Connective tissue activation. XII. Platelet abnormalities in patients with rheumatoid arthritis.

Patients with rheumatoid arthritis frequently have an unexplained thrombocytosis which appears to be related to the severity of the disease process. This report shows that rheumatoid platelets have reduced saline soluble protein per 10(9) platelets, less of a lysosomal enzyme, acid phosphatase, and decreased connective tissue activating peptide (CTAP-III) activity. CTAP-III is a potent connective tissue mitogen, and promotes glycolysis and glycosaminoglycan synthesis, characteristics which make it an interesting candidate for a role as a mediator of inflammation.