Rituximab-associated progressive multifocal leukoencephalopathy

The definition "Progressive Multifocal Leukoencephalopathy" (PML) was first used in 1958 to describe a fatal demyelinating central nervous system (CNS) disease in patients with lymphoproliferative disorders. In 1971, the virus responsible for the disease was isolated and named John Cunningham virus (JCV). We present a rare case of a 62-year-old male with chronic lymphocytic leukemia and PML. In our work, we discuss the diagnostic and therapeutic challenges and offer suggestions for preventing PML development. The main learning points are: 1. Regularly check the level of immunoglobulins and the CD4+ : CD8+ T-cell ratio, intravenous administration of immunoglobulins should be considered when recording their reduction. 2. In checking the CD4+ : CD8+ T-cell ratio and verifying the impossibility of raising the level of immunoglobulins, we must weigh the possible benefits of continuing treatment with monoclonal antibody against the risks. 3. Physicians should maintain a high index of suspicion for the development of PML in patients under treatment with monoclonal antibodies, especially when there is a new development of neurological signs or symptoms.Key words: JC virus - progressive multifocal leukoencephalopathy - recommendation - rituximab.

Plasminogen Activator Inhibitor Type-1 (PAI-1) Levels Are Decreased in NIDDM Patients treated with Insulin

We examined 25 non-insulin-dependent diabetes mellitus (NIDDM) patients treated with sulfonylurea (SU) regi mens, 14 NIDDM patients with 8-12 weeks long-acting insulin (INS) treatment and 15 age-matched normoinsulinemic healthy controls. Plasminogen activator inhibitor-1 (PAI-1) levels were significantly increased in NIDDM patients treated by SU agents (median 58.9, range 14-217 ng/ml) compared to patients with insulin therapy (median 20.7, 4-53 ng/ml) and normal controls (median 10.8, 4-52 ng/ml) (p < 0.001). Non-insulin- dependent diabetes mellitus subgroups were not different in other hemostatic (von Willebrand factor, thrombomodulin, tis sue factor pathway inhibitor, platelet factor-4 levels) and meta bolic (C-peptide, triglycerides) parameters and PAI-1 levels did not correlate with these hemostatic and metabolic parameters. This finding suggests that insulin application itself may cause decreased PAI-1 levels, probably by influence on intracellular calcium. This hypothesis requires further research. Key Words: PAI-1—Insulin treatment—Non—insulin—dependent diabetes mellitus.

Severe Hemophilia and Physiologic Inhibitors of Coagulation

Patients with hemophilia demonstrate quite variable clinical phenotype even in cases with the same level of deficient factor or the same molecular abnormality. Different interacting factors including congenital and acquired alterations of coagulation inhibitors can modulate both clinical expression and severity of hemophilia. In this study, plasma levels of factor VIII (FVIII), factor IX (FIX) as well as protein C (PC), protein S (PS), and antithrombin (AT) plasma levels were measured in 80 patients with severe hemophilia A and B. Patients were divided into two groups according to the risk of bleeding: the first group (n = 32) with mild bleeding (< 2 bleeds/year), and the second group (n = 48) with severe bleeding (≥ 2 bleeds/year). Both hemophilia groups showed significantly decreased PC plasma levels compared to levels in healthy control subjects (the first group: p < 0.0001 and second group: p < 0.01). The difference in PC plasma levels between the first and second hemophilia group was significant (p < 0.05). Moreover, there was positive correlation between age and the functional PC in both hemophilia groups. Our results suggest that decreased PC plasma levels can testify to a slightly protective effect of the PC pathway on the severity and frequency of bleeding in patients with severe hemophilia A and B.

Factor V Leiden and Prothrombin G20210A Mutations and the Risk of Atherothrombotic Events in Systemic Lupus Erythematosus

