Higher Type 1 Interferon Levels in Plasma of Asymptomatic HIV-2 than in HIV-1 Individuals

A number of cytokines are secreted during HIV infection that enhances both innate and adaptive immune responses. Interferon-α/β/γ, IL-12, IL-15 and IL-18 have been found to contribute to the development, maturation, differentiation and function of NK and other immune cells. The levels of IFN-α/β/γ, IL-12, IL-15 and IL-18 were compared in the plasma of 90 HIV-1 infected and 90 HIV-2 infected subjects by ELISA or Cytometric Beads Array assays. The HIV-infected subjects were stratified according to CD4+ T cell counts into three groups: >500, 200 - 500 and <200 cells/ul, with 30 subjects in each group. Cytokine levels were also determined in the plasma of 50 HIV uninfected blood bank donors. Among the cytokines tested, IFN-α was found to be significantly increased in HIV-2 infected compared to HIV-1 infected subjects at high CD4+ T cell counts (p = 0.001). The levels of IFN-β were seen to differ between the two infections in patients from the category of medium CD4+ T cell counts: this was significantly increased in HIV-2 infected patients (p < 0.001) as well as compared to uninfected controls (p = 0.001). The levels of IFN-γ were similar at all the CD4+ T cell categories except for an increase in HIV-2 infected patients at low CD4+ T cell counts (p = 0.02). The levels of these cytokines were similar in all HIV-1 subjects. Also, the level of IL-12p70 was similar between the two infections but significantly higher in HIV-2 at low compared to medium CD4+ T cells categories (p = 0.047). Similar to IFN-γ and IL-12p70, the levels of both IL-18 and IL-15 were found to be significantly higher in HIV-2 infected patients compared to HIV-1 at low CD4+ T cell counts (p < 0.05). These data show that there is variability in the levels of innate cytokines at different stages of HIV infection but the finding of increased IFN-α in HIV-2 infected asymptomatic subjects is consistent with the high innate NK responses previously noted at this stage of infection.

Seroprevalence and Risk Factors of Syphilis Infection among Antiretroviral Therapy Naive HIV Patients at the Cape Coast Teaching Hospital, Ghana

Diagnosis of sexually transmitted infections is very important considering the spread of HIV and the extensive use of highly active antiretroviral therapy worldwide. This will assist in planning of treatment schedule in controlling these infections. The study therefore aimed at determining the prevalence of syphilis in HIV positive antiretroviral therapy naive patients in Cape Coast and the associated risk factors involved in infection. A cross-sectional study was carried out using initial HIV rapid and confirmation tests, and then Venereal Disease Research Laboratory test with the Ultra Rapid Test Kits for syphilis. Demographic data, risky sexual behaviours capable of co-transmission of both HIV and Syphilis, were also collected through the use of questionnaires. In all, 150 HIV positive antiretroviral naive subjects were studied and 15 (10%) were positive for VDRL test, with females (6.00%) and males (4.00%), who were mainly within the age group of 20 - 39 years. A significant number of males (p = 0.019) and females (p = 0.015) participants were not smoking with a fewer number of the females (p = 0.002) having multiple sexual partners. Also a smaller number of those who were infected with the bacteria (p = 0.004) did not support the control of sexually transmitted infection (p = 0.022). The result showed that co-infection of Syphilis in HIV positive antiretroviral therapy naive patients persists in the Cape Coast Metropolis, which is an indication of prominence of STIs that require further study on a larger scale to ascertain the extent of co-infection and to formulate policy for treatment to help minimize the rate of infection.

