An epidemic of veno-occlusive disease of the liver in Afghanistan. Pathologic features.

A large outbreak of veno-occlusive disease occurred in Afghanistan in which approximately 7,800 in a population of 35,000 subjects were estimated to have been affected. It was caused by consumption of wheat flour heavily contaminated with seeds of a plant of the heliotropium species. These were found to contain pyrrolizidine alkaloids, chiefly heliotrine. Fourteen percutaneous liver biopsies, representing different stages of diseases and liver tissue from eight autopsies were studied. Morphological changes in the liver were characteristic. Centrilobular hemorrhagic necrosis was followed by occlusive changes in the hepatic veins, finally resulting in nonportal cirrhosis. The sequence of changes observed suggests primary parenchymal injury and possibly obstructive lesions at the sinusoidal level. Collagenization of the sinusoids and reorganization of the lobular reticulin begin early in disease. Occlusive changes in the efferent veins apparently follow.