Hypercoagulability and chronic atrial fibrillation: the role of markers of thrombin generation

BACKGROUND: We have studied 64 patients with congestive heart failure, half of them also with chronic nonvalvular atrial fibrillation (AF). Patients were also stratified according to a history of prior stroke. METHODS: The generation of thrombin was investigated by means of the molecular markers prothrombin fragment 1 + 2 (F1 + 2) and thrombin-antithrombin III complex (TAT), because AF patients may have a hypercoagulable state. There was only a trend toward higher values of TAT and F1 + 2 for AF patients, while subjects with previous stroke (irrespective of AF) had increased levels of the markers of thrombin generation (TAT stroke+ 18.95 +/- 5.15 vs TAT stroke- 8.34 +/- 2.41; F1 + 2 stroke+ 2.22 +/- 0.29 vs F1 + 2 stroke- 1.32 +/- 0.12). The presence of spontaneous echo contrast (SEC) within left atrium was also investigated in 32 AF patients by transesophageal echocardiography. RESULTS: TAT were significantly higher in subjects (n = 11) with SEC (TAT sec+ 37.5 +/- 13.41 vs TAT sec- 8.7 +/- 2.51, p = 0.008). CONCLUSIONS: Finally, when we grouped into 1) those with both AF and stroke, 2) AF alone, 3) stroke alone and 4) sinus rhythm without stroke, levels of F1 + 2 were higher (and marginally higher TAT) in patients with AF and stroke than in those without stroke, revealing that there is a true clotting activation state in these subjects.     

Crypt hyperplasia related to increased lymphocyte activation in the rectal mucosa of children with ulcerative colitis

The presence of cells positive for interleukin-2 receptors (CD25) and the proportion of Ki-67 positive dividing cells in the crypts were studied with monoclonal antibodies using sensitive immunohistochemical techniques in the rectal biopsy specimens taken from 13 children with inflammatory bowel disease (4 Crohn's disease and 9 ulcerative colitis) and 10 controls. In all specimens, but one, from patients CD25+ cells were found in the surface and crypt epithelium, while in none of controls were seen such cells. The mean percentage of dividing crypt cells was significantly higher in ulcerative colitis (36.0%) and in Crohn's disease (34.6%) than in controls (18.4) (p < 0.001 in both comparisons). In ulcerative colitis, a correlation between CD25/CD3 ratios in the surface and crypt epithelium and the percentage of dividing crypt cells was found. We conclude that activated lymphocytes have a role in the crypt hyperplasia of ulcerative colitis.     

Persistent thrombin generation in humans during specific thrombin inhibition with hirudin

BACKGROUND: The degree to which antithrombotic drugs suppress thrombin generation is unknown. Because hirudin, unlike antithrombin III, binds intravascular thrombin rapidly and selectively to yield a circulating inactive complex of 3- to 4-hour half-life, we used intravenous hirudin in humans to investigate the course of thrombin generation during and early after anticoagulation with this potent, direct antithrombin. METHODS AND RESULTS: Intravascular thrombin was measured with an ELISA for the thrombin-hirudin complex formed during and for 18 hours after stopping a 6-hour infusion of hirudin at 0.1, 0.2, and 0.3 mg.kg-1.h-1 in three groups of six patients each. With free hirudin in 20- to 10,000-fold molar excess of thrombin and peak activated partial thromboplastin times of 2.3 to 3.0 times baseline, mean plasma thrombin-hirudin complex increased from 794 +/- 85 pg/mL (mean +/- SEM) 15 minutes after the start of the infusion to 1617 +/- 151 pg/mL at 6 hours of infusion to 2667 +/- 654 pg/mL at 24 hours. During the 24-hour observation period, plasma concentration of fragment 1.2 (the peptide released during conversion of prothrombin to thrombin) never fell below baseline but rather increased transiently during the hirudin infusion. Plasma concentrations of thrombin-antithrombin III complex (in ng/mL) decreased from 4.34 +/- 0.40 at baseline to 1.64 +/- 0.13 at 6 hours (P < .001) and gradually increased after stopping the infusion to 5.7 +/- 0.87 at 24 hours (nonsignificant compared with baseline). CONCLUSIONS: Measurement of thrombin-hirudin complex may be used as a marker of thrombin generation in humans. Persistent accumulation of thrombin-hirudin complex and generation of fragment 1.2 during and after completion of potent anticoagulation with hirudin suggest thrombin generation is not blocked by high-affinity thrombin inhibition. The persistent formation of thrombin during declining plasma levels of hirudin may contribute to the pathogenesis of rethrombosis early after antithrombin therapy or during inadequate anticoagulation.     

