Changes in the factor VIII complex in diabetic ketoacidosis: evidence of endothelial cell damage?

Thrombotic Thrombocytopenic Purpura in a Child with Diabetic Ketoacidosis

Thrombotic thrombocytopenic purpura (TTP) secondary to diabetic ketoacidosis has been rarely reported and is considered as a rare complication. If left untreated, this condition could be life threatening with considerable morbidity and mortality. Herein, we report a 6-year-old girl with reduced consciousness and respiratory distress with a history of polydipsia and polyuria in the 2 weeks before hospitalization. The patient was initially diagnosed as diabetic ketoacidosis based on clinical and laboratory findings and treated accordingly. After treatment and during hospitalization although she had gained relative consciousness, she experienced seizure and reduced consciousness again. Considering laboratory and clinical findings and the patient's underlying conditions (thrombocytopenia, renal failure, and high lactate dehydrogenase), TTP was suspected although ADAMTS13 test could not be done. Treatment with plasmapheresis was initiated, and after 48 h, the patient was conscious, and laboratory indices became normal within a few days. The patient was discharged after full recovery. TTP should be considered as a rare complication of diabetic ketoacidosis in patients with thrombocytopenia, renal failure, and reduced consciousness and should be immediately treated.

Thrombocytopenia-associated multiorgan failure occurring in an infant at the onset of type 1 diabetes successfully treated with fresh frozen plasma

TAMOF is a devastating microangiopathy that can occur in association with the new onset of T1DM, and should be considered with the onset of thrombocytopenia, renal failure, and raised LDH. Treatment with fresh frozen plasma should be considered as a first‐line option in such cases prior to plasma exchange.

Coagulation and anticoagulation in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is an incurable, progressive interstitial lung disease with a prognosis that is worse than that of many cancers. Epidemiological studies have demonstrated a link between IPF and thrombotic vascular events. Coagulation and fibrinolytic systems play central roles in wound healing and repair, processes hypothesised to be abnormal within the IPF lung. Animal models of pulmonary fibrosis have demonstrated an imbalance between thrombosis and fibrinolysis within the alveolar compartment, a finding that is also observed in IPF patients. A systemic prothrombotic state also occurs in IPF and is associated with increased mortality, but trials of anticoagulation in IPF have provided conflicting results. Differences in methodology, intervention and study populations may contribute to the inconsistent trial outcomes. The new oral anticoagulants have properties that may prove advantageous in targeting both thrombotic risk and progression of lung fibrosis.

Thrombin-anti-thrombin levels and patency of arterio-venous fistula in patients undergoing haemodialysis compared to healthy volunteers: a prospective analysis

Background

Patients on haemodialysis (HD) are at an increased risk of sustaining thrombotic events especially to their vascular access which is essential for maintenance of HD.

Objectives

To assess whether 1) markers of coagulation, fibrinolysis or endothelial activation are increased in patients on HD compared to controls and 2) if measurement of any of these factors could help to identify patients at increased risk of arteriovenous (AVF) access occlusion.

Patients/Methods

Venous blood samples were taken from 70 patients immediately before a session of HD and from 78 resting healthy volunteers. Thrombin-antithrombin (TAT), D-dimer, von Willebrand factor (vWF), plasminogen activator inhibitor-1 antigen (PAI-1) and soluble p-selectin were measured by ELISA. C-reactive protein (hsCRP) was measured by an immunonephelometric kinetic assay. Determination of the patency of the AVF was based upon international standards and was prospectively followed up for a minimum of four years or until the AVF was non-functioning.

Results

A total of 70 patients were studied with a median follow-up of 740 days (range 72-1788 days). TAT, D-dimer, vWF, p-selectin and hsCRP were elevated in patients on HD compared with controls. At one year follow-up, primary patency was 66% (46 patients). In multivariate analysis TAT was inversely associated with primary assisted patency (r= -0.250, p= 0.044) and secondary patency (r = -0.267, p= 0.031).

Conclusions

The novel finding of this study is that in patients on haemodialysis, TAT levels were increased and inversely correlated with primary assisted patency and secondary patency. Further evaluation is required into the possible role of TAT as a biomarker of AVF occlusion.

