The effect of HIV infection and HAART on inflammatory biomarkers in a population-based cohort of women

Relationships among the concentrations of 25 inflammation-associated proteins during the first postnatal weeks in the blood of infants born before the 28th week of gestation

BACKGROUND

Inflammation appears to be involved in processes leading to organ damage in preterm newborns, yet little is known about the relationships among elevated concentrations of inflammation-associated proteins in the blood of preterm newborns.

METHODS

In this exploratory study, we used an electrochemiluminescence method to measure 25 proteins in blood obtained on postnatal day 1 (range 1-3), day 7 (range 5-8), and day 14 (range 12-15) from 939 children born before the 28th week of gestation and evaluated to what extent those whose concentration of each protein was elevated (defined as in the highest quartile for gestational age and day the specimen was obtained) also had an elevated concentration of every other protein the same day or on a day 1 or 2 weeks later (p<.0001).

RESULTS

On each of the 3 days assessed, elevated concentrations of 17 proteins were associated with elevated concentrations of 15 or more of the other 24 proteins. VEGF, VEGF-R1, VEGF-R2 were among these proteins, while IGFBP-1 was associated with 13 other proteins on day 7. An elevated concentration of eight proteins on day 1 predicted an elevated concentration of 10 or more proteins on day 7, while an elevated concentration of only two proteins on day 7 were associated with elevated concentrations of 10 or more proteins on day-14. Few associations were seen between days 1 and 14. CONCLUSIONS/INFERENCES: Inflammation is a diffuse process in ELGANs, with elevated concentrations of cytokines, chemokines, adhesion molecules, matrix metalloproteinases, a growth factor and its receptors, as well as a growth factor binding protein associated with each other the same day, as well as on subsequent days.

Multisite comparison of high-sensitivity multiplex cytokine assays

The concentrations of cytokines in human serum and plasma can provide valuable information about in vivo immune status, but low concentrations often require high-sensitivity assays to permit detection. The recent development of multiplex assays, which can measure multiple cytokines in one small sample, holds great promise, especially for studies in which limited volumes of stored serum or plasma are available. Four high-sensitivity cytokine multiplex assays on a Luminex (Bio-Rad, BioSource, Linco) or electrochemiluminescence (Meso Scale Discovery) platform were evaluated for their ability to detect circulating concentrations of 13 cytokines, as well as for laboratory and lot variability. Assays were performed in six different laboratories utilizing archived serum from HIV-uninfected and -infected subjects from the Multicenter AIDS Cohort Study (MACS) and the Women's Interagency HIV Study (WIHS) and commercial plasma samples spanning initial HIV viremia. In a majority of serum samples, interleukin-6 (IL-6), IL-8, IL-10, and tumor necrosis factor alpha were detectable with at least three kits, while IL-1β was clearly detected with only one kit. No single multiplex panel detected all cytokines, and there were highly significant differences (P < 0.001) between laboratories and/or lots with all kits. Nevertheless, the kits generally detected similar patterns of cytokine perturbation during primary HIV viremia. This multisite comparison suggests that current multiplex assays vary in their ability to measure serum and/or plasma concentrations of cytokines and may not be sufficiently reproducible for repeated determinations over a long-term study or in multiple laboratories but may be useful for longitudinal studies in which relative, rather than absolute, changes in cytokines are important.