Oral lymphoma in human immunodeficiency virus infection: a report of six cases and review of the literature

It has been suggested that blood coagulation be activated and fibrinolytic activity be impaired in patients with coronary artery disease (CAD). With regard to the activation of coagulation and fibrinolysis occurring during exercise in healthy individuals, we examined the hypothesis that rehabilitative exercise in patients with CAD might give rise to an exaggerated activation of coagulation. In 12 patients with angiographically documented CAD without myocardial infarction within the preceding 6 months (male, age 55+/-9 years [SD]) and in 12 healthy controls (male, 52+/-7 years), molecular markers of thrombin, fibrin, and plasmin formation were determined before and after a rehabilitative group exercise session lasting 1 hour. Resting levels of prothrombin fragment 1+2 were lower in patients with CAD (0.67+/-0.2 [SE] vs 1.04+/-0.2 nmol/L, p <0.001) and remained unchanged after exercise, whereas a significant increase was noted in controls (p <0.01). After exercise, plasma levels of thrombin-antithrombin III complexes and of fibrinopeptide A increased significantly in both groups, although there were more pronounced changes in controls. Exercise resulted in a marked generation of plasmin as indicated by plasmin-alpha2-antiplasmin complexes increasing 2.5-fold in patients (p <0.001) and threefold in controls (p <0.001). Repeated experiments in control subjects after administration of aspirin (day 1: 500 mg; days 2 to 5: 100 mg) documented that differences between groups could not be attributed to aspirin medication (100 mg/day) in patients with CAD. We concluded that rehabilitative exercise in patients with CAD beyond the immediate postinfarction period has no detrimental effects on thrombin, fibrin, and plasmin formation.     

The majority of myeloid-antigen-positive (My+) childhood B-cell precursor acute lymphoblastic leukaemias express TEL-AML1 fusion transcripts

BACKGROUND & AIMS: Crohn's disease and ulcerative colitis show a familial aggregation. In both diseases, anti-goblet cell autoantibodies (GABs) have been described. The aim of this study was to define the role of GABs in the pathogenesis of inflammatory bowel disease. METHODS: The study population comprised 61 patients with ulcerative colitis, 76 patients with Crohn's disease, 101 first-degree relatives of patients with ulcerative colitis, and 105 first-degree relatives of patients with Crohn's disease. Thirty-five patients with infectious enterocolitis and 56 healthy unrelated subjects served as controls. Autoantibodies were detected by indirect immunofluorescence. RESULTS: Thirty-nine percent of patients with ulcerative colitis (24 of 61) and 30% of patients with Crohn's disease (23 of 76) were positive for GABs. GABs were detected in 21% (21 of 101) of first-degree relatives of patients with ulcerative colitis and in 19% (20 of 105) of first-degree relatives of patients with Crohn's disease. In patients with infectious enterocolitis and in healthy controls, GABs were seen in 3% (1 of 35) and 2% (1 of 56), respectively. The differences between control groups and both groups of patients or their first-degree relatives were significant. CONCLUSIONS: The high prevalence in first-degree relatives suggests that GABs may represent a marker characterizing susceptibility to inflammatory bowel disease.     

Interleukin-1 receptor antagonist in differential diagnosis of inflammatory bowel diseases

