Diseases, Bangkok, Thailand, with malaria during the years 2000-2005. Twenty-one cases of malaria were identified, of which 12 (57%) were Plasmodium vivax infections and 9 (43%) were P. falciparum infections. There was one mixed case with vivax and falciparum infection. Only 1 P. falciparum case had complications. All cases were successfully treated with standard antimalarial drugs. Only 3 of the 21 cases were thought to be acquired in Thailand, the rest were regarded to be imported.

6-month evaluation of JinHuang Chinese herbal medicine study in asymptomatic HIV infected Thais.

Good results of in vitro study of anti-HIV effects of JinHuang, a Chinese herbal medicine led to in vivo study of safety and efficacy among asymptomatic HIV infected individuals. It was a prospective open study of 21 asymptomatic HIV infected Thai volunteers. Twelve and 9 were female and male, respectively, with mean age of 29.24 +/- 3.94 years. JinHuang preparation, 6 capsules and 2 bottles of liquid formula orally three times a day, was given on an outpatient basis initially for 6 months. Regular close monitoring and follow-up were done. The side effects reported included : increased bowel movements (81%), vague taste, and smell of drug after initiation (52%). No serious adverse event related to JinHuang was detected during study. No significant changes in terms of log viral load and CD4 count were observed after 6-months' duration. Most of the patients felt that the quality of life was better in terms of better appetite, good sleep and healthy during study participation, however, these were subjective.