Evaluation of a polymerase chain reaction diagnostic method and risk factors for cytomegalovirus pneumonia

In order to evaluate the diagnostic methods and risk factors for cytomegalovirus (CMV) pneumonia, 22 patients with suspected CMV pneumonia were examined by means of the polymerase chain reaction (PCR) and serological (Ab) methods (complement fixation test = CF and enzyme-immunoassay = EIA: IgG, IgM). Thirteen patients showed positive for either the PCR or serological method; the PCR method was positive in 77% (10/13) (sputum = 8/10, bronchoalveolar lavage fluid = 3/4, peripheral blood = 3/12, urine = 2/11) and the serological method in 64%(7/11)(CF = 5/10, IgG = 3/11, IgM = 0/11). All patients diagnosed as having CMV pneumonia had underlying disease, most of which were idiopathic interstitial pneumonia and malignancies. Twelve out of 13 patients had been treated with steroids for long- or short (pulse)-periods. The cure rate was high for these patients whose PCR results became negative following anti-CMV treatments. These results indicate that a) the steroid treatment acts as a risk factor for the CMV pneumonia, b) the PCR method is a useful tool not only for early diagnosis but also for assessment of the therapeutic effect on CMV pneumonia, and c) concomitant assays of PCR and Ab may be preferable in making a conclusive diagnosis of CMV pneumonia.