BACKGROUND: Immunoregulatory properties of cytokines may mediate disordered inflammatory events in inflammatory bowel diseases (IBDs). On the basis of data obtained in experimental colitis, the hypothesis has been advanced that in IBD the balance between interleukin-1 (IL-1) and the naturally occurring IL-1 receptor antagonist (IL-1ra) might influence disease expression. OBJECTIVE: We studied the profiles of IL-1ra and acute phase proteins produced by activated macrophages to determine whether the level of IL-1ra in peripheral blood is a marker of disease activity in IBD and a possible differential diagnostic marker. PATIENTS AND METHODS: Levels of IL-1ra, serum neopterin, urinary neopterin, alpha 1-glycoprotein and C-reactive protein (CRP) were measured in 80 patients with ulcerative colitis, Crohn's disease or infectious colitis. RESULTS: Levels of IL-1ra were markedly increased in patients with active ulcerative colitis or active Crohn's disease compared with those in patients with infectious colitis. Patients with active Crohn's disease had significantly higher serum IL-1ra levels than patients with active ulcerative colitis. Moreover, a positive correlation was found between levels of C-reactive protein, alpha 1-glycoprotein, and serum neopterin and the level of IL-1ra in active Crohn's disease but not in active ulcerative colitis, strongly suggesting that the pathogenesis of the two conditions differs. CONCLUSION: Levels of IL-1ra in the peripheral blood of patients with IBD are of clinical relevance, representing a potent marker of disease activity and a possible differential diagnostic marker.     

Thrombin generation measured ex vivo following microvascular injury is increased in SLE patients with antiphospholipid-protein antibodies

Antiphospholipid-protein antibodies (APA) include lupus-type anticoagulant (LA) and antibodies recognizing complexes of anionic phospholipids (e.g. cardiolipin) and proteins (e.g. prothrombin and beta2-glycoprotein I). The presence of APA is associated with an increased risk of both arterial and venous thrombosis. However, the pathogenic mechanism leading to thrombosis in patients with APA remains unclear. We studied 32 patients with systemic lupus erythematosus (SLE) who were divided into two groups depending on the presence (n = 19) or absence (n = 13) of APA. Healthy volunteers (n = 12) matched by age and sex served as controls. In all subjects LA and IgG class anticardiolipin antibodies (ACA) were determined. Thrombin generation was monitored ex vivo measuring fibrinopeptide A (FPA) and prothrombin fragment F1 + 2 (F1 + 2) in blood emerging from a skin microvasculature injury, collected at 30 second intervals. In subjects with antiphospholipid antibodies mean FPA and F1 + 2 concentrations were significantly higher at most blood sampling times than in controls. In some SLE patients with APA the process of thrombin generation was clearly disturbed and very high concentrations of fibrinopeptide A were detected already in the first samples collected. Two minutes after skin incision SLE patients without APA produced slightly more FPA, but not F1 + 2, as compared to healthy subjects. Mathematical model applied to analyze the thrombin generation kinetics revealed that APA patients generated significantly greater amounts of thrombin than healthy controls (p = 0.02 for either marker). In contrast, in the same patients generation of thrombin in recalcified plasma in vitro was delayed pointing to the role of endothelium in the phenomenon studied. In summary, these data show for the first time that in SLE patients with antiphospholipid-protein antibodies thrombin generation after small blood vessel injury is markedly increased. Enhanced thrombin generation might explain thrombotic tendency observed in these patients.     

Activation of the extrinsic coagulation pathway in patients with severe sepsis and septic shock

OBJECTIVES: To obtain systematic information on the extrinsic coagulation pathway, as well as to investigate the time course of the coagulation abnormalities in sepsis. DESIGN: Prospective observational study. SETTING: General intensive care unit. PATIENTS: Nineteen patients with the diagnosis of severe sepsis or septic shock and nine control patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Tissue factor antigen concentration (tissue factor antigen), prothrombin fragment F1+2, thrombin antithrombin III complex, fibrinopeptide A, D-dimer, and antithrombin III concentrations were measured on the day of diagnosis of severe sepsis and septic shock, and on days 1, 2, 3, and 4 after diagnosis. The concentrations of tissue factor antigen, prothrombin fragment F1+2, fibrinopeptide A, and D-dimer were significantly increased in patients with severe sepsis and septic shock compared with control subjects. However, the concentrations of thrombin antithrombin III complex showed no statistical differences between the septic patients and the control subjects. Significantly, low antithrombin III concentrations were observed in the septic patient groups compared with control subjects. With the exception of D-dimer, the concentrations of the hemostatic markers were similar between severe sepsis and septic shock patients. Significant correlations were noted between tissue factor antigen and the disseminated intravascular coagulation score (r2=.236, p< .0001) and the number of dysfunctioning organs (r2=.229, p=.035). CONCLUSIONS: We systematically elucidated coagulation disorders in newly defined sepsis. The extrinsic coagulation pathway is activated in patients with severe sepsis and septic shock. In these patients, enhanced thrombin generation and activation, and fibrin formation were demonstrated when compared with the control subjects. Furthermore, the thrombin generated appears not to be fully neutralized by antithrombin III.     