Because genetic predisposition to atherothrombosis in systemic lupus erythematosus (SLE) remains to be determined, the most common genetic prothrombotic factors, prothrombin G20210A and factor V Leiden mutations, were studied. Seventy-four SLE patients with vascular ischemia (SLE cases) were studied and stratified into myocardial infarction and/or cerebrovascular accident subgroup (MI/CVA), and coronary heart disease subgroup without overt arterial thrombotic events (CHD). Seventy-one SLE patients without atherothrombosis were investigated as SLE controls. Factor V Leiden was detected in six cases (five in MI/CVA, one in CHD group) and three controls (OR 2.00, 95%CI 0.48-8.32). Two cases (both CHD patients) had prothrombin G20210A mutation vs. three controls (OR 0.63, 95%CI 0.1-3.88). Anticardiolipin antibodies (aCL) were increased in cases vs. controls (39/74 vs. 27/71); however, this was not statistically significant (OR 1.82, 95%CI 0.94-3.52). Neither univariate nor multivariate analysis indicated that investigated mutations are risk factors for atherothrombosis in SLE cases, MI/CVA, or CHD subgroups. Overall, disease activity was the strongest risk factor for atherothrombosis (p=0.0014) in SLE cases. Combination of disease activity+gender was the best predictor of atherothrombotic process (p=0.00045) in this cohort. In MI/CVA subgroup, disease activity was the only predictor (p=0.0058). In CHD patients, the best predictive value was conferred by combination of hypertension+gender+disease activity (p=0.00077). No other investigated risk factor (including aCL) conferred an increased risk individually or potentiated the other risk factors. The results deny the role of investigated mutations in atherothrombosis in SLE, but they underscore the importance of disease activity (i.e., ongoing inflammation) in pathogenesis of atherosclerosis and arterial thrombosis.

Some Hemostatic Changes During the Course of Hemodialysis in Patients with Erythropoietin Treatment

The recombinant human erythropoietin (rHuEPO), an effective agent in the treatment of renal anemia, can predispose chronic uremic patients to thrombotic events with regular hemodialysis (HD). It has been proposed that increased release of tissue plasminogen activator (t-PA) from endothelial cells, together with consumption of plasminogen activator inhibitor-1 (PAI- 1), is likely to be a leading cause of enhanced fibrinolytic activity (FA) during HD. In our study, rHuEPO-treated patients manifested PAI-1 Ag (antigen) plasma levels that were significantly augmented after HD, suggesting FA inhibition during the HD session. The elevated predialysis beta-thromboglobulin (BTG) and platelet factor-4 (PF-4) plasma levels were increased in rHuEPO-treated patients during HD; the platelet protein levels were simultaneously decreased in the control group. Both findings reflect decreased FA and greater activity of platelets in the course of HD with administration of rHuEPO and a possible correlation of these mechanisms with the questioned prothrombotic performance of rHuEPO. Key Words: Erythropoietin—Hentodiatysts—Fibrinotytic activity—Platelet proteins.

Soluble P-Selectin During a Single Hemodialysis Session in Patients With Chronic Renal Failure and Erythropoietin Treatment

In several studies, hemodialysis (HD) patients treated with recombinant human erythropoietin (rHuEPO) because of renal anemia showed increased levels of soluble adhesion molecules. The purpose of the study was to investigate the changes of soluble P-selectin (sSELP) and its relationship to platelet activation during a single HD session in patients with long-term rHuEPO treatment. Fifty-two HD patients with chronic renal failure were involved—26 with rHuEPO treatment (EPO group) and 26 without (non-EPO group). Thirty healthy subjects served as the control group. The sSELP, β-thromboglobulin, and platelet factor 4 plasma levels were measured before and after a single 4-hour HD session on a cuprophane dialyzer. The basal β-thromboglobulin and platelet factor 4 plasma levels were significantly increased in both HD groups compared with healthy controls but did not change after a single HD session, except for a significant decrease of platelet factor 4 in the non-EPO group. The predialysis sSELP plasma levels did not differ significantly compared with those of the healthy controls, but there was a significant increase of sSELP levels after a single HD session in both groups (EPO, P < .005; non-EPO, P < .05, respectively). These results suppose that the increased sSELP level was released from platelets during the course of a single HD session. The more significant increase of the sSELP plasma levels in EPO group during HD indicates that platelets are more activated in patients with long-term rHuEPO treatment, and this fact could partially explain the suspected tendency for thrombosis in these patients.

