Clinical significance of respiratory torque teno virus in immunocompromised patients with acute respiratory failure.

Objectives: Among immunocompromised patients with acute respiratory failure, identification of those at higher risk for opportunistic infections is crucial to optimize management. The torque teno virus (TTV) DNA burden in the blood has been identified as a surrogate marker of functional immunity in solid organ transplant recipients. This study investigates the clinical relevance of the presence of TTV DNA in nasopharyngeal swabs of immunocompromised patients with acute respiratory failure (ARF).

Methods: We enrolled immunocompromised patients with ARF admitted to 32 intensive care units. Nasopharyngeal swabs collected on admission were tested for TTV DNA. Causes of ARF were reviewed by three expert investigators blinded to TTV results, with specific attention to the presence of opportunistic infections. The primary endpoint was the association between TTV DNA burden in nasopharyngeal swabs and the rate of opportunistic infections causing the ARF.

Results: Of the 505 patients, respiratory TTV DNA was detected in 304 of 505 (60%), with TTV burden ≥2.9 log₁₀ copies/mL in 184 of 305 (36%). TTV burden ≥2.9 log₁₀ copies/mL was significantly associated with a higher prevalence of opportunistic infections (20% [36/178] vs. 11% [33/307]; adjusted odds ratio, 2.41; 95% CI, 1.35-4.28; p 0.002). High TTV burden ≥2.9 log₁₀ copies/mL was also associated with a higher rate of all cause pulmonary infections (67% [119/178] vs. 56% [108/192] when not detected), microbiologically documented bacterial infections (35% [62/178] vs. 23% [45/192]), and with a higher rate of influenza-like respiratory virus detection in nasopharyngeal swabs (15% [27/184] vs. 6% [12/201] when not detected). Furthermore, TTV detection was associated with a higher rate of mechanical ventilation or death at day 28 (59% [179/304] vs. 48% [97/201] when not detected).

Discussion: In immunocompromised patients with ARF, high TTV burden in the respiratory tract is associated with higher rates of pulmonary infections due to opportunistic pathogens and with adverse outcomes.