Cytomegalovirus (CMV) infection – Correlation between CMV-DNA PCR in bronchoalveolar lavage (BAL), CMV pp65 antigen load in PBMCs and clinical symptoms in lung transplant recipients

Introduction: Cytomegalovirus (CMV) is a significant cause of morbidity and mortality in lung transplant recipients (LTRs) either by causing pneumonitis or by contributing to the development of bronchiolitis obliterans or chronic rejection. Objectives: Aim of our study was to compare the correlation between CMV-DNA PCR in BAL and CMV pp65 antigen load in peripheral blood mononuclear cells (PBMCs) with the clinical symptoms of LTRs assessed by a clinical score. Methods: We analyzed 950 BAL samples taken from 73 LTRs during 2007-2009 using PCR and CMV pp65 antigen load in PBMCs. We used a clinical score from 0-6 (defined as symptoms including cough, sputum, dyspnea, exercise capacity, auscultation, temperature) to define a symptomatic or asymptomatic patient. Especially, we compared the clinical score in patients with CMV pp65=0 (n=62) to patients with CMV pp65>0 (n=11). Results: 73 of the 950 samples (7.7%) were positive either for CMV-DNA PCR in BAL or CMV pp65 antigen. We found no association between CMV-DNA PCR in BAL and the clinical score. There was a significant correlation between the positivity of PBMCs for CMV pp65 antigen and the clinical score (r=0.31; p=0.006). In patients without CMV pp65 antigen detection the clinical score was 2.0±2.1 whereas in patients with CMV pp65 detection the clinical score was 3.7±2.2. Conclusion: Assessment of CMV-DNA PCR in BAL does not correlate with the symptoms of CMV infected LTRs. Our results suggest that CMV pp65 is the better predictive marker for symptomatic CMV infection. Further prospective studies to identify patients who need antiviral treatment are necessary.