Outcomes ofMycobacterium aviumcomplex lung disease based on clinical phenotype

Abstract

The effect of the clinical phenotype of complex (MAC) lung disease on treatment outcome and redevelopment of nontuberculous mycobacterial (NTM) lung disease after treatment completion has not been studied systematically.We evaluated 481 treatment-naïve patients with MAC lung disease who underwent antibiotic treatment for ≥12 months between January 2002 and December 2013.Out of 481 patients, 278 (58%) had noncavitary nodular bronchiectatic (NB) disease, 80 (17%) had cavitary NB disease and 123 (25%) had fibrocavitary disease. Favourable outcome was higher in patients with noncavitary disease (88%) than in patients with cavitary disease (76% for fibrocavitary and 78% for cavitary NB disease; p<0.05). Cavitary disease was independently associated with unfavourable outcomes (p<0.05). Out of 402 patients with favourable outcomes, 118 (29%) experienced redevelopment of NTM lung disease, with the same MAC species recurring in 65 (55%) patients. The NB form was an independent risk factor for redevelopment of NTM lung disease (p<0.05). In patients with recurrent MAC lung disease due to the same species, bacterial genotyping revealed that 74% of cases were attributable to reinfection and 26% to relapse.Treatment outcomes and redevelopment of NTM lung disease after treatment completion differed by clinical phenotype of MAC lung disease.

Amikacin Inhalation as Salvage Therapy for Refractory Nontuberculous Mycobacterial Lung Disease

“…Refractory NTM-LD was defined as persistent positive sputum cultures after at least 6 months of multidrug treatment. All patients received standardized multidrug treatment according to the etiologic organisms, as reported previously (26,(38)(39)(40)(41)(42). None of the included patients had previously received AMK inhalation therapy.…”

“…The fibrocavitary form of NTM-LD was defined by the presence of cavitary opacities predominantly in the upper lobes. The nodular bronchiectatic form was defined by the presence of multifocal bronchiectasis and clusters of small nodules, regardless of the presence of small cavities in the lungs (26,40,42).…”

“…For semiquantitative culture analysis, each culture was scored using a slight modification of methods described in previous reports (31,44) as follows: (i) negative, no growth in liquid or solid medium; (ii) liquid only, growth in liquid medium only; (iii) trace, growth of Ͻ50 colonies on solid medium; (iv) 1ϩ, growth of 50 to 100 colonies on solid medium; (v) 2ϩ, growth of 100 to 200 colonies on solid medium; (vi) 3ϩ, growth of 200 to 500 colonies on solid medium; and (vii) 4ϩ, growth of Ͼ500 colonies on solid medium. NTM species were identified using a reverse blot hybridization assay of the rpoB gene (26,40,42). Drug susceptibility testing was performed using the broth microdilution method (45).…”

“…Conversion to a negative sputum culture was defined as three consecutive negative cultures. The time of conversion was defined as the date of the first negative culture (26,40,42).…”

Mycobacterium aviumcomplex infection: phenotypes and outcomes

“…The number of ( predominantly cohort) studies has increased, a phase III multicentre study for refractory MAC has recently completed [16], and we await the imminent publication of guidelines from the British Thoracic Society, and a separate collaboration between the European Respiratory Society, American Thoracic Society, Infectious Disease Society of America, and European Society of Clinical Microbiology and Infectious Diseases. Studies such as that in this issue [8], which include large, prospective cohorts, certainly help inform best practise but, despite this, treatment success is suboptimal, and the need for RCTs and drugs to determine better regimens remains as acute as ever.…”