Persistence of hemostatic alterations in patients affected by Crohn's disease after bowel surgery

In Crohn's disease (CD) a condition of hypercoagulability with increased risk for thrombotic events has been reported. In this study we have investigated hemostatic parameters in thirty-one patients affected by CD before, 3 and 12 months after bowel operation, and in thirty healthy controls. Before surgery platelet number (PLT), fibrinogen (Fbg), prothrombin fragment F1 + 2 (F1 + 2), PAI and whole blood-spontaneous platelet aggregation (WB-SPA) were significantly higher (p at least < 0.0005) in patients than in controls, while factor XIII (F XIII) was significantly lower (p at least < 0.005). Three and twelve months after surgery PLT, FBG and WB-SPA significantly decreased in comparison to pre-surgery values (respectively p at least < 0.05 and p < 0.01), but PLT and Fbg were still significantly higher than in controls at 3 and 12 months (p < 0.01). At three and 12 months after operation F XIII was significantly higher in comparison with pre-surgery values (p at least < 0.05). The presence of antiphospholipid antibodies (aPL) was not different between CD patients and controls before surgery, whereas it significantly increased 12 months after surgery (p < 0.05). Our results suggest that in CD hemostatic changes are only in part influenced by local flogistic processes and that an inflammatory systemic condition may provoke both the bowel and extraintestinal manifestations of CD.

Acute T-cell activation is detectable in unstable angina

BACKGROUND

Recent studies suggest a role for inflammation in the pathophysiology of unstable angina. This study was designed to investigate whether circulating lymphocytes are involved in the inflammatory reaction associated with the episodes of unstable angina.

METHODS AND RESULTS

Twenty-nine patients with proven unstable angina, 36 with stable angina, and 30 healthy subjects were studied. Both early and short-lived (interleukin-2 receptor [IL-2R], alpha-chain CD25, and transferrin receptor CD71) and late antigen (HLA-DR) expression were investigated by flow cytometric analysis. Soluble IL-2R (sIL-2R) was also measured in plasma by ELISA. Lymphocyte activation was studied at day 1 of hospital admission and after 7, 15, 30, 60, and 90 days. In patients with unstable angina, the number of HLA-DR+ CD3 lymphocytes and levels of sIL-2R were higher (P < .001) than in patients with stable angina and control subjects. Both CD4+ and CD8+ lymphocytes expressed HLA-DR antigens. No differences were found among the different groups of subjects in regard to the expression of CD25 and CD71. Lymphocyte activation was more marked in patients with urgent revascularization. No relationships were found between the number of HLA-DR+ lymphocytes and either the severity of coronary angiographic lesions or the number of ischemic episodes. Observations over time showed a gradual decrease in the number of HLA-DR+ lymphocytes and sIL-2R levels from weeks 3 through 8 to 12.

CONCLUSIONS

The present results indicate that (1) CD4+ and CD8+ circulating lymphocytes are activated in patients with unstable angina, and their activation state lasts 6 to 8 weeks; and (2) activation of lymphocytes is not a consequence of myocardial ischemia. These results support the immune system-mediated inflammatory nature of unstable angina.

Effects of estrogen replacement therapy on thrombin generation

The aim of this study was to investigate the hemostatic system in menopausal women before and after three months of treatment with transdermal estradiol (TTS 50, 50 micrograms/die, n = 13) or coniugated equine estrogen (CEE, 0.625 mg/die, n = 9) by evaluating : beta-thromboglobulin, platelet factor 4, factor VIIag, factor VIIc, fibrinopeptide A-FPA-, thrombin-antithrombin-TAT-complexes, antithrombin-AT-activity, protein C, plasma fibrinolytic activity (euglobulin clot lysis time), plasminogen and antiplasmin activity. FPA levels significantly increased during TTS 50 treatment (p < 0.001) while protein C showed a slight but significant decrease in both treatments (TTS 50 p < 0.001, CEE p < 0.05). TAT complexes and AT were found unaltered. Platelet function and fibrinolytic activity did not significantly change. A significant relationship between FPA and estradiol levels, which were significantly increased during. TTS 50 therapy, was found (r = 0.40, p < 0.05). These findings indicate that unopposed estradiol given by transdermal route induces a slight but significant blood clotting activation, which seems strictly related to its biological activity.

