Diagnosis of cytomegalovirus infection in HIV-infected patients with respiratory disease

Abstract

Background: The role of the cytomegalovirus (CMV) in the respiratory morbidity and mortality of HIV-infected patients remains unclear. This is due in part to difficulties in making an accurate and rapid diagnosis. There has been a limited number of studies, often with few or no AIDS patients, on the use of DNA–DNA in situ hybridization (ISH) and polymerase chain reaction to diagnose CMV respiratory infection directly on bronchoalveolar fluid samples. Objectives: To compare the centrifugation culture (CC), ISH, and nested-primer polymerase chain reaction (npPCR) techniques on bronchoalveolar fluid for the diagnosis of respiratory CMV infection. Study design: Samples were obtained prospectively from a group of 35 HIV-infected homosexual men evaluated for pneumonia at a university hospital. Sensitivity, specificity, and predictive values of the three techniques were measured and compared, using the conventional roller tube cell culture (CRTC) as the gold standard. Results: Sensitivity, specificity, positive and negative predictive values were as follows: 86%, 86%, 90%, and 80% for the CC; 5%, 100%, 100%, and 41% for ISH; and 86%, 57%, 75%, and 73% for npPCR. Of the six false positive samples by npPCR, two were positive by CC (none by ISH). If the latter were considered true positives, the specificity and positive predictive values of npPCR would increase to 67% and 83%, respectively. Conclusions: CC appeared to be the best of the three techniques compared in this study for diagnosis of respiratory CMV infection in HIV-infected patients. The sensitivity and predictive values of DNA–DNA ISH were very poor. Results with npPCR were acceptable, and this technique may be considered in situations when rapid diagnosis of CMV infection is necessary.