Imbalance of tissue-type plasminogen activator (t-PA) and its specific inhibitor (PAI-1) in patients with rheumatoid arthritis associated with disease activity

Summary The relationship between plasma fibrinogen, D-dimer (DD), t-PA and PAI-1 and their correlation with disease activity (DA) were studied in 45 patients with rheumatoid arthritis (RA) (group B) to further understand the implication of fibrinolysis in the pathophysiology of RA. The control group constituted 24 healthy subjects (group A). A Stoke index (SI) of DA was assigned to each patient. Patients were divided into two groups: C, minimal-mild DA (SI 1–7); D, moderate-severe DA (SI 8–17). Fibrinogen was elevated in RA correlating positively with SI and CRP. Hypercoagulability counteracted by reactive fibrinolysis was inferred from a 10-fold increase of DD in group B as compared to group A. The relatively lower levels of DD in group D compared to group C and their negative correlation with SI (r_s=–0.45, –0.49, p=0.0006) indicate the tendency of fibrinolysis to decrease with the increase of DA. Significant elevation of t-PA and PAI-1 were found in group B compared to group A. While t-PA progressively decreased with the increase of DA (r_s=–0.45, p=0.0019), a positive relation of PAI-1 to DA was observed (r_s=0.42, p=0.0042). A 2-fold increase of PAI-1/t-PA molar ratio in group D compared to groups A and C as well as its positive correlation with SI (r_s=0.63, p=0.0001) indicate the displacement of balance between t-PA and PAI-1 in favour of the inhibitor with the increase of DA in RA. The involvement of inflammatory mediators in PAI-1/t-PA imbalance was proposed from the relation of fibrinolytic abnormalities with the activity of systemic inflammatory process.     

Increased adipose tissue secretion of interleukin-6, but not of leptin, plasminogen activator inhibitor-1 or tumour necrosis factor alpha, in Graves' hyperthyroidism

OBJECTIVE: This study was designed to investigate adipose tissue secretion of interleukin-6 (IL-6), leptin, tumour necrosis factor alpha (TNF-alpha) and plasminogen activator inhibitor-1 (PAI-1) in Graves' hyperthyroidism. DESIGN: We studied 10 patients before and during (after 8 weeks) anti-thyroid treatment for Graves' hyperthyroidism and 16 healthy, euthyroid control subjects. METHODS: Plasma levels of thyroid hormones and serum/plasma levels of IL-6, leptin, TNF-alpha and PAI-1 were analysed. Subcutaneous fat biopsies were taken for subsequent measurement of IL-6, leptin, TNF-alpha and PAI-1 protein secretion. RESULTS: In patients with Graves' disease, the anti-thyroid treatment resulted in significant reductions of plasma thyroxine and triiodothyronine levels. No differences in serum concentration or adipose tissue secretion of leptin or TNF-alpha were observed either before, as compared with during, anti-thyroid treatment, or in comparison with euthyroid controls. In contrast, plasma PAI-1 activity, but not adipose tissue secretion of PAI-1, was increased both in Graves' disease before as compared with during anti-thyroid treatment (P=0.01) and in thyrotoxic patients compared with euthyroid controls (P=0.0001). Finally, adipose secretion of IL-6 was increased both before (8-fold, P=0.001) and during (6-fold, P<0.0001) treatment as compared with control subjects. Accordingly, serum concentration of IL-6 was also increased by about 50% in thyrotoxic patients as compared with healthy controls (P=0.03). CONCLUSIONS: In Graves' hyperthyroidism regardless of thyroid status, adipose tissue secretion of IL-6, but not of leptin, TNF-alpha or PAI-1, is markedly increased in comparison with euthyroid controls. This suggests that autoimmune thyroidal disorder may regulate adipose tissue release of IL-6.     