Prevalence of factor V Leiden mutation in non-European populations

A difference in the prevalence of venous thromboembolism (TE) in major human groups has been described and an uneven distribution of FV Leiden mutation over the world has recently been reported. We investigated FV Leiden mutation in 584 apparently healthy subjects mostly from populations different from those previously investigated: 170 Europeans (Spanish, Italians), 101 sub-saharan Africans (Fon, Bariba, Berba, Dendi), 115 Asians (Indonesians, Chinese, Tharus), 57 Amerindians (Cayapa), 84 Afroamericans (Rio Cayapa, Viche), and 57 Ethiopians (Amhara, Oromo). The mutation was detected in only 1/115 Asian (Tharu) and in 5/170 Europeans (4 Italians, 1 Spanish). These data confirm that in non-Europeans the prevalence of FV mutation is at least 7 times lower than in Europeans and provide indirect evidence of a low prevalence not only of the FV Leiden gene but also of other genes leading to more severe thrombophilia. Finally, findings from the literature together with those pertaining to this study clearly show a marked heterogeneity among Europeans.

D-dimer plasma levels during normal pregnancy measured by specific ELISA

A progressive increase in D-dimer plasma levels together with an increase in fibrinogen has been previously reported during normal pregnancy. However, significantly different D-dimer levels have been observed in different assays, due to different specificity of the antibodies employed. The aim of this study was to verify the increase in fibrin degradation product levels during normal pregnancy, using a recently introduced specific D-dimer ELISA. We determined D-dimer (ELISA) and fibrinogen (clotting method) plasma levels in 63 normal pregnant women, during three different periods of pregnancy (A, 7-20 weeks; B, 21-30 weeks; C, > 30 weeks). During period A, D-dimer plasma levels (range 2-103 ng/ml) showed an insignificant increase compared with a control group of non-pregnant women (range 2-73 ng/ml). During periods B and C, we observed an increase in D-dimer level (P < 0.0001) compared with period A, with a significant correlation between D-dimer levels and gestational age (P < 0.0001). Period A fibrinogen levels (range 3.24-6.43 g/l) were significantly higher (P < 0.0001) than in controls (range 2.31-4.71 g/l), with a further increase in periods B and C. In conclusion, we confirmed a progressive increase in plasma concentrations of fibrin degradation product during normal pregnancy, but D-dimer levels were significantly lower than those reported in the literature for other ELISAs.

Identification of candidates for prevention of venous thromboembolism

The rationale for prophylaxis of venous thromboembolism (VTE) is based on the frequently clinically silent nature of the disease. A number of risk factors for VTE have been known for a long time, even if some of them are still controversial. Many studies have been performed in the surgical field, and have established different risk classes for VTE. Such risk stratification is especially determined by type of surgery and to some extent by personal characteristics of patients, and it defines operations at high, intermediate, and low risk for VTE. According to this classification, prophylaxis of VTE is mandatory in some cases, less useful in others. Less information is available on medical diseases, in which the clinical conditions and the intrinsic characteristics of patients determine the class of risk for VTE. Different strategies for identifying patients who should undergo prophylaxis have been proposed based on risk factor evaluation in the individual patient. However, even if such an approach may be of help for the physician, its validity is still impaired by the difficulty of taking into account all of the variables possibly involved in VTE occurrence.

Blood clotting activation during normal pregnancy

Pregnancy is considered as a hypercoagulable state and an increased incidence of thromboembolic phenomena has been reported in pregnant women. Relevant changes in the hemostatic mechanism have been reported during physiological pregnancy: briefly, increased levels of coagulation factors, enhanced thrombin generation and suppression of fibrinolysis are commonly found in women with uncomplicated pregnancy. We recently described progressive increases in fibrinogen and D-dimer plasma levels during normal pregnancy. The increase in D-dimer levels makes difficult their interpretation for the exclusion of thromboembolic phenomena in pregnancy. The behavior of prothrombin fragment 1+2 (F1+2) levels during physiological pregnancy is scarcely known. The aim of this preliminary study was to establish range values of F1+2 plasma levels for different periods of normal pregnancy.

