A case of pneumonia caused by infection with Tropheryma whipplei complicated by cryptococcus during treatment with a Janus kinase inhibitor: a case report

This report describes the case of a 41-year-old male patient complaining of a hacking cough. The patient was treated with a Janus kinase (JAK) inhibitor for psoriasis. Blood tests revealed mild lymphopenia and high levels of serum cryptococcal antigen. Chest computed tomography revealed infection in the lower lobe of the left lung. Metagenomic next-generation sequencing of bronchoalveolar lavage fluid revealed Tropheryma whipplei. Tropheryma whipplei and Cryptococcus antimicrobial therapies were sequentially administered. During follow-up, the patient showed clinical and radiographic improvement. Tropheryma whipplei is an opportunistic Gram-positive rod-shaped bacterium belonging to the family Actinomycetes. Lung involvement is an unusual but classic manifestation of Whipple's disease. This is the first report of pneumonia caused by infection with Tropheryma whipplei complicated by Cryptococcus. To our knowledge, this is the first case report of Tropheryma whipplei infection following the use of JAK inhibitors. Clinicians should be aware of opportunistic infections that can occur during treatment with JAK inhibitors.