Insulin Treatment Inhibits PAI-1 Production in NIDDM Patients with Endothelial Dysfunction

We examined 34 non-insulin-dependent diabetes mellitus (NIDDM) patients treated with sulfonylurea regimens, 24 NIDDM patients with 2-3 months long-acting insulin treat ment and 19 age-matched normoinsulinemic healthy controls. NIDDM patients were divided into two subgroups, with and without endothelial dysfunction according to von Willebrand factor level 0.14 IU/mL. There were significant differences in PAI-1 levels among patients without endothelial dysfunction treated by sulfonylurea agents (median 48.1, range 14-108 ng/ mL) or insulin (27.9, 2-53 ng/mL) and patients with endothe lial dysfunction treated by sulfonylurea regimens (80.7, 43-217 ng/mL) or insulin, respectively, (16.7, 7-34 ng/mL) (analysis of variance p < .001). NIDDM subgroups were not different in metabolic parameters (C-peptide and triglyceride levels, body mass index) and platelet activation marker (platelet factor 4 values). von Willebrand Factor and thrombomodulin levels were elevated in groups with endothelial dysfunction (analysis of variance p < .001, p = .025, respectively). Insulin treatment was accompanied by decreased PAI-1 levels especially in pa tients with endothelial dysfunction. Insulin is the inhibitor of endothelial PAI-1 production induced by cytokines. Therefore, we suggest that long-term insulin application may decrease PAI-1 levels by direct inhibitive action on the endothelial PAI-1 compartment. This hypothesis requires further research.

Progress in the Understanding of Sticky Platelet Syndrome

The knowledge on the etiology of thrombosis has increased tremendously over the past decades. Nevertheless, Virchow triad is still traditionally invoked to explain mechanisms leading to thrombosis, alleging concerted roles for abnormalities in blood composition, vessel wall components, and blood flow in the development of arterial and venous thrombosis. Recent decades have been focused primarily on describing abnormalities in blood composition, including defects of coagulation proteins and platelets. Although defects of coagulation factors are relatively well-described in the literature, prothrombotic platelet disorders are still less understood. One such defect, the Wien-Penzing defect was first described in 1991. Another platelet defect is sticky platelet syndrome (SPS). In this article, we review information about SPS, and we propose a new definition and standardization of diagnostic criteria. We also attempt to explain the causes and consequences of this condition.

The Impact of Type 2 Diabetes on the Efficacy of ADP Receptor Blockers in Patients with Acute ST Elevation Myocardial Infarction: A Pilot Prospective Study

Background. The aim of this study was to validate the impact of type 2 diabetes (T2D) on the platelet reactivity in patients with acute ST elevation myocardial infarction (STEMI) treated with adenosine diphosphate (ADP) receptor blockers. Methods. A pilot prospective study was performed. Totally 67 patients were enrolled. 21 patients had T2D. Among all study population, 33 patients received clopidogrel and 34 patients received prasugrel. The efficacy of ADP receptor blocker therapy had been tested in two time intervals using light transmission aggregometry with specific inducer and vasodilator-stimulated phosphoprotein phosphorylation (VASP-P) flow cytometry assay. Results. There were no significant differences in platelet aggregability among T2D and nondiabetic (ND) group. The platelet reactivity index of VASP-P did not differ significantly between T2D and ND group (59.4 ± 30.9% versus 60.0 ± 25.2% and 33.9 ± 25.3% versus 38.6 ± 29.3% in second testing). The number of ADP receptor blocker nonresponders did not differ significantly between T2D and ND patients. The time interval from ADP receptor blocker loading dosing to the blood sampling was similar in T2D and ND patients in both examinations. Conclusion. This prospective study did not confirm the higher platelet reactivity and higher prevalence of ADP receptor blocker nonresponders in T2D acute STEMI patients.

Type 2 Diabetes and ADP Receptor Blocker Therapy

Type 2 diabetes (T2D) is associated with several abnormalities in haemostasis predisposing to thrombosis. Moreover, T2D was recently connected with a failure in antiplatelet response to clopidogrel, the most commonly used ADP receptor blocker in clinical practice. Clopidogrel high on-treatment platelet reactivity (HTPR) was repeatedly associated with the risk of ischemic adverse events. Patients with T2D show significantly higher residual platelet reactivity on ADP receptor blocker therapy and are more frequently represented in the group of patients with HTPR. This paper reviews the current knowledge about possible interactions between T2D and ADP receptor blocker therapy.

