Lack of evidence for abnormal fibrinolysis in chronic low back pain

It has been reported that plasma fibrinolytic activity is abnormal in some patients with chronic low back pain. In an attempt to confirm this finding we studied 22 patients with chronic mechanical low back pain and compared them with 18 healthy controls who denied symptoms of back pain. Factors known to interfere with plasma fibrinolysis such as age, weight, seasonal and diurnal variation, exercise, smoking and drugs were controlled as far as possible. Plasma fibrinogen was significantly higher (2.8 versus 2.3 g/l, P < 0.005) in patients than in controls, but there were no significant differences in the median plasma concentrations of euglobulin clot lysis time, fibrin plate lysis area, plasminogen, alpha-2-antiplasmin, tissue plasminogen activator activity, and antigen, tissue plasminogen activator inhibition and plasminogen activator inhibitor-1 antigen level. The results fail to confirm abnormalities of plasma fibrinolytic activity in a group of unselected cases of chronic low back pain.