Tropheryma whipplei detection by metagenomic next-generation sequencing in bronchoalveolar lavage fluid

Abstract Background: Whipple's disease is a chronic systemic infectious disease that mainly affects the gastrointestinal tract. Tropheryma whipplei is common in healthy individuals, but in some cases, Tropheryma whipplei can cause infection at the implant site or even throughout the body. The delay between the first clinical symptoms and diagnosis of Whipple's disease and Whipple's trophoblast infection exceeds 6 years, and recurrence is often observed. Therefore, clinical doctors need to understand the characteristics of this infection. Methods: We collected blood, sputum, and alveolar lavage fluid samples from all patients with Tropheryma whipplei from 2020 to 2022, and retrospectively analyzed the clinical data of Sample with Tropheryma whipplei . Patient's past history, clinical manifestations, laboratory examinations, chest CT findings, treatment, and prognosis were recorded. Results: 16 BALFs (70/1725, 4.0%) from 16 patients were positive for Tropheryma whipplei . 8 patients were male with an average age of 50 years. The main clinical symptoms of patients included fever (9/16), cough (7/16), dyspnea(7/16), and Expectoration(5/16), but neurological symptoms and arthralgia and were rare. Cardiovascular and cerebrovascular diseases were the most common comorbidity (n=8).The main laboratory characteristics of the patient are red blood cell count, hemoglobin, total protein and albumin below normal levels(11/16) , and/or creatinine above normal levels(14/16). Most chest computer tomography manifestations include focal or patchy heterogeneous infection (n=5) and pleural effusion (n=8). Among the 6 samples, Tropheryma whipplei was the sole agent, and Klebsiella pneumoniae was the most common detected other pathogens. Conclusions: Metagenomic next-generation sequencing technology has improved the detection rate and attention of Tropheryma whipplei . Further research is needed to distinguish whether Tropheryma whipplei present in respiratory samples is a pathogen or an innocent bystander.