To assess the management and outcomes of patients with non-HIV associated pulmonary Mycobacterium avium complex (MAC).
We performed a retrospective cohort study of patients referred to a tertiary care institution with pulmonary MAC isolates who were assessed by one of the investigators between January 1, 2001 and March 20, 2004. We collected data regarding demographic, clinical, radiographic, microbiologic and physiologic studies, as well as treatment information and clinical response.
Forty-nine patients were studied. The median age was 75 (interquartile range 62-78) years and 32 were female (65%). Twenty-one (43%) patients had predominantly middle lobe and lingular involvement. Eighteen (37%) patients were treated for at least 3 months with a multi-drug, macrolide-containing regimen (17, 14, 6 patients treated with fluoroquinolone, ethambutol and rifampin, respectively). Symptoms primarily drove the decision to treat, but retrospective analysis showed that 14/18 (78%) met diagnostic criteria. No patient discontinued therapy due to intolerance. After a median of 13 months of treatment, symptoms improved in 13/18 (72%) and sputum conversion occurred in 3/18 subjects (17%). Subjects with middle lobe and lingular involvement were treated less often than those with other imaging patterns (27% vs. 59%, p=0.04), and tended to respond better to treatment (88% vs. 60% clinical response, p=0.20). Nineteen patients had baseline and follow-up pulmonary function tests (PFTs) at a median follow-up of 28 (IQR 18-33) months. Agreement between symptoms and PFT change was poor.
Pulmonary MAC patients with middle lobe and lingular involvement were less commonly treated and had a tendency toward better response. Antimicrobial therapy with a macrolide-based, predominantly non-rifamycin containing regimen was very well tolerated, and resulted in clinical but not microbiologic improvement in most patients. In this cohort, we were unable to demonstrate agreement between PFT and symptom changes.
In patients with pulmonary MAC, middle lobe and lingular involvement represents milder disease and may predict better treatment response. Macrolide-based treatment improves symptoms, but the role of PFTs in disease monitoring is unclear.
S.R. Pendharkar, None.