Infection and Drug Resistance (Mar 2022)
Pulmonary and Disseminated Mycobacterium avium Complex Cases Confirmed by Tissue-Direct Polymerase Chain Reaction-Based Nucleic Acid Lateral Flow Immunoassay of Formalin-Fixed Paraffin-Embedded Tissues
Abstract
Daisuke Fukushi,1 Keigo Murakami,2 Yuji Watanabe,3 Norihiko Sugimoto,4 Hirotsugu Uehara,4 Masafumi Seki5 1Division of Gastroenterology, Tohoku Medical and Pharmaceutical University Hospital, Sendai City, Miyagi, Japan; 2Division of Pathology, Tohoku Medical and Pharmaceutical University Hospital, Sendai City, Miyagi, Japan; 3Laboratory for Clinical Microbiology, Tohoku Medical and Pharmaceutical University Hospital, Sendai City, Miyagi, Japan; 4Fuso Pharmaceutical Industry, Osaka City, Osaka, Japan; 5Division of Infectious Diseases and Infection Control, Tohoku Medical and Pharmaceutical University Hospital, Sendai City, Miyagi, JapanCorrespondence: Masafumi Seki, Division of Infectious Diseases and Infection Control, Tohoku Medical and Pharmaceutical University, 1-15-1 Fukumuro, Miyagino-ku, Sendai City, Miyagi, 983-8536, Japan, Tel +81-22-983-1221, Fax +81-22-290-8959, Email [email protected]; [email protected]: Detection of Mycobacterium avium complex (MAC) in tissue is essential for the diagnosis of MAC infections when the Mycobacterium is not isolated from sputum. However, detection of MAC in paraffin-embedded sections has not been established.Methods: We encountered two patients with suspected MAC infections after surgery: patient 1 had a pulmonary nodule that was initially suspected to be lung cancer and was excised under video-assisted thoracoscopic surgery (VATS). Patient 2, who was under treatment with steroids and anti-IL-6 inhibitors for rheumatoid arthritis, was suspected to have disseminated ileocecal cancer with metastasis to the lung and skin. In both cases, we postoperatively detected MAC genes in paraffin-embedded tissue sections using the novel mycobacterial nucleic acid identification test, ie tissue-direct polymerase chain reaction (tdPCR)-based nucleic acid lateral flow immunoassay (NALFIA). Both patients showed granulomatous lesions with hematoxylin-eosin staining, and mycobacteria by Ziehl–Neelsen staining in tissue sections from the lung and skin, respectively, although MAC were not isolated from the sections. MAC genes were finally detected by tdPCR-NALFIA in both cases.Conclusion: Although Ziehl–Neelsen staining and culture tests are the gold standard in identifying causative mycobacteria, the rapid results of tdPCR-NALFIA performed simultaneously with sputum and/or tissue culture may make it an important auxiliary diagnostic tool for identifying mycobacterial infection, leading to improvement in the management of MAC patients.Keywords: Mycobacterium avium complex, MAC, Ziehl–Neelsen staining, rapid diagnosis