Effectiveness of heparin in preventing thrombin generation and thrombin activity in patients undergoing coronary intervention

BACKGROUND: Thrombus is important in the pathophysiology of several complications of angioplasty, including abrupt closure and restenosis. Levels of prothrombin fragment F1.2 and fibrinopeptide A reflect thrombin generation and activity. The effect of angioplasty on levels of these markers is unclear. METHODS: Patients undergoing either balloon angioplasty (n = 30) or directional atherectomy (n = 9) were treated with heparin to maintain an activated clotting time of >300 seconds. Levels of F1.2, fibrinopeptide A, and thrombin-antithrombin complex were measured in the coronary sinus and coronary artery before and after intervention. Angiograms were reviewed for lesion morphologic characteristics and dissection. RESULTS: There was no evidence for thrombin generation or increased thrombin activity after angioplasty regardless of lesion morphologic characteristics, dissection, type of intervention, or blood sampling site. In fact, coronary sinus concentrations of F1.2 decreased after intervention (median 0.31 nmol/L; 25th percentile 0.26 nmol/L, 75th percentile 0.37 nmol/L) before intervention to 0.23 nmol/L (25th percentile 0.19 nmol/L, 75th percentile 0.34 nmol/L) after intervention (P =.002). CONCLUSIONS: Angioplasty performed in the presence of adequate heparin inhibited thrombin even when there was complex lesion morphology or dissection. These data suggest that heparin provides satisfactory thrombin inhibition during routine angioplasty.     

Coagulation and thrombomodulin in response to exercise of different type and duration

PURPOSE: The present study was conducted to evaluate the role of the duration of exercise and the impact of the exercise type for exercise-induced activation of coagulation. METHODS: Eleven male triathletes were subjected to stepwise maximal (17 min) and 1-h maximal exercise in swimming, cycling, and running. Changes of hemostatic variable sand of plasma thrombomodulin, a marker of endothelial cell activation, were monitored. RESULTS: Irrespective of the type of exercise, alterations in markers of thrombin (prothrombin fragment 1 + 2, thrombin-antithrombin III complexes) and fibrin formation (fibrinopeptide A) were more pronounced after 1-h exercise than after stepwise maximal exercise. Hemostatic parameters rose to the highest levels after running resulting in substantial fibrin formation as indicated by fibrinopeptide A increasing from 1.33 ng.mL-1 to 2.25 ng.mL (P < 0.05) after 1-h exercise testing. Significant changes of plasma thrombomodulin were detected exclusively after running with increases from 38.2 ng.mL-1 to 44.2 ng.mL-1 (1 h, P < 0.01). CONCLUSIONS: The data demonstrated that prolonged exercise is necessary for exercise-induced activation of coagulation resulting in thrombin and fibrin formation and suggested that endothelial cell activation possibly due to mechanical factors associated with running might play a role.     

Correlation of a common mutation in the methylenetetrahydrofolate reductase gene with plasma homocysteine in patients with premature coronary artery disease

BACKGROUND: Recent clinical trials have demonstrated that methotrexate may have an important therapeutic role in the treatment of patients with inflammatory bowel disease, who are either refractory or intolerant to traditional medical therapy. The aim of this study was to evaluate the pharmacokinetics of low-dose oral methotrexate in patients with inflammatory bowel disease. METHODS: Methotrexate (12.5 mg) was given orally to nine patients with inflammatory bowel disease: five with Crohn's disease, and four with ulcerative colitis, and to six patients with rheumatoid arthritis who served as a control group. Blood samples were drawn at specific intervals to evaluate methotrexate plasma levels. RESULTS: Methotrexate was rapidly absorbed in all patients. Peak concentrations (Cmax) varied considerably, ranging from 0.25-0.87 micro M. The mean Cmax values were similar in all patient groups (0.59 +/- 0.12, 0.69 +/- 0.16 and 0.54 +/- 0.18 micro M, P not significant) for Crohn's disease, ulcerative colitis and rheumatoid arthritis, respectively. The mean area under curve in 120 min (AUC0-120) was also similar in all patient groups (32.9 + 11.3, 43.6 + 9.9 and 41.8 + 14.9 ng.min/mL, P not significant) for Crohn's disease, ulcerative colitis and rheumatoid arthritis, respectively. The mean time to reach Cmax, (tmax), varied between patient groups (84, 112 and 95 min, respectively, with a significant difference, P < 0.02, between the Crohn's disease and ulcerative colitis groups. A negative correlation was found between methotrexate dosage/kg and Cmax (r = -0.74) only in Crohn's disease patients but not in the other patient groups. CONCLUSIONS: Orally administered methotrexate is well absorbed in patients with inflammatory bowel disease including those with severe small bowel disease or resection. If methotrexate is proven to be effective in inflammatory bowel disease, it should be administered orally.     

