An increased factor VIII antigen as an indicator of endothelial damage in measles

Effect of cyclosporine A on the release of tissue factor pathway inhibitor from endothelial cells in heart transplant patients and cell culture

We investigated the influence of cyclosporine A on the concentration of tissue factor pathway inhibitor and von Willebrand factor antigen in plasma of heart transplant outpatients. Tissue factor pathway inhibitor was quantified in plasma of blood donors (n = 50) and heart transplant outpatients (n = 50) by a chromogenic substrate assay with a mean of 32.4 micrograms/l and 98.2 micrograms/l, respectively. Von Willebrand factor antigen was determined with an enzyme-linked immunoassay with a mean of 90.9% for blood donors and 184.5% in plasma of heart transplant recipients. In addition, we investigated the effect of cyclosporine A on endothelial cell cultures over an incubation period of four days. A dose-dependent effect of cyclosporine A on the release of endothelial tissue factor pathway inhibitor and von Willebrand factor antigen was determined in a concentration range from 100 to 200 micrograms/l cyclosporine A. The tissue factor pathway inhibitor and von Willebrand factor antigen concentrations in the cell culture supernatant increased during the incubation time according to the cyclosporine A concentration 2-3 fold and 2 fold, respectively. For a further elucidation of the cyclosporine A effect we investigated the influence of cremophor EL, the vehicle of cyclosporine A. Cremophor EL alone did not increase the tissue factor pathway inhibitor release. However, the release was enhanced 2-4 fold after co-stimulation with the calcium ionophore A 23187 (10(-4) mol/l) in a concentration-dependent mode. We conclude that a generalized endothelial damage or activation is most probably caused by cyclosporine A and its vehicle cremophor EL. This process probably depends upon the increase of cytosolic free calcium, as described for the liberation of von Willebrand factor by endothelial cells.

Systemic responses in patients with intermittent claudication after treadmill exercise

The effect of 5 min treadmill exercise was investigated in claudicant patients and healthy controls; systemic neutrophil count, plasma thromboxane and von Willebrand's factor (a marker for endothelial injury) were measured. Median (interquartile range (i.q.r.)) resting neutrophil count was 5.6 (5.2-6.0) x 10(6) cells l-1 in claudicants and 2.8 (2.6-3.2) x 10(6) l-1 in controls (P < 0.05); this increased in those with claudication to 7.1 (6.2-7.7) x 10(6) l-1 immediately after exercise (P < 0.05). The resting plasma thromboxane level was 32.1 (25.0-60.0) pg ml-1 in claudicants and rose to 135.0 (104.0-141.3) pg ml-1 15 min after exercise, compared with a rise from 25.0 (22.0-33.5) to 55.5 (33.0-67.0) pg ml-1 in controls (P < 0.05). The resting serum von Willebrand's factor level was 127 (110-135) units dl-1 in claudicants compared with 60 (48-71) units dl-1 in controls; this difference persisted after exercise (P < 0.01). In patients with claudication, the level of von Willebrand's factor increased to 150 (140-156) units dl-1 60 min after exercise (P < 0.05). Free radical scavenging capacity was also investigated by measuring the plasma antioxidant activity of glutathione peroxidase and its essential non-metal cofactor selenium. Scavenging capacity was lower in claudicant patients whose median (i.q.r.) glutathione peroxidase activity (change in absorbance per min per ml plasma) was 2.84 (2.39-3.61) versus 3.24 (3.06-3.79) in controls (P < 0.05). Similarly, plasma concentrations of selenium were lower in claudicants at a median (i.q.r.) of 75.0 (58.0-81.0) micrograms l-1 compared with 88.0 (75.0-92.5) micrograms l-1 in controls (P < 0.05). Exercise in claudicant patients leads to neutrophilia and thromboxane production with subsequent endothelial injury. The antioxidant activity of glutathione peroxidase is reduced in patients with claudication and may allow the unopposed action of free radicals to damage endothelium.

Von Willebrand factor antigen in assessment of vasculitis in patients with connective tissue diseases

Von Willebrand factor antigen (vWF:Ag) is synthesized and secreted by endothelial cells. In the present study we tried to assess the relationship between plasma level of vWF:Ag and vascular damage in patients with vasculitis. The study was carried out on 59 patients with connective tissue diseases. Vasculitis was diagnosed by biopsies of the skin. The patients with vasculitis had a significantly elevated level of vWF:Ag; however, no significant correlation between the amount of plasma vWF:Ag and the degree of vasculitis was found. The obtained results show that the plasma level of vWF:Ag may reflect the presence of vascular, especially endothelial, damage in patients with connective tissue diseases.

Quantitative and qualitative assessment of plasma von Willebrand factor in classic Kaposi's sarcoma

BACKGROUND

von Willebrand factor (vWF) is synthesized almost exclusively by endothelial cells and is stored there as ultra-high-molecular-weight multimers. The vWF multimers that are detected in the plasma are smaller than those stored within the endothelium. In two previous studies, comprising small series of cases with classic Kaposi's sarcoma (KS), an endothelium-derived tumor, increased levels of plasma von Willebrand factor antigen (VWF:Ag, the antigenic structure) were reported, suggesting that vWF:Ag may be a marker of endothelium proliferation.