Platelet and blood clotting activation in patients with mitral valve prolapse

In patients with mitral valve prolapse (MVP) a high incidence of valvular abnormalities with a history of previous cerebrovascular disease has been reported and an embolic mechanism has been proposed. Aim of this study is the study of platelet and coagulation activation in patients with MVP. Fifty-four patients affected by MVP (mean age 46 +/- 15 yrs, 22 males, 32 females) and 50 control subjects, age- and sex-matched, were tested for platelet activation [P-selectin and GpIIb-IIIa platelet surface expression at rest and after stimuli by flow cytometric analysis, Beta-Thromboglobulin (TG) and Platelet Factor 4 (PF4) plasma levels by ELISA, platelet-rich-plasma (PRP) and whole blood spontaneous platelet aggregation (SPA)] and for activation of blood coagulation (Prothrombin activation fragment F1+2 plasma levels by ELISA). P-selectin, GpIIb-IIIa expression, Beta-TG, PF4 and SPA were found similar in MVP patients and in controls. However, in patients with severe mitral regurgitation (MR) the percentage of activated platelets which express P-selectin after stimuli was slightly but significantly (p < 0.05) lower in comparison to MVP patients without or with mild to moderate MR and to controls. Moreover, in patients with severe MR F1+2 levels (median 1.6 nmol/L, range 0.6-2.6 nmol/L) were significantly higher (p < 0.001) than both in controls (median 0.95 nmol/L, range 0.2-1.4 nmol/L) and in patients without or with mild to moderate MR (median 1.0 nmol/L, range 0.4-2.3 nmol/L). Our findings suggest that MVP is not responsible per se for blood clotting activation, but in patients with severe mitral insufficiency an increase in thrombin generation can occur. These alterations in hemostatic system may represent a mechanism by which MR increases the risk of thromboembolic events in patients with MVP.

[Therapeutic ranges of oral anticoagulant therapy in different diseases. Guidelines of the Federation of Centers of Surveillance of Patients on Anticoagulation. Ad hoc Study Group]

The "ad hoc" Study Group of the Federation of Italian Anticoagulation Clinics has proposed a series of guidelines for oral anticoagulant therapy in different pathological states for which this treatment is indicated. These indications are based on the scientific literature available through March 1996. While there is wide consensus for some indications, opinions diverge regarding others. Finally, there are a number of indications which are potentially useful but are not supported by adequate studies. For the applications of guidelines in individual cases, however, careful clinical evaluation is necessary.

Antiphospholipid antibodies (aPL) increase the potential monocyte procoagulant activity in patients with systemic lupus erythematosus

Lupus anticoagulant (LA) and anticardiolipin antibodies (aCL) are frequently detected in sera from patients affected by systemic lupus erythematosus (SLE). However, the role of antiphospholipid antibodies (aPL) in thrombus formation has not been defined as yet. Twenty-two patients affected by SLE, all fulfilling the 1982 ARA revised criteria, and twenty healthy subjects were investigated for the presence of LA, aCL and other aPLs. Monocyte procoagulant activity-PCA (Tissue Factor production) was evaluated by one stage plasma recalcification time. In all patients the plasma levels of F1 + 2 and of plasminogen activator inhibitor (PAI) were also determined. Monocyte PCA was significantly higher in SLE patients with LA and/or aCL in comparison to SLE patients without LA and/or aCL (p < 0.01) and to controls (p < 0.05). However, no connection was observed between PCA expression by mononuclear cells and LA or aCL levels. No differences in F1 + 2 and PAI plasma levels were found between SLE patients with or without aPL and controls. In our SLE patients LA and/or aCL positivity appears strictly related to an increased monocyte activation that could play an important role in the occurrence of thrombotic events.

