SummaryThe fibrinolytic system was investigated in 120 patients with spontaneous or recurrent deep vein thrombosis (DVT) without any known organic disease able to explain by itself the occurrence of a thrombosis and without any known defect of antithrombin III, Heparin Cofactor II, Protein C, or Protein S. The assays included: Euglobulin fibrinolytic activity (EFA), tissue-type plasminogen activator related antigen (t-PA-Ag) and plasminogen activator inhibitor activity (PA inhibitor), which were measured before and after 10 min of venous occlusion (V. O.). On the basis of the results, the patients could be classified in 3 groups:good responders with an at least two-fold increase of EFA after venous occlusion (n = 76), poor responders with a lesser increase of EFA due to deficient release of t-PA (n = 12), and poor responders with a normal t-PA release but an increased level of PA-Inhibitor (n = 32).The poor responders due to deficient t-PA release (10% of total) had a higher incidence of recurrence of deep vein thrombosis, than the other groups (p <0.01). An overall correlation was found between the level of PA-Inhibitor activity and the triglyceride level (r = 0.40, p <0.01), suggesting that these elevations may be due to a common cause, at least in some of the patients.It is concluded that a poor fibrinolytic response to venous occlusion occurs in 35 percent of DVT patients. Poor responders however fall into two categories, one fourth with deficient t-PA release who have a high risk for recurrent venous thrombosis, and three fourth with increased PA-Inhibitor levels which may be associated with underlying diseases also causing hypertriglyceridemia. Further elucidation of the correlation between recurrent venous thrombosis and deficient fibrinolysis is expected to result in more specific and adequate treatment and prevention of DVT.

Vascular access thrombosis (VAT) is frequent in some hemodialysis patients. Antiphospholipid antibodies (APL) have been involved in thrombosis, and have been reported to be present in a high proportion of patients with chronic renal failure. We studied the relationship between APL and thrombosis in 97 hemodialysis patients (HD). Lupus anticoagulant (LA) was assessed by activated partial thromboplastin time (APTT) and by tissue thromboplastin inhibition assay (TTI). IgG-anticardiolipin (ACA) was measured by a solid phase ELISA. The prevalence of APL was 31%; LA was found in 16.5% and was detected in all cases by TTI. Only one patient was positive for APTT. ACA was found in 15.5%. Only one patient was positive for LA and ACA. We found no relation between APL and age, length of time on dialysis, sex, type of dialysis membrane, drugs, and chronic B and C hepatitis. A high prevalence of APL was found in patients with undetermined nephropathy. When histories of thrombosis were examined, VAT was found to be significantly more frequent in patients with LA than in patients without LA (62% vs. 26%; P = 0.01). This relation was not present with ACA. Since VAT is one of the most frequent causes of morbidity for HD, diagnostic evaluation of VAT in HD should now include assay for LA.

F Fi ib br ri in no ol ly yt ti ic c a an nd d i in nf fl la am mm ma at to or ry y p pr ro oc ce es ss se es s i in n p pl le eu ur ra al l e ef ff fu us si io on ns s F. Philip-Joët*, M-C. Alessi**, C. Philip-Joët**, M. Aillaud**, J-R. Barriere*, A. Arnaud*, I. Juhan-Vague** Sixty patients with pleural effusion were studied. The underlying aetiology was empyema in 10 cases, tuberculosis in 9, cancer in 31, cardiac failure in 7, and undetermined in 3. Plasminogen, plasminogen activator inhibitor 1 (PAI-1) and 2 (PAI-2), tissue type plasminogen activator (t-PA), urokinase (u-PA) and D-dimers (D-D) were quantified in plasma samples and pleural effusion specimens. These data were then correlated with inflammatory or infectious parameters, i.e. fibrinogen, von Willebrand factor (vWF), erythrocyte sedimentation rate (ESR), protein concentration, and white blood cell count.D-D levels were higher in pleural fluid than in plasma. D-D levels were not correlated with either plasminogen activator or plasminogen activator inhibitor levels, suggesting the presence of other fibrinolytic pathways. PAI levels (PAI activity, PAI-1 antigenicity, PAI-2 antigenicity) and vWF levels were significantly higher in patients with tuberculosis and empyema than in patients with cancer or cardiac failure. Regression analysis between inflammatory and fibrinolytic parameters showed that pleural PAI levels were significantly correlated with pleural neutrophil count, vWF levels, and plasma fibrinogen levels. D-D levels were correlated with blood ESR. No significant difference in pleural t-PA, u-PA and D-D levels was observed between aetiologies. The highest pleural t-PA and u-PA values were noted in patients with cancer, especially lymphoma. Plasma t-PA levels were higher in patients with pleural effusion secondary to congestive heart failure, but this difference did not reach statistical significance.In conclusion, pleural PAI levels are related to polymorphonuclear count and vWF levels, i.e. to inflammatory processes. Elevated levels of plasminogen activators suggest a possible role in some malignant pleural diseases.

SummaryThe mechanism underlying diurnal variations in PAI-1 as well as the cellular origin of PAI-1 in subjects with high PAI-1 levels are unknown. We evaluated diurnal changes (8:00 am vs 4:00 pm) in PAI-1 (functional and immunological assays), t-PA Ag and t-PA/PAI-1 complex levels in controls and subjects with high PAI-1 levels. Three test groups were recruited among obese hyperinsulinmic subjects, emergency care unit patients with inflammatory syndrome or infection and pregnant women.The classical afternoon decrease of PAI-1 level was observed in controls and obese subjects but its amplitude was greater in the latter. The decrease in t-PA Ag and t-PA/PAI-1 complex levels was the same in controls and in obese. As, in previous studies, elevated PAI-1 levels have been correlated with insulin resistance and a decrease in insulin sensibility has been described in the early morning, it is proposed that this “dawn phenomenon” could be implicated in the circadian variations of PAI-1 in controls and could be amplified in obese subjects. Great variability in PAI-1, t-PA Ag or t-PA/PAI-1 complex levels was observed in patients with acute inflammatory syndrome or infection for whom classical biorhythms are suppressed. No diurnal changes in PAI-1 and other fibrinolytic parameters were observed in patients with inflammatory syndrome or in pregnant women suggesting that other sources and/or other regulatory mechanisms of PAI-1 production are involved.