Platelet surface activation was surveyed by electron microscopy (EM) in 40 patients with classical rheumatoid arthritis (RA) without clinical evidence of recent intravascular coagulation. Increased platelet surface activity (PSA) was noted in 8 of 25 females and 8 of 15 males (16 of 40 or 40%). Abnormal PSA failed to correlate with either the presence of rheumatoid nodules or the titer of rheumatoid factor. Hyperactive platelet populations, however, did tend to correlate with a serum urate level above 5 mg% (7 of 12 vs 9 of 28). Neither "low" nor "anti-inflammatory" levels of serum salicylate appear to afford protection from abnormal PSA. The authors consecutively reviewed 100 patients with classical RA diagnosed and followed at Henry Ford Hospital (72 females and 28 males) to determine their incidence of thrombotic episodes. The mean age of the group was 59 years and the mean duration of follow-up was 14 years. They found 43 clotting episodes in 30 patients (21 females). There were 14 myocardial infarctions (5 in females); 19 episodes of thrombophlebitis (12 in females); 4 pulmonary embolisms (females); 5 cerebral vascular accidents (4 in females); and one female with peripheral arterial occlusive disease. No significant correlation with rheumatoid nodules, stage of disease progression or functional class of disease was noted when those patients with thromboembolic complications were compared to the others who manifested no clinical thrombosis. This study suggests that in vivo salicylate fails to inhibit PSA as determined by EM and by retrospective review of 100 patients who used prolonged daily dosage of salicylate. The thrombotic episodes were as frequent as in general population surveys, except for data from a cerebral vascular (stroke) survey.
Bluhm, Gilbert B.; Riddle, Jeanne M.; Pica, Donald G.; and Langejans, Gordon D.
"Salicylate effect on platelets and vascular thrombosis in rheumatoid arthritis,"
Henry Ford Hospital Medical Journal
: Vol. 25
Available at: https://scholarlycommons.henryford.com/hfhmedjournal/vol25/iss2/3