Delayed spontaneous remission of acquired factor V inhibitor refractory to immunosuppressive therapy with pregnancy-associated improvement

Introduction: Acquired factor V inhibitor (AFVI) is a rare autoimmune bleeding disorder. The treatment of AFVI is challenging, and patients often require both bleeding control and inhibitor eradication. Methods: We conducted a retrospective analysis of the medical records of a 35-year-old Caucasian woman who presented with severe AFVI-induced bleeding and subsequent immunosuppressive therapy. Results: To provide haemostasis, rFVIIa was given with good efficacy. The patient was treated with various combinations of immunosuppressive regimens over the course of 2.5 years, including plasmapheresis plus immunoglobulins, dexamethasone + rituximab, cyclophosphamide + dexamethasone + rituximab + cyclosporine, cyclosporin + sirolimus + cyclophosphamide + dexamethasone, bortezomib + sirolimus + methylprednisolone, and sirolimus + mycophenolate mofetil. Although these treatment modalities resulted in intermittent partial reversals of AFVI over 2.5 years, eventually the inhibitor became therapy-resistant. However, following the discontinuation of all immunosuppressive therapy, the patient experienced a partial spontaneous remission, which was followed by a pregnancy. During the pregnancy, the FV activity increased to 54% and the coagulation parameters returned to normal levels. The patient underwent Caesarean section without any bleeding complications and delivered a healthy child. Discussion: The use of an activated bypassing agent for bleeding control is effective in patients with severe AFVI. The presented case is unique because the treatment regimens included multiple combinations of immunosuppressive agents. This demonstrates that AFVI patients may undergo spontaneous remission even after multiple courses of ineffective immunosuppressive protocols. Additionally, pregnancy-associated improvement of AFVI is an important finding that warrants further investigation.

Complement Inhibition in Paroxysmal Nocturnal Hemoglobinuria (PNH): A Systematic Review and Expert Opinion from Central Europe on Special Patient Populations

INTRODUCTION

Hemolysis in paroxysmal nocturnal hemoglobinuria (PNH) is complement-mediated due to the lack of complement inhibitors in the hemopoietic cell membranes, making complement inhibition the best approach to manage PNH. Three complement inhibitors are approved by the European Medicines Agency as targeted therapy for PNH: eculizumab and ravulizumab, two humanized monoclonal antibodies targeting the same complement 5 (C5) epitope, approved in 2007 and 2019, respectively, and the more recently approved cyclic peptide, the complement 3 (C3) inhibitor pegcetacoplan. Although national and international PNH treatment guidelines exist, they do not take into consideration the latest clinical trial evidence. Given the lack of evidence-based data for some clinical situations encountered in real life, we identified specific populations of patients who may benefit from switching to proximal C3 from terminal C5 inhibition.

METHODS

The expert recommendations presented here were created using a Delphi-like process by a group of expert PNH specialists across Central Europe. Based on an initial advisory board meeting discussion, recommendations were prepared and reviewed as part of a Delphi survey to test agreement.

RESULTS

Using a systematic approach, literature databases were searched for relevant studies, and 50 articles were reviewed by the experts and included as supporting evidence.

CONCLUSION

Implementation of these recommendations uniformly across healthcare institutions will promote the best use of complement inhibition in managing PNH, and has the potential to positively impact patient outcomes in Central Europe and worldwide.

von Willebrand factor neutralizing and non-neutralizing alloantibodies in 213 subjects with type 3 von Willebrand disease enrolled in 3WINTERS-IPS

BACKGROUND

Type 3 von Willebrand disease (VWD) is the most severe form of this disease owing to the almost complete deficiency of von Willebrand factor (VWF). Replacement therapy with plasma-derived products containing VWF or recombinant VWF rarely cause the development of alloantibodies against VWF that may be accompanied by anaphylactic reactions.

OBJECTIVE

The objective of this study was to assess the prevalence of anti-VWF alloantibodies in subjects with type 3 VWD enrolled in the 3WINTERS-IPS.

METHODS

An indirect in-house enzyme-linked immunosorbent assay has been used to test all the alloantibodies against VWF. Neutralizing antibodies (inhibitors) have been tested with a Bethesda-based method by using a VWF collagen binding (VWF:CB) assay. Samples positive for anti-VWF antibodies were further tested with Bethesda-based methods by using the semiautomated gain-of-function glycoprotein-Ib binding (VWF:GPIbM) and a VWF antigen (VWF:Ag) enzyme-linked immunosorbent assay.

