Congenital thrombotic risk factors in beta-thalassemia

Natural Anticoagulant Protein Levels in Patients With Beta-Thalassemia Major: A Case-Control Study

Background

β-thalassemia is a group of inherited blood disorders that affect the production of β-globin chains, leading to the reduction or absence of these chains. One of the complications observed in patients with β-thalassemia major (β-TM) is thrombosis, especially in those who receive frequent blood transfusions. This may be due to a decrease in the levels of the natural anticoagulants: protein C (PC), total protein S (PS), and antithrombin (AT).

Methods

In this case-control study, patients with β-TM, who had received at least 20 packed cell transfusions during their lifetime, were included. Patients with other underlying diseases like bleeding or thrombotic disorders were excluded. Totally, 118 patients with β-TM and 120 healthy individuals were included.

Results

The mean level of PC and AT was significantly lower in patients with β-TM (48.2 ± 65.4 and 57.42 ± 13.6, respectively) compared to the control group (97.1 ± 21.46 and 81.79 ± 14.3, respectively), with P value of 0.001 and 0.01, respectively. Although the difference was not statistically significant (P = 0.1), a similar trend was observed for total PS (61.12 ± 21.12 for patients versus 72.2 ± 35.2 for the control group). Of note, the decrease in PC, AT, and total PS levels compared to the control group was 50.36%, 27.5%, and 15.34%, respectively.

Conclusions

It seems that β-TM patients who receive prolonged blood transfusions frequently are at an increased risk of decreased in natural anticoagulants levels and therefore potentially are at risk of thrombosis.

Low levels of coagulation inhibitors: A high-risk thrombotic factor in thalassemic patients

BACKGROUND AND AIM

The β-thalassemia major (β-TM) is defined as a hereditary red blood cell-related disease. Thrombotic events are associated with thalassemia in adult patients. Thus, the present investigation was aimed to examine some hemostatic parameters, including anti thrombin-III (AT-III), protein-C (PRC) and protein-S (PRS) in β-TM patients.

METHODS

Thirty B-TM patients who referred for routine follow-up admission to the thalassemia clinic of Kerman Special Disease Center alongside with 30 healthy subjects were selected and enrolled in the present study. Further registration, the peripheral blood specimens were collected after 3 weeks of last transfusion and then the plasma concentrations of AT-III, PRC and PRS were measured in them.

RESULTS

We have observed that the concentrations of natural coagulation inhibitors (PRC and PRS) were significantly attenuated in β-TM patients (P<0.05), while the plasma level of AT-III was not remarkably differed in β-TM patients in compare to healthy subjects.

CONCLUSION

According to the findings of present work, significant changes in the PRC, PRS and AT-III which could be observed in multi transfused β-TM patients may attribute as critical risk factors for the development of upcoming thromboembolic events in their future life.

Protein C and Anti-Thrombin-III Deficiency in Children With Beta-Thalassemia

Background

Thromboembolic events (TEEs) are recently described complications in thalassemia patients. Many mechanisms were postulated for thrombosis. Conflicting results of natural anticoagulants values were reported in previous studies. Our aim was to investigate protein C and anti-thrombin-III (AT-III) levels in thalassemics and to detect risk factors for their decrement.

Methods

A cross-sectional study for 60 beta-thalassemia patients (35 major and 25 intermedia) and 35 healthy children were tested for protein C and AT-III levels, liver function tests and Sr. ferritin.

Results

A significant reduction in protein C and AT-III levels was noticed in patient group compared to healthy children (82.50% (32 - 175) vs. 104% (60 - 204), P = 0.041 and 237.52 ± 53.19 mg/L vs. 322.99 ± 56.57 mg/L, P value ≤ 0.001, respectively). Protein C was lower among older patients (> 10 years) than younger patients (< 10 years), and splenectomized category than non-splenectomized one (P = 0.02 and 0.011, respectively). AT-III was significantly lower among splenectomized patients as compared to those who did not undergo splenectomy (P = 0.04). Significant correlations were found between protein C and AT-III with older age and liver functions.

Conclusions

Protein C and AT-III were significantly lower among thalassemics with the main risk factors for their deficiencies being: splenectomy and increasing age. This allows establishment of early prophylactic policy against TEE for the vulnerable group.

Coagulation defects in thalassemic patients

BACKGROUND

Regular blood transfusion and compliance with iron chelation therapy has markedly improved life expectancy in thalassemia; however, this improvement is accompanied by several complications of this chronic disease including thromboembolic disorders. The objective of this work is to study natural coagulation inhibition as well as the fibrinolysis processes in thalassemic children who are otherwise in a steady state with no overt clinical manifestations of thromboembolism.

METHODS

In a case-control study design conducted at Sohag University Hospital, Sohag, Egypt, 50 thalassemic children and 20 age- and sex-matched healthy controls were compared as regards prothrombin concentration, international normalized ratio, partial thromboplastin time, protein C, protein S, antithrombin III, D-dimers, and thrombin activatable fibrinolysis inhibitor (TAFI).

RESULTS

When compared to healthy controls, natural coagulation inhibitors (protein C, protein S, and antithrombin-III) were significantly lower in thalassemic children (p < 0.0001). While D-dimers showed a significant increase in thalassemic children, TAFI was significantly lower (p < 0.0001). Splenectomized thalassemic children showed significantly lower levels of protein C, protein S and TAFI (p < 0.001, p < 0.0001, p < 0.0001, respectively) when compared to nonsplenectomized thalassemic children.

