Ya Shen,1,2,* Shun-Shun Cui,3,* Xiao-Bao Teng,2,* Ming-Feng Han,2 Yan-Bei Zhang1 

1Department of Geriatric Respiratory and Critical Care Medicine, The First Affiliated Hospital of Anhui Medical University, Hefei, 230000, People’s Republic of China; 2Department of Respiratory and Critical Care Medicine, Fuyang Infectious Disease Clinical College of Anhui Medical University, Fuyang, 236000, People’s Republic of China; 3Department of Respiratory and Critical Care Medicine, Fuyang People’s Hospital, Fuyang, 236000, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Yan-Bei Zhang, Department of Geriatric Respiratory and Critical Care Medicine, The First Affiliated Hospital of Anhui Medical University, No. 218 of Jixi Road, Shushan District, Hefei, 230000, People’s Republic of China, Tel +86-13093340370, Email zhangyanbeizyb@126.com Ming-Feng Han, Department of Respiratory and Critical Care Medicine, Fuyang Infectious Disease Clinical College of Anhui Medical University, No.1088 of Yinghexi Road, Yingzhou District, Fuyang, 236000, People’s Republic of China, Tel +86-16655800262, Email mingfeng_han@126.com

Objective: The aim of this study was to assess the prevalence of Tropheryma whipplei (TW) infection in the population and to investigate the clinical symptoms, as well as the laboratory and imaging characteristics of patients testing positive for TW using next-generation sequencing (NGS).
Methods: A retrospective review was conducted on 1346 bronchoalveolar lavage fluid (BALF) samples collected between January 2021 and September 2023. The case group comprised patients with TW detected using NGS while the control group included 65 randomly chosen Gram-positive bacterial infection patients without TW. Comparative analyses were carried out on the basic demographics, laboratory parameters, and imaging findings between the two groups. Additionally, the case group underwent an in-depth examination of underlying diseases, pathogens, final diagnoses, treatment strategies.
Results: The case group comprised of 51 patients with TW, constituting 3.8% of the total. There was no significant difference in gender and age between the case and control groups (P = 0.84, P = 0.07). Symptoms such as coughing, expectoration, wheezing, fever, and hemoptysis are less commonly detected in the case group with a higher incidence of chest pain when compared to the control group (P > 0.05). The case group exhibited decreased albumin levels and increased C-reactive protein and D-dimer levels compared to normal levels. Imaging findings in the case group commonly included nodules, patchy images, and interstitial changes, the most common underlying disease is cardiovascular disease, and the most frequently co-occurring pathogen is the human herpesvirus. Among the case group, 27 patients received a final diagnosis of pneumonia, and 3 patients clinically diagnosed with Whipple’s disease demonstrated improvement in both symptoms and imaging after treatment.
Conclusion: NGS revealed a relatively low overall detection rate of TW-positive patients using BALF. TW was more prevalent in middle-aged and elderly male patients characterized by symptoms such as cough, expectoration, shortness of breath, and fever. Chest imaging in these cases typically showed nodules and interstitial changes.

Keywords: bronchoalveolar lavage fluid, feature, image, NGS, Tropheryma whipplei