Prothrombotic changes in platelet, endothelial and coagulation function following hemodialysis

PURPOSE

Patients on hemodialysis (HD) have an increased risk of thrombotic events, including myocardial infarction and vascular access thrombosis. The study hypothesis is that a single session of dialysis leads to platelet, endothelial and coagulation activation. Our aim is to determine the effect of a single HD session on prothrombotic vascular biomarkers before and after a single session of hemodialysis.

METHODS

Blood samples were taken from the vascular access of 55 patients immediately before and after a hemodialysis session. Platelet function was assessed by (1) flow cytometric measurement of P-selectin expression and fibrinogen binding +/- ADP stimulation, (2) Ultegra rapid platelet function assay (RPFA) using the agonists thrombin receptor activating peptide (TRAP) and arachidonic acid (AA), (3) soluble P-selectin, and (4) soluble CD40L. Coagulation (thrombin-antithrombin III [TAT] and D-dimer), endothelial von Willebrand factor (vWF) and high sensitivity C-Reactive protein (hsCRP) were assessed by ELISA.

RESULTS

Unfractionated heparin was given to all patients during dialysis and 30 patients (55%) were on antiplatelet agents. Post-hemodialysis there were significant increases in unstimulated platelet P-selectin (p=.037), stimulated P-selectin (p<.001), soluble P-selectin (p<.001) and soluble CD40L (p=.036). Stimulated platelet fibrinogen binding was increased post-hemodialysis (p<.001) but unstimulated fibrinogen binding was unchanged. TRAP- (p<.001] and AA-(p=.009) stimulated aggregation were reduced post-hemodialysis. There were increases post-hemodialysis in TAT (p<.001), D-dimer (p<.001), vWF (p<.001) and hsCRP (p=.011).

CONCLUSION

This study has shown that despite heparin therapy, a single session of HD induced increases in platelet, endothelial, and coagulation activation. More effective medical strategies to reduce the prothrombotic state of patients on hemodialysis should be investigated.

Diabetic ketoasidosis is associated with prothrombotic tendency in children

Children and adolescents with type I diabetes mellitus (DM) may present with diabetic ketoacidosis (DKA), which is associated with significant morbidity and mortality. This study aimed to evaluate the hematological parameters at diagnosis (0th hour) and 96th hour after the initiation of treatment in children with DKA. Twenty-six children with DKA treated in Dicle University Faculty of Medicine between September 2002 and August 2003 were included in this study. General characteristics of the patients and hematological parameters (platelet count, white blood cell count, prothrombin time, partial thromboplastin time (PTT), bleeding time, coagulation time, protein C, protein S, antithrombin III, fibrinogen, D-dimer, factor VIII, factor IX, and factor X levels) at diagnosis (0th hour) and 96th hour after the initiation of treatment were determined. The mean age of the children (10 girls and 16 boys) was 9.15 ± 3.85 years (range: 4-15 years). DKA developed for the first time in 58.3% of these children and they had recently been diagnosed as DM. After hematological parameters at 0th hour were evaluated, increased platelet count, decreased PTT, low protein C, and high factor VIII levels were determined at diagnosis, indicating prothrombotic tendency. If the hematological parameters at 0th hour were compared with those at 96th hour; platelet count decreased, PTT increased, protein C and factor VIII levels turned to be normal at 96th hour. When all the results are considered together, children with DKA appeared to have a prothrombotic tendency. Although this tendency was not reflected in clinical findings in this study, it should be kept in mind that children with DKA are prone to the development of thrombosis and they need to be investigated for the possibility of thrombosis.

Diabetic ketoacidosis-associated stroke in children and youth

Diabetic ketoacidosis (DKA) is a state of severe insulin deficiency, either absolute or relative, resulting in hyperglycemia and ketonemia. Although possibly underappreciated, up to 10% of cases of intracerebral complications associated with an episode of DKA, and/or its treatment, in children and youth are due to hemorrhage or ischemic brain infarction. Systemic inflammation is present in DKA, with resultant vascular endothelial perturbation that may result in coagulopathy and increased hemorrhagic risk. Thrombotic risk during DKA is elevated by abnormalities in coagulation factors, platelet activation, blood volume and flow, and vascular reactivity. DKA-associated cerebral edema may also predispose to ischemic injury and hemorrhage, though cases of stroke without concomitant cerebral edema have been identified. We review the current literature regarding the pathogenesis of stroke during an episode of DKA in children and youth.

