Cytomegalovirus Load in Bronchoalveolar Lavage Fluid: A Clue to the Diagnosis of Cytomegalovirus Pneumonia

    Institute of Microbiology and Service of Infectious Diseases, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland

    We read with interest the article by Westall et al. [1], recently published in the Journal of Infectious Diseases, addressing the issue of human cytomegalovirus (HCMV) load in lung transplant recipients (LTRs) with or without HCMV pneumonia. Although these authors add a substantial amount of data to the few published studies that include histopathological documentation of HCMV pneumonia [2, 3], we feel that some clarifications are necessary.

    Clarifying these points is important, since other authors have presented evidence similar to that of Westall et al.namely, evidence that a substantial overlap does exist in the BAL HCMV loads in patients with and without HCMV pneumonia [24]. Whether this diagnostic problem could be resolved by expressing the relationship between HCMV load and the probability of HCMV pneumonia as a sigmoid curve for HCMV load varying from 10,000 to 30,000 copies/mL rather than as a dichotomous relationship, as shown by Riise et al. [3], or by estimating HCMV load in the epithelial lining fluid (as computed using urea dilution) with a cutoff of 10,000 copies/mL, similarly to Zedtwitz-Liebenstein et al. [4], is yet unclear to us. We hope this letter will provide Westall et al. with an opportunity to clarify these points in their interesting article.

    References

    1.  Westall GP, Michaelides A, Williams TJ, Snell GI, Kotsimbos TC. Human cytomegalovirus load in plasma and bronchoalveolar lavage fluid: a longitudinal study of lung transplant recipients. J Infect Dis 2004; 190:107683. First citation in article

    2.  Chemaly RF, Yen-Lieberman B, Castilla EA, et al. Correlation between viral loads of cytomegalovirus in blood and bronchoalveolar lavage specimens from lung transplant recipients determined by histology and immunohistochemistry. J Clin Microbiol 2004; 42:216872. First citation in article

    3.  Riise GC, Andersson R, Bergstrom T, Lundmark A, Nilsson FN, Olofsson S. Quantification of cytomegalovirus DNA in BAL fluid: a longitudinal study in lung transplant recipients. Chest 2000; 118:165360. First citation in article

    4.  Zedtwitz-Liebenstein K, Jaksch P, Bauer C, et al. Association of cytomegalovirus DNA concentration in epithelial lining fluid and symptomatic cytomegalovirus infection in lung transplant recipients. Transplantation 2004; 77:18979. First citation in article