The Study On Clinical Characteristics And Immune Mechanisms Of HAART Associated Immune Reconstitution Inflammatory Syndrome In AIDS

HAART (highly active antiretroviral therapy) is more and more widely used in AIDS patients since it has been introduced in 1995. To the end of October 2009, China CDC reported nearly 320,000 cases of AIDS, while receiving antiretroviral treatment to more than 60,000 cases. Although there is HIV plasma viral load reduction and CD4+T lymphocytes increase during HAART, a subgroup of patients experience clinical deterioration as a direct consequence of rapid and dysregulated restoration of antigen-specific immune responses. For example, the re-emergence of opportunistic infections or the discovery of new pathogens soon after HAART starts, while it was controlled before initial HAART. Paradoxically, these infections re-emergence in the treatment of disease, deterioration, and even endanger the lives of patients in the first few months after HAART. This phenomenon is known as IRD (immune reconstitution disease), or IRIS (immune reconstitution Inflammatory syndrome).There are more and more HIV infected people started HAART in China. The number of HIV infections develop into IRIS will not be ignored with the increasing cases of patient who initialed HAART, and it has become an increasingly prominent issue in our country. However, scholars at home and abroad have different opinions on the risk factors, clinical characteristics, diagnosis and treatment of IRIS, the pathogenesis is still unclear at present. Currently the domestic study on clinical characteristics and immune mechanisms of HAART associated immune reconstitution inflammatory syndrome has not yet been reported. In this article we observation and analysis 238 cases of HIV infections for a period of 24 weeks through the prospective cohort method for the first time in China. The comparative analysis will be introduced in the clinical data, HIV viral load and CD4+cell count, and immunophenotype of lymphocyte subsets, lymphocyte activation and changes in regulatory T cells and cytokines environment between IRIS group and non-IRIS group. The risk factors, clinical characteristics and treatment of IRIS will be summarized and its immune mechanisms will be preliminary investigated. Very few of such studies were reported even in the other country. Our study will have a better scientific value and clinical significance to research and clinical of IRIS for future. The study included the following two parts:PartⅠThe Study on Risk Factors and Clinical Characteristics of HAART Associated Immune Reconstitution Inflammatory Syndrome in AIDSObjective:There is lack of clinical data on HIV infections with IRIS occurring after HAART in China. Our study analysis and summary the morbidity, mortality, clinical manifestation and characteristics, Incidence and risk factors for IRIS in our country. We hope that it will prevent or reduce the incidence of IRIS and improve the survival rate and even the quality of patient's life, and provide information and guidance to IRIS during HAART in future.Methods:From October 2007 to September 2009 there are 238 cases of HIV-1 infected individuals initialed HAART and participate into the prospective study for 24 weeks of regular follow-up. Infections that meet the diagnostic criteria of INSHI for IRIS will in the IRIS group and those who are observed not occur at the end of 24 weeks will enroll in the non-IRIS group. The general information, clinical data and treatment of two groups will be collected. Blood samples will be collected in both group at the follow-up of the pre-and post-HAART 12 weeks,24 weeks. HIV viral load will be detected by real time quantitative PCR and CD4+ cell count by flow cytometry. The collected data will be processed by statistical analysis.Results:There are 47(19.7%,47/238) IRIS cases in our prospective study. The median onset of IRIS was 28 (9-36) days (mean+IQR). Tuberculosis IRIS is the predominately clinical manifestation in our study, a total of 29 cases (61.7%,29/47). The mortality of IRIS group is 4.3% (2/47). There no difference was found in age, sex, route of transmission and antiretroviral treatment programs between IRIS group and non-IRIS group. However, The cases of opportunistic infections before HAART in IRIS group is significantly more than non-IRIS group (68.1%vs. 22.5%, p<0.01). HIV viral load at baseline,12 weeks,24 weeks, respectively, are 4.94,2.82,2.65 log 10 copies/ml in IRIS group, and 5.18,2.86,2.63 log10 copies/ml in non-IRIS group. Both groups show significant viral load decline without significant difference. CD4+cell count at baseline,12 weeks,24 weeks, respectively, are 48,118,165/ul in IRIS group, and 146,174,269/ul in non-IRIS group. Both groups showed significant CD4+cell count increase, and CD4+cell count in IRIS group is significant lower than non-IRIS group (48 vs.146 cells/ul, p<0.01). CD4+cell count in most cases are less than 100/ul in IRIS group at the baseline of HAART, with the percentage of 85.1%(40/47). Absolute change in CD4 cell count (117 vs.123 cells/ul, p>0.05) from baseline at 24 weeks shows non-significant difference in both groups.Conclusions:As the first prospective study on risk factors and clinical characteristics of IRIS in China, our preliminary study found that IRIS mostly occurs within 3 months of HAART initiation in domestic HIV infected individuals. The morbidity, mortality and the duration between HAART initiation and IRIS in patients initialed