CONCLUSION

Significant changes in natural coagulation inhibition and fibrinolysis processes favoring thromboembolism can be detected in otherwise healthy thalassemic children. Because these changes are more pronounced in splenectomized patients, study of primary prophylactic strategies in this subgroup is warranted.

Cerebral thrombosis in patients with β-thalassemia: a systematic review

A hypercoagulable state has been documented in patients with β-thalassemia. It could result in thromboembolic events in several organs including brain involvement, which deserves particular attention. We summarized the prevalence of cerebral involvement in patients with β-thalassemia worldwide. We conducted an electronic search on PUBMED (MEDLINE), SCOPUS, and Google Scholar databases up to January 2011. Overall 152 thalassemic patients with cerebral thromboembolic events and a proportion of 1.13% (134 of 11770) were recorded. From all patients with cerebral thromboembolic events, 74 (48%) were splenectomized. Cerebral thromboembolic events were reported after transfusion in six β-thalassemia major, and two β-thalassemia intermedia patients. Three β-thalassemia major patients had irregular transfusion and 22 β-thalassemia intermedia patients were not transfused. Thrombocytosis were determined in 11 β-thalassemia major, and 15 β-thalassemia intermedia patients. Cardiomyopathy was present in 13 β-thalassemia major and four β-thalassemia intermedia patients. Also, nine β-thalassemia major patients had diabetes. Activated protein C resistant, decreased protein C or protein S or plasminogen level was detected in eight β-thalassemia major patients. Cerebral involvement appears to be associated with increasing age, transfusion naivety, splenectomy, thrombocytosis, intensive transfusion, decreased protein C level, and having risk factors for cerebrovascular accident such as cardiomyopathy, and diabetes. In light of these findings, diagnostic MRI is recommended in high-risk groups to screen for early asymptomatic brain damage. If brain ischemia is found, the administration of antiplatelet aggregants or blood transfusion is likely to be beneficial. In addition, in thalassemic patients who complicated with a thromboembolic event, secondary prophylaxis could be helpful to prevent cerebral thromboembolic events.

The Dual Diverse Dynamic Reversible Effects of Ankaferd Blood Stopper on EPCR and PAI-1 Inside Vascular Endothelial Cells With and Without LPS Challenge

Objective: Ankaferd blood stopper (ABS) is comprised of a mixture of the plants Thymus vulgaris, Glycyrrhiza glabra, Vitis vinifera, Alpinia officinarum, and Urtica dioica. ABS is used as a topical hemostatic agent due to its antihemorrhagic effect, yet its hemostatic mechanism of action remains to be investigated. ABS does not affect the levels of coagulation factors II, V, VII, VIII, IX, X, XI and XII. The aim of this study was to investigate the effects of ABS on endothelium and immune response. As such, we evaluated changes in endothelial cell protein C receptor (EPCR) and plasminogen activator inhibitor type-1 (PAI-1) expression inside human umbilical vein endothelial cells (HUVECs) in the presence and absence of lipopolysaccharides (LPSs).

Material and Methods: We exposed HUVECs to 10 μL and 100 μL of ABS for 5 min, 25 min, 50 min, 6 h, and 24 h. Additionally, 10 μg mL–1 of LPS was administered for 1 h to observe the effects of LPS challenge on HUVECs, and then the cells were treated with ABS for 5 min, 25 min, 50 min, and 6 h to observe the effects of ABS on HUVECs. Total RNA was isolated from HUVECs and then the level of expression of EPCR and PAI-1 mRNA was measured.

Results: Cells were microscopically observed to arise from the surface and adhere to each other following the administration of ABS to HUVECs. Additionally, after 24 h the cells had normal growth and physiology, which suggests that the adhesive cellular effects of ABS might be reversible. ABS had a negative effect on EPCR and PAI-1 expression; the effect in response to 100 µL was greater than that to 10 µL. EPCR and PAI-1 expression increased over time in response to LPS and 10 µL of ABS. EPCR and PAI-1 expression was very low during the first hour of exposure to LPS and 100 µL of ABS, but after 6 h increased to levels similar to those observed in response to LPS and 10 µL of ABS.

Conclusion: It was observed that ABS had dual diverse dynamic reversible effects on EPCR and PAI-1 expression in HUVECs, which were dependent on dose and concentration. ABS might play a role in numerous cellular mechanisms, in addition to having hemostatic effects.

Conflict of interest:None declared.

Normalized coagulation markers and anticoagulation proteins in children with severe β-thalassemia disease after stem cell transplantation

The hypercoagulable state is well recognized in patients with severe β-thalassemia disease. One of the mechanisms of chronic hypercoagulable state is the abnormal expression of phosphatidylserine on red blood cells (RBC). This study aimed to determine the coagulable state in patients with severe β-thalassemia disease following successful stem cell transplantation (SCT). Subjects were classified into three groups: normal controls (NC), β-thalassemia disease receiving regular transfusion (Thal-RT) and β-thalassemia disease post SCT (Thal-SCT). Sixty eight subjects, aged 3-17years, consisting of 21 NC, 28 Thal-RT and 19 Thal-SCT were enrolled. After SCT, the annexin V level in Thal-SCT was normalized. At the median follow-up time of 70.3 (50.9-84.2) months after SCT, the levels of coagulation markers (thrombin antithrombin complex, prothrombin fragment and D-dimer) and anticoagulation proteins (protein C, S and antithrombin activities) returned to the levels similar to controls.