RESULTS

In total, 18 of the 213 (8.4%) subjects tested positive for anti-VWF antibodies and 13 of 213 (6%) had VWF:CB inhibitors. These 13 were among the 18 with anti-VWF antibodies. Of the 5 without VWF:CB inhibitors, 3 had non-neutralizing antibodies, 1 only inhibitor against VWF:GPIbM, and one could not be tested further. Ten of the 13 subjects with VWF:CB inhibitors also had VWF:GPIbM inhibitors, 6 of whom also had VWF:Ag inhibitors. Subjects with inhibitors were homozygous for VWF null alleles (11/14), homozygous for a missense variant (1/14), or partially characterized (2/14).

CONCLUSIONS

Anti-VWF antibodies were found in 8.4% of subjects with type 3 VWD, whereas neutralizing VWF inhibitors were found in 6%, mainly in subjects homozygous for VWF null alleles. Because inhibitors may be directed toward different VWF epitopes, their detection is dependent on the assay used.

Combined immunosuppression for acquired hemophilia A: CyDRi is a highly effective low-toxicity regimen

Acquired hemophilia A (AHA) is a rare severe autoimmune bleeding disorder with significant morbidity and mortality. Although critical for disease control, there is no consensus for the best immunosuppressive regimen. Most authors use steroids first line, followed by other agents for steroid failures. Upfront combined regimens offer the advantage of reduced steroid exposure and toxicity as well as increased efficacy. We retrospectively analyzed data from 32 patients with AHA treated on an identical such institutional protocol: cyclophosphamide 1000 mg on days 1 and 22, dexamethasone 40 mg on days 1, 8, 15, and 22, and rituximab 100 mg on days 1, 8, 15, and 22 (the regimen was termed CyDRi). All patients received at least 1 cycle of CyDRi. If necessary, CyDRi was repeated until remission, no sooner than day 43 of the previous cycle. Bleeding control was rapidly achieved. The median time for bleeding control was 15.5 days (range, 0-429 days; interquartile range, 2.5-29.5 days). Thirty-one (96.8%) of 32 patients achieved durable complete remission (CR); 29 (90.6%) of 32 patients were alive at last follow-up, all of them in CR. The median time to reach first CR was 77 days (range, 19-939 days; interquartile range, 31-115 days). Toxicity and side effects were acceptable and milder than those of commonly used, prolonged steroid therapies. In conclusion, the CyDRi regimen produced markedly higher CR rates and overall survival than currently used sequential regimens. Taken together, CyDRi proved to be an attractive option for the immunosuppression of elderly patients with AHA.

Case Report: A Child With Hemophilia A Serves as Donor for Hematopoietic Stem Cell Transplantation to Cure His Brother's Severe Aplastic Anemia

The first-line treatment of severe aplastic anemia is allogeneic hematopoietic stem cell transplantation with a matched sibling donor. However, co-morbidities of the identical donor can make donation difficult. We present a transplantation where in parallel with the patient's conditioning treatment, the preparation of the donor with severe hemophilia A required a special management with perioperative factor VIII substitution. Donation was successful without complications, and 18 months after transplantation, the patient and his donor are well without any long-term sequelae. To our knowledge, this is the first reported succesfull transplantation with hemophilic child serving as a bone marrow donor. The procedure did not mean a significant risk to donor health, so donors with hemophilia should not be excluded from donation.

Von Willebrand factor propeptide and pathophysiological mechanisms in European and Iranian patients with type 3 von Willebrand disease enrolled in the 3WINTERS-IPS study

BACKGROUND

Type 3 von Willebrand disease (VWD) is a severe bleeding disorder caused by the virtually complete absence of von Willebrand factor (VWF). Pathophysiological mechanisms of VWD like defective synthesis, secretion, and clearance of VWF have previously been evaluated using ratios of VWF propeptide (VWFpp) over VWF antigen (VWF:Ag) and factor (F)VIII coagulant activity (FVIII:C) over VWF:Ag.

OBJECTIVE

To investigate whether the VWFpp/VWF:Ag and FVIII:C/VWF:Ag ratios may also be applied to understand the pathophysiological mechanism underlying type 3 VWD and whether VWFpp is associated with bleeding severity.

METHODS

European and Iranian type 3 patients were enrolled in the 3WINTERS-IPS study. Plasma samples and buffy coats were collected and a bleeding assessment tool was administered at enrolment. VWF:Ag, VWFpp, FVIII:C, and genetic analyses were performed centrally, to confirm patients' diagnoses. VWFpp/VWF:Ag and FVIII:C/VWF:Ag ratios were compared among different variant classes using the Mann-Whitney test. Median differences with 95% confidence intervals (CI) were estimated using the Hodges-Lehmann method. VWFpp association with bleeding symptoms was assessed using Spearman's rank correlation.

RESULTS

Homozygosity/compound heterozygosity for missense variants showed higher VWFpp level and VWFpp/VWF:Ag ratio than homozygosity/compound heterozygosity for null variants ([VWFpp median difference, 1.4 IU/dl; 95% CI, 0.2-2.7; P = .016]; [VWFpp/VWF:Ag median difference, 1.4; 95% CI, 0-4.2; P = .054]).

