Australian Regenerative Medicine Institute

Pulmonary Disease From Nontuberculous Mycobacteria in Patients With Human Immunodeficiency Virus: Literature Review

The literature on MAC and AIDS has emphasized the frequency and importance of disseminated disease, and reports of specific pulmonary manifestations have been few. Two autopsy series from the early years of the AIDS epidemic suggested that although MAC can frequently be cultured from lung tissue, it is not commonly associated with histologic or clinical evidence of infection. Welch et al reviewed autopsy findings in 35 patients with AIDS who died before June 1983. Cytomegalovirus and Pneumocystis carinii were the most common pulmonary pathogens. Mycobacteria were cultured from pulmonary sources in eight: five MAC, two M tuberculosis (MTb), one uncharacterized. Of three patients with positive MAC cultures who died of pulmonary disease, all had concurrent P carinii pneumonia (PCP) as well. Canada health and care mall so In a smaller series of ten autopsies, six patients had positive cultures for MAC either antemortem or at autopsy but only two had histologic evidence of pulmonary infection. In one of these, the pathologic significance was unclear, but the second patient was believed to have died from M avium pneumonia with “extensive bilateral pneumonia with abscess formation and pulmonary hemorrhage/’ Histologic study in this case revealed numerous acid-fast organisms in the lung parenchyma.
Murray et al. in a multicenter review, reported 441 serious pulmonary infections among 1,067 patients with AIDS. Seventy-four of these (17 percent) had MAC cultured from respiratory sources (37 coexistent with PCP). However, biopsy specimens from most patients with MAC revealed only minimal pathologic change or the finding of poorly formed granulomas. In most cases, the diagnosis of mycobacterial infection was not suspected until culture results became positive. A review of all records of positive MAC respiratory cultures from Mt. Sinai Medical Center over a 10-year period (1979 to 1988, including HIV-seropositive and HIV-seronegative patients) identified pulmonary MAC infection in 244 patients based on a definition of infection that required (1) three positive cultures, or (2) demonstration of AFB in lung tissue, or (3) evidence of dissemination. Four patterns of MAC disease were identified: solitary pulmonary nodules (n=78), chronic bronchitis/bronchiectasis (58), upper lobe disease resembling tuberculosis (12), and disseminated (systemic) infection (n=96; patients in this group had positive sputum cultures as well as positive cultures from other body sites or fluids). The last group was composed almost entirely of patients with AIDS. Although a variety of radiographic abnormalities were noted in this group (including local consolidation, nodules, cysts, diffuse infiltrates), the authors report that “most radiographic abnormalities were due to PCP, MTb, bacterial infection, CMV or fungal infections, nonspecific pneumonitis, or lymphocytic interstitial pneumonia.”

Category: Respiratory Symptoms

Tags: AIDS, atypical Mycobacterium infections, HIV infection, Mycobacterium avium-intracellulare infection