[Acquired immunodeficiency syndrome and pulmonary Mycobacterium xenopi infection. Role of computerized tomography]

Abstract

Introduction: Mycobacterium xenopi is one of the most common agents responsible for nontubercular mycobacterial pulmonary disease on AIDS patients. These lesions have been studied with conventional radiography, while CT has been used in patients with aspecific mycobacterioses or non-AIDS pulmonary conditions from Mycobacterium xenopi.

Purpose: We investigated the yield of CT in the study of lung lesions from Mycobacterium xenopi in AIDS patients.

Material and methods: We examined 12 AIDS patients with pulmonary lesions from Mycobacterium xenopi, patients age ranged 30 to 46 years. All patients had CD4 blood levels lower than 250 cells/mL and Mycobacterium xenopi in the sputum. All patients underwent a standard chest radiograph and a CT examination. CT images were evaluated by three radiologists independently and the definitive diagnosis was made in the presence of a fourth radiologist.

Results: Chest CT showed parenchymal consolidation in 66% of cases, associated with bilateral basal bands in 16% of cases. Consolidation was unilateral in 41% of cases and most frequently involved the right lower lobe. Bilateral reticular interstitial involvement was seen in the patients (41%). Micronodules in 1 patient (8%) and mediastinal adenopathy in 33% of cases. Two patients had pre-xisting emphysema and 1 had bronchiectasis.

Discussion and conclusions: The frequency of lung disease from Mycobacoerium xenopi has increased because of the spreading of the HIV infection. Such lung lesions in AIDS patients are aspecific in appearance and localization, which the clinical radiologist needs to consider to address treatment planning. The frequent finding of parenchymal consolidation and the absence of cavitary lesions may be referred to the poor capability of AIDS to produce an adequate inflammatory response. The lung lesions tend to distribute in the lower lobes unilaterally. Adenopathy was also a frequent finding. CT plays a fundamental role in studying the chest of these patients because it permits to locate lung lesions with higher accuracy than conventional radiography and to detect adenopathies, micronodules reticular interstitial involvement and bronchiectases.