Soluble CD14 as a Diagnostic Biomarker for Smear-Negative HIV-Associated Tuberculosis.

Area of Science:

• Immunology and Infectious Diseases
• Biomarker Discovery

Background:

• Diagnosing sputum smear-negative HIV-associated tuberculosis (TB) presents significant clinical challenges.
• Soluble CD14 (sCD14), a marker of monocyte activation, has been explored as a potential TB biomarker.
• The utility of sCD14 specifically for smear-negative, HIV-associated TB remains largely uninvestigated.

Purpose of the Study:

• To evaluate the diagnostic accuracy of soluble CD14 (sCD14) as a biomarker for smear-negative HIV-associated tuberculosis (TB).
• To determine if sCD14 levels can differentiate active TB from latent infection or absence of TB in HIV-infected individuals.

Main Methods:

• Optimized a sensitive sandwich ELISA for quantifying sCD14 in serum samples.
• Analyzed serum sCD14 concentrations in HIV-infected individuals with smear-negative pulmonary TB (culture-positive and negative) and HIV-infected controls.
• Compared sCD14 levels between TB patients and controls, considering geographical origin and latent TB infection status.

Main Results:

• Sera sCD14 concentrations were significantly elevated in HIV-associated smear-negative TB patients compared to HIV-infected controls (p < 0.0001).
• sCD14 levels were consistent across different countries and independent of latent tuberculosis infection status in controls.
• At 96% specificity, sCD14 achieved 95% sensitivity for detecting culture-confirmed smear-negative TB.

Conclusions:

• Soluble CD14 (sCD14) is a highly accurate biomarker for the detection of HIV-associated tuberculosis.
• sCD14 offers a promising tool to aid in the diagnosis of challenging smear-negative TB cases in HIV-infected populations.