Urinary cytokines for assessing inflammation in HIV-associated wasting

Area of Science:

• Immunology
• HIV Medicine
• Biochemistry

Background:

• The link between cytokines and HIV-related weight loss remains unclear.
• Interleukin-6 (IL-6), soluble tumor necrosis factor receptor type II (sTNFR-II), and interleukin-1 receptor antagonist (IL-1ra) are systemic inflammatory markers.
• 24-hour urine concentrations offer an integrated measure of systemic cytokine levels.

Purpose of the Study:

• To investigate the relationship between spot urine measurements of IL-6, sTNFR-II, and IL-1ra and their 24-hour concentrations.
• To determine if spot urine cytokine levels correlate with prior HIV-related weight loss.

Main Methods:

• Eighteen HIV-infected individuals with severe wasting and six HIV-negative controls were studied.
• Spot and 24-hour urine samples were collected to measure IL-6, sTNFR-II, and IL-1ra concentrations, adjusted for creatinine.
• Weight loss history was recorded for correlation analysis.

Main Results:

• Elevated 24-hour urinary concentrations of IL-6, sTNFR-II, and IL-1ra were observed in HIV-infected patients compared to controls.
• Spot urine concentrations strongly correlated with 24-hour excretion rates for all three cytokines (r=0.80-0.87).
• IL-1ra levels (spot and 24-hour) showed significant correlations with various measures of weight loss (r=0.66-0.73).

Conclusions:

• Spot urine collections provide a reliable estimation of 24-hour cytokine excretion rates.
• This method can be valuable for assessing the inflammatory response in HIV-associated wasting.
• Urinary IL-1ra may serve as a biomarker for HIV-related weight loss.