FVIII

C/VWF:Ag ratio was similarly increased in both. VWFpp level did not correlate with the bleeding symptoms (r = .024; P = .778).

CONCLUSIONS

An increased VWFpp/VWF:Ag ratio is indicative of missense variants, whereas FVIII:C/VWF:Ag ratio does not discriminate missense from null alleles. The VWFpp level was not associated with the severity of bleeding phenotype.

Comparison of von Willebrand factor platelet-binding activity assays: ELISA overreads type 2B with loss of HMW multimers

BACKGROUND

A number of new assays with different measuring principles are available to measure von Willebrand factor (VWF) glycoprotein Ib (GPIb)-binding activity, but little is known about how these assays might behave differently for subtypes of von Willebrand disease (VWD).

OBJECTIVES

The Comparison of Assays to Measure VWF Activity (COMPASS-VWF) study was designed to compare all available VWF GPIb-binding activity assays for VWF. We specifically searched for particular assay behavior differences.

PATIENTS/METHODS

To sort out random differences from systematic assay behavior deviations, all assays were performed in different laboratories on the same samples in a blinded fashion. Samples from 53 normal controls and 42 well-characterized VWD patients were reanalyzed in this study to dissect assay-specific discrepancies.

RESULTS

No assay behavior differences were found for 53 normal controls. For VWD patients, we found the following systematic assay behavior patterns: (a) All ELISA assays for VWF:GPIbR as well as VWF:GPIbM are insensitive to detect the low VWF activity of VWD type 2B patients with loss of high molecular weight multimers; (b) VWF:Ab assay reports higher activity for the p.V1665E mutation than all other assays; and (c) all ristocetin-based assays (including VWF:RCo using fixed platelets) but the AcuStar assay report discrepantly low VWF activity for the p.P1467S polymorphism. No systematic assay-specific difference was observed for either the particle agglutination VWF:GPIbM assay or the AcuStar assay using magnetic beads.

CONCLUSIONS

Different assay principles may lead to discrepant results for certain VWD types or mutations. Therefore, a more extensive study for a large number of patients is needed to better characterize the incidence and relevance of such assay-specific differences.

Bleeding symptoms in patients diagnosed as type 3 von Willebrand disease: Results from 3WINTERS-IPS, an international and collaborative cross-sectional study

BACKGROUND

Type 3 von Willebrand's disease (VWD) patients present markedly reduced levels of von Willebrand factor and factor VIII. Because of its rarity, the bleeding phenotype of type 3 VWD is poorly described, as compared to type 1 VWD.

AIMS

To evaluate the frequency and the severity of bleeding symptoms across age and sex groups in type 3 patients and to compare these with those observed in type 1 VWD patients to investigate any possible clustering of bleeding symptoms within type 3 patients.

METHODS

We compared the bleeding phenotype and computed the bleeding score (BS) using the MCMDM-1VWD bleeding questionnaire in patients enrolled in the 3WINTERS-IPS and MCMDM-1VWD studies.

RESULTS

In 223 unrelated type 3 VWD patients, both the BS and the number of clinically relevant bleeding symptoms were increased in type 3 as compared to type 1 VWD patients (15 versus 6 and 5 versus 3). Intracranial bleeding, oral cavity, hemarthroses, and deep hematomas were at least five-fold over-represented in type 3 VWD. A more severe bleeding phenotype was evident in patients having von Willebrand factor antigen levels < 20 IU/dL at diagnosis in the two merged cohorts. In type 3 patients, there was an apparent clustering of hemarthrosis with gastrointestinal bleeding and epistaxis, whereas bleeding after surgery or tooth extraction clusters with oral bleeding and menorrhagia.

CONCLUSIONS

In the largest cohort of type 3 VWD patients, we were able to describe a distinct clinical phenotype that is associated with the presence of a more severe hemostatic defect.

Clinical Utilization and Cost of Thrombophilia Testing in Patients with Venous Thromboembolism

Introduction  Testing for inherited and acquired thrombophilias adds to the cost of care of patients with venous thromboembolism (VTE), though results may not influence patient management.

Methods  This is a single-center, retrospective study conducted at Emory University Hospitals from January to December 2015 to (1) determine the pattern of thrombophilia testing in patients with VTE, (2) study the impact of results of thrombophilia testing on clinical decision-making, and (3) determine the direct costs of thrombophilia testing in patients with VTE.

