Quantitative pulmonary gallium scanning in interstitial lung disease

Abstract

The mechanisms responsible for gallium uptake in chronic, non-infective, diffuse lung disease are not completely understood. This study attempted to clarify some of them. A lung/liver gallium index was calculated in 113 subjects, some normal and some with various interstitial lung diseases, predominantly those associated with connective tissue disease. The mean gallium index was significantly higher in the groups with active interstitial lung disease (5.7) and non-infective bronchiolitis (4.1) compared with non-smoking normals (3.0; P less than 0.05). To investigate the mechanisms responsible for gallium uptake, the gallium index was correlated with bronchoalveolar lavage findings, respiratory function tests and clinical features. Significant correlations (P less than 0.05) were found with age in non-smoking normals; lavage macrophages in smoking normals; age but no other parameter in bronchiolitis; lavage lymphocytes, lavage albumin and improvement in diffusion capacity for carbon monoxide in those with active interstitial lung disease. It is concluded that in normal smokers gallium uptake may be due to a macrophage-mediated process. Gallium uptake in active interstitial lung disease associated with connective tissue disease appears to be an immunological process in which transport and retention of gallium is associated with that of albumin.

Effects of cigarette smoking on diagnostic tests for work‐related hypersensitivity pneumonitis: Data from an outbreak of lung disease in metalworkers

“…This might suggest that augmented gallium uptake in the pulmonary parenchyma is more related to smoking than to the development of HP. However, that conclusion is not supported by previous studies that have shown that cigarette smoking per se does not significantly increase gallium uptake in the lungs [Kennedy et al, 1985;Cairns et al, 1991Cairns et al, , 1992Ramsey et al, 1992]. Thus, the most reasonable interpretation of our results may be that some of our non-case patients were in fact misclassified; that is, the gallium scans identified individuals with atypical presentations of HP (perhaps because as smokers or Ex they failed to develop crackles, elevated ESRs, and/or simple restrictive spirometric changes).…”