OBJECTIVE

Our purpose was to investigate the quantitative as well as qualitative alterations of plasma vWF in a large series of patients with classic KS at various stages of the disease.

METHODS

Levels of plasma vWF:Ag were studied in 38 patients with classic KS confined to the skin at various stages of the disease and compared with a control group. Thirty-three patients had active KS (i.e., with skin lesions) and five were in remission. In five patients with active KS multimeric analysis of plasma vWF was also performed.

RESULTS

The levels of vWF:Ag were significantly higher among KS patients than in the control group (n = 29, p < 0.01). Levels of vWF:Ag were also significantly higher in patients with active disease as compared with those in remission (p < 0.05). No correlation was found between vWF:Ag levels and the extent of KS. Analysis of the multimeric pattern of plasma vWF showed enhanced staining of all bands, particularly the intermediate and high molecular weight forms, which resemble the endothelial forms as opposed to normal circulating vWF multimers.

CONCLUSION

Quantitative as well as qualitative alterations in plasma vWF were found in patients with KS, which may reflect the destruction or activation of endothelial cells within the lesions. vWF:Ag may serve as a marker of disease activity in classic KS; however, it is not a good marker for the extent of the disease.

Changes in plasma factor VIII complex and serum lipid profile during atherogenesis in cynomolgus monkeys

If endothelial injury plays a prominent role in early atherogenesis, the plasma levels of von Willebrand factor (VWF), which is made within and normally released from endothelial cells, might be expected to rise as a marker of the cellular damage. To evaluate this hypothesis, we measured plasma VWF (as VIIIR:Ag), factor VIII:C, and serum lipids serially up to 37 weeks in 29 adult male cynomolgus monkeys on an atherogenic diet. Factor VIII:C peaked at 113% above baseline by week 10 (p less than 0.0001), then fell and remained 53% below baseline (p less than 0.04) during weeks 20 to 37. However, the overall rise in VWF was not significant. In contrast, serum cholesterol continued to rise after week 21. Serum phospholipids (PL), triglycerides (TG), and free fatty acids (FFA) showed a temporal pattern similar to VIII:C. Significant positive correlations with VIII:C were noted for PL (r = 0.59, p = 0.0001) and TG (r = 0.36, p = 0.0096). At autopsy, small to moderately advanced atherosclerotic lesions were distributed throughout the aortas of the majority of the animals. We conclude that changes in plasma VIIIR:Ag do not correlate with atherogenesis in this model. However, the similar course of VIII:C, TG, and PL suggests that these substances may be involved and perhaps interrelated early in atherogenesis.

Factor VIII related antigen (von Willebrand's factor) in Kawasaki disease

Kawasaki disease is a systemic vasculitis in which secondary development of coronary artery aneurysms can occur. Because Factor VIII related antigen has been found increased in other vasculiditides, VIII R:Ag was measured serially in patients with Kawasaki disease. Factor VIII related antigen was prospectively evaluated in the acute phase of ten patients with Kawasaki disease, all of whom showed increased values at this stage (p greater than 0001). In six children a second sample was drawn at the convalescent phase, and all were normal. Of the original ten patients, two developed coronary artery aneurysms. Acute Factor VIII related antigen levels were not higher nor did Factor VIII related antigen fail to return to baseline in these two patients. Based on our findings, Factor VIII related antigen is elevated in the acute phase of Kawasaki disease and returns to normal levels in the convalescent phase.

Cutaneous and plasma values of von Willebrand factor in AIDS: a marker of endothelial stimulation?

Patients infected by the human immunodeficiency virus (HIV) represent a model in which endothelial proliferation and/or damage are of concern. We studied Von Willebrand factor (VWF) plasma values as a presumed marker of endothelial proliferation in patients with the lymphadenopathy syndrome (LAS) (n = 45), AIDS-related Kaposi's sarcoma (KS) (n = 23), and AIDS opportunistic infections (n = 9), in comparison with normal controls (n = 19) and classical KS (n = 12). VWF was increased in AIDS patients with KS (p less than 10(-6)), in AIDS patients without KS (p less than 10(-7)), and to a lesser extent in classical KS (p less than 10(-3)) and LAS (p less than 10(-2] patients. To evaluate the diffusion of the vascular proliferation in HIV-infected patients, we studied the number of vessels within the superficial dermis of clinically uninvolved skin by an indirect immunoperoxidase method. We used an antibody directed against VWF in skin biopsies from 20 LAS patients and 10 AIDS-related KS patients compared to 11 controls and 10 classical KS patients. An increase in the number of blood vessels in normal skin was found in LAS (p less than 10(-2)), classical KS (p less than 0.05), and AIDS-related KS (p less than 10(-2]. Statistical studies and comparisons between plasma and cutaneous values of VWF indicate that plasma VWF is a good marker of endothelial damage but a poor marker of vascular proliferation in HIV-infected patients.