Sticky platelet syndrome: an important cause of life-threatening thrombotic complications

Sticky platelet syndrome (SPS) is a prothrombotic thrombocytopathy with familial occurrence, characterized by hyperaggregability of platelets in response to adenosine diphosphate (ADP), epinephrine (EPI) or both. The syndrome has been identified in approximately 21% of unexplained arterial thrombotic episodes, regarded to be the most common thrombophilia in arterial thrombosis and 13.2% of unexplained venous thromboembolism (VTE). The relatively young age at the first manifestation, relation to fertility and pregnancy, seriousness of the symptoms, easy and effective management of the disorder indicate to the necessity to take it into account in the differential diagnosis of the underlying cause of the thrombotic event. As the various localizations of the thrombosis in SPS have been reported, its management often requires a multidisciplinary approach. This review deals with the clinical aspects of thrombophilia, its etiopathogenesis, diagnosis as well as novel advances in the treatment and outlines the challenges for the further research.

Monitoring of Hemostasis by Rotational Thrombelastometry During Normal Pregnancy and Postpartum

Background: Rotational thrombelastometry (ROTEM) is a real-time clotting test that provides insight into clotting factors, the fibrinolytic system and platelet function. We obtained the longitudinal values on ROTEM in normal pregnancy and in puerperium.

Material and Methods: After ethics committee approval and subject informed consent, citrated blood was sampled from healthy pregnants four times during pregnancy and one time postpartum. As controls we used nonpregnant women undergoing voluntary blood donation. Extem and Intem tests and basic coagulation test were carried out.

Results: We included 112 women in our study, 55 non-pregnant women (controls) and 57 healthy pregnants with 5 samplings. The values of maximum clot firmness (MCF - in EXTEM and INTEM) were significantly higher up to 34th-36th week of pregnancy than those in non-pregnant subjects. MCF in 6th-7th week after delivery was significantly higher in both tests. Clotting time (CT) in pregnant women was significantly shorter (EXTEM) compared to non-pregnant subjects. We also found a very strong correlation between MCF and platelet count in all gestational weeks.'

Conclusions: Rotation thromboelastometry clearly demonstrates the hypercoagulability in pregnancy and can reflect the higher risk of venous thromboembolism in both pregnancy and puerperium. Strong correlation between MCF and platelet count can suggest role of platelets in hypercoagulability in pregnant women. This study provides a better knowledge about physiological changes in ROTEM measurement during pregnancy and postpartum.

Monitoring of dabigatran therapy using Hemoclot(®) Thrombin Inhibitor assay in patients with atrial fibrillation

Dabigatran, a new direct thrombin inhibitor, achieves strong anticoagulation that is more predictable than warfarin. Nevertheless, a patient on dabigatran therapy (DT) may suffer from thrombotic or bleeding events. The routine monitoring of DT is not recommended, and standard coagulation tests are not sensitive enough for the assessment of DT activity. The aim of this study was to examine the clinical usefulness of the Hemoclot(®) Thrombin Inhibitor (HTI) assay in the assessment of dabigatran plasma levels in patients with non-valvular AF. Nineteen patients (12 men, 7 women) on DT were included in this preliminary prospective observational study. Dabigatran was administrated twice daily in a two dose regimens: 150 mg (5 patients) and 110 mg (14 patients). Blood samples were taken for the assessment of trough and peak levels of dabigatran. Dabigatran concentrations were measured with the HTI assay. The average dabigatran trough level was 69.3 ± 55.5 ng/ml and the average dabigatran peak level was 112.7 ± 66.6 ng/ml. The dabigatran trough plasma concentration was in the established reference range in 15 patients and the dabigatran peak plasma concentration was in the established reference range in 9 patients, respectively. Despite the fact that the activated partial thromboplastin and thrombin times were generally changed (prolonged), these tests failed to identify the patients with too low or too high dabigatran concentrations. The study confirmed the high sensitivity of the HTI assay for the assessment of dabigatran plasma levels. When compared to standard coagulation tests, the HTI is a more suitable assay for the monitoring of patients treated with dabigatran. Monitoring of DT may be beneficial in selected patients; however, further studies will be needed for the final clarification of this issue.

Genetic variations of the GP6 regulatory region in patients with sticky platelet syndrome and miscarriage

INTRODUCTION

Thrombophilia increases the risk of venous thrombosis during pregnancy and may predispose to gestational vascular complications.

OBJECTIVE

The aim of this study is to evaluate the variability of GP6 regulatory regions in a group of patients with platelet hyperaggregability manifested as miscarriage compared with control subjects.

METHODS

We examined 27 female patients with platelet hyperaggregability and history of spontaneous abortion and 42 healthy women. Platelet hyperaggregability was established by light transmission aggregometry. We also assessed eight SNPs within the GP6 gene.

