PULMONARY-DISEASE DUE TO INFECTION BY MYCOBACTERIUM-AVIUM COMPLEX IN PATIENTS WITH AIDS

We reviewed the clinical, radiographic, and histologic features of nin e patients with AIDS and pulmonary disease due to Mycobacterium avium complex (MAC), Pulmonary MAC disease was defined by (1) the isolation of MAC from two or more lower respiratory tract specimens or from a si ngle lung biopsy sample, (2) an infiltrate revealed by chest radiograp hy, and (3) the absence of other identified pulmonary pathogens or mal ignancies. Pulmonary MAC disease was present in five (2.5%) of 200 pat ients with disseminated MAC infection and in four additional patients without evidence of dissemination, as assessed by blood culture. The m edian CD4 cell count at the time of presentation was 90/mu L. Pulmonar y MAC disease was the initial AIDS-defining infection in five patients and presented within a median of 5 months after the initial infection in four patients. Radiographic patterns for these nine patients inclu ded consolidating or nodular infiltrates and cavitation. The histopath ology of pulmonary MAC disease was characterized by granulomatous infl ammation, often associated with necrosis and few evident organisms. Th e conditions of all patients treated with multidrug regimens clinicall y improved.