Comparison Of Immune Status Between Children And Adults With AIDS In China

The immune system safeguards against foreign organisms through a complex network of cells and cytokines. Human immunodeficiency virus (HIV) preferentially destroys CD4+ T lymphocytes and interferes with the function of the immune system, weakening the host's defenses against infectious agents. In addition to lymphocytes, the destruction of the immune system involves immune factors such as Chemokines, Th1/Th2 type cytokines, and some inflammatory factors. The common Chemokines regulated on activation, normal T cell expressed and secreted (RANTES), stromal cell-derived factor-1 (SDF-1), and monocyte chemoattractant protein 1 (MCP-1) regulate inflammation and influence disease progression through antagonism of HIV coreceptors. Th1/Th2 cytokines balance the humoral and cellular immune responses, which also influence disease progression of HIV infection. The typical Th1 and Th2 cytokines interleukin (IL)-2, interferon-γ, IL-4, IL-10, and IL-5 have been well studied.China is experiencing an HIV/AIDS epidemic. Many children are currently infected with HIV, and the numbers continue to increase. Mother-to-child transmission accounts for the majority of cases. Hundreds of pediatric AIDS patients received free highly-active antiretroviral therapy in 2005, and this number will increase in the following years.Studies of adult and pediatric AIDS patients have shown that pediatric AIDS patients have some distinctive clinical characteristics due to their immature immune system. Pediatric AIDS patients have poorer immune activity, earlier disease onset, higher viral load, and more rapid disease progression. Hypoevolutism is also common in HIV-infected children as the result of malnutrition and metabolic disorder. Furthermore, children with AIDS are more susceptible to opportunistic infections and Kaposi's sarcoma. However, little is known about the immune status of pediatric AIDS patients. The important role of interleukines and chemokins in the pathogenesis of HIV infection/AIDS has been well validated in adult patients. But they have not been well studied in HIV infected pediatric patients. RANTES, MCP-1,SDF-1α and SDF-1β are important α- and β-chemokines. IL-10, IL-16 and IL-18 are all interesting interleukins involed in HIV infection. In the present study, we measured some cytokine levels in pediatric AIDS patients in China and compared their levels with adult AIDS patients. We wished to know whether monitoring cytokine production in addition to CD4+ T cell counts and viral load could provide additional useful information in pediatric patients with AIDS.1. Background and aimsThe immunological differences between children and adults with AIDS in China are not well documented. This study aimed to identify changes in plasma levels of Thl/Th2 cytokines (IL-18, IL-16, IL-10), Chemokines (RANTES, MCP-1, SDF-1α, SDF-1β), and MSP in HIV-1-infected children and adults in China.2. MethodsSeventy five children with AIDS and 35 adult AIDS patients were recruited. CD4+ T lymphocyte counts were measured by flow cytometery and plasma HIV RNA levels were measured by quantitative reverse transcriptase-polymerase chain reaction. Plasma levels of IL-18, IL-10, IL-16, RANTES, MCP-1, SDF-1α, SDF-1β, and MSP were quantified by enzyme-linked immunosorbent assay. The levels of β 2-MG and sFas were measured to validate the activation of immune system.3. ResultsThe mean levels of all cytokines in pediatric patients were significantly higher than in healthy children (P <0.01). The mean cytokine levels were also higher in adult patients with the exception of MSP, whose levels were lower than in healthy adults (P <0.01). The mean levels of these cytokines were higher in pediatric patients than in adult patients (P <0.01) except for SDF-1α and β 2-MG, whose levels did not differ. Some of the cytokines of pediatric patients younger than 6 years old was higher than both older children and adults with AIDS (SDFa, IL-18, MCP, RANTES, IL-10 and sFas, P <0.05). Levels of IL-18, IL-10, RANTES and β2-MG of pediatric patients increased as the levels of viral load ascending (P<0.05), Comparison between pediatric and adult patients indicated that levels of these cytokines ofpediatric patients were higher than adult patients(P <0.05).4. ConclusionAbnormal immune activation is highly initiated in pediatric and adult patients with AIDS. Children with AIDS have higher levels of immune activation than adult patients and it is the highest in pediatric AIDS patients younger than 6 years old. The cytokines levels are cioncided with disease progression of AIDS, but have no direct relationship with total CD4+ T cell count.