Relationship among serum levels of IL-6, sIL-6R, s gp130 and CD126 on T-cell in HIV-1 infected and uninfected men participating in the Los Angeles Multi-Center AIDS Cohort Study.

INTRODUCTION: Interleukin 6 (IL-6) activates cells through its unique heterodimeric signaling complex of IL-6 receptor (IL6R) subunit and interleukin 6 signal transducer ß-subunit glycoprotein 130 (gp130). The objective of this study was to investigate associations among serum levels of IL-6, sIL-6R, sgp130 and relative fluorescence intensity (RFI) of the α-subunit of the IL-6 receptor (CD126) on T-cells of HIV-1 infected and uninfected men. METHODS: Blood samples were obtained from 69 HIV-1-infected men on Highly Active Antiretroviral Therapy (HAART) with mean age of 49.1 and 52 HIV-1-uninfected with mean age of 54.3 years -. All men were participating in the Los Angeles Multi-Center AIDS Cohort Study (MACS). Serum levels of IL-6, sIL-6R, sgp130 were measured by enzyme-linked immunoassays and T-cell phenotypic analysis and RFI of CD126 on CD4+ and CD8+ by flow cytometry. RESULTS: Mean serum levels of IL-6, sIL6R, sgp130 and of CD126 RFI on CD4+ were 4.34 pg/mL, 39.3 ng/mL, 349 ng/mL and 526 RFI respectively for HIV-1-infected men and 2.74 pg/mL, 41.9 ng/mL, 318 ng/mL and 561 RFI respectively for HIV-1-uninfected men. The mean serum concentrations of IL-6, sIL-6R in HIV-1-infected and uninfected men were not significantly different (p>0.05). There was a positive correlation between plasma HIV-1 RNA and the levels of IL-6 (p<0.001), sIL6R (p = 0.002) but no correlation with sgp130 (p = 0.339). In addition, there was a negative correlation between serum levels of IL-6 with RFI of CD126 on CD4+ (p = 0.037) and a positive correlation between serum levels of sgp130 (p = 0.021) and sIL-6R in HIV-1-infected men. CONCLUSION: Knowledge of biological variation, differences in the blood levels of biomarkers among healthy individuals and individuals experiencing illness, are very important for selection of appropriate tests for stage and progression of disease. Our data suggest no correlation among IL-6, and sIL-R6, in the treated phase of HIV-1 infection. The action and blood level of IL-6 and its receptors may be different at each stage of a disease progression.

Long-term intra- and inter-individual biological variation of serum lipid of HIV-infected and uninfected men participating in the Los Angeles Multi-Center AIDS Cohort Study (MACS).

BACKGROUND: To assess the long-term biological coefficient of variation within individuals (CVI) and between individuals (CVG), effect of aging and cholesterol lowering drugs on blood levels of lipids in HIV-1-infected and -uninfected men. METHODS: Bloods were analyzed every six months over 17 years for total cholesterol (TC), triglycerides (TGs), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) in 140 HIV-uninfected (38-66 years old) and 90 HIV-treated infected (48-64 years old) white Caucasian men to examine CVI, CVG, and the effect of cholesterol lowering drugs (CLDs) on lipid levels, and estimated changes per year of biomarkers. RESULTS: With exception of HDL-C, the long term CVI compared with CVG were higher for serum levels of TC, TGs, and LDL-C in both HIV-1 infected and uninfected men not taking CLDs. Excluding results of TGs in HIV positive men, the CVI compared with CVG were lower for serum levels of TC, HDL-C, and LDL-C in both groups not taking CLDs. There were significant (p < 0.05) differences in the median serum values of lipid biomarkers among 77 HIV negative men taking and 63 not taking CLDs. Also, with exception of HDL, there were significant (p < 0.05) differences in the median values of TC, TGs and LDL-C among 28 HIV positive men taking or not taking CLDs. CONCLUSION: Long term CVI and CVG of biomarkers will be useful for monitoring antiviral therapy side effects on lipid profiles in HIV-infected men. CVI of HIV-infected men for TC, TGs, HDL, LDL were higher significantly than CVI of HIV-uninfected men. Interestingly the long term CVI were higher than CVG for the men, who were on CLDs compared to men not on CLDs. The long-term pattern of CVI and CVG of lipid markers in both HIV-infected and uninfected men on CLDs differed from their short-term pattern.

Measles surveillance in five major US cities: Chicago, Houston, Los Angeles, Miami, and New York.

Endemic measles, if it occurs in the United States, will likely be found in cities, because large populations are required to sustain transmission and importations of measles virus are most frequent in cities. We investigated measles surveillance systems in 5 cities (Chicago, Houston, Los Angeles, Miami, New York City) during 1995-1999. The passive reporting of a measles case activated the systems to look for more cases and to intervene to prevent more cases. During 1995-1999, 1363 suspected measles cases were investigated. Only 58 of these were confirmed as measles (0.24 cases/100000 people), and the majority (57%) of confirmed cases were imported or linked to an importation. Most (83%) suspected cases that met the case definition had a complete case investigation, including a laboratory test for measles. We conclude that surveillance in these 5 cities shows no evidence of endemic measles transmission.