ORIGINAL CLINICAL PAPERS: LONGITUDINAL BONE MINERAL DENSITY CHANGES IN EARLY RHEUMATOID ARTHRITIS

A prospective longitudinal study of patients with early RA wasperformed to examine the influence of disease duration, diseaseactivity and physical activity on bone loss. Sixty-seven patientswith non-steroid treated RA of less than 5 yr duration, including16 patients with disease duration less than 6 months, had BMDmeasurements of the femoral neck and the lumbar spine over a12-month period using dual energy X-ray absorptiometry. TheBMD changes were compared with values from 72 control patientsand were also correlated with serial measurements of diseaseactivity (measured by the Stoke Index) and disability [measuredby the Health Assessment Questionnaire (HAQ) score], at 3-monthlyintervals over the 12-month period. No significant differencesin BMD changes were found between RA patients and controls overall.Patients with disease duration of less than 6 months had significantlygreater loss of BMD at the femoral neck (–3.9%, S.E.M.1.5) than the remainder of the cohort (–0.2%, S.E.M. 0.7)(P = 0.02) and controls (–0.8%, S.E.M. 0.6). Lumbar spineBMD changes correlated with the initial Stoke Index (Rs–0.373,P = 0.01) but not mean Stoke Indices. There was no correlationof BMD changes with age or HAQ scores. These findings suggestthat significant bone loss occurs within the first few monthsof disease in patients with RA. KEY WORDS: Rheumatoid arthritis, Bone mineral density, Stoke Index, Health Assessment Questionnaire     

丹红注射液对不稳定型心绞痛病人炎症反应物及纤溶活性的影响

目的探讨丹红注射液对不稳定型心绞痛(UA)病人血浆炎症反应物及纤溶活性的影响。方法140例UA病人随机分为常规治疗组(67例)和丹红治疗组(73例),另设正常对照组50名。丹红治疗组于常规治疗基础上加用丹红注射液20mL静脉输注,每日1次,疗程为3周。两组分别于治疗前及结束时测定血清C-反应蛋白(CRP)、白细胞介素-6(IL-6)、纤维蛋白原(FIB)、D-二聚体(DD)浓度和组织型纤溶酶原激活物(t-PA)、纤溶酶原激活物抑制物-1(PAI-1)活性。结果丹红注射液治疗3周后,CRP,IL-6,FIB,DD,PAI-1水平下降(P<0.05或P<0.01),t-PA活性升高(P<0.01)。治疗前UA病人的CRP与IL-6,PAI-1,DD呈正相关(P<0.05或P<0.01),与t-PA呈负相关(P<0.01)。丹红治疗组治疗后CRP与IL-6,PAI-1呈正相关(P<0.05或P<0.01),与t-PA呈负相关(P<0.05)。结论UA病人应用丹红注射液治疗,可能有利于抑制炎症反应,改善内皮功能,提高纤溶活性,稳定斑块。     

Treatment of Raynaud's phenomenon with intravenous prostaglandin E1alpha-cyclodextrin improves endothelial cell injury in systemic sclerosis

OBJECTIVE: To evaluate the efficacy and safety of prostaglandin (PG) E1alpha-cyclodextrin for Raynaud's phenomenon (RP) secondary to systemic sclerosis (SSc) and its effect on variables of immune activation and endothelial injury in SSc such as tumor necrosis factor-alpha (TNF-alpha), soluble interleukin 2 receptor (sIL-2R), circulating intercellular adhesion molecule-1 (cICAM-1), von Willebrand factor (vWF), and tissue-type plasminogen activator (t-PA). METHODS: We studied 36 women with SSc, 24 of them given three 60 microg intravenous PGE1alpha-cyclodextrin infusions on 5 consecutive days at 6 week intervals during the winter. RP symptoms and healing of digital lesions were evaluated. Twenty age matched healthy women were the controls. TNF-alpha, sIL-2R, cICAM-1, vWF, and t-PA were measured after the first and last infusion of PGEE1alpha-cyclodextrin and correlated with clinical features. RESULTS: RP symptoms improved in 87% of the patients. The benefit of each 5 day cycle lasted 4 or more weeks in 75%. PGE1alpha-cyclodextrin reduced the daily frequency of RP symptoms by 20% (p < 0.05), 41% (p < 0.005), and 53% (p < 0.0005) from baseline after the 1st, 2nd, and 3rd infusions, respectively. The severity of the attacks was reduced to a limited degree. In 12 of the 14 patients with digital lesions, these healed completely. Ten patients had mild side effects during treatment (headache, increased intestinal motility, flushing). TNF-alpha, sIL-2R, cICAM-1, vWF, and t-PA plasma concentrations were significantly higher in patients with SSc than controls (p < 0.05, p < 0.001). TNF-alpha, sIL-2R, and cICAM-1 were higher in diffuse SSc and patients with lung involvement. The plasma levels of cICAM-1 and t-PA were significantly reduced after the 1st infusion of PGE1alpha-cyclodextrin (both p < 0.005) and further reduced after the last (p < 0.0005 and p < 0.005). CONCLUSION: PGE1alpha-cyclodextrin reduces RP symptoms and plasma levels of the markers of endothelial injury in SSc, suggesting that an improvement of endothelial dysfunction contributes to its prolonged therapeutic effect.     

