Clinical Significance of Respiratory Torque Teno Virus in Immunocompromised Patients with Acute Respiratory Failure.

Objective: 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 TTV DNA in nasopharyngeal swabs of immunocompromised patients with acute respiratory failure (ARF).

Methods: We enrolled immunocompromised patients with acute respiratory failure admitted to 32 ICUs. Nasopharyngeal swabs collected on admission were tested for TTV DNA. Causes of ARF were reviewed by three expert investigators blinded to TTV results, with a 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 304/505 (60%), with TTV burden≥2.9 logcopies/mL in 184/305 (36%). TTV burden≥2.9 logcopies/mL was significantly associated with a higher prevalence of opportunistic infections (20% (36/178) vs. 11% (33/307), adjusted OR 2.41, 95%CI 1.35 to 4.28; p=0.002). High TTV burden ≥2.9 logcopies/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).

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