RESULTS

We found a higher occurrence of three SNPs in patients with platelet hyperaggregability and history of miscarriage (rs1671152, rs1654433, rs1671215). The haplotype analysis showed a significant higher occurrence of two haplotypes (ACGG, CCGT).

CONCLUSIONS

Our results support the idea that genetic variability of GP6 regulatory regions can be associated with platelet hyperaggregability - a possible cause of miscarriage.

Endovascular stenting in malignant obstruction of superior vena cava

INTRODUCTION

Superior vena cava syndrome (SVCS) is obstruction of blood flow through the SVC. It is a medical emergency and most often manifests in patients with a malignant disease process within the thorax. A patient with SVCS requires immediate diagnostic evaluation and therapy.

PRESENTATION OF CASE

A 33-years-old woman presented with complaints of dyspnoea and chest pain. Computer tomography revealed a large mass in the anterior mediastinum. This mass compressed surrounding structures. Stenting was indicated for early symptoms of SVCS. The diagnosis of Hodgkin's lymphoma (HL) was confirmed with biopsy. The patient's stage II HL has been subsequently treated with six cycles of chemotherapy with doxorubicin, bleomycin, vinblastine, dacarbazine (ABVD), followed by radiotherapy. Presently she is doing well.

DISCUSSION

Although lymphomas are a common cause of SVCS but almost always SVCS is caused by non-Hodgkin's lymphoma (NHL). HL despite its common presentation with mediastinal lymphadenopathy rarely causes SVCS.

CONCLUSION

Lymphomas are a common cause of SVCS in young age. HL may present as SVCS. Pathological confirmation of diagnosis should be done before initiating therapy while dealing with a case of SVCS. SVC stenting is effective and has few complications in patients with SVCS.

Endothelial and platelet markers in diabetes mellitus type 2

Diabetes mellitus (DM) is an extremely common disorder which carries a risk of vascular impairment. DM type 2 (DM2) can be characterized by the dysfunction of haemostasis manifesting by stimulated coagulation process, disorder of platelet function and decreased fibrinolytic activity. These all are the reasons why DM2 is the most common acquired thrombophilia. Endothelial dysfunction along with platelet hyperactivity are unquestionably involved in the hyperactivation of platelets and clotting factors in DM. As a natural consequence of continuous investigation, many markers of endothelial dysfunction and diabetic thrombocytopathy have been identified and considered for implementation in clinical practice. Endothelial function can be assessed by the evaluation of endothelial markers, circulating molecules synthesised in various amounts by the endothelium. These markers precede the signs of evident microangiopathy. Platelets have an ethiopathogenic relation to the microangiopathy in DM. Their increased activity was confirmed in both types of DM. Predictors of endothelial and platelet disorder could improve the screening of individuals at increased risk, thus leading to the early diagnosis, appropriate treatment, as well as to the effective prevention of the complications of DM2. In the article we deal with the mechanisms involved in the pathogenesis of endothelial and platelet functional abnormalities, endothelial and platelet markers of DM2 considered for implementation in clinical practice and possibilities of their detection.

Different models of inheritance in selected genes in patients with sticky platelet syndrome and fetal loss

INTRODUCTION

The aim of this study was to evaluate the genetic variability of selected single nucleotide polymorphisms (SNPs) within GAS6 and PEAR1 genes and explore the association between selected SNPs and risk for fetal loss in women with sticky platelet syndrome (SPS).

MATERIALS AND METHODS

We examined 23 female patients with SPS and history of spontaneous abortion, and 42 healthy women who served as controls. The diagnosis of SPS was established by light transmission aggregometry according to methods and criteria developed by Mammen et al. We also assessed four SNPs within the GAS6 gene (rs7400002, rs1803628, rs8191974, rs9550270) and two SNPs within PEAR1 gene (rs12041331, rs12566888).

RESULTS

We identified two SNPs within PEAR1 gene (rs12041331, rs12566888) and one SNP within GAS6 gene (rs9550270) that have higher occurrence in SPS patients with history of abortion. An increased risk for abortion was observed in carriers of the rs7400002 within GAS6 gene. Conversely, we found that the T allele of PEAR1 c. -9-4663G > T polymorphism appears to be protective for fetal loss.

CONCLUSION

Our results support the idea that genetic variability of GAS6 and PEAR1 genes may be associated with platelet hyperaggregability. The study also suggests a possible polygenic type of SPS heredity.