Impact of Aspergillus precipitating antibody test results on clinical outcomes of patients with Mycobacterium avium complex lung disease.

BACKGROUND AND

OBJECTIVE

Chronic pulmonary aspergillosis (CPA) is associated with mortality in patients with Mycobacterium avium complex lung disease (MAC-LD). However, the clinical significance of the positivity of Aspergillus precipitating antibody (APAb), a serodiagnostic test for pulmonary aspergillosis (PA), at the time of MAC-LD diagnosis is unknown. The objective of this study was to investigate the effects of APAb test results on the clinical outcomes of patients with MAC-LD.

METHODS

We retrospectively analyzed patients who were newly diagnosed as having MAC-LD between 2007 and 2014 in our hospital and checked for APAb at the time of diagnosis.

RESULTS

We enrolled 131 patients in this study. Of these patients, 20 (15.3%) tested positive for APAb at the diagnosis of MAC-LD. The APAb-positive patients were more frequently male (70.0% vs. 37.8%, P = 0.013) and more frequently had pulmonary emphysema (60.0% vs. 13.5%, P < 0.001) and interstitial pneumonia (15.0% vs. 1.8%, P = 0.025) compared with the APAb-negative patients. During a median follow-up period of 4.0 years, PA developed in 12 of the APAb-positive patients (60.0%, CPA: 9 and allergic bronchopulmonary aspergillosis: 3) and 12 APAb-negative patients (10.8%, CPA: 12) (P < 0.001). The APAb-positive patients had a significantly higher rate of mortality than did the APAb-negative patients (P = 0.004). A multivariate analysis indicated that older age, lower albumin, fibrocavitary or fibrocavitary and nodular/bronchiectatic radiographic features, and APAb positivity were negative prognostic factors.

CONCLUSIONS

APAb-positive patients with MAC-LD more frequently develop PA and may have an unfavorable prognosis.