Systemic immune activation in HIV and potential therapeutic options

Effect of Probiotic Supplementation on CD4 Cell Count in HIV-Infected Patients: A Systematic Review and Meta-analysis

Progressive decline in CD4 cell counts is associated with human immunodeficiency virus (HIV) disease progression. Loss of CD4 cells might contribute to gut microbiota alteration and bacterial translocation. Probiotics, by inducing epithelial healing, may promote the restoration of the intestinal CD4+ T-cell population. The aim of this meta-analysis was to systematically review all randomized controlled trials (RCTs) of probiotic/prebiotic/synbiotic supplementation on CD4 cell counts in HIV-infected patients. A systematic search of RCTs was conducted through PubMed, Scopus, and Google Scholar databases up to August 2015. Effect sizes of eligible studies were pooled using random-effects models (the DerSimonian-Laird estimator). Eleven studies with 14 treatment arms met the inclusion criteria. Pooled analysis showed no significant reduction in CD4 counts (-7.5 mg/l, p = .7) in intervention-treated individuals. Subgroup analysis on potential influencing factors highlighted sex, country of origin, study duration, and the type of intervention as having significant effects on CD4 cell counts. As a whole, the results of this meta-analysis suggested that supplementation with probiotic may not change CD4 counts. However, a significant increase in CD4 counts was seen in females and following synbiotics as opposed to treatment with pro- or prebiotics alone.

[Key role played by the gut associated lymphoid tissue during human immunodeficiency virus infection]

The gut associated lymphoid tissue (GALT) is the site of numerous immunological disturbances during HIV-1 infection. It constitutes the largest reservoir for HIV, not or very poorly susceptible to antiretroviral therapy (ART), making it a major obstacle to HIV cure. Moreover, the GALT is involved in systemic immune activation in HIV-infected individuals: intestinal damage due to viral replication and severe CD4(+) T cell depletion in the GALT leads to microbial translocation, a key driver of immune activation, and in turn, disease progression. In this review, we describe the role of the GALT in HIV infection and we discuss therapeutic options to decrease the intestinal viral reservoir and to preserve immune function in the gut of HIV-infected people. Achieving these goals is necessary for a long-term infection control after the interruption of ART.

Intestinal tract and acquired immunodeficiency syndrome

The intestinal tract is closely associated with the transmission, disease progression and the prevention and control of acquired immune deficiency syndrome (AIDS). It has been noticed early in AIDS research that a large percent of AIDS patients presented abnormalities in their intestinal tract, such as diarrhea. Now it is known that the intestinal tract has close and complex relationships with AIDS: (1) the intestinal tract is directly involved in the transmission of human immunodeficiency virus-1 (HIV-1); (2) the damage of the intestinal barrier of HIV/AIDS patients directly promotes AIDS disease progression; and (3) most importantly, the intestinal tract is an important target for the treatment and prevention of HIV/AIDS. The author has previously reviewed the progress in understanding the roles of the intestinal tract in HIV-1 infection and the changes of the intestinal tract after HIV-1 infection. In the current review, I discuss the progress in understanding the roles of the damage of the intestinal mucosal immune system in AIDS disease progression, and the potential application value of the restoration of intestinal mucosal immunity in the treatment of AIDS.

Aging with HIV infection: a journey to the center of inflammAIDS, immunosenescence and neuroHIV

In the last years, a significant improvement in life expectancy of HIV+ patients has been observed in Western countries. The parallel increase in the mean age of these patients causes a parallel increase in the frequency of non-AIDS related complications (i.e., neurocognitive, cardiovascular, liver and kidney diseases, metabolic syndrome, osteoporosis, non-HIV associated cancers, among others), even when antiviral treatment is successful. Immune activation and persistent inflammation characterizes both HIV infection and physiological aging, and both conditions share common detrimental pathways that lead to early immunosenescence. Furthermore, HIV-associated neurocognitive disorders represent important consequences of the infection. The persistent systemic immune activation, the continuous migration of activated monocytes to the central nervous system and progressive patients' aging contribute to develop neuronal injuries, that are in turn linked to HIV-associated neurocognitive disorders, which can persist despite successful antiretroviral treatment.