Clinical studies and thrombin generation in patients homozygous or heterozygous for the G20210A mutation in the prothrombin gene

A genetic variation in the prothrombin gene, the G-->A transition at nucleotide 20210, is a risk factor for venous thrombosis in heterozygotes and is associated with increased prothrombin activity. The homozygous phenotype and the extent of thrombin generation in heterozygous and homozygous subjects are unknown. We investigated a family that included 2 homozygous and 5 heterozygous carriers of the 20210 A allele. The homozygous propositus and his presumably heterozygous father suffered from deep-vein thrombosis. His presumably heterozygous mother and his homozygous sister had recurrent phlebitis at a young age. The remaining 5 affected family members are still asymptomatic. We studied thrombin generation in the family and in 22 unrelated carriers of the 20210 A allele by measuring (1) prothrombin fragment F1+2 (F1+2) as an index of ongoing thrombin generation and (2) the endogenous thrombin potential (ETP) as an index of the possible thrombin-forming capacity. Their F1+2 levels were not different from those of age-matched controls, and thus, ongoing hemostatic system activation was not detectable. A significantly increased ETP was found in the heterozygous carriers of the 20210A allele compared with the controls (527.8+/-114.9 versus 387+/-50.1 nmol/L x min, P<0.0001). In the 2 homozygotes, the ETP was almost twice (639 and 751 nmol/L x min, respectively) as high as in the controls. We conclude that homozygosity for the G20210A mutation in the prothrombin gene is associated with a severe, albeit more benign, thrombotic diathesis compared with homozygosity for deficiencies of antithrombin, protein C, or protein S. In carriers of the 20210 A allele, the pathomechanisms leading to thrombosis should be sought in the higher amounts of thrombin that may be formed once thrombin generation is triggered, rather than in ongoing thrombin generation in vivo.     

Systemic recombinant human interferon-beta treatment of relapsing-remitting multiple sclerosis: pilot study analysis and six-year follow-up

The role of the spleen in patients with ulcerative colitis and Crohn's disease was assessed by counting pitted erythrocytes with differential interference microscopy and by splenic ultrasound. The findings were compared with those from age- and sex-matched controls and a group of splenectomized patients. The incidence of hyposplenism was lower than previously reported, being found in six of 29 patients with ulcerative colitis (of whom five had relapsed pancolitis and one had quiescent pancolitis) and two of 21 patients with Crohn's disease. Pitted erythrocyte counts were significantly higher in patients with ulcerative colitis compared with age- and sex-matched controls (p < 0.001), but there was no difference in counts between patients with Crohn's disease and controls. Patients with relapsed but not quiescent ulcerative colitis had significantly smaller spleens than controls. Patients with the highest pitted erythrocyte counts had the smallest spleens on ultrasound. More effective medical and surgical therapy may account for the lower incidence of functional hyposplenism observed in this study. Nonetheless, patients may show marked hyposplenism and remain at risk of overwhelming infection and operative complications. Differential interference microscopy is a simple technique that can be used to assess splenic function in patients thought to be susceptible to infection.     

