Intrathoracic nontuberculous mycobacterial infections in otherwise healthy children

Abstract

Background Nontuberculous mycobacterial (NTM) infection is typically associated with lymphadenitis in immune competent children, and disseminated disease in children with immune deficiencies. Isolated pulmonary NTM disease is seen in cystic fibrosis, and is increasingly recognized in immunocompetent elderly women, where it is associated with an increased incidence of cystic fibrosis transmembrane regulator (CFTR) mutations. Thoracic NTM infection has been reported rarely in otherwise healthy children. We aimed to determine whether otherwise healthy children with pulmonary NTM disease had immunologic abnormalities or CFTR mutations. Study Design Clinical presentations of five otherwise healthy children with pulmonary NTM were reviewed. Immunologic studies were performed including a complete blood cell count (CBC), flow cytometric lymphocyte phenotyping and IFN-gamma receptor expression, in vitro cytokine stimulation, and serum immunoglobulin levels. Mutational analysis was performed for CFTR. Results The children ranged in age from 12 months to 2.5 years at diagnosis. Four presented with new onset wheezing or stridor failing bronchodilator therapy. One child was asymptomatic. Endobronchial lesions and/or hilar lymph nodes causing bronchial obstruction were identified in all patients. Mycobacterium avium complex was cultured from four patients, and M. abscessus from one patient. All patients were successfully treated with anti-mycobacterial therapy with or without surgery. No definitive immunologic abnormalities were identified. No clinically significant mutations were found in CFTR. Conclusions Pulmonary NTM infection should be considered in otherwise healthy young children presenting with refractory stridor or wheezing with endobronchial lesions or hilar lymphadenopathy. It does not appear to be associated with recognized underlying immune deficiency or CFTR mutations.

Endobronchial Lesions Caused by Nontuberculous Mycobacteria in Apparently Healthy Pediatric Patients

“…M. avium is the predominant NTM species causing pulmonary disease in general 32,34 and intrathoracic disease in pediatric patients in particular. 20,27 In 1 of our patients, PCR products typical for M. chelonae, in one other patient not specifiable mycobacterial PCR products were identified in the molecular pathological investigation only. The full standard ATS criteria for pulmonary NTM disease were thus not fulfilled (i.e., confirmatory identification in a further sample on a second occasion).…”

“…Other reports describe the endobronchial masses caused by NTM to be fleshy, mucoid, cheesy friable or rubbery gray-white. 20,25,27,35,36 Most commonly, the lesions were characterized as granulation tissue, although 1 author 25 noted a caseous node. In all our cases, endobronchial masses significantly obstructed a large bronchus; after debulking, an intact bronchial wall was found.…”

Diversity of Mycobacterium avium subsp. hominissuis mycobacteria causing lymphadenitis, France

“…Therefore, several previously investigated patients have been reported as MAC lymphadenitis without further identification [16,[26][27][28][29][30][31]. Moreover, a false-positive hybridization result has been observed when using commercial MAC hybridization tools with Mycobacterium saskatchewanense [32] and Mycobacterium palustre, a non-MAC species also responsible for mycobacterial lymphadenitis [33].…”

Host susceptibility to non-tuberculous mycobacterial infections

“…[165][166][167] Rarely, non-tuberculous mycobacterial disease can also manifest as endobronchial disease or hilar adenopathy in immunocompetent children usually presenting with cough or wheezing. 168,169 To date, neither CFTR mutations nor other primary immune defects have been often noted in these patients. 4,168 Generally, irrespective of initial management, the cure rates are almost 100%, and the recurrence rate after clearance of the infection is essentially nil.…”

“…168,169 To date, neither CFTR mutations nor other primary immune defects have been often noted in these patients. 4,168 Generally, irrespective of initial management, the cure rates are almost 100%, and the recurrence rate after clearance of the infection is essentially nil.…”