Mycobacterium avium-intracellulare pulmonary infection in HIV-negative patients without preexisting lung disease - Diagnostic and management limitations

Study objectives: To review the experience of an outpatient pulmonary clini c with Mycobacterium avium-intracellulare (MAI) pulmonary disease in the HI V-negative population without preexisting lung disease. Design: Retrospective clinical series, Setting: University medical center. Patients: The clinic charts of all patients who fulfilled the current Ameri can Thoracic Society criteria for MAI pulmonary infection and who had no pr eexisting lung disease or immunosuppression were reviewed. Measurements and results: Of 31 patients identified, 94% were female, 90% w ere white, and the median age at diagnosis was 63 years. The median time in terval from symptom onset to diagnosis was 10 months. Bronchiectasis or sma ll nodules without predilection for any lobe was found in 93%. Bronchoscopy or open lung biopsy for diagnosis was required in 45% because of nondiagno stic sputum cultures. At greater than or equal to 12 months, 50% failed the rapy, 86% continued to be symptomatic, and 58% did not tolerate their initi al multidrug regimen. Conclusions: These results emphasize the observed chronic nature of MAI pul monary disease in this population, both before diagnosis and despite therap y, The sensitivity of sputum culture in this population is low, so an aggre ssive diagnostic approach, including bronchoscopy, should be considered if sputum cultures are negative. Current treatments are suboptimal because of poor drug tolerance and significant failure rates. Last, the preponderance of disease in older white women argues for a genetic or acquired immune def iciency to explain disease susceptibility.