Characteristics and comparison of rapidly growing and slowly growing nontuberculous mycobacterial pulmonary disease.

Abstract

Nontuberculous mycobacterial (NTM) pulmonary disease (PD) has rapidly increased globally. The characteristics and comparison of rapidly growing mycobacteria PD (RGM-PD) and slowly growing mycobacteria PD (SGM-PD) are still unclear. Our study enrolled 31 NTM-PD patients. Clinical data, including baseline, symptoms, underlying disease, laboratory tests, metagenomic next-generation sequencing (mNGS) results, radiological images, treatment, and outcome were recorded and analyzed. Of the 31 patients with NTM-PD, 22 patients were female and 9 were male. It included 11 RGM-PD and 20 SGM-PD. There was no difference in age (P = 0.425) and body mass index (P = 0.152) between the two groups. The common respiratory diseases in prevalence included bronchiectasis and chronic obstructive pulmonary disease. Three patients had positive results of T-SPOT tuberculosis (TB), and none had positive Xpert-Mycobacterium tuberculosis/rifampin results. On admission, patients were symptomatic and included cough/sputum production, fever, weight loss, fatigue, and hemoptysis. In comparison to RGM-PD, patients with SGM-PD had a greater chance of experiencing fatigue (P = 0.012). No significance was found in serum biomarkers between RGM and SGM-PD, including CD4/CD8 ratio, white blood cells, neutrophils, lymphocytes, procalcitonin, ferritin, C-reactive protein, and erythrocyte sedimentation rate. No liver or kidney impairment was found. Patients with RGM-PD were more likely to have right lower lobe (RLL) impairment (P = 0.021) and a cavity characteristic (P = 0.012). All 31 cases had positive mNGS results. The duration of mNGS was shorter than conventional methods (3.4 ± 0.7 vs. 26.4 ± 20.9, P < 0.001). Patients with SGM-PD were more likely to experience fatigue. The cavity and RLL involvement were more frequent in the RGM-PD. mNGS increases the identification of NTM specimens and complements the capabilities of conventional methods.