Results  Of the 266 eligible patients, 189 (71%) underwent testing; 51 (26.9%) tested positive and the results impacted management in 32 (16.9%) of tested patients. Patient undergoing testing were more likely to be younger than 40 years (30.9 vs. 18.2%), have had prior pregnancy loss (9.0 vs. 0%), or known family history of hypercoagulability (24.9 vs. 10.4%), and were less likely to have had provoked VTE (37 vs. 79.2%). The most common thrombophilias tested were antiphospholipid syndrome (60.1%), factor V Leiden (59.7%), and prothrombin gene mutation (57.5%). Direct costs of thrombophilia testing were $2,364.32 per patient, $12,331.55 to diagnose 1 positive, and $19,653.41 per patient-management affected.

Conclusion  We noted significant variability in selection of patients and panel of tests, sparse utilization of test results in patient management, but high cost associated with thrombophilia testing in patients with VTE. With guidelines advocating selective use of thrombophilia testing and attention to potential impact of test results in patient management, we propose the need for measures at institutional levels to improve test-ordering practices.

An international collaborative study to compare different von Willebrand factor glycoprotein Ib binding activity assays: the COMPASS-VWF study

Essentials New VWF activity assays are increasingly used but information on their comparability is limited. This is an ISTH SSC-organized study (expert labs, 5 countries) to compare all available assays. VWF activity by six assays correlated well with each other. The new assays show improved characteristics - minor differences are noted. SUMMARY: Background Several new assays have become available to measure von Willebrand factor (VWF) activity. The new assays appear to have improved performance characteristics compared with the old reference standard, ristocetin cofactor activity (VWF:RCo), but information is limited about how they compare with VWF:RCo and each other. Methods The von Willebrand factor Subcommittee of the International Society for Thrombosis and Haemostasis (ISTH) Scientific and Standardization Committee (SSC) designed a collaborative study involving expert laboratories from several countries to compare available tests with each other and with VWF:RCo. Eight laboratories from five countries were provided with blinded samples from normal healthy individuals and well-characterized clinical cases. Laboratories measured VWF activity using all tests available to them; data from six laboratories, not affected by thawing during transportation, are included in this study. Results All tests correlated well with VWF:RCo activity (r-values ranged from 0.963 to 0.989). Slightly steeper regression lines for VWF:Ab and VWF:GPIbM were clinically insignificant. The new assays showed improved performance characteristics. Of the commercially available assays, the VWF:GPIbR using the AcuStar system was the most sensitive and could reliably detect VWF activity below 1 IU dL-1 . The lower limit of the measuring interval for the VWF:GPIbM and the VWF:GPIbR assays was in the 3-4 and 3-6 IU dL-1 range, respectively. Inter-laboratory variation was also improved for most new assays. Conclusion All VWF activity assays correlated well with each other and the VWF:RCo assay. The slight differences in characteristics found in the COMPASS-VWF study will assist the VWF community in interpreting and comparing activity results.

Co-infections in Visceral Pentastomiasis, Democratic Republic of the Congo

Results of PCR and histology indicate this infection is endemic to this country.

Snakeborne Armillifer pentastomiasis is an emerging human parasitic infection in rural tropical areas where snake meat is eaten. After a series of severe ocular A. grandis larval infections and anecdotal abdominal infection in Sankuru District, Democratic Republic of the Congo, during 2014–2015, we systematically investigated possible pentastomid etiology in patients who underwent surgery in the region. Histologic and molecular analyses by established pentastomid 18S rDNA- and newly developed Armillifer-specific cytochrome oxidase PCRs revealed larval pentastomid lesions in 3.7% of patients. Some persons had A. armillatus and A. grandis co-infections. Another pentastomid larva, Raillietiella sp., was molecularly detected in 1 patient who had concomitant A. grandis and A. armillatus infection. The PCRs used were suitable for detecting pentastomid species even in highly necrotic tissues. Phylogenetic analyses of Armillifer cytochrome oxidase genes detected multiple local strains.

Armillifer-Infected Snakes Sold at Congolese Bushmeat Markets Represent an Emerging Zoonotic Threat

African pythons (Pythonidae) and large vipers (Bitis spp.) act as definitive hosts for Armillifer armillatus and Armillifer grandis parasites (Crustacea: Pentastomida) in the Congo Basin. Since the proportion of snakes in bushmeat gradually increases, human pentastomiasis is an emerging zoonotic disease. To substantiate the significance of this threat, we surveyed snakes offered for human consumption at bushmeat markets in the Kole district, Democratic Republic of the Congo, for the presence of adult pentastomids. In Bitis vipers (n = 40), Armillifer spp. infestations exhibited an 87.5% prevalence and 6.0 median intensity. Parasite abundance covaried positively with viper length, but not with body mass. In pythons (n = 13), Armillifer spp. exhibited a 92.3% prevalence and 3.5 median intensity. The positive correlations between parasite abundance and python length or mass were statistically nonsignificant. Ninety-one percent of A. grandis were discovered in vipers and 97% of infected vipers hosted A. grandis, whereas 81% of A. armillatus specimens were found in pythons and 63% of infected pythons hosted A. armillatus. Thus, challenging the widespread notion of strict host specificity, we found 'reversed' infections and even a case of coinfection. In this study, we also gathered information about the snake consumption habits of different tribal cultures in the area. Infective parasite ova likely transmit to humans directly by consumption of uncooked meat, or indirectly through contaminated hands, kitchen tools or washing water.