Diabetic ketoacidosis promotes a prothrombotic state

Cerebrovascular accidents are one of the life-threatening complications of diabetic ketoacidosis (DKA) in children and adolescents. Our objective was to evaluate the effect of DKA and its treatment on factors known to affect thrombotic activity (protein C; protein S; von Willebrand factor, fibrinogen; homocysteine; and folate) by comparing seven adolescents with DKA prior to treatment and at 6, 24, and 120 hours after initiation of treatment. We found that protein C activity was significantly decreased by DKA, but normalized slowly following treatment. Free protein S was low throughout the study. Protein C antigen and protein S antigen showed varying degrees ofchange within the first 24 hours, but remained in the normal range, with the exception of the initial value of protein C antigen, which was elevated. von Willebrand factor (vWF) antigen and vWF activity were both significantly increased prior to treatment, but decreased with treatment. However, vWF activity remained elevated at 120 hours. Fibrinogen concentrations showed no significant changes throughout the study. Homocysteine was significantly decreased prior to treatment and increased with the initiation of treatment Folate was significantly increased prior to treatment, and decreased to high normal levels. The increased vWF and the decreased levels of protein C activity and of free protein S support the hypothesis that DKA and its treatment results in a prothrombotic state and activation of the vascular endothelium, which, in turn, predispose to cerebrovascular accidents.

Plasma Levels of Nitrites/Nitrates in Patients with Chronic Atrial Fibrillation are Increased after Electrical Restoration of Sinus Rhythm

INTRODUCTION

Patients with persistent atrial fibrillation (AF) have hemodynamic changes, which impair endothelial cell function resulting in decreased nitric oxide (NO) production. The aim of this work was to assess endothelial function in AF patients before and at various time points after cardioversion.

METHODS

Forty-two patients with AF and 21 normal and age-adjusted healthy controls were studied. Nitrites and nitrates (NO(x)) and von Willebrand factor (vWf) concentrations were measured on blood samples taken just before cardioversion and over a 30 day period after the procedure.

RESULTS

Plasma levels of NO(x) in AF were significantly lower compared to healthy controls (p < 0.001), but after cardioversion gradually increased to approach to those of the healthy controls by the end of the first month of sustained sinus rhythm (p = 0.004). Interestingly plasma levels of NO(x) were negatively correlated to left atrial volume measured by ultrasonography (r = -0.34, p < 0.05). Plasma levels of vWf in AF patients were significantly higher compared to the healthy controls (p < 0.01) but with sustained sinus rhythm decreased (p = 0.02).

CONCLUSION

The parallel normalization of the NO(x) titers and vWf levels suggests that vascular endothelial function improves after 30 days of normal sinus rhythm.

Acute hyperglycemia increases soluble P-selectin in male patients with mild diabetes mellitus

The aim of this study was to examine if acute hyperglycemia (an oral glucose tolerance test) activates platelet function, endothelial cells or thrombin generation in diabetic patients and healthy controls. Eleven males with mild type II diabetes mellitus and 11 healthy male volunteers, matched for age and body mass index, were investigated before and after the glucose load. Soluble P-selectin, von Willebrand factor antigen and markers of thrombin generation in plasma were determined by immunoassays, and platelet P-selectin expression (unstimulated and agonist-stimulated) by flow cytometry in whole blood. Acute hyperglycemia elevated plasma soluble P-selectin from 32.5 to 50.9 ng/ml in the diabetic group (P = 0.05) but not in the controls (from 27.3 to 28.8 ng/ml; P = 0.6). Also, soluble P-selectin levels were higher in patients with diabetes than in healthy controls during hyperglycemia, but not in the fasting state. Adenosine diphosphate- and thrombin-induced platelet P-selectin expression was slightly, but significantly, decreased by the glucose load, whereas platelet P-selectin expression in unstimulated samples was not affected. Plasma levels of von Willebrand factor and thrombin generation were similar in patients and controls, and were not altered by hyperglycemia. In conclusion, we found that acute hyperglycemia elevates soluble P-selectin in plasma in males with mild type II diabetes mellitus. Our observation of unaltered plasma levels of the endothelial marker von Willebrand factor is in agreement with platelets being the main source of P-selectin released into plasma following hyperglycemia. Thus, platelets in individuals with type II diabetes may be more susceptible to hyperglycemia than platelets in non-diabetic individuals.

