Chin Med J (Taipei) 1996;57:S249.

Lung Injury Induced by Consumption Sauropus Androgynus vegetables -- Assessment with Tc-99m DTPA Radioaerosol Inhalation Lung Scan

J.-L. Wu

Division of Chest Medicine, Taichung Veterans General Hospital, Taichung, Taipei, R.O.C.

Abstract

Taking Sauropus androgynus, a Malaysian food, to reduce weight began as a fad in Taiwan since 1994. Some advocates of this fad developed respiratory distress including dry cough, exertional dyspnea, and even respiratory failure gradually. From July to November 1995, there were 104 non-smoking patients enrolled in our hospital and we investigated these patients with chest roentgenography (CXR), pulmonary function test (PFT), and Technetium 99m-labeled diethylene triamine penta-acetate (Tc-99m DTPA) radioaerosol inhalation lung scintigraphy, an index of lung epithelial permeability. In patients (n=90) receiving Tc-99m DTPA lung scan, there were 50 patients with abnormalities, including faster clearance of Tc-99m DTPA from lung (n=30), inhomogenous deposition of the submicronoc radioaerosol (n=4) and both (n=16). In patients (n=100) receiving PFT, there were 19 patients who had abnormal ventilatory impairment including obstructive type (n=14), restrictive type (n=1) and both (n=4). Analyzing the results, we found that the patients with respiratory symptoms (n=42) had lower FEV1 (p=0.001), FEV1/FVC (p<0.001), FEF25-75% (p=0.001), VC (p=0.002), D1co (p=0.009) and faster clearance of Tc-99m DTPA (p=0.010) than the patients without respiratory symptoms (n=62). We also found that Tc-99m DTPA inhalation lung scan was more sensitive than PFT in detecting the lung injury related to consumption of Sauropus androgynus (51.1% vs. 18%), especially in patients without respiratory symptoms and signs (40% vs. 1.6%). In conclusion, taking Sauropus androgyrus can result in lung injury, manifesting as obstructive ventilatory impairment, inhomogenous aerosol distribution and increased lung epithelial permeability symptomatically or asymptomatically. Measurement of the Tc-99m DTPA clearance is a sensitive test to detect this lung injury and conventional PFT only discloses it in severe cases. Thus, those subclinical patients with normal PFT should be checked with Tc-99m DTPA inhalation lung scan to certify the absence of lung injury or recovery.

Keywords: Sauropus androgynus, Technetium 99m-labeled diethylene triamine pentaacetate (Tc-99m DTPA), Lung epithelial permeability

[Chin Med J (Taipei) 1996; 57: S249.]