Lung inflammation in patients with systemic lupus erythematosus detected by quantitative 67Ga-citrate lung scanning

The severity of lung inflammation in 34 patients with systemic lupus erythematosus (SLE) was measured by quantitative 67Ga-citrate lung scanning. The severity of lung inflammation in SLE was represented by the 67Ga uptake index (GUI). Quantitative 67Ga lung scanning was also performed on 20 normal controls for comparison with the SLE patients. The patients were divided into two subgroups according to the following two criteria: (a) stable or flare stage according to clinical features; or (b) positive or negative results of chest X-ray. The GUI values of the subgroups were also compared. The results revealed a trend towards higher values of GUI in SLE patients than in the normal controls. The GUI values were also higher for SLE cases with a flare stage or a negative chest X-ray than in SLE cases with a stable stage or a positive chest X-ray. The statistical results reveal that the differences in the GUI values are not significant. However, we found that (1) positive chest X-ray findings may be a later manifestation of a lung inflammation and (2) the values of GUI parallel clinical features in SLE patients.