Lymph-node and thymus pathology in fatal drug addiction

Lymph-node sections from the porta hepatis, the lung hilus, the para-aortic and axillary regions and from the neck from totally 50 drug addicts submitted for medico-legal autopsy at the Institute of Forensic Medicine in Copenhagen were studied together with tissue sections from 23 normal persons. In addition thymus sections from 30 drug addicts and 20 normal persons were investigated. Enlargement of lymph-nodes was found significantly more often in active drug addicts compared to normals except for the nodes on the neck. Birefringent material was seen in portal lymph-nodes in 42% of addicts, in para-aortic and lung hilus nodes in 18% each and in the axillary nodes in 12%. Signs of antigenstimulation evaluated by the number of germinal centre and plasma cells were found in about 60% or more in active drug addicts compared to about 30-40% in normals. There was not significant relation between the size of the lymph-nodes and the immunoactivity nor to the duration of the abuse. Examination of the thymus showed that the average weight in active drug addicts was 34 g, in normals 25 g. Histologically the tissue was in 48% of the active addicts composed of more than 80% lymphatic tissue compared to 15% of the normals. The results indicate that the enlargement and histological signs of activation in all the lymph-nodes investigated are caused by continuous antigenstimulation due to repeated injections of various antigens. The same may in part be applied to the thymus changes demonstrated.