A high-sensitivity ELISA for detection of human FGF18 in culture supernatants from tumor cell lines.

Fibroblast growth factor 18 (FGF18) is elevated in several human cancers, such as gastrointestinal and ovarian cancers, and stimulates the proliferation of tumor cells. This suggests that FGF18 may be a promising candidate biomarker in cancer patients. However, the lack of a high-sensitivity enzyme-linked immunosorbent assay (ELISA) does not permit testing of this possibility. In this study, we generated monoclonal antibodies against human FGF18 and developed a high-sensitivity ELISA to measure human FGF18 at concentrations as low as 10 pg/mL. Of the eight tumor cell lines investigated, we detected human FGF18 in culture supernatants from four tumor cell lines, including HeLa, OVCAR-3, BxPC-3, and SW620 cells, albeit the production levels were relatively low in the latter two cell lines. Moreover, the in-house ELISA could detect murine FGF18 in sera from mice overexpressing murine Fgf18 in hepatocytes, although the sensitivity in detecting murine FGF18 was relatively low. This FGF18 ELISA could be a valuable tool to validate FGF18 as a potential biomarker for cancer patients and to test the contribution of FGF18 for various disease models invivo and in vitro.

Impact of chronic co-infection in pulmonary Mycobacterium avium complex disease after treatment initiation.

BACKGROUND: The impact of co-infection with other pathogenic microorganisms after initiation of treatment for Mycobacterium avium complex pulmonary disease (MAC-PD) has not been clearly described. This study sought to clarify the clinical outcomes of co-infection with MAC after antimycobacterial therapy for MAC. METHODS: Co-infection status was defined as the detection of pathogenic microorganisms other than MAC in at least two consecutive sputum cultures 6-24 months after initiation of treatment. Chest computed tomography (CT) findings and culture results were compared between co-infection and MAC alone groups. RESULTS: The co-infection and MAC alone groups comprised 12 and 36 patients, respectively. The proportion of patients with sputum culture positive for MAC after 24 months of therapy did not differ significantly between the two groups [25% (3/12) vs. 16.7% (6/36); p = 0.671]. The proportion of patients with improved chest CT score after 24 months of starting treatment compared to baseline was significantly lower for the co-infection group than for the MAC alone group [16.7% (2/12) vs. 79.4% (27/34); p < 0.001]. In the co-infection group, median CT score values at 12 and 24 months did not differ from baseline. However, the MAC alone group showed significant improvement at 12 and 24 months compared with baseline. CONCLUSIONS: In the patient group with co-infection of other pathogenic microorganisms after treatment initiation for MAC there was no impact on therapeutic efficacy compared to the MAC alone group. However, therapeutic intervention interfered with improvement in chest CT findings such as nodule formation, bronchiectasis, infiltration, and cavitary lesions.

Bronchial Brushing and Diagnosis of Pulmonary Nontuberculous Mycobacteria Infection.

BACKGROUND: The optimal bronchoscopy procedure for diagnosis of pulmonary nontuberculous mycobacteria (NTM) infection is unclear. OBJECTIVE: This study investigated the usefulness of bronchial brushing in bronchoscopy for diagnosis of pulmonary NTM infection in patients with suspected NTM lung disease and nodular bronchiectasis on chest computed tomography (CT) images. METHODS: Bronchoscopy was prospectively performed for 69 patients with clinically suspected pulmonary NTM infection on chest CT from December 2017 through December 2019. Before and after bronchial brushing, bronchial washing was performed with 20 or 40 mL of normal sterile saline at the same segmental or subsegmental bronchi. Before and after bronchial brushing, samples of the washing fluid (pre- and postbrushing samples) and brush deposits (brush samples) were obtained and cultured separately. RESULTS: NTM was detected in 37 of the 69 (53.6%) patients (Mycobacterium avium in 27, Mycobacterium intracellulare in 7, M. abscessus in 2, and M. kansasii in 2). NTM was detected in 34 (49.3%) prebrushing samples, in 27 (39.1%) postbrushing samples, and in 20 (29.0%) brush samples from the 69 patients. In 2 (2.9%) patients, NTM was detected only in postbrushing samples; in 1 (1.4%) patient, NTM was detected only in a brush sample. As compared with bronchial washing only, additional bronchial brushing increased the NTM culture-positive rate by 4.3% (3/69). Bronchial brushing caused bleeding, requiring hemostasis in 5 (7.2%) patients. CONCLUSION: Additional bronchial brushing increased the NTM culture-positive rate by only 4.3% (3/69), as compared with bronchial washing alone. Thus, the usefulness of brushing appears to be limited.