Incidence of inflammatory bowel diseases in the department of Puy-de-D?me in 1993 and 1994. EPIMICI. Epidémiologie des Maladies Inflammatoires Cryptogenetiques de l'Intestin group

The aim of this prospective epidemiological study was to investigate the incidence of Inflammatory Bowel Disease in the Puy-de-D?me county using the same methodology as EPIMAD's registry. METHODS: From 01/01/93 to 31/12/94, each gastroenterologist (n = 22) collected patients consulting for the first time with clinical symptoms compatible with inflammatory bowel disease. Data were reported on a questionnaire by an interviewer practitioner. The final diagnosis of Crohn's disease and ulcerative colitis was made in a blind manner by two expert gastroenterologists and recorded according to the Calkin's criteria as definite, probable, or possible diagnosis, or unclassifiable chronic colitis or acute colitis. RESULTS: 167 new cases were identified: 112 (67.1%) inflammatory bowel disease for the combined group of definite and probable cases with 79 Crohn's disease (70.5%), 29 ulcerative colitis (25.9%) of which 11 ulcerative proctitis (37.9%), 4 unclassifiable chronic colitis (3.6%) and 55 acute colitis (32.9%). The crude and age-adjusted incidence (per 10(5)/year) was respectively 6.6 and 5.7 for Crohn's disease and 2.4 and 1.9 for ulcerative colitis. The highest age-specific incidence rate for Crohn's disease was between 40-49 years (14.1) and for ulcerative colitis between 80-89 years (6.8). The female/male ratio was 0.8 for Crohn's disease and 1.1 for ulcerative colitis. The median age at the time of diagnosis was 42.6 years for Crohn's disease and 35.3 years for ulcerative colitis. CONCLUSIONS: These preliminary findings revealed a high incidence of Crohn's disease and low of ulcerative colitis in this county. However, these results must be managed carefully because these data were recorded only on two years and the inflammatory bowel disease classified possible and acute colitis require a follow-up.     

Abnormal mucosal glycoprotein synthesis in inflammatory bowel diseases is not related to cigarette smoking

Patients with ulcerative colitis are usually non- or ex-smokers in contrast to Crohn's disease where smoking is common. Abnormalities of quantity and quality of intestinal mucus have been postulated in the pathogenesis of these diseases. It is possible that smoking habit may exert its effects via changes in mucus in inflammatory bowel disease. We have therefore studied incorporation of N-acetylglucosamine into synthesized colonic mucin in explants from 85 controls with normal colonoscopic appearances and histology, including 27 smokers and 58 nonsmokers, 36 patients with ulcerative colitis and 19 with ileocolonic Crohn's disease over 24 h in tissue culture. Incorporation of N-acetylglucosamine into normal explants was 31.3 +/- (SD) 7.1 dpm/microgram biopsy protein, incorporation was increased in patients with active Crohn's disease (mean 41.2 +/- (SD) 10.4 dpm/microgram biopsy protein, p = 0.003), decreased in inactive ulcerative colitis (mean 24.1 +/- 7.8 dpm/microgram biopsy protein, p = 0.0006) but normal in active ulcerative colitis (mean 35.0 +/- 13.8 dpm/microgram biopsy protein, p = 0.44). No significant relationship was found between cigarette smoking habits and mucus synthesis in controls with normal mucosa (nonsmokers, n = 58, mean 31.0 +/- (SD) 7.52 dpm/microgram biopsy protein; smokers, n = 27, mean 31.8 +/- (SD) 6.1 dpm/microgram biopsy protein, p = 0.9). This study shows that mucus glycoprotein synthesis is reduced in inactive ulcerative colitis, rising to normal levels in active disease and that synthesis is increased in Crohn's disease. There is no effect of smoking on mucus synthesis by control biopsies suggesting that the differences seen in inflammatory bowel disease are not related to cigarette smoking.     

An increased risk of Crohn's disease in individuals who inherit the HLA class II DRB3*0301 allele