n-3 PUFA supplementation, monocyte PCA expression and interleukin-6 production

n-3 polyunsaturated fatty acids (PUFA) can affect several monocyte functions and the biochemistry of blood cells, thus possibly influencing the initiation of thrombosis, inflammatory disease and atherosclerosis. In this study, we have investigated the effect of dietary supplementation with n-3 PUFA ethyl esters on procoagulant activity (PCA) and interleukin-6 (IL-6) production by human mononuclear cells. Nine healthy volunteers received 4 g/d of n-3 PUFA ethyl esters (4 x 1 g capsules with at least 85% eicosapentaenoic + docosahexaenoic acid ethyl esters) for 18 weeks. Before and at the end of the treatment, mononuclear cells were obtained from peripheral citrated blood by Ficoll-Hypaque density gradient centrifugation. Cellular suspensions (10(7) cells/ml) were incubated at 37 degrees C for 4 h in the absence and presence of lipopolysaccharide (10 micrograms/ml); PCA was determined by one-stage clotting assay and IL-6 concentrations were assayed in supernatants by specific ELISA. After 18-week treatment, both unstimulated and stimulated monocyte PCA were significantly reduced by 66% and 63%, respectively (P < 0.01). Similarly, a significant inhibitory effect by n-3 PUFA treatment on basal and LPS-stimulated IL-6 monocyte production was observed (50% and 46%, respectively, P < 0.05). These data indicate that 18-week n-3 PUFA supplementation may influence monocyte activities, which play a specific role in atherosclerosis and its thrombotic complications.

Effect of n-3 polyunsaturated fatty acid intake on phospholipid fatty acid composition in plasma and erythrocytes

To characterize the time course of plasma and red blood cell (RBC) changes after n-3 polyunsaturated fatty acid (PUFA) supplementation, 20 healthy male volunteers were randomly assigned to receive either four 1-g capsules of n-3 PUFA ethyl esters or four 1-g capsules of olive oil (as placebo) for a period of 4 mo, followed by a 3-mo washout period. Fatty acids of plasma and RBC phospholipid fractions were analyzed at 0, 2, and 4 mo of treatment and at 1, 2, and 3 mo of washout. During n-3 PUFA supplementation, accumulations of eicosapentaenoic (EPA), docosapentaenoic (DPA), and docosahexaenoic (DHA) acids were marked after 2 mo with differences among different fractions of plasma and RBCs in further accumulation up to 4 mo. During the first and second months of the washout, slight differences were observed in changes of various fatty acids among different phospholipid fractions, but after 3 mo of washout, only minor alterations were still detectable with respect to pretreatment values. These data confirm the complex relations among different fatty acid pools after n-3 PUFA supplementation.

Antiphospholipid antibodies and pregnancy disorders in women with insulin dependent diabetes

Insulin dependent diabetes (IDD) is considered to be an immune endocrinopathy as in such patients a disorder of the immune system is involved; however, up to now no data are available on the occurrence of antiphospholipid antibodies (aPL) in IDD pregnant women and on possible correlation between the presence of aPL and the high fetomaternal morbidity reported in these patients. The presence of lupus anticoagulant (LA) and of anticardiolipin antibodies (ACA) was monthly evaluated. In 35 IDD pregnant women referring within the 7 degrees week of pregnancy to the High Risk Pregnancy Medical Unit. Levels of D-dimer, fibrin degradation product, were also assayed. Twelve IDD pregnant women resulted to be aPL positive with a markedly high prevalence of positivity (34%). aPL positive did not significantly differ from aPL negative women in age, duration and severity of diabetes and in metabolic control throughout pregnancy. Pregnancy induced hypertension (PIH) and intrauterin growth retard (IUGR) were observed in 6/12 aPL positive and in only 2/23 aPL negative patients (p < 0.02). A pathological increase in D-dimer levels occurred in 6/12 aPL positive patients and in none aPL negative (p < 0.03). The high frequency of aPL positivity and its strict relation to pregnancy complications strongly support a major role for an autoimmune pathogenetic mechanism in the occurrence of feto-maternal morbidity in IDD pregnant women. The identification of this subgroup at risk for complications may be clinically relevant.