The evolutionary logic of sepsis

The recently proposed Microbiome Mutiny Hypothesis posits that members of the human microbiome obtain information about the host individuals' health status and, when host survival is compromised, switch to an intensive exploitation strategy to maximize residual transmission. In animals and humans, sepsis is an acute systemic reaction to microbes invading the normally sterile body compartments. When induced by formerly mutualistic or neutral microbes, possibly in response to declining host health, sepsis appears to fit the 'microbiome mutiny' scenario except for its apparent failure to enhance transmission of the causative organisms. We propose that the ability of certain species of the microbiome to induce sepsis is not a fortuitous side effect of within-host replication, but rather it might, in some cases, be the result of their adaptive evolution. Whenever host health declines, inducing sepsis can be adaptive for those members of the healthy human microbiome that are capable of colonizing the future cadaver and spread by cadaver-borne transmission. We hypothesize that such microbes might exhibit switches along the 'mutualist - lethal pathogen - decomposer - mutualist again' scenario, implicating a previously unsuspected, surprising level of phenotypic plasticity. This hypothesis predicts that those species of the healthy microbiome that are recurring causative agents of sepsis can participate in the decomposition of cadavers, and can be transmitted as soil-borne or water-borne infections. Furthermore, in individual sepsis cases, the same microbial clones that dominate the systemic infection that precipitates sepsis, should also be present in high concentration during decomposition following death: this prediction is testable by molecular fingerprinting in experimentally induced animal models. Sepsis is a leading cause of human death worldwide. If further research confirms that some cases of sepsis indeed involve the 'mutiny' (facultative phenotypic switching) of normal members of the microbiome, then new strategies could be devised to prevent or treat sepsis by interfering with this process.

Does the frequency of molecular monitoring after tyrosine kinase inhibitor discontinuation affect outcomes of patients with chronic myeloid leukemia?

BACKGROUND

To the authors' knowledge, the optimal frequency of monitoring after tyrosine kinase inhibitor (TKI) discontinuation in patients with chronic myeloid leukemia (CML) has not been established. Data regarding the discontinuation of second-generation TKIs used in first-line treatment or after the failure of first-line treatment with TKIs are limited. Herein, the authors report real-world experience with "reduced frequency" molecular monitoring in patients with CML in all phases who discontinued treatment with imatinib, dasatinib, or bosutinib.

METHODS

The records of patients who discontinued TKIs were reviewed. Patients who discontinued TKIs were monitored prospectively on an intended schedule of monthly blood quantitative reverse transcriptase-polymerase chain reaction for BCR-ABL1 for 3 months, quarterly for 12 months, and every 6 months thereafter until loss of major molecular response (MMR). After loss of MMR, the TKI that previously was discontinued was reinitiated.

RESULTS

Between January 2010 and September 2015, a total of 24 patients in chronic (21 patients), accelerated (2 patients), and lymphoid blast (1 patient) phase discontinued imatinib (16 patients), dasatinib (5 patients), or bosutinib (3 patients) used in the front-line treatment or beyond. Blood quantitative reverse transcriptase-polymerase chain reaction for BCR-ABL1 was performed 1.3 ± 0.7 times within the first 3 months (24 patients) and 2.7 ± 1.4 times in the following 12 months (18 patients). With a median follow-up of 36.5 months (range, 3.2-67.4 months), the probabilities of treatment-free remission at 1 year and 2 years were 65.7% (95% confidence interval, 55.8%-75.6%) and 59.7% (95% confidence interval, 49.1%-70.3%), respectively. Loss of MMR was observed in 9 patients at a median of 2.8 months (range, 1.8-14.2 months) after discontinuation of TKIs.

CONCLUSIONS

With the limitations of a small sample size, the results of the current study demonstrate that less frequent monitoring of BCR-ABL1 does not appear to affect outcomes, and that discontinuation of TKIs used as first-line treatment or beyond after resistance or intolerance to first-line treatment appears feasible. Cancer 2017;123:2482-88. © 2017 American Cancer Society.

