Tissue Iron and the Reticulo-Endothelial System in Rheumatoid Arthritis

Abstract

Samples of liver, spleen, lymph node, lung, and suprarenal were collected at necropsy from 34 patients with rheumatoid arthritis who died in hospital. Similar samples were obtained from 43 control cases who died from other causes. The control cases were chosen in such a way that the influence of age and of sex on the tissue iron concentration could be assessed. The organs were examined histologically for iron by the Prussian blue reaction. Comparable tissue samples were analysed chemically for non-haem iron. The concentration of iron in the liver, spleen, lungs, lymph nodes, and suprarenals in cases of rheumatoid arthritis not known to have received treatment with iron therapeutically or blood by tranfusion was compared with that in the same organs of control cases. No difference in tissue iron concentration was found which could not be explained by invoking the demonstrated increase of storage iron with age, particularly in the male. Histological examination of the organs of the reticulo-endothelial system revealed no satisfactory evidence for the nature of the hyperplasia or overactivity of this system which has been suggested as a likely explanation for the abnormal rapidity with which injected saccharated oxide of iron is removed from the plasma in patients with rheumatoid arthritis. Evidence of lymphoid hyperplasia was provided by the demonstration of significant splenic enlargement. On the basis of this splenic enlargement it is tentatively suggested that the spleen may contain approximately twice as much iron in this disease as is normally the case. Proof of this suggestion must await chemical analyses of total splenic iron in further cases of rheumatoid arthritis.