Fibrinogen and factor VIIag in healthy adolescents: the Floren-teen (Florence teenager) Study

At least five studies based on more than twenty thousand healthy subjects indicated that fibrinogen is an independent risk factor for cardiovascular events; less clear-cut is the relation between factor VII and risk for arterial thrombotic disorders, which was demonstrated in two of the three studies investigating this association. However, no study has investigated the behaviour of fibrinogen and factor VII in an adolescent population. In a study of Preventive Medicine and Education Program, fibrinogen (clotting method) and factor VIIag (ELISA), in addition to other metabolic parameters, life-style and familial history, were investigated in 451 students (313 females and 138 males, age 15-17 years) from two high schools of Florence. Fibrinogen levels were significantly higher in women than in men, whereas factor VIIag levels did not significantly differ. Both fibrinogen and factor VIIag significantly correlated with total cholesterol (p < 0.05) while only fibrinogen correlated with body mass index (p < 0.01). Factor VIIag was significantly correlated with systolic blood pressure (p < 0.001). This study provides information on coagulation risk factors in a population of adolescents which may be of importance in planning coronary heart disease prevention programs.

Hemostatic abnormalities in inflammatory bowel disease

Patients affected by inflammatory bowel disease (IBD) frequently suffer from thromboembolic events. Aims of this study were to investigate hemostatic system and the presence of antiphospholipid antibodies (aPL) in IBD patients. Forty-one patients affected by Crohn's disease (CD) and 19 by ulcerative colitis (UC) were studied, compared to 40 healthy control subjects. Platelet count (PLT), PT, aPTT, fibrinogen (Fib), prothrombin fragment F1+2, antithrombin (AT), protein C (PC), protein S (PS), factor XIII (FXIII), plasminogen (PLG), plasminogen activator inhibitor (PA1), spontaneous platelet aggregation in platelet-rich plasma (PRP-SPA) and in whole blood (WB-SPA), and antiphospholipid antibodies (aPL) were evaluated. PLT, Fib, F1+2 and WB-SPA were significantly increased in IBD patients (p at least <0.05) both in active and inactive phases; aPL positivity was more frequent (p<0.05) and FXIII was significantly decreased (p<0.05) in comparison to control subjects. The thrombophilic state of IBD patients is not related to the degree of activity of the disease or to previous thrombotic events; aPL express the immunological alterations connected with IBD and are not the main cause of thrombotic events.

Fibrin generation and digestion in patients with angina pectoris

Fibrin generation and lysis were studied in 28 patients with angina pectoris (14 with active disease and 14 with inactive disease) and in 14 normal controls. The fibrinolytic response was evaluated by comparing the ratio between the plasma levels of fibrinopeptide A and fibrin degradation products. Levels of both were higher in patients than in controls (P < 0.001), with higher levels in active than in inactive disease (P < 0.001). The fibrinopeptide A/fibrin degradation products ratio was much higher (P < 0.001) in the active group than in other groups. Thus, in patients with angina pectoris, especially in the active state, the increased thrombin generation is not paralleled by an equivalent increase in fibrinolytic activity.

Clottable to immunological fibrinogen ratio in plasma from control subjects and hyperfibrinogenemic patients

The measurement of fibrinogen (Fg) plasma levels is one of the more frequently performed tests in clinical practice, usually by clotting assay. However, for the diagnosis of dysfibrinogenemia the use of an immunological assay is necessary to compare total and clottable protein. Little information is available on the range of the ratio clottable (C) Fg/immunological (I) Fg levels in normal population. This study aimed at evaluating the CFg/IFg ratio in 70 control subjects (age range 17-74 years-group A), in 57 acute patients (age range 17-79 years-group B) and in 14 pregnant women (age range 27-41 years, pregnancy weeks 30-40-group C), as a physiologic model of hyperfibrinogenemia. CFg was assayed on citrated plasma by the Clauss clotting method and IFg was assayed by radial immunodiffusion technique. In the three groups, CFg/IFg ratios were not significantly different (respectively group A 0.98 +/- 0.17, group B 1.02 +/- 0.18 and group C 1.01 +/- 0.11), whereas both CFg (310 +/- 45 mg/dl) and IFg (326 +/- 70 mg/dl) levels were lower (p < 0.001) in control subjects than in patients (CFg 556 +/- 92 mg/dl; IFg 561 +/- 121 mg/dl) and in pregnant women (CFg 530 +/- 65 mg/dl; IFg 530 +/- 77 mg/dl). The analysis of the relationship between CFg and IFg in the three groups (group A: y = 11.53 + 1.01x, r = 0.64, p < 0.001; group B: y = 68.72 + 0.88x, r = 0.67, p < 0.0001; group C: y = 71.59 + 0.87x, r = 0.73, p < 0.01) indicates that a good correlation exists (p < 0.001) for values of fibrinogenemia ranging from 180 to over 700 mg/dl. A reference range of CFg/IFg (mean +/- 2 SD in group A) was 0.64-1.32. These data could be of practical importance for a rapid screening of dysfibrinogenemias.