HAART are consistent with foreign reports. The age, sex, route of transmission and antiretroviral treatment programs of patients initialed HAART are not a risk factor for the development of IRIS. However, the proportion of cases that suffered opportunistic infections before HAART in IRIS Group was significantly higher than non-IRIS group, suggesting that opportunistic infections individuals are more likely to develop IRIS during HAART. HIV RNA viral load decrease and CD4+counts increase in both IRIS and non-IRIS group had no significant difference. HIV infected individuals with CD4+cell count<100/ul are more vulnerable to developing IRIS. The treatment of IRIS was mostly symptomatic treatment based. If necessary, a small amount of short-term use of corticosteroids would be considered. It is no need to stop HAART during IRIS.Part II The Study on Immune Mechanisms of HAART Associated Immune Reconstitution Inflammatory Syndrome in AIDS Objective:Although some elucidations or hypothesis have been use to describe the immunological pathogenesis of IRIS in international AIDS circles, there is no sufficient evidence to reach more broad consensus. The debates and obscurities still exist. So far there's no research article has been seen in China yet on the elucidation of IRIS pathogenesis. To further investigate the immunological pathogenesis of IRIS, in this prospective cohort study we analysis the immunophenotype of lymphocyte subsets, lymphocyte activation, changes in regulatory T cells, and Thl and Th2 cytokines in both IRIS and non-IRIS group. Very few of such studies were reported even in the other country.Methods:From October 2007 to September 2009 there are 238 cases of HIV-1 infected individuals initialed HAART and participate into the prospective study for 24 weeks of regular follow-up. Infections that meet the diagnostic criteria of INSHI for IRIS will in the IRIS group and those who are observed not occur at the end of 24 weeks will enroll in the non-IRIS group. There are a total of 47 cases of IRIS group and randomly selected 50 cases of non-IRIS group will to be analysised. Blood samples will be collected in both group at the follow-up of the pre-and post-HAART 12 weeks,24 weeks. Using flow cytometry to detect the immunophenotype of lymphocyte subset (CD4+CD45RA+CD62L+, CD8+CD45RA+CD62L+, naive T cells; CD4+CD45RO+, CD8+CD45RO+, memory T cells), lymphocyte (CD4+CD38+, CD8+CD38+, activated T cells), and regulatory T cells (CD4+CD25+Foxp3+). Blood samples collected at the follow-up of the pre-and post-HAART 4 weeks,12 weeks,24 weeks will use ELISA to detect Th1 cytokines (IL-2, IFN-γ), Th2 cytokines (IL-4, IL-10) and IL-7 serum levels.Results:The percentages of CD4+and CD8+naive T cells and memory T cells exhibited no significantly differences at the baseline,12 weeks,24 weeks in both IRIS and non-IRIS group, but CD4+and CD8+ memory T cells demonstrated a trend towards to increase while compared to baseline during HAART. The percentages of CD4+/CD8+CD38+ activated T cells are significantly higher at the baseline while compared to normal control and demonstrated a downward trend, but between the two groups showed no significant difference. The percentages of CD4+CD25+Foxp3+regulatory T cell were lower than non-IRIS group at the baseline,12 weeks,24 weeks and the onset of IRIS. Th1 cytokines IL-2 and IFN-γwere lower than normal control at the baseline in two groups. They showed an upward trend during HAART and the levels in IRIS group had significantly increase at 4 weeks and the onset of IRIS. Th2 cytokines IL-4 and IL-10 were higher than normal control at the baseline in two groups. They showed a downward trend during HAART and the levels of IL-10 in IRIS group had significantly decrease at 4 weeks and the onset of IRIS. IL-7 was higher than normal control at the baseline in two groups and showed a downward trend during HAART. The level of IL-7 was higher than non-IRIS group at all follow-up points.Conclusion:As the first systematic prospective cohort IRIS study in China, we investigate the immunologic mechanism of IRIS occurred during HAART in AIDS patients. Very few of such studies were reported even in the other country. We found that memory T cells appear rapid increase in the early stage of HAART and may play a significant role in the inflammatory response of IRIS. With a significantly higher percentages at the baseline, CD4+and CD8+activated T cells gradually decreased after HAART initialed. CD4+and CD8+naive T cells, memory T cells and activated T cells showed no significant difference in IRIS and non-IRIS group within 24 weeks after HAART started. There was a significantly reduction in the frequency of regulatory T cells in IRIS group without obvious upward trend during HAART, suggesting that the immune suppression function of regulatory T cells in IRIS was impaired. Thl cytokines including IL-2 and IFN-y exhibit upward trend while Th2 cytokines IL-4 and IL-10 exhibit downward trend in two groups. IL-2 and IFN-y significantly increased while IL-10 significantly decreased at 4 weeks post-HAART and onset of IRIS in IRIS group, suggesting that IRIS was related to cytokines environment disorder. That is, a significant increase in inflammatory cytokines, while the relative lack of non-inflammatory cytokines. The level of IL-7 decreased gradually after HAART started, and it was higher in IRIS group when compared to non-IRIS group in the first 24 weeks after HAART started. IL-7 may play a role in the pathogenesis of IRIS.