Clinical Features and Radiological Findings of Adenovirus Pneumonia Associated with Progression to Acute Respiratory Distress Syndrome: A Single Center Study in 19 Adult Patients

Cha, Min Jae; Chung, Myung Jin; Lee, Kyung Soo; Kim, Tae Jung; Kim, Tae Sung; Chong, Semin; Han, Jungho

It is curious that adenovirus pneumonia developed into ARDS with such a high percentage in our study. It is known that adenovirus causes cytolysis, which accounts for tissue damage, and damaged pulmonary capillaries can contribute to respiratory failure (24) . Another possible explanation is the unregulated complement activation, producing C5a and resulting in activation of phagocytic cells, generation of oxidants, release of histones, and, eventually, a cytokine storm (25, 26) . Many previous cases of respiratory failure resulting from influenza A viruses H1N1, H5N1, and H7N9, In terms of the radiological findings of adenovirus pneumonia, the CT features were so diverse that it was difficult to define specific findings for adenovirus pneumonia. Although the most common CT feature was bilateral ground-glass opacities, the findings were variable, from unilateral lobar consolidation to clustered micronodules. With regard to the initial chest radiographic findings, two patients (11%) were normal, while focal opacity was noted in nine patients (47%). Despite the well-known imaging features of viral pneumonia, which causes diffuse and bilateral interstitial involvement (28) , two patients in our study presented with unilateral consolidation and GGO with or without pleural effusion. Features of focal opacity on chest radiograph and unilateral dense consolidation on CT were likely to be interpreted as community-acquired pneumonia. In fact, there have been several reports describing adenovirus pneumonias that have presented with unilateral lobar infiltrates (6, 8, 20) . Thus, we should not discard the possibility of adenoviral pneumonia in patients suspected of having an acute lower respiratory tract infection with unilateral airspace lesion, especially when response to antibiotics was ineffective, and sputum Gram stain and culture were negative for bacterial infection. Every effort should be made to achieve a confirmative diagnosis and timely treatment in such cases.