D-Dimer in intra-uterine growth retardation and gestational hypertension

Pregnancy is sometime related to thromboembolic complications (1) and alterations in different hemostatic parameters have been reported in pregnancy (2-4). In particular, a progressive increase in fibrinogen and D-dimer levels occurs during normal pregnancy (5-9). D-dimer levels may be predictive for some complications such as preeclampsia (10) and they have been also reported to be useful for diagnosis of abruptio placentae (6). However, it remains to be established if common ELISA for D-dimer are able to discriminate pathologic samples in conditions such as intrauterine growth retardation (IUGR) or gestational hypertension (GH). Aim of the present study has been to evaluate the behavior of D-dimer in pregnant women with IUGR and GH.

Platelet activation and platelet lipid composition in pulmonary cancer

In order to investigate the possible mechanisms underlying platelet functional changes in patients affected by neoplasms, platelet lipid composition, plasma beta-thromboglobulin (Beta-TG) and serum thromboxane B2 (TXB2) were investigated in 16 male patients affected by pulmonary carcinoma and in 16 comparable control subjects. In patients high levels of plasma Beta-TG (67 +/- 9 versus controls 14 +/- 4 ng/ml, p < 0.001) and serum TXB2 (434 +/- 56 versus 223 +/- 48 ng/ml, p < 0.001) were observed. Also platelet lipid composition was found altered in patients with respect to controls (lower percent levels in n-3 fatty acids and in linoleic acid esterified in the main platelet phospholipid fractions: at least p < 0.05). These results indicate that in vivo platelet activation is detectable in neoplastic patients and it is associated with alterations in platelet lipid composition. In the light of the important role played by membrane lipids in platelet functions related to thrombosis and haemostasis we conclude that platelet lipid changes could cooperate in platelet activation and increased thrombotic risk so frequently observed in neoplastic disease.

D-dimer concentrations during normal pregnancy, as measured by ELISA

In pregnant women a number of changes in blood clotting and fibrinolysis proteins have been reported so indicating the existence of a state of hypercoagulability. In addition to fibrinogen and antithrombin III (AT), D-dimer is frequently checked during pregnancy, in particular during at risk pregnancy, but the exact pattern of D-dimer modifications during uncomplicated pregnancy is not definitively described. The aim of this study was to establish the range values in three different periods of uncomplicated pregnancy (A: 1-20 wks; B: 21-30 wks; C: 31-40 wks). We measured plasma levels of D-dimer, clottable fibrinogen and AT in 108 consecutive normal pregnant women aged 16 to 42 years. In period A, the range of D-dimer values was 43-211 ng/mL, not different from controls, while fibrinogen levels were significantly higher (p < 0.05) than in matched non pregnant women. Mean D-dimer levels were higher in periods B (p < 0.05) and C (p < 0.05) vs period A. Similarly, mean fibrinogen levels were found more elevated in periods B and C vs period A (p < 0.05). A significant correlation was found between fibrinogen and D-dimer levels (p < 0.001). No differences in AT levels were found among the three periods of pregnancy. The results of this study indicate that levels of D-dimer up to 685 micrograms/L may be reached at the end of physiological pregnancy. This fact should be taken into account in the evaluation of hemostatic studies performed in uncomplicated and complicated pregnant women.