Anti-PcrV titers in non-cystic fibrosis patients with Pseudomonas aeruginosa respiratory tract infection

Objective: The epidemiology and role of the anti-PcrV titer in non-cystic fibrosis patients with Pseudomonas aeruginosa airway tract infections is not fully understood. This study was performed to compare the anti-PcrV titers of patients with and without P. aeruginosa respiratory tract infections. Methods: This prospective cohort study was conducted at Hokkaido University Hospital in Japan. Participants had blood and sputum specimens collected on admission. They were divided into two groups based on their sputum culture results. Those with a P. aeruginosa infection were assigned to the P. aeruginosa (PA) group and those without a P. aeruginosa infection were assigned to the non-PA group. Serum anti-PcrV titers were measured using a validated ELISA. Results: Of the 44 participants, 15 were assigned to the PA group and 29 were assigned to the non-PA group. In the PA group, 10/15 participants (66.7%) had an anti-PcrV titer >1000 ng/ml compared to 3/29 participants (10.3%) in the non-PA group (p < 0.001). In the PA group, two of the five participants with an anti-PcrV titer <1000 ng/ml died of recurrent P. aeruginosa pneumonia; the other three participants did not develop pneumonia. Conclusion: The anti-PcrV titers in participants with P. aeruginosa infection varied considerably. Patients with low anti-PcrV titers and refractory P. aeruginosa infections need to be monitored closely.