[Rare case of a pregnancy in a woman with paroxysmal nocturnal hemoglobinuria. Case report]

Paroxysmal nocturnal hemoglobinuria is a rare hematological disease. It is associated with increased maternal and fetal complications to such an extent that pregnancy has been considered relatively contraindicated in woman with paroxysmal nocturnal haemoglobinuria. Recently, eculizumab, a monoclonal antibody, has been shown to decrease complications during pregnancies. The highest risk is thromboembolic complication and, therefore, anticoagulant is a standard therapy during pregnancy. In the presented case, a 29-year-old woman with a 5-year history of paroxysmal nocturnal haemoglobinuria had a pregnancy. It was her first pregnancy and was complicated by a sinus thrombosis at the 11th gestational week. After the introduction of eculizumab treatment, the remaining period of pregnancy and delivery were uncomplicated. There are only a few cases in the literature about pregnancy in woman with paroxysmal nocturnal hemoglobinuria who are treated with eculizumab. This monoclonal antibody seems to be safe and it likely prevents many of the complications otherwise observed.

[Prognostic factors in light chain amyloidosis]

INTRODUCTION

Light chain amyloidosis is characterized by extracellular deposition of a fibrillar material derived from immunglobulin light chain fragments.

AIM

The aim of the authors was to assess survival depending on cardiac involvement, therapy, and presence of myeloma.

METHOD

The authors studied a retrospective cohort of 29 patients with light chain amyloidosis (13 kappa, 16 lambda) treated in their institution between 2005 and 2014.

RESULTS

Twenty-one patients had primary amyloidosis, while 8 had coexisting multiple myeloma. One, two and three or more organs were involved in 4, 8, and 17 patients, respectively. Cardiac involvement (22 cases) inversely correlated with survival. Fifteen (52%) patients received chemotherapy only, while 14 (48%) underwent autologous stem cell transplantation with a median survival of 87 and 11.4 months, respectively. Two patients had heart transplantation and survived 70 and 30 months. Median overall survival was 75.8 months.

CONCLUSIONS

Cardiac transplantation followed by autologous stem cell transplantation is feasible in selected patients with light chain amyloidosis and heart failure.

Inflammation and oxidative stress caused by nitric oxide synthase uncoupling might lead to left ventricular diastolic and systolic dysfunction in patients with hypertension

OBJECTIVE

To investigate the role of oxidative stress, inflammation, hypercoagulability and neuroendocrine activation in the transition of hypertensive heart disease to heart failure with preserved ejection fraction (HFPEF).

METHODS

We performed echocardiography for 112 patients (≥ 60 years old) with normal EF (18 controls and 94 with hypertension), and determined protein carbonylation (PC), and tetrahydrobiopterin (BH4), C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), fibrinogen, plasminogen activator inhibitor type-I (PAI-I), von Willebrand factor, chromogranin A (cGA) and B-type natriuretic peptide (BNP) levels from their blood samples.

RESULTS

We found that 40% (38/94) of the patients with hypertension (HT) had no diastolic dysfunction (HTDD-), and 60% (56/94) had diastolic dysfunction (HTDD+). Compared to the controls, both patient groups had increased PC and BH4, TNF-α, PAI-I and BNP levels, while the HTDD+ group had elevated cGA and CRP levels. Decreased atrial and longitudinal left ventricular (LV) systolic and diastolic myocardial deformation (strain and strain rate) was demonstrated in both patient groups versus the control. Patients whose LV diastolic function deteriorated during the follow-up had elevated PC and IL-6 level compared to their own baseline values, and to the respective values of patients whose LV diastolic function remained unchanged. Oxidative stress, inflammation, BNP and PAI-I levels inversely correlated with LV systolic, diastolic and atrial function.

CONCLUSIONS

In patients with HT and normal EF, the most common HFPEF precursor condition, oxidative stress and inflammation may be responsible for LV systolic, diastolic and atrial dysfunction, which are important determinants of the transition of HT to HFPEF.

von Willebrand disease and platelet disorders

The diagnosis and management of bleeding disorders is made difficult by the complexity and variety of disorders, clinical symptoms and bleeding type and severity. von Willebrand disease (VWD) and platelet disorders are disorders of primary haemostasis and together represent the most common inherited bleeding disorders. In this article, we describe the diagnosis of VWD and platelet disorders and the treatment options for VWD.

Ocular pentastomiasis in the Democratic Republic of the Congo

Ocular pentastomiasis is a rare infection caused by the larval stage of pentastomids, an unusual group of crustacean-related parasites. Zoonotic pentastomids have a distinct geographical distribution and utilize reptiles or canids as final hosts. Recently, an increasing number of human abdominal infections have been reported in Africa, where pentastomiasis is an emerging, though severely neglected, tropical disease. Here we describe four ocular infections caused by pentastomids from the Democratic Republic of the Congo. Two cases underwent surgery and an Armillifer grandis infection was detected by morphological and molecular approaches. Thus far, 15 other cases of ocular pentastomiasis have been reported worldwide. Twelve cases were caused by Armillifer sp., recorded almost exclusively in Africa, where such infections occur as a consequence of hunting and consuming snakes, their final hosts. Seven further cases were caused by Linguatula serrata, a cosmopolitan pentastomid whose final hosts are usually canids. Intraocular infections caused permanent visual damage in 69% and a total loss of vision in 31% of reported cases. In contrast, ocular adnexal cases had a benign clinical course. Further research is required to estimate the burden, therapeutic options and pathogenesis of this neglected disease.