Plasma t-PA/PAI-1 complex and blood coagulability in patients with coronary artery disease.

The t-PA/PAI-1 complex is a good indicator of the release of fibrinolysis activators and inhibitors from the vascular wall, but its clinical significance in chronic ischemic heart disease is unclear. The plasma levels of tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), and the t-PA/PAI-1 complex (including various coagulation factors) were assayed in 72 patients with coronary artery disease (CAD) and 29 control (C) subjects. The CAD patients were subdivided into 3 groups: single-vessel disease (G1, n = 30), double-vessel disease (G2, n = 20), and triple-vessel disease (G3, n = 22). The patients with triple-vessel disease had higher fibrinogen values (G3: 318 +/- 75 mg/dl, C: 263 +/- 56), factor VII activity (G3: 143 +/- 36%, C: 123 +/- 14), and t-PA antigen levels (G3: 4.7 +/- 0.8 ng/ml, C: 3.3 +/- 0.7) than controls. Patients with double- and triple-vessel disease also showed higher levels of factor VIII, vWF antigen, thrombin-antithrombin III complex (G1: 2.3 +/- 0.6 ng/ml, G2: 2.7 +/- 0.5, G3: 3.1 +/- 0.5, C: 2.0 +/- 0.5), and t-PA/PAI-1 complex (G1: 13.9 +/- 6.1 ng/ml, G2: 16.4 +/- 4.6, G3: 18.2 +/- 5.9, C: 10.7 +/- 4.9) than control subjects. The t-PA/PAI-1 complex levels were correlated significantly with the activities of factors VII and VIII and the thrombin-antithrombin III complex. These findings suggest that patients with CAD have greater blood coagulability than controls, and that this difference is related to the severity of the disease.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effects of TNF alpha inhibition on plasma fibrinolytic balance in patients with chronic inflammatory rheumatical disorders

OBJECTIVE: Recent studies support an inflammatory basis for atherosclerosis. Patients with chronic inflammatory rheumatical disorders are at increased risk for cardiovascular events, and this can be partially attributed to the inhibition of fibrinolytic system. TNF a inhibitors such as infliximab are shown to retard the progression of inflammatory arthritides. In this study, we investigated the effects of infliximab on plasma fibrinolytic parameters. METHODS: Thirteen patients (7 female, 6 male; mean age: 44 +/- 11 years) with a clinical indication for infliximab (rheumatoid arthritis (RA) (n = 8), ankylosing spondylitis (AS) (n = 5)) were selected. Plasma plasminogen activator inhibitor (PAI-1), tissue plasminogen activator (t-PA) antigens (Ag) and high sensitive C-reactive protein (hs-CRP) levels were measured during low salt intake at baseline. All patients received infliximab (Remicaide, i.v. infusion, 3 mg/kg). Plasma PAI-1 Ag, t-PA Ag and hs-CRP were measured during low salt intake at the end of 2 weeks. All samples were collected at 9 AM. Antigen levels were determined using a 2-site enzyme-linked immunosorbent assay. RESULTS: Patients experienced significant improvement in disease related activity scores after infliximab treatment. DAS score (for rheumatoid arthritis) and BASDAI index (for ankylosing spondylitis) decreased significantly after treatment (p = 0.01 and p = 0.04 respectively). Infliximab significantly reduced the marker of inflammation (hs-CRP) (8.3 +/- 3.9 vs. 4 +/- 4.1 mg/L, p < 0.01). Plasma PAI-1 antigen (64.7 +/- 26.9 vs. 40 +/- 31.1 ng/ml, p = 0.03) and PAI-1/t-PA ratio (10.8 +/- 5.9 vs. 6.6 +/- 3.8, p = 0.02) were significantly lower after the treatment. In contrast, plasma t-PA levels were unchanged (9.4 +/- 4.4 vs. 9.0 +/- 4.3 ng/ml, p = 0.73). CONCLUSION: This study provides evidence that TNF alpha inhibition with infliximab decreases PAI-1 Ag level and PAI-1/t-PA ratio, and hence activates fibrinolytic system in patients with chronic inflammatory disorders.     

