Background:Non Tuberculous mycobacteria (NTM) pulmonary infection commonly complicates bronchiectasis. Determination of NTM- pulmonary disease (NTM-pd) requires that certain clinical, radiologic and microbiologic criteria are met. However, clinical features of NTM-pd are very similar to those of bronchiectasis. There is a need for a radiologic prediction tool to distinguish people with NTM-pd from those with bronchiectasis and no NTM-pd.
Purpose: To investigate radiologic features associated with NTM-pd in bronchiectasis. To develop a radiologic prediction tool for NTM-pd in bronchiectasis.
Methods: We reviewed clinical, laboratory and radiological characteristics in patients with bronchiectasis from two centers in Israel. Diagnosis of NTM pulmonary disease (NTM- pd) was made by the treating physicians. Radiologic features on CT scans and the individual components of the Bhalla scoring system were compared between people with and without NTM pulmonary disease. Logistic regression and receiver- operating curve (ROC) analysis were performed to predict NTM pulmonary disease.
Results:A total of 242 people with bronchiectasis with complete clinical data and available CT scans were included in the study, 32 of them had NTM-pd. People with NTM were significantly older (mean-72 vs 66 years, p=0.034). Radiologic distinguishing features of NTM- pd were: more lung segments involved (13±5 vs. 11±5, p=0.03), presence of mucus plugging (47% vs. 19%, p<0.0001) and presence of consolidations in at least two pulmonary segments (53% vs. 28%, p=0.004). The total modified- Bhalla score was higher (worse) among people with NTM- pd (median [IQR] 11[9, 13] vs. 9[8, 12], p=0.03). Logistic regression identified the number of pulmonary segments involved, presence of bullae, two or more consolidations, and a total score above 9 to be independently associated with presence of NTM- pd. ROC analysis with age, gender, and presence of mucus plugs, identified an AUC of 72.6% (CI 0.62-0.83, p<0.0001).
Conclusions:Radiological features together with advanced age and female gender may predict NTM- pd among people with bronchiectasis.