Computer analysis of magnetic resonance imaging of the brain in children and adolescents after treatment of diabetic ketoacidosis

Cerebral vascular accidents are one of the causes of morbidity and mortality in children with diabetic ketoacidosis. We investigated the possible occurrence of asymptomatic cerebrovascular infarcts and the course of subclinical brain edema in six patients. Neurologic examinations and computer analysis of magnetic resonance imaging were performed immediately after, and again at 14 days after, correction of DKA. None of the patients had clinical evidence of a neurologic deficit. Neither radiologic evaluation nor computer analysis of MRI identified changes indicating asymptomatic ischemic events. However, a computer analysis of the MRI identified a significant increase of the total ventricle area between Day one and Day 14. Our study does not establish whether this change is a return to the baseline prior to DKA or a new baseline, representing an early manifestation of diabetic encephalopathy.

Elevated circulating levels of von Willebrand factor and D-dimer in patients with heart failure and mechanical prosthesis

To test the hypothesis of association between heart failure and altered haemostatic balance in patients with a mechanical valve prosthesis, comparisons were made between 20 patients with mitral valve replacement and stable chronic heart failure (group A), 20 with the same prosthesis but satisfactory haemodynamics (group B) and 20 age-matched controls (group C). The left ventricular ejection fraction was significantly highest (p < 0.001) in group A. The pulmonary artery systolic pressure was also highest in group A (p < 0.001), without significant difference between groups B and C. Two group A patients had a transient ischaemic attack. The D-dimer plasma concentrations and the antigenic and biologic von Willebrand factor activities were significantly greatest in group A. Significant correlation was found between the plasma concentrations of these activities and pulmonary artery systolic pressure and between D-dimer and ejection fraction. Platelet-activating factor was detected only in six group A patients. The observed relationship between haemostatic factors and heart failure in patients with mechanical heart-valve prosthesis advocates careful evaluation of von Willebrand factor and D-dimer in order to prevent embolic events in such cases.

Transcranial Doppler ultrasound assessment of intracranial hemodynamics in children with diabetic ketoacidosis

The pathophysiology of acute neurological complications of diabetic ketoacidosis (DKA) in children and adolescents is not completely understood. We sought to establish whether transcranial Doppler (TCD) was able to monitor the changes of cerebral blood flow regulatory mechanisms, as measured by cerebral blood velocities (CBF-V), Gosling's pulsatility index (PI), and cerebral vascular reactivity (VR), prior to and during treatment of DKA. The increased values of PI suggested an increase of intracranial pressure (ICP) due to the existence of cerebral vasoparalysis, based on the low values of VR prior to treatment and 6 hours after initiation of treatment. At 24 hours, the correction of hematocrit and pH was associated with a significant decrease of PI, suggesting a decrease of ICP, likely due to a return of vascular tone in response to the low PaCO2. This was further supported by an increase of VR in all patients. At 48 hours, when PaCO2 returned to normal, the PI remained low and the VR increased further, suggesting a complete reversal of vasoparalysis and a return of cerebral blood flow regulatory mechanisms.

