Isolated Pulmonary Mycobacterium avium Complex Infection in Patients with Human Immunodeficiency Virus Infection: Case Reports and Literature Review

Abstract

We report 4 cases of isolated pulmonary Mycobacterium avium complex (MAC) infection and review the 20 previously reported cases in the human immunodeficiency virus literature. All 4 patients had acquired immune deficiency syndrome, and 3 were believed to have had an immune reconstitution syndrome as a cause of MAC infection. Two patients underwent bronchoscopy with biopsy, revealing endobronchial lesions and granuloma formation, and all 4 patients responded well to MAC therapy.

Acquired Immune-deficiency Syndrome with Focal Onset of <i>Mycobacterium avium</i> Infection Displaying a Histological/Genetic Pattern of Disseminated Mycobacteria

“…The presence of unorganized granulomas composed of foamy histiocytes packed with numerous AFB has been reported to represent the typical histological characteristics of disseminated lesions caused by M. avium infection (3,12). In contrast, previous studies have shown that most localized pulmonary lesions developing after the initiation of ART display organized granulomas with scarce AFB (6). Therefore, the histological findings in the present case were compatible with those of disseminated MAC disease rather than those of typical lesions.…”

“…However, the histological characteristics of localized lesions before the initiation of ART have not yet been systematically studied. In addition, it has been reported that non-caseating granulomas with numerous AFB are observed in cases of MACrelated IRIS (6). Therefore, we cannot conclude that this case was a consequence of systemic infection based on the histological characteristics alone.…”

“…These clinical manifestations are thought to result from inflammatory responses against quiescent pathogens and residual antigens following the restoration of cell-mediated immune responses (5). However, isolated pulmonary MAC infection is uncommon in patients with HIV before the administration of ART (6,7). In the present report, we describe a rare case of the focal onset of mycobacterial lesions in the mediastinal lymph nodes in an AIDS patient; however, the histology and the genetic pattern of the isolated M. avium strain showed disseminated disease.…”

AIDS and Opportunistic Infections

“…The radiologic findings of pulmonary MAC include consolidation, cavities, nodules, bronchiectasis and adenopathy (Erasmus et al, 1999). While focal infiltration is extremely rare, a frequent finding is endobronchial lesion without pneumonia (Mehle et al, 1989;Salama et al, 2003). Pleural involvement in nontuberculous mycobacterium infection has also been reported rarely (Haider et al, 2009).…”

Cerebral Mycobacterium avium abscesses: Late immune reconstitution syndrome in an HIV‐1‐infected patient receiving highly active antiretroviral therapy

“…MAC-IRS most commonly presents as focal lymphadenitis without mycobacteremia, with or without suppuration (8)(9)(10)(11). Other localized MAC-IRS have included skin disease (14,15), isolated pulmonary disease (16,17), bowel involvement (18), and osteomyelitis including vertebral involvement (19). We report the case of an HIV-1-infected patient who developed an unusual and potentially devastating localized brain infection due to MAC almost two years after starting effective HAART and 17 months after attaining a sustained elevation of CD4 cell count over 150 cells/µL.…”