Haemostatic alterations in malaria correlate to parasitaemia

Fibrin(ogen) degradation products, platelet counts, antithrombin III, and the components of the Factor VIII complex were studied in a total of 80 patients with Plasmodium falciparum, Plasmodium vivax or Plasmodium ovale infections. The haemostatic findings were correlated to the numbers of parasitized erythrocytes and to each other. The results indicate that haemostatic changes in malaria correlate with the degree of parasitaemia. Evidence for moderate hyperfibrinolysis was found in patients with high P. falciparum parasitaemias only. Thrombocytopenia closely corresponded to parasitaemia and to von Willebrand factor levels, but appeared not to be linked to a consumption of coagulation factors. It was concluded that thrombocytopenia in malaria is not indicative of disseminated intravascular coagulation (DIC) but may relate to endothelial damage.

Increased von Willebrand factor antigen in the plasma of patients with vasculitis

The plasma concentrations of von Willebrand factor antigen (vWF:Ag) were determined in 101 patients who had the following diagnoses: vasculitis 8 patients, systemic lupus erythematosus (SLE) 51, rheumatoid arthritis (RA) 28, asthma 7, hereditary angioedema 7. The greatest mean concentration of vWF:Ag, 469% (normal 100% +/- 50), was observed in patients with vasculitis, often without elevation of the erythrocyte sedimentation rate. The mean concentration of vWF:Ag was also increased in both SLE (277%) and RA (194%). Twenty-four patients (15 with SLE, 6 with vasculitis, 3 with RA) had vWF:Ag concentrations greater than 300%. Four of these patients died within 1 year of the date of the study. Of the 15 SLE patients, 9 had vasculitis and 2 had active glomerulonephritis. The 3 RA patients had severe disease associated with extraarticular manifestations. Elevated vWF:Ag may reflect vascular damage, while markedly elevated levels of vWF:Ag appear to indicate a poor prognosis.

Increased factor VIII related antigen in cerebral thrombosis

Changes of Factor VIII related antigen (FVIIIR:Ag) were measured in patients with cerebral thrombosis on day 1-15 (125 cases), 16-45 (acute reaction phase, 70 cases), and during 1.5-5 months (recovery phase, 29 cases) after onset of the disease. FVIIIR:Ag was significantly (P less than 0.001) increased in both acute and recovery phase as compared to 108 healthy controls, although slightly decreased in recovery than in acute phase. The persistently high FVIIIR:Ag levels in acute phase are unlikely to be caused by the so-called acute phase reaction but are probably due to increased synthesis and endothelial changes in atherosclerotic lesions releasing FVIIIR:Ag from its endothelial pool. It suggested that increased FVIIIR:Ag mainly reflects the degree of vascular involvement and it may be used as a marker (or indicator) of arterial endothelial injury in patients with cerebral thrombosis.

Factor VIII-related antigen and procoagulant activity in manic-depressive patients

Factor VIII-related antigen (VIIIR:AG) and procoagulant activity (VIII:C) were measured at weekly intervals in 11 manic-depressive patients during their hospital stay. There were significant correlations between VIII:C (P less than 0.02), VIIIR:AG (P less than 0.05) and the number of hospital admissions over a 10-year period. The patients' VIIIR:AG showed a wider range of results as compared to a control group (P less than 0.01). The age of onset of the disease (but not the age of the patient) was related to VIIIR:AG (P less than 0.02).

Factor VIII complex in myelomatosis and related disorders

The behaviour of the factor VIII/von Willebrand factor complex (VIII:C, VIIIR:Ag and VIIIR:RCof) was investigated in 23 patients with secretory myeloma, in 2 patients with non-secretory myeloma and in 5 patients with macroglobulinemia. In most patients (21 of 25 patients with plasma cell myeloma and 2 of 5 patients with macroglobulinemia) VIIIR:Ag was increased usually without corresponding increases in VIII:C and VIIIR:RCof. There was no correlation between the VIIIR:Ag levels and paraprotein Ig type or level nor with the presence or the absence of Bence Jones proteins in serum and urine. Furthermore, increased levels of VIIIR:Ag were found in patients with non-secretory myeloma. In general, VIIIR:Ag was higher in patients with extensive bone lesions and there was a significant correlation between cell mass and the VIIIR:Ag level. The crossed-immunoelectrophoresis of plasmas with discrepant VIIIR:Ag and VIIIR:RCof showed variation from the normal pattern.

Relationships between metabolic and hemostatic variables in uncomplicated diabetes

Several metabolic (HbA1, HDL-C, triglycerides) and hemostatic (VIIIR: Ag, VIII:C, B-TG variables were investigated in 35 non-obese, insulin-dependent diabetics without clinically evident vascular complications. B-TG was high but did not correlate with other metabolic and hemostatic parameters, suggesting that elevated B-TG in diabetes might be an expression of in vitro platelet activation. VIIIR: Ag and the ratio of VIIIR: Ag to VIII: C were markedly increased. There was a significant correlation of the HbA1 and HDL-C levels with VIIIR: Ag, indicating that VIIIR:Ag is another reflection of metabolic control in diabetes. Additional pathogenic mechanisms, however, appear to be involved in causing the changes in VIIIR: Ag in diabetes.