Immunoenzymometric analysis for plasma von Willebrand factor degradation in diabetes mellitus using monoclonal antibodies recognizing protease-sensitive sites

High-molecular-weight von Willebrand factor (vWf) multimers were separated from their smaller multimers by molecular-sieve chromatography and were measured by several sandwich enzyme-linked immunosorbent assays (ELISA) with monoclonal antibodies (moABs) against human vWf. The epitopes of these moABs were mapped partially using fragments generated by V-8 protease digests of native vWf. Large multimers were more immunoreactive with the sandwich ELISA using immobilized VW28-1 and enzyme-labeled VW92-3 than with any other ELISA. The epitopes recognized by these two moABs were sensitive to trypsin and plasmin digestion, and the other moABs appeared to be reactive with the extensively digested antigen. Relative reactivities of this ELISA to plasma vWf multimers in diabetes mellitus were significantly reduced compared to those in healthy subjects. These data demonstrate that molecular abnormalities of vWf circulating in diabetic patients may be caused by some plasma proteases that increase in the microcirculation of patients with diabetic vascular diseases.

von Willebrand factor, endothelial cell damage and atherosclerosis

von Willebrand factor (vWf) is an interesting and potentially important molecule whose biology in health and disease warrants attention. A growing body of knowledge now suggests that plasma levels of this specific product of the endothelial cell may have potential as a marker for the assessment of endothelial injury in vivo. As its functions include platelet aggregation and mediation of platelet adhesion to the subendothelium, it may also have a role in the pathogenesis of progression of atherosclerosis. In comparison to asymptomatic controls, increased levels of vWf are found in atherosclerotic vascular disease and in the presence of several of its major risk factors (smoking, hypercholesterolaemia, hypertension, obesity and diabetes). High plasma levels of vWf are also associated with the prediction of adverse clinical events such as myocardial infarction and poor outcome following arterial surgery, possibly by the promotion of thrombus formation. These and other studies indicate that research directed towards determining whether therapy to reduce levels of vWf also influences the progression of arterial disease should prove to be profitable.

Is raised von Willebrand factor a marker of endothelial cell damage?

This hypothesis proposes that, in the absence of actively metastasising neoplasia, damage to the endothelium can be monitored by measuring circulating levels of von Willebrand factor. This specific product of the endothelial cell is important in thrombo-genesis as its functions include platelet aggregation and mediation of platelet adhesion to the subendothelium. High levels are found in all major risk factors of atherosclerosis, in frank atherosclerotic vascular disease and in most of the inflammatory vasculitides, and the highest levels are also associated with more severe disease and risk of mortality. It follows that high levels of von Willebrand factor may be a new risk factor for the development of thrombosis and atherosclerosis.

Endothelium damage and von Willebrand factor antigen

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von Willebrand factor antigen in plasma and urine in patients with type I (insulin-dependent) diabetes mellitus with and without nephropathy

von Willebrand factor (vWF) antigens were quantitatively and qualitatively analyzed in plasma and urine in 41 patients with type I (insulin-dependent) diabetes. The patients were divided into three groups according to their albumin excretion: group N (n = 24) without any excretion (less than 20 micrograms/min), group M (n = 8) with microalbuminuria (20-200 micrograms/min), and group P (n = 9) with persistent albuminuria (greater than 200 micrograms/min). Healthy subjects served as controls (n = 28). The plasma concentration of vWF was higher (p less than 0.05) in the patients with diabetes mellitus than in the controls. Differences between the groups of patients were not statistically significant. The typical multimeric structure described for vWF in normal plasma was observed in all patients. In urine, significantly higher excretion of vWF fragments was observed in the three diabetic study groups as compared with the controls. In group P the patients' urinary vWF/creatinine levels tended to be higher than in groups N and M. Qualitative analysis of urinary vWF fragments demonstrated a similar distribution pattern of fragments, with three distinctive peaks, in the patients of groups N and M and in the controls. The distribution pattern of vWF fragments in group P, however, differed clearly from that in the controls and showed a great variation within the group. The urinary fragments tended to be of a higher molecular weight and several less distinct fragments with the whole spectrum of molecular weight were observed. Because in these patients with proteinuria no qualitative changes appeared in plasma, it is suggested that abnormal degradation of vWF occurred in the kidneys.(ABSTRACT TRUNCATED AT 250 WORDS)

von Willebrand factor in plasma: a novel risk factor for recurrent myocardial infarction and death

OBJECTIVE

To evaluate as predictors of reinfarction and mortality tissue plasminogen activator antigen and activity before and after venous occlusion, plasminogen activator inhibitor, von Willebrand factor, and established risk factors.