The role of inflammatory T cells in Crohn's disease suggests that inherited variations in major histocompatibility complex (MHC) class II genes may be of pathogenetic importance in inflammatory bowel disease. The absence of consistent and strong associations with MHC class II genes in Caucasian patients with inflammatory bowel disease probably reflects the use of less precise typing approaches and the failure to type certain loci by any means. A PCR-sequence-specific oligonucleotide-based approach was used to type individual alleles of the HLA class II DRB1, DRB3, DRB4, and DRB5 loci in 40 patients with ulcerative colitis, 42 Crohn's disease patients, and 93 ethnically matched healthy controls. Detailed molecular typing of the above alleles has previously not been reported in patients with inflammatory bowel disease. A highly significant positive association with the HLA-DRB3*0301 allele was observed in patients with Crohn's disease (P = 0.0004) but not in patients with ulcerative colitis. The relative risk for this association was 7.04. Other less significant HLA class II associations were also noted in patients with Crohn's disease. One of these associations involved the HLA-DRB1*1302 allele, which is known to be in linkage disequilibrium with HLA-DRB3*0301. These data suggest that a single allele of an infrequently typed HLA class II locus is strongly associated with Crohn's disease and that MHC class II molecules may be important in its pathogenesis.     

Antineutrophil cytoplasmic antibodies in Estonian patients with inflammatory bowel disease. Prevalence and diagnostic role

BACKGROUND/AIMS: In Estonia, the incidence of ulcerative colitis and especially Crohn's disease appears to be rare. Antineutrophil cytoplasmic antibodies (ANCA) are frequently found in ulcerative colitis but less frequently in Crohn's disease, their pathophysiological significance is still unclear. METHODOLOGY: Fifty-nine serum samples from patients with ulcerative colitis, 17 with Crohn's disease, 25 with irritable bowel syndrome, and 86 healthy persons were studied. Sera were analyzed for the presence of ANCA by indirect immunofluorescence, and enzyme-linked immunosorbent assay for specific ANCA using different antigens was performed. RESULTS: ANCA were detected in 29 of 59 (49%) patients with ulcerative colitis, 4 of 17 (24%) patients with Crohn's disease, and in 4 of 111 (4%) controls. The immunofluorescence staining was mostly perinuclear (pANCA). There was no correlation between ANCA and the duration or extent of the inflammatory bowel disease. In specific enzyme-linked immunosorbent assays, only 14 sera elicited binding above the normal range. CONCLUSIONS: Although the prevalence of ulcerative colitis and Crohn's disease in Estonia is much lower than in European countries, there seem to be no differences in the presence of ANCA.     

Consumption of reduced-fat products: effects on parameters of anti-oxidative capacity

Plasma levels of fibrinogen, factor VIIc and prothrombin fragment F1 + 2, a marker of thrombin generation in vivo, were studied in 68 subjects with serum total cholesterol (TC) levels between 135 and 349 mg/dl but without clinical evidence of cardiovascular disease and other atherosclerotic risk factors. F1 + 2 plasma levels were directly correlated with TC (p < 0.0004), low-density lipoprotein cholesterol (LDL-C; p < 0.0018) and factor VIIc (p < 0.024). Thirty-five subjects with TC greater than 249 mg/dl (median value of the whole group) showed higher levels of F1 + 2 (p < 0.0001) and fibrinogen (p < 0.0015) than those with TC lower than 249 mg/dl. In subjects with TC > 249 mg/dl and F1 + 2 > 1.2 nM (median value of the whole group), a cholesterol-lowering drug (simvastatin) was able to reduce F1 + 2 (p < 0.009) as well as TC and LDL-C. This study shows a relationship between serum cholesterol and the rate of thrombin generation supporting the hypothesis that a hypercoagulable state may occur in hypercholesterolemic subjects before the onset of clinical evidence of atherosclerotic cardiovascular disease.     

Activation of the haemostatic system in children with juvenile rheumatoid arthritis correlates with disease activity

Twenty-four children with juvenile rheumatoid arthritis (JRA) and 10 children with postinfectious arthropathies were investigated for markers of blood coagulation and fibrinolytic activity: Prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT), and D-Dimer were measured using solid phase enzyme linked immunosorbent assays (ELISA). Results were compared with clinical and conventional laboratory signs of disease activity. F1+2, TAT, D-Dimer, and fibrinogen were significantly elevated in children with JRA as compared with healthy children and children with postinfectious arthropathies. F1+2, TAT, and D-Dimer correlated significantly with disease activity, assessed by determination of the joint index score and C-reactive protein (CRP). The study demonstrates a subclinical activation of the haemostatic system in children with JRA correlating with disease activity, which might be caused by the action of several immunomediators on cells (monocytes, endothelial cells) playing a role in the regulation of blood coagulation activity.