Cytomegalovirus pneumonitis preceded infectious mononucleosis in an immunocompetent middle-aged female
Lung involvement in cytomegalovirus (CMV) infection is uncommon in immunocompetent adult patients. In addition, when such associated findings with CMV infection are the initial manifestation before CMV infectious mononucleosis syndrome is apparent, making a correct diagnosis is difficult. Here, we experienced a rare case of CMV pneumonitis preceding CMV mononucleosis in an immunocompetent middle-aged female who needed anti-CMV treatment. She presented with fever and dry cough, and treatment with levofloxacin did not improve her symptoms. Chest computed tomography revealed diffuse ground-glass opacities over bilateral upper lobes for two weeks and she was referred to our department. Blood examinations showed impaired liver function, but no lymphocytosis or atypical lymphocytes. Serum CMV IgM and an antigenemia assay (C7-HRP) were positive, indicating an acute CMV infection. CMV polymerase chain reaction of bronchoalveolar lavage fluid was positive. The number of lymphocytes increased, and atypical lymphocytes appeared on day 11 after referral consultation; therefore, she was diagnosed with CMV pneumonitis preceding CMV mononucleosis. Anti-CMV treatment with ganciclovir improved her symptoms. Because the incidence of CMV seropositivity is decreasing in Japan, the characteristics of CMV mononucleosis are non-specific, and CMV pneumonitis may precede mononucleosis, it is important to consider CMV infection, even in immunocompetent adults, so as not to delay anti-CMV treatment if needed.