DESIGN

Prospective study with a mean observation time of 4.9 years.

SETTING

Secondary referral centre, the Department of Internal Medicine, University Hospital of Umeå.

PATIENTS

123 consecutive survivors of myocardial infarction under the age of 70 years.

MAIN OUTCOME MEASURES

Reinfarction and deaths from all causes.

RESULTS

23 patients died and 36 patients had at least one reinfarction. High concentrations of von Willebrand factor were independently associated with both reinfarction and mortality. A history of angina at entry into the study was also independently associated with reinfarction and mortality. Hypertension was independently associated with mortality but not with reinfarction. None of the fibrinolytic or lipid variables was associated with reinfarction or death.

CONCLUSION

A high concentration of von Willebrand factor was a novel index of increased risk for reinfarction and mortality in survivors of myocardial infarction.

Qualitative and quantitative abnormalities of von Willebrand antigen in patients with diabetes mellitus

Previous reported studies of vVWf antigen (vWf:Ag) in patients with diabetes mellitus have not shown qualitative abnormalities despite frequent documentation of raised vWf:Ag. Twenty two patients with established diabetes mellitus have been studied and qualitative abnormalities of vWf:Ag multimers were found in 10 patients who had poorer glycaemic control (as judged by plasma fructosamine) than the other 12 patients. Seven of the 22 patients were restudied after a 3 month period of improved glycaemic control and the vWf:Ag multimer abnormalities disappeared in 6 of these. Some of the structural abnormalities were accompanied by loss of vWf functional activity. As vWf:Ag is synthesised in the endothelial cell, vWf:Ag abnormalities during periods of poor glycaemic control may reflect endothelial cell damage with vWf:Ag release and possibly subsequent proteolysis.

Diabetes-like alterations in hemostatic parameters after growth hormone administration for one week in normal man

Excess production of growth hormone (GH) in poorly controlled diabetes is believed to be a causal factor in the development of diabetic angiopathy, the mechanism(s) of which is unknown. The present study was undertaken to determine whether exogenous growth hormone would specifically change some quantities and functional parameters known to often be abnormal in long-standing diabetes and thought to result from the development of vascular lesions in general. The authors studied capillary resistance, factor VIII coagulant antigen (F VIII:Ag), von Willebrand factor (vWf:Ag), fibronectin, fibrinogen, and tissue-type plasminogen activator (t-PA) before, during, and after 1 week's subcutaneous GH administration (6 IU per day divided into two doses). Capillary resistance decreased insignificantly, but returned to higher levels (p less than 0.05) 1 week after withdrawal. F VIII:Ag, vWf:Ag, fibronectin, and fibrinogen all increased significantly during GH treatment. Except for F VIII:Ag, these quantities returned to pre-medication levels 7 days after termination of GH administration. The present results may contribute to the clarification of the role of GH hypersecretion in diabetic microangiopathy and macroangiopathy.

Venous thromboembolism and transient thrombocytopenia in a patient with diabetes insipidus treated with desmopressin acetate (DDAVP)

A 22 year-old woman with diabetes insipidus on chronic therapy with desmopressin acetate (DDAVP) developed recurrent venous thromboembolism and transient thrombocytopenia temporally related to the administration of DDAVP. Large increases in plasma von Willebrand factor (vWF), vWF-activity, and relative increases in the concentrations of the larger multimeric forms of vWF-antigen were observed, as well as a plasma factor which sensitized normal platelets to undergo spontaneous aggregation in vitro. Additional studies showed that the patient's plasma retained the platelet aggregation inducing activity after selective removal of vWF by immunoabsorption. The nature of the platelet activating factor and the relationship of this factor and the excessively increased and transiently abnormal vWF to the recurrent venous thromboembolism in this patient remain uncertain. Although the findings do not implicate definitively DDAVP in the elevation of vWF in this patient, it is suggested that its use be considered with caution in patients with diabetes mellitus and increased levels of vWF.