Differential Expressions of Selected Activating and Inhibitory Receptors on K562-Stimulated Natural Killer (NK) Cells in HIV-1 and HIV-2 Infections

Context: The functional activity of NK cells depends on the balance between the engagement of activating and inhibitory receptors on the cell surface with their ligands, which enables them to kill infected cells. Objectives: The aim of this study was to evaluate and compare expressions of selected activating and inhibitory receptors on stimulated NK cells in HIV-1 and HIV-2 infections. Methods: PBMCs were analysed for activating (NKp30, NKp44, NKp46) and inhibitory (CD158a, CD158b, p70) receptor expressions in 30 HIV-1, 30 HIV-2 and 30 HIV uninfected healthy control (HC) subjects by flow cytometry after stimulating with K562 cells. Results: There was an expression of other receptors following an already in vitro engagement of NK cells with K562 cells. Higher expression of the activating receptors, NKp44 (p = 0.029) and NKp46 (p = 0.032) on NK cells from HIV-2 compared to HIV-1 infected individuals but similar NKp30 expression (p = 0.980). The levels of expression of inhibitory receptor CD158a were similar between HIV-1 and HIV-2 infected subjects (p = 0.309) but there was significant up-regulation of inhibitory receptors p70 (p = 0.010) and CD158b (p = 0.05) in HIV-1 compared to HIV-2 subjects. Conclusion: Despite the in vitro engagement of NK cells with stimulating K562 cells, our data showed differential expressions of other selected activating and inhibitory receptors in HIV-1 and HIV-2 infected subjects.

Greater Expansion of IFN-<i>γ</i>^﹣CD4⁺NKT Cells in HIV-1 Compared with HIV-2-Infected Subjects with Preserved CD4⁺T Cell Counts

Context: Human Natural Killer T cells are T lymphocytes that express an invariant αβ T cells receptors and NK cells receptors. They regulate innate and adaptive immune response but are susceptible to HIV-1 infection. Objective: We compare the frequency and the activity of NKT cells in HIV-1 and HIV-2 infected individuals with CD4+ counts greater than 500/mm3 using flow cytometry after overnight stimulation with phytohemagglutinin (PHA). Results: The frequency of NKT cells was similar between both groups and also to sero-negative control subjects. There were also no significant differences in the proportions of total NKT cells and the CD4+ NKT subset that secreted interferon gamma (IFN-γ) after polyclonal stimulation. However, there was a significantly higher frequency of IFN-γ﹣ CD4+ NKT cells in HIV-1-infected compared with HIV-2 infected subjects (p = 0.043). Conclusion: These data suggest there is no relationship between the functional activity of NKT cell subsets and the total NKT cell population in HIV infection. The expansion of IFN-γ﹣ CD4+ NKT cells in HIV-1 infection may serve as target for viral infection and may eventually result in their depletion during chronic infection.

Incidence of Human Immunodeficiency Virus in Sickle Cell Patients in the Cape Coast Metropolis, Ghana

Context: Human immunodeficiency virus (HIV) is a well-known pathogen that causes acquired immunodeficiency syndrome (AIDS). The course of HIV infection and progression may be influenced by sickle cell traits. Objectives: The aim of this study was to determine the incidence of HIV among sickle cell patients in the Cape Coast metropolis. Methods: A cross sectional study was conducted among patients who visited the Central Regional Hospital, Cape Coast. About 2 ml of blood sample was drawn from each participant for sickle cell test using sodium metabisulphite solution. Sickle cell positive samples were selected and tested for the presence of HIV using Alere DetermineTM?HIV-1/2. Results: A total of 75 patients made up of 25 males and 50 females were enrolled. Their age ranges between 4 to 59 years (27, 1 - 15 years;24, 16 - 30 years;17, 31 - 45 years;7, 46 - 60 years). Fifteen (15) (20%) had received at least a single blood transfusion while the remaining 60 (80%) had never received blood transfusion before the study. Thirty-six patients (48.0%) were married and the other 39 patients (52.0%) were single. Five patients (6.7%) had antibodies to HIV whereas 70 patients (93.3%) were not with the virus. Conclusion: The incidence rate of HIV among sickle cell trait children and the youths of Cape Coast metropolis were found to be 6.7%. This may suggest that sickle cell traits in children and the youth may be associated with HIV transmission.