Common large partial VWF gene deletion does not cause alloantibody formation in the Hungarian type 3 von Willebrand disease population

BACKGROUND

Type 3 von Willebrand disease (VWD) is an autosomal recessive bleeding disorder, characterized by virtually undetectable plasma von Willebrand factor (VWF) and consequently reduced plasma factor VIII levels. Genetic mutations responsible for type 3 VWD are very heterogeneous, scattered throughout the VWF gene and show high variability among different populations.

METHODS

Twenty-five severe VWD patients were studied by direct sequencing of the 51 coding exons of the VWF gene. The total number of VWD type 3 families in Hungary is 24, of which 23 were investigated.

RESULTS

Fifteen novel mutations were identified in 31 alleles, five being nonsense mutations (p.Q1238X, p.Q1898X, p.Q1931X, p.S2505X and p.S2568X), four small deletions and insertions resulting in frame shifts (c.1992insC, c.3622delT, c.5315insGA and c.7333delG), one a large partial deletion (delExon1-3) of the 5'-region, four candidate missense mutations (p.C35R, p.R81G, p.C295S, p.C623T) and one a candidate splice site mutation (c.1730-10C>A). Six previously described mutations were detected in 17 alleles, including the repeatedly found c.2435delC, p.R1659X and p.R1853X. Only one patient developed alloantibodies to VWF, carrying a homozygous c.3622delT.

CONCLUSION

We report the genetic background of the entire Hungarian type 3 VWD population. A large novel deletion, most probably due to a founder effect, seems to be unique to Hungarian type 3 VWD patients with high allele frequency. In contrast to previous reports, none of the five patients homozygous for the large partial deletion developed inhibitors to VWF. This discrepancy raises the possibility of selection bias in some of the reports.

Possible genetic sign of heat stress adaptation in Hungarian Grey Bos taurus breed

The synthesis of Heat Shock Protein 70.2 mRNA is also regulated by the Upper Promoter elements of the gene. This promoter region is polymorphic in cattle. These polymorphisms have a major effect on the activity of the mRNA transcription. In a comparison of quantity of transcribed mRNA from the wild type and AP2 mutant allele the wild type can produce 2-3-fold more transcripts.The Hungarian Grey Cattle (HG) and Norwegian Red (NFR) as control breed were genotyped with PCR-RFLP method. Our results showed that the frequencies of alleles in breeds (p(wt)HG = 0.859419, p(wt)NFR = 0.5) are different. The effective response to heat stress in the Norwegian Red seems to be less important than in the Hungarian Grey breed. The extensive keeping in hot and arid region during centuries could have been proved as selection pressure for the heat tolerance.Our results combined with the global climate forecasts emphasize the role of autochthonous, well adopted, heat tolerant breeds in the near future.

Accelerated clearance alone explains ultra-large multimers in von Willebrand disease Vicenza

BACKGROUND

von Willebrand disease (VWD) Vicenza is characterized by low plasma von Willebrand factor (VWF) levels, the presence of ultra-large (UL) VWF multimers and less prominent satellite bands on multimer gels, and the heterozygous amino acid substitution R1205H in the VWF gene. The pathogenesis of VWD Vicenza has been elusive. Accelerated clearance is implicated as a cause of low VWF level.

OBJECTIVES

We addressed the question, whether the presence of ultra-large multimers is a cause, or a result of accelerated VWF clearance, or whether it is an unrelated phenomenon.

PATIENTS/METHODS

We studied the detailed phenotype of three Hungarian patients with VWD Vicenza, expressed the mutant VWF-R1205H in 293T cells and developed a mathematical model to simulate VWF synthesis and catabolism.

RESULTS

We found that the half-life of VWF after DDAVP was approximately one-tenth of that after the administration of Haemate P, a source of exogenous wild-type (WT) VWF (0.81 + or - 0.2 vs. 7.25 + or - 2.38 h). An analysis of recombinant mutant VWF-R1205H showed that the biosynthesis and multimer structure of WT and mutant VWF were indistinguishable. A mathematical model of the complex interplay of VWF synthesis, clearance and cleavage showed that decreasing VWF half-life to one-tenth of normal reproduced all features of VWD Vicenza including low VWF level, ultra-large multimers and a decrease of satellite band intensity.

CONCLUSION

We conclude that accelerated clearance alone may explain all features of VWD Vicenza.