Susceptibility for and clinical manifestations of rheumatoid arthritis are associated with polymorphisms of the TNF-alpha, IL-1beta, and IL-1Ra genes

OBJECTIVE: To analyze the association of genetic polymorphisms of pro-inflammatory cytokines with rheumatoid arthritis (RA) in comparison with healthy controls from Northern Sweden and the potential contribution of these genetic variants for disease severity and development of cardiovascular complications. METHODS: Polymerase chain reaction amplification was used for analysis of TaqI restriction fragment length polymorphism (RFLP) of interleukin-1 beta (IL-1beta), variable tandem repeat polymorphism of IL-I receptor antagonist (IL-1Ra) gene and NcoI RFLP at position -308 of tumor necrosis factor-alpha (TNF-alpha) gene. One hundred and fifty-four patients with RA, 42 men and 112 women, were consecutively recruited into the study through the Department of Rheumatology. RESULTS: The allele A1 of TNF-alpha was more common in the patient group (p < 0.01; OR = 1.62). Patients having the genotype A1A2 seemed to develop more severe disease compared with patients with A1A1 genotype: they were younger at disease onset (p < 0.05), had a higher accumulated disease activity (p < 0.05) and worse functional class (p < 0.05). Patients with genotype A2A2 of IL- 1beta had higher accumulated disease activity score than patients with A1A1 and A1A2 (p < 0.05). The allelic combination Al IL-1beta/A2 IL-1Ra was less prevalent in RA patients who developed cardiovascular complications (p < 0.005; OR = 0.20). CONCLUSIONS: The Al allele of TNF-alpha associates with RA. Genotypes A1A2 of TNF-alpha and A2A2 of IL-1beta are associated with more severe disease. The allelic combination A1IL-1beta/A2 IL-1Ra is less often present in RA patients who developed cardiovascular complications.     

Suppression of circulating interleukin-6 concentrations is associated with decreased endothelial activation in rheumatoid arthritis

BACKGROUND: Circulating interleukin (IL)-6 concentrations are associated with endothelial activation in rheumatoid arthritis (RA). OBJECTIVE: To assess endothelial activation before and after suppression of cytokine production in RA. METHODS: Twenty-one patients (mean (SD) age 59 (9) years; disease duration 6 (4) years) were treated with intraarticular methylprednisolone acetate (417 (152) mg) together with disease modifying agent (DMARD) initiation (n = 10) or intensification (n = 11) employing methotrexate (n = 11), leflunomide (n = 8), minocyclin (n = 6) and sulphasalazine (n = 1). Disease activity, circulating cytokines (IL-1, tumor necrosis factor alpha (TNF-alpha) and IL-6) and biomarkers of endothelial activation (circulating vascular adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and endothelial leukocyte adhesion molecule-1 (ELAM-1)) were evaluated before and 2 weeks after treatment. RESULTS: The intervention resulted in reductions in 8 disease activity markers (p < or = 0.002). Serum IL-6 concentrations decreased from 17 (2.9) to 4.9 (4.6) pg/ml (p = 0.0008). Serum IL-1 and TNF-alpha levels did not change (p > or = 0.4). Serum VCAM-1 concentrations decreased from 912 (402) to 752 (252) (p = 0.003), ICAM-1 from 398 (205) to 323 (179) (p = 0.04) and ELAM-1 from 68 (28) to 53 (25) (p = 0.02) pg/ml, respectively. Baseline rheumatoid factor titers were associated with reductions in VCAM-1 (r(s) = 0.481, p = 0.03). In multivariable regression models, decreases in circulating interleukin-6 concentrations were associated with reductions in VCAM-1 (p < 0.0001), ICAM-1 (p = 0.005) and ELAM-1 (p = 0.02) independent of changes in disease activity, weight and blood pressure. CONCLUSION: Our results suggest that suppression of circulating IL-6 concentrations attenuates atherogenesis in active RA.     

