Background: Human cytomegalovirus (HCMV) infection in lung transplant patients induces an inflammatory response, including local production of cytokines involved in viral clearance. The aim of this study was to evaluate the potential value of monitoring interleukin (IL)-10 with respect to HCMV persistence in blood and/or bronchoalveolar lavage (BAL).
Methods: A quantitative polymerase chain reaction assay was used for HCMV-DNA detection in plasma and BAL. IL-10 was measured with an enzyme-linked immunosorbent assay in blood and with BAL in 101 lung transplant patients. IL-10 levels were correlated with clinical outcome.
Results: A total of 23 patients of 35 (66%) with detectable HCMV in plasma and/or BAL exhibited increased levels of IL-10 in plasma and/or BAL. Complete clearance of HCMV was observed after 168 (median 130) days in the IL-10-positive group (n=23) in comparison with 87 (median 58) days in the IL-10-negative group (n=12; P<0.024). In the seven HCMV-positive patients with positive IL-10 levels in BAL only, HCMV persisted in BAL for a median of 579 days without signs of systemic infection (positive plasma levels) or clinical symptoms.
Conclusions: We show that in lung transplant patients with elevated levels of IL-10 in plasma and/or BAL, HCMV clearance is prolonged because of the influence of anti-inflammatory cytokines.