Deficiencies of copper and a compound with ion-exchange characteristics of pyridinoline in skin from patients with abdominal aortic aneurysms.

A spontaneously aneurysm-prone mouse has a mutation on the X chromosome, which results in an abnormality of copper metabolism. A deficiency of the copper metalloenzyme, lysyl oxidase, results in a deficiency of lysyl-derived cross-linkages in collagen and elastin. Homology of the X chromosome suggests that this model may be relevant to the human abdominal aortic aneurysm (AAA). The present studies on skin from eight AAA patients suggest that copper deficiency occurs in humans, by comparison to skin of paired control subjects with atherosclerotic occlusive disease of the aorta. The lysyl-derived cross-linkage pyridinoline (or some compound with similar ion exchange elution characteristics) is also deficient in patients with AAA; while there is an excess of one of the cross-linkage precursors, hydroxylysine. In addition, the fluorescent properties of hydrolysates of skin from the patients with AAA differ from those of the controls, suggesting that simple biochemical markers might be defined on the basis of these differences in the future. These experiments support the hypothesis that the mouse model is relevant to the disease as it occurs in humans.