Effect of PAI-1 levels on the molar concentrations of active tissue plasminogen activator (t-PA) and t-PA/PAI-1 complex in plasma

We determined the in vivo molar concentrations of active tissue plasminogen activator (t-PA), active plasminogen activator inhibitor type 1 (PAI-1), and t-PA/PAI-1 complex. t-PA activity was measured in plasma stabilized by immediate acidification. PAI-1 activity and t- PA/PAI-1 complex antigen were measured in citrated plasma; these measurements were corrected for the loss in PAI-1 activity and increase in complex that occurs in unacidified plasma samples due to the continued reaction between t-PA and PAI-1 after the sample was drawn. To convert t-PA and PAI-1 activity measurements into molar concentrations we determined the specific molar activity of t-PA and PAI-1 in vivo: 4.48 x 10(13) IU/mol. Of 72 subjects studied, 13 had less than 150 pmol/L active PAI-1; in these individuals 33% +/- 21% of their t-PA was active and the molar ratio of active t-PA to active PAI- 1 was 0.20 +/- 0.13. In the 11 subjects with greater than 500 pmol/L active PAI-1, 1.5% = 1.1% of the t-PA was active and the molar ratio of active t-PA to active PAI-1 was 0.0043 +/- 0.0036. Overall, the fraction of active t-PA declined exponentially as a function of the active PAI-1 concentration. During the day, the percentage of total t- PA that was active increased from 12% at 8:00 AM to 31% at 8:00 PM, while the molar ratio of active t-PA to active PAI-1 increased from 0.05 to 0.22 from morning to evening (n = 12).     

Mirthful laughter differentially affects serum pro- and anti-inflammatory cytokine levels depending on the level of disease activity in patients with rheumatoid arthritis

OBJECTIVES: To examine the effect of mirthful laughter in rheumatoid arthritis (RA), we evaluated the levels of serum cytokines before and after patients experienced mirthful laughter. METHODS: Forty-one patients with RA and 23 healthy subjects were enrolled. They listened to 'Rakugo', a traditional Japanese comic story, to induce mirthful laughter. We measured serum IL-6, IL-1beta, TNF-alpha, IL-4 and IL-1 receptor antagonist (IL-1Ra) concentrations before and after patients listened to the story. The RA subjects were divided into two groups. One was designated the 'difficult-to-control RA' group (CRP > or =1.0 mg/dl); The other group was regarded as the 'easily controlled RA' group (CRP <1.0 mg/dl). RESULTS: The basal levels of serum IL-6 and TNF-alpha in the RA patients were significantly higher than those in the healthy group. After experiencing mirthful laughter, the levels of serum IL-6 decreased significantly in the RA group but not in the healthy subjects. Interestingly, the level of serum TNF-alpha decreased only in the easily controlled RA group. Serum IL-4 concentration in the RA group was significantly higher than that in healthy subjects before the story. After the story, the level of serum IL-4 significantly decreased in the RA group, especially in the difficult-to-control RA group. In contrast, serum IL-1Ra concentration was statistically higher in the RA group than that in healthy subjects before the story, and a further increase was observed after the story, especially in the easily controlled RA group. CONCLUSIONS: Our findings suggest that mirthful laughter affects the levels of serum pro- and anti-inflammatory cytokines differentially, depending on the RA disease activity.     

Serum and in vitro production of IL-1 receptor antagonist correlate with C-reactive protein levels in newly diagnosed, untreated lupus patients

