Monoclonal characteristics of organising arterial thrombi: Significance in the origin and growth of human atherosclerotic plaques.

The clonal characteristics of 26 arterial thrombi at different stages of organisation were determined using the X-linked enzyme, glucose-6-phosphate dehydrogenase (G.-6-P.D.), as a clonal marker in 13 women heterozygous for electrophoretically separable G.-6-P.D. isoenzymes. A gradation of increasing monoclonality was observed with increasing organisation of the thrombi, such that only 21% of poorly organised (red) thrombi displayed monoclonal characteristics similar to those of atherosclerotic plaques, whereas 78% of moderately organised (pink) thrombi and 91% of well-organised (white) thrombi showed such characteristics. These results provide objective evidence for the role of thrombosis in the formation of human atherosclerotic plaques.