Study On The T Lymphocyte Subpopulation And Viral Co-infection Among Intravenous Drug Users

Opioids addiction existed throughout the world and was a major global public health and social problem. Intravenous Drug Users (IDU) formed a special subgroup of the population who often shared contaminated needles of opiate dependent drug injectors. Opioids use was known to alter immune function. Opiate suppressed cell-mediated immunity and humoral immunity, and decreased natural killer cells activity. Therefore, injection drugs, by disturbing the immune response, may facilitate immune tolerance to pathogens and the pathogens can entry into the host. Because HBV, HCV, HIV and HGV had some transmission routes in common, IDU were obviously exposed to transmitting many blood-borne pathogens. The pathogens may resulte in the immune system dysfunction. IDU with blood-borne pathogens infection was considerably higher than in the healthy population. In IDU, an adequate level of information on the epidemiology of blood-borne viruses and altering of T lymphocyte subsets, had not been available so far, although a few epidemiological studies and immune function studies had reported in addict users in China. In the present study, we investigated the molecular-based epidemiological survey of HBV, HCV, HIV, and HGV et al, and association of the virus infection with Th lymphocyte response in IDU.Objective1. Investigated of the viral infection and co-infection condition and the factors of impact infection in IDU.2. In order to assess the T lymphocyte subpopulation and function in IDU, and the relationship of T lymphocyte subpopulation and the duration of addict or the addict dose.3. To study on the interactional mechanism of viruses and the relationship between T lymphocyte subsets and superinfection in IDU.These studies may make for the research of the immune response of co-infection and the prevention and treatment of viral infection. MethodsWe tested 508 serum samples, including samples of 406 IDU (383 male and 23 female, with mean age 32.4 years, range 17-61 years and with drug addiction 1～18 years on heroin maintenance) and 102 controls (64 male and 38 female, with mean age 30.5 years, range 18-58 years) in Southwestern China. All of the IDU without hepatitis clinical symptoms were discovered. 199 cases shared needles with partners who injected drugs. Informed consent for participation in this study was obtained from each individual. These blood samples were collected from 2002 to 2003 and serum stored at -40 °C or below until use. It was detected that anti-HBV, HCV, HDV, HGV, HSV, HIV, and HCMV markers by enzyme-lined immunosorbent assay (ELISA) and immunochromatographic tests. HBV-DNA and HCV-RNA were identified by Polymerase chain reaction (PCR) and Fluorescence Quantitative PCR methods. Peripheral blood mononuclear cells (PBMC) were isolated from fresh heparinized blood obtained from each subject by Ficoll centrifugation. The PBMC were suspended in RPMI 1640 and cultured with PHA-M. Supernatants were removed after 60 h incubation for determination of IFN-γ and IL-4. The levels of IFN-γ and IL-4 were determined by commercial ELISA. The serum levels of IL-2 and IL-4 were determined by radioactive immune assay (RIA). T lymphocyte subpopulation was detected bymeans of fluorescence immunoassay. The results were analyzed by Student's t-test andchi-square test. A P-value less than 0.05 was considered significant.Results1. Our investigation showed that the infection rates of the viruses among 406 IDU were as follows: 36.45% for HBcAb, 69.7% for anti-HCV, 47.3% for anti-HTVl/2, 3.45% for anti-HCMV and 2.22% for HDV-Ag. In contrast, for 102 healthy controls HBV infection rate was 17. 65 % while other infection rate was 0%. IDU were at risk for HCV (69.7%, 283/406) and HIV (47.3%, 192/406) infection. More than 80% (161/192) of subjects infected with HIV were co-infected with the other virus (HBV, and HCV etc). The rate of virus co-infection in IDU was very high (62.81%, 255/406). Triple infection and fourfold infection were detected in the study. From a total of 312 IDU with anti-HCV antibodies and HBcAb, 72 (23.08%) were found to be serum HCV-RNA or HBV-DNA positive. In no infection markers IDU, serum HCV-RNA or HBV-DNA could not be detected. The infection rates and co-infection rates were very prominent in the injector co-users of IDU.2. Our investigation showed that CD3 cells, CD4 cells and CD4/CD8 ratio were obviously lower in IDU than in controls (P<0.01). The levels of phytohemagglutinin (PHA)-induced IFN-γ and IL-4 in peripheral blood mononuclear cell (PBMC) and serum IL-2 were obviously decreased in IDU, but the serum IL-4 was increased (P<0.01). The decrease of CD4 subsets and function was associated with the duration of addict and addict dose.3. The production of EFN-γ and CD4 lymphocyte were significantly decreased in the IDU with HCV infection. IDU with HTV and HBV coinfection was 15.1% (29/192). 51.72% (15/29) and 37.93% (11/29) were HBV-DNA positive and HBeAg positive. But the IDU of no-infection HIV only had 1.68% (2/119) HBV-DNA positive. The level of IFN-γ was continuously lower among single HIV or co-infection HCV/HBV group as compared to uninfected group (P < 0.05).Conclusion1. Our result suggested HCV and HIV infection were widespread in IDU. The susceptibility to viral co-infection was increased. The infection rates and co-infection rates were very prominent in the injector co-users of IDU.2. CD3 cells, CD4 cells and CD4/CD8 ratio were obviously lower in IDU than in controls. The levels of PHA-induced IFN-γ and IL-4 in PBMC and serum IL-2 were obviously decreased in IDU, but the serum IL-4 was increased. Opioids can impair Th response. In IDU, the balance of Thl/Th2 cells was disturbed, the ability of antivirus is weakened. There were statistically negative correlation between CD4 cell count/function and addict duration/addict dose.3. The infection inversely accelerates the disturbance of Th function. IDU with HIV and HBV/HCV coinfection showed both of lower expression of Th1 cytokine without enhancement of the Th2 response. HIV infection had led to a high incidence of impaired Th1 cytokine levels. HFV infection was associated with HBV activity (HBeAg and HBV-DNA positive). HIV may be a reason causing HBV replication through decreasing the Th function.