OBJECTIVE: To examine the correlation between C-reactive protein (CRP) and CRP-inducing cytokines (IL-1 beta, IL-6, TNF-alpha) and IL-1 receptor antagonist (IL-1ra), as well as to study their relationship with systemic lupus erythematosus disease activity (SLEDAI) in newly diagnosed, untreated lupus patients. METHODS: Sera from newly diagnosed untreated lupus and rheumatoid arthritis (RA) patients were examined for CRP and cytokines. Data were compared among patient groups and correlated individually among the lupus group. Lupus monocytes and neutrophils were cultured in vitro to produce IL-1ra and experimental results were related to CRP levels and SLEDAI. RESULTS: Within lupus, serum CRP, IL-6, IL-1 beta and TNF-alpha levels were significantly lower than those of RA (all p values were < 0.005) and generally higher than those in the controls (p = 0.002, < 0.001, > 0.2, and < 0.001, respectively). Except IL-1ra, which was correlated with CRP (p = 0.045), no substantial correlation was discovered between CRP and IL-6, IL-1 beta or TNF-alpha individually. Moreover, excluding IL-1ra (p = 0.024), there was no association between cytokines and SLEDAI. In vitro IL-1ra as secreted by monocytes correlated with serum CRP and SLEDAI. CONCLUSION: In lupus patients, serum IL-1 beta, IL-6 or TNF-alpha levels failed to correlate with low CRP levels. This indicates a complicated CRP production process, which can not be explained solely by single cytokines as reported previously. Both serum and in vitro produced IL-1ra may be applied clinically as a surrogate CRP marker in untreated lupus patients as they are both correlated with serum CRP.     

老年糖尿病患者脂肪餐后血管内皮活性因子的变化

目的 观察老年糖尿病患者脂肪餐后血管内皮活性因子的动态变化及其与血脂的关系. 方法 选择老年糖尿病患者(糖尿病组)36例和健康老年人(对照组)20例进行6 h脂肪餐负荷试验.糖尿病组根据空腹和脂肪餐后4 h三酰甘油(TG)水平分为空腹TG增高组、餐后TG增高组和餐后TG正常组3个亚组.各组均测定脂肪餐前后血清一氧化氮(NO)、内皮素-1(ET-1)、纤溶酶原激活物抑制物-1(PAI-1)、组织型纤溶酶原激活物(t-PA)的浓度,并分析与TG的相关性. 结果 (1)NO、ET-1及NO/ET-1的变化:对照组脂肪餐后2 h NO浓度显著升高、ET-1水平显著降低,6 h均恢复至餐前水平;而糖尿病各亚组脂肪餐后NO逐渐降低、ET-1逐渐升高,餐后6 h变化最为明显.与对照组比较,糖尿病各亚组脂肪餐后各点NO/ET-1均显著降低(P<0.01),而餐后TG增高组和空腹TG增高组与餐后TG正常组比较差异有统计学意义(P<0.05或P<0.01).(2)t-PA、PAl-1及PAl-1/t-PA的变化:各组脂肪餐后4 h PAl-1水平轻度升高、t-PA水平轻度降低;与对照组比较,糖尿病组PAI-1/t-PA显著升高,糖尿病各亚组比较,餐后TG增高组和空腹TG增高组显著高于餐后TG正常组(P<0.05或P<0.01).(3)与TG的相关性分析:直线相关分析显示,糖尿病组TG与NO、t-PA显著负相关(r=-0.360,P<0.05;r=-0.649,P<0.01),与ET-1、PAI-1显著正相关(r=0.421,P<0.01;r=0.520,P<0.01). 结论 老年糖尿病患者存在血管内皮活性因子平衡失调,血脂异常可加重这一改变和血管内皮功能的损伤.     

辛伐他汀对冠心病患者纤溶参数的影响

目的了解冠心病患者纤溶参数的变化,并观察辛伐他汀对冠心病患者纤溶参数的影响。方法测定87例正常对照者和108例冠心病患者血浆组织型纤溶酶原激活物(t-PA)活性和纤溶酶原激活物抑制物-(1PAI-1)活性,随后108例冠心病患者被随机分成常规治疗组和常规治疗+辛伐他汀40mg每日一次(辛伐他汀组)。治疗14d后复测t-PA活性和PAI-1活性。结果与正常对照组相比较,冠心病患者纤溶参数异常,t-PA活性下降,PAI-1活性上升(P<0.01)。常规治疗组治疗后纤溶参数无显著变化(P>0.05)。辛伐他汀组纤溶参数明显改善,表现为t-PA活性上升,PAI-1活性下降(P<0.01)。结论冠心病患者纤溶参数明显异常,辛伐他汀能改善冠心病患者纤溶参数。     

A lifelong bleeding disorder associated with a deficiency of plasminogen activator inhibitor type 1

