Viral Pneumonia Requiring Differentiation from Acute and Progressive Diffuse Interstitial Lung Diseases

Ishiguro, Takashi; Kobayashi, Yasuhito; Uozumi, Ryuji; Takata, Naomi; Takaku, Yotaro; Kagiyama, Naho; Kanauchi, Tetsu; Shimizu, Yoshihiko; Takayanagi, Noboru

We retrospectively analyzed 109 patients who were admitted to Saitama Cardiovascular and Respiratory Center from January 2010 to December 2017, and whose differential diagnosis included acute progressive (! 30 days) ILDs and pneumonia. All patients had been provided with a diagnosis on discharge. During the hospitalization period, respiratory physicians licensed by the Japanese Respiratory Society performed BAL according to conventional methods (2) on these patients for differential diagnosis. The obtained BALF was transported on dry ice, stored at -70ºC, and used for the detection of respiratory pathogens on a Rotor-Gene Q instrument (Quiagen, Hilden, Germany) with a multiplex, realtime PCR (RT-PCR) using an FTD Resp 21 Kit (Fast Track Diagnostics, Silema, Malta). The kit detects the following respiratory pathogens: influenza A and B viruses; coronaviruses (CoV) NL63, 229E, OC43, and HKU1; human parainfluenza viruses (HPIV) 1, 2, 3, and 4; human metapneumovirus A/B (hMPV); rhinovirus; respiratory syncytial virus (RSV) A/B; adenovirus; enterovirus; human parechovirus (HPeV); bocavirus; and Mycoplasma pneumoniae. An EZ1 Virus Mini Kit v2.0 was used for nucleic acid extraction (Quiagen). A threshold cycle value of <33 was considered to be a positive result in the RT-PCR, as indicated in the instruction manual.