Tropheryma whipplei detection by metagenomic next-generation sequencing in bronchoalveolar lavage fluid: A cross-sectional study

Abstract

Tropheryma whipplei is the bacterium associated with Whipple’s disease (WD), a chronic systemic infectious disease primarily involving the gastrointestinal tract. T. whipplei can also be detected in different body site of healthy individuals, including saliva and feces. Traditionally, Tropheryma whipplei has a higher prevalence in bronchoalveolar lavage fluid (BALF) of immunocompromised individuals. Few studies have explored the significance of the detection of T. whipplei in BALF. Herein, we retrospectively reviewed 1725 BALF samples which detected for metagenomic next-generation sequencing (mNGS) from March 2019 to April 2022 in Zhuhai, China. Seventy BALs (70/1725, 4.0%) from 70 patients were positive for T. whipplei. Forty-four patients were male with an average age of 50 years. The main symptoms included cough (23/70), expectoration (13/70), weight loss (9/70), and/or dyspnea (8/70), but gastrointestinal symptoms were rare. Chronic liver diseases were the most common comorbidity (n=15, 21.4%), followed by diabetes mellitus (n=13, 18.6%). Only nine patients (12.9%) were immunocompromised. Twenty-four patients (34.3%) were finally diagnosed with reactivation tuberculosis and 15 patients (21.4%) were diagnosed with lung tumors, including 13 primary lung adenocarcinoma and two lung metastases. Fifteen patients (21.4%) had pneumonia. Among the 20 samples, T. whipplei was the sole agent, and Mycobacterium tuberculosis complex was the most common detected other pathogens. Among the non-tuberculosis patients, 31 (31/46, 67.4%) had ground glass nodules or solid nodules on chest CT. Our study indicates that T. whipplei should be considered as a potential contributing factor in some lung diseases. For non-immunocompromised patients, the detection of T. whipplei also needs attention. The mNGS technology improves the detection and attention of rare pathogens. In the future, the infection, colonization, and prognosis of T. whipplei in lung still need to be studied.

Tropheryma whipplei infection in the lung of a patient with long COVID: a case report

“…Seventy BALs (70/1725, 4.0%) from 70 patients were positive for T. whipplei . Only nine patients (12.9%) were immunocompromised [ 17 ]. For non-immunocompromised patients, the detection of T. whipplei needs to be considered.…”

Whipple's disease of the respiratory system: A case report

“…Clinical symptoms of WD improve significantly within a few days to weeks after treatment with antibiotics, but WD requires a certain period of maintenance therapy to prevent recurrence ( 22 ). Nevertheless, WD has a lifelong potential for relapse, and Lin et al ( 6 ) suggested that the disease requires lifelong monitoring.…”

“…The imaging manifestations of WD lung involvement are also diverse, with the most common chest imaging manifestations being nodules, interstitial changes and patchy infiltrates, of which nodules are the most commonly observed, with cavitation-like changes, pleural thickening and pleural effusion being less common ( 6 ). WD is mainly a chronic infection with multi-organ involvement, with occasional acute onset ( 7 ).…”

Diagnosis and treatment of Whipple disease after kidney transplantation: A case report

“…to identify T. whipplei nurturing bodies, the disease is difficult to diagnose and is mainly confirmed using tissue biopsy and pathogenetic genetic testing[ 15 ]. Upon suspicion, despite gastrointestinal symptoms, small intestinal mucosal specimens should be obtained via microscopy for periodic acid Schiff staining, polymerase chain reaction (PCR), and mNGS testing[ 16 ]. If the results of small intestinal tissue examination are not diagnostic, the above tests should be performed by sampling the corresponding lesion sites (synovial membrane, lymph nodes, alveolar lavage fluid, cerebrospinal fluid, blood, etc. )…”