A 36-year-old patient was investigated for a lifelong history of epistaxis and delayed bleeding after minor surgeries. Deficiencies or abnormalities of the coagulation system, of platelet function, or of factor XIII and alpha-2-antiplasmin were excluded. Consistently, however, over a period of 7 years, a high basal euglobulin fibrinolytic activity was observed that was characterized by a high tissue-type plasminogen activator (t-PA) activity, normal t-PA antigen, and undetectable plasminogen activator inhibitor type-1 (PAI-1) antigen and activity. The high specific activity of t-PA (640,000 IU/mg) and the minimal amounts of t-PA/PAI-1 complexes detected by fibrin zymography suggest that in this patient all t-PA was active. This is in striking contrast to normal plasma, where the majority of t-PA is complexed to PAI-1. Thus, in this patient, a severe deficiency of PAI-1 is associated with a delayed type bleeding tendency. Our observation underscores the importance of plasma PAI-1 for the stabilization of the hemostatic plug.     

Effect of levothyroxine replacement therapy on coagulation and fibrinolysis in severe hypothyroidism

OBJECTIVE: We previously demonstrated that patients suffering from moderate hypothyroidism were at increased risk of thrombosis contrasting with the bleeding tendency of those presenting severe hypothyroidism. The latter state is associated with hemostatic anomalies including von Willebrand type 1 disease and increased fibrinolytic capacity. With the exception of von Willebrand type 1 disease, reversibility of hemostatic changes is not established after levothyroxine replacement therapy. Therefore our objective was to analyze the reversibility of these anomalies. MATERIALS AND METHODS: We analyzed the impact of levothyroxine treatment on lipid parameters, fibrinogen, platelet count, D-dimers, alpha2 antiplasmin activity, plasminogen activity, tissue plasminogen activator antigen (t-PA Ag), plasminogen activator inhibitor type 1 antigen (PAI-1 Ag) and coagulation factors (factor VIII coagulant, von Willebrand factor antigen, von Willebrand factor and factor IX) in 23 patients with severe hypothyroidism (TSH level > 50 mU/ I). RESULTS: Mean fibrinogen levels increased by 14.2% while t-PA Ag and PAI-1 Ag increased by 42.6 and 69%, respectively, after correction of hypothyroidism. Interestingly, post-treatment PAI-1 Ag levels tended to be higher in patients with normal-high final TSH levels than in patients with normal-low final TSH levels. Our results suggest that normalization of fibrinolysis is obtained after a transient decrease of fibrinolytic activity. We also confirmed the correction of coagulation factor abnormalities upon levothyroxine replacement therapy. CONCLUSIONS: We demonstrated that the coagulation disorders and the hyperfibrinolytic status of severe hypothyroid patients were corrected upon levothyroxine therapy. However, the clinical consequences of the transient decrease of the fibrinolytic activity during the course of TSH normalization need further studies.     

High serum and synovial fluid granulocyte colony stimulating factor (G-CSF) concentrations in patients with rheumatoid arthritis

OBJECTIVE: To determine the relationship between serum G-CSF, RA disease activity and the levels of inflammatory cytokines. METHODS: Sixty-one patients (5 men and 56 women; mean age; 56.1 +/- 11.4 [+/- SD] years, range, 22-70 years) who were selected at random and met the American College of Rheumatology criteria for RA were examined. Granulocyte-colony stimulating factor (G-CSF) levels in sera and synovial fluid were measured by solid-phase radioimmunoassay (RIA). We also measured various indices of RA disease activity and serum levels of IL-1 beta, IL-6 and TNF-alpha by ELISA. RESULTS: The morning stiffness, number of tender or swollen joints, ESR, Lansbury index and serum G-CSF levels in patients with active RA were significantly higher than the corresponding levels in patients with inactive RA. Serum G-CSF levels correlated significantly with morning stiffness, the number of tender or swollen joints and the Lansbury index. However, there was no correlation between serum G-CSF and ESR. High levels of IL-1 beta, IL-6 and TNF-alpha were detected in RA patients. The number of tender or swollen joints, ESR, Lansbury index, and IL-1 beta were significantly higher in G-CSF-positive RA patients than in G-CSF-negative RA patients. CONCLUSION: Our results suggest that G-CSF produced by synovial cells stimulated by inflammatory cytokines might contribute to inflammatory arthritis in RA patients.     

