Abstract
Whipple’s disease(WD) is a rare chronic and systemic disease caused by the rod-shaped, Gram-positive bacterium Tropheryma whipplei (T. whipplei) that primarily affects the gastrointestinal tract, however, the involvement of the lung is rare, and few study have explored the significance of the detection of TW in bronchoalveolar lavage fluid (BALF). So, we performed a retrospective study in patients with T. whipplei positive in 848 BALF samples which detected by metagenomic next-generation sequencing (mNGS) from 21 September 2022 to 1 March 2024 in The First Hospital of Changsha. Forty-three BALF samples from forty-four (44/848, 5.2%) patients were positive for T. whipplei (one patient was excluded due to incomplete data). Twenty-nine patients were male with an average age of 46.9 years. The main symptoms included cough (36/43), expectoration (22/43), dyspnea/shortness of breath (14/43), fever (13/43), hemoptysis/bloody sputum (5/43), vomiting (2/43), abdominal pain (1/43), and only one patient complained about neurological symptoms. Chronic liver disease (including fatty liver, chronic hepatitis C and chronic hepatitis B) were the most common comorbidity (n = 11, 25.6%), followed by chronic lung disease (n = 8, 18.6%). Only 11 patients (25.6%) were immunocompromised. One patient was finally diagnosed with reactivation tuberculosis and two patients were diagnosed with lung tumors (including one primary lung adenocarcinoma and one primary lung squamous carcinoma), and twenty-two patients (53.5%) had pneumonia. T. whipplei was the sole agent in 6 samples, and Epstein-Barr virus was the most common detected pathogens, followed by Haemophilus influenzae. The most common chest CT imaging manifestation is lung nodules (18/43, 41.9%), including fourteen solid nodules and five ground-glass nodules (three cases of calcified nodules caused by pulmonary tuberculosis were excluded). Our study indicates that T. whipplei is a causative pathogen in various lung diseases, and clinicians should be wary of this. The mNGS technology improves the detection and attention of rare pathogens and provide guidance for treatment in clinical practice. In the future, the natural history of T. whipplei infections and the possible pathogenesis still need to be studied.