Endothelin-1 enhances plasminogen activator inhibitor-1 production by human brain endothelial cells via protein kinase C-dependent pathway.

The effects of endothelin-1 (ET-1) on the production of plasminogen activator inhibitor 1 (PAI-1) and tissue plasminogen activator (t-PA) by human brain-derived endothelial cells in culture were studied. At 100 nmol/L, ET-1 increased PAI-1 production by 88+/-6% within 72 hours, and increased PAI-1 mRNA expression within 1 hour of stimulation; there was no significant effect on t-PA production. PAI-1 activity was also examined and found to increase with ET-1 treatment. Suboptimal concentrations of ET-1 and tumor necrosis factor-alpha (TNF-alpha) acted synergistically to increase PAI-1 production. ET-1 activated protein kinase C and cAMP-dependent protein kinase pathways within 3 to 5 minutes of treatment, with the peak at 10 minutes. Activation of protein kinase C by phorbol-12-myristate-13-acetate (PMA) resulted in increased PAI-1 production, whereas activation of the cAMP-dependent protein kinase by forskolin or dibutyryl cAMP (dBu-cAMP) significantly decreased PAI-1 production. However, simultaneous activation of protein kinase C by PMA and cAMP-dependent protein kinase by dBu-cAMP only slightly attenuated PMA-induced PAI-1 increase. Inhibition of protein kinase C by GF-109213X abolished the effects of ET-1. These results demonstrate that ET-1 and TNF-alpha function synergistically to induce procoagulant activity of brain endothelial cells in a process that involves a protein kinase C-dependent pathway.     

Tumor necrosis factor-alpha production is associated with less body cell mass in women with rheumatoid arthritis

OBJECTIVE: To examine the relationship between inflammatory cytokine production and body cell mass (BCM) in women with stable, medically well-controlled rheumatoid arthritis (RA). METHODS: Case-control study of 20 women with RA and 20 healthy women matched for age, race, and body mass index (kg/m2). Tumor necrosis factor-alpha (TNF-alpha), interleukin 1beta (IL-1beta), and IL-6 production were measured by specific, non-cross-reacting ELISA of peripheral blood mononuclear cells (PBMC) cultured with and without 100 ng/ml of endotoxin. Total BCM was assessed by the reference method of whole-body counting of naturally occurring radioactive potassium-40. RESULTS: Patients with RA were cachectic, with 14% less BCM (p < 0.001) and higher TNF-alpha production (p < 0.05) than controls. TNF-alpha production was inversely associated with BCM both without (r = -0.51, p = 0.03) and with (r = -0.57, p = 0.01) endotoxin stimulation in patients but not in controls. In multivariate linear regression models, these inverse associations remained significant after adjustment for age and physical activity. No association was found for IL-1beta or IL-6 production in these models. CONCLUSION: Women with stable, medically well-controlled RA have lower than normal BCM that is inversely associated with elevated TNF-alpha production.     

Diurnal variation of tissue-type plasminogen activator and its rapid inhibitor (PAI-1)

Previous studies have shown that overall fibrinolytic activity in blood follows a diurnal rhythm with a peak in the morning and a trough in the evening. The purpose of this study was to determine which fibrinolytic factor(s) was responsible for this diurnal rhythm. Resting and postvenous occlusion tissue-type plasminogen activator (t-PA) activity, resting t-PA antigen, and resting plasminogen activator inhibitor 1 (PAI-1) activity were measured in the morning and evening in 33 healthy men (mean age, 31 years) and in 15 patients (mean age, 57 years) with previous myocardial infarction or unstable angina. PAI-1 activity and t-PA antigen were significantly higher (p less than 0.01) in the morning compared with the evening in controls and patients. In contrast, resting t-PA activity was significantly lower in the morning (p less than 0.01) in both groups and was inversely correlated with PAI-1 activity (r = -0.57, p less than 0.0001). Postvenous occlusion t-PA activity and t-PA capacity were not significantly different between morning and evening in either group. Because t-PA antigen levels and PAI-1 activity were highest in the morning, the variation in t-PA activity was probably not due to decreased secretion of t-PA but instead to changes in the secretion of PAI-1. Our findings indicate that diurnal variations in PAI-1 activity may reduce fibrinolytic activity in the morning in healthy individuals and in patients with coronary artery disease.