[Characterization of age dependent alterations of the cup of the incisor on the basis of data from Hungarian and German horses]

The authors give a short orientation about the age related parameters of the incisors based on the literature. They examined the question of breed differences with respect to the age determination of horses in the different counties, especially in regard to the English Thoroughbred. In this context they present a new parameter as well as a new approach in data-processing. The cup depth and the yearly abrasion showed high breed-specificity. The relative abrasion indicated that the most intensive wear out is typical for the Thoroughbred. The cup depth and the yearly wear out were different according to the incisor's type in respect to the merged Thoroughbred populations of the two countries. The deviations observed in the cup depth can be explained by body size differences of the breeds. The degree of the absolute and the relative abrasion of the cup can also be associated with the early utilisation (racing) and with the intensive feeding (concentrate). The authors assume that the selection for the early utilisation of the English Thoroughbred resulted in an automatic change of the well inherited chronology of dentition; i. e. the earlier maturity of dentition. In of the bone system manifests also in the narrowing of the teeth. As the recent cup depth values deviate from the earlier ones, the authors suggest correcting the age of the disappearance of the cup from the current 6-7-8 years to 5-7-9 years for the English Thoroughbred.

An Alu-mediated novel large deletion is the most frequent cause of type 3 von Willebrand disease in Hungary

BACKGROUND

We studied 24 Hungarian patients from 23 unrelated families to identify the genetic background of the entire type 3 von Willebrand disease (VWD) population in this country. The current report focuses on the molecular characterization of a novel large deletion.

RESULTS

A large partial deletion (delExon1-3) of the 5'-region of the von Willebrand factor gene (VWF) was detected in 12/48 alleles (25% of all type 3 alleles). The 5'-deletion breakpoint is located in the untranslated region between VWF and CD9, whereas the 3' breakpoint is in intron 3 of VWF. Analysis of the breakpoints showed Alu Y and Alu SP repetitive sequences at the ends of the deletion, suggesting that a recombination event caused the subsequent loss of the 35-kb fragment. DelExon1-3 was not found in any of the other screened populations.

CONCLUSION

We report a large novel deletion including exons 1, 2 and 3 of VWF commonly causing type 3 VWD in the Hungarian population. This mutation, probably caused by an Alu-mediated recombination event, and subsequently distributed in Hungary by a founder effect, seems to be unique to Hungarian patients with a high allele frequency. Together, delExon1-3 and 2435delC make up 37.5% of the genetic defects in Hungarian patients with VWD type 3. This offers a rational approach to molecular testing of relevant families in Hungary.

Thrombosis risk in systemic lupus erythematosus: the role of thrombophilic risk factors

OBJECTIVES

Thromboembolic episodes are frequent manifestations of systemic lupus erythematosus (SLE). Although the presence of anti-phospholipid antibodies (aPL) is known to contribute to thromboembolism (TE), the relative contribution of other TE risk factors is unknown. The aim of this study was to determine the prevalence of TE in a Caucasian SLE population, to identify the risk factors of highest importance, and to assess the clinical value of thrombophilia screening among SLE patients.

METHODS

Samples from 105 patients were analysed with a screen including aPL, activated protein C resistance, factor V Leiden (FVL) and prothrombin G20210A mutations; protein C, protein S and antithrombin activity; factor VIII (FVIII) and von Willebrand factor (vWF), and homocysteine (Hcy) levels.

RESULTS

The annual incidence of arterial and venous TE events in our SLE population was 5.4 and 12.4 per 1000, respectively. The highest risk of thrombosis was carried by the simultaneous presence of lupus anticoagulant (LA) and anti-cardiolipin (aCL) [relative risk (RR) = 4.03, 95% confidence interval (CI) 2.06-7.86] or anti-beta2-glycoprotein I antibodies (abeta2-GPI) (RR = 5.10, 95% CI 2.58-10.1). Positivity for the individual aPL tests all carried an elevated TE risk. The presence of other risk factors seemed to be of less importance.

CONCLUSIONS

In SLE patients, the presence of aPL is a more significant risk factor for the development of thrombosis than the known inherited deficiencies. Based on these data, routine screening for additional hereditary risk factors seems to be unwarranted.

Type 1 von Willebrand disease mutation Cys1149Arg causes intracellular retention and degradation of heterodimers: a possible general mechanism for dominant mutations of oligomeric proteins

Some families affected by von Willebrand disease type 1 show high penetrance with exceptionally low von Willebrand factor (VWF) levels. Previously, a mutation associated with this dominant phenotype, Cys1149Arg, was found to decrease the secretion of coexpressed normal VWF, and the mutation was proposed to cause intracellular retention of pro-VWF heterodimers. To demonstrate heterodimer formation, a model was developed in which subunits could be distinguished immunologically and by size. Recombinant VWF lacking domain A1 (dA1), A3 (dA3), or both (dA13) was secreted efficiently as a full range of multimers. Cotransfection of Cys1149Arg and dA13 resulted in the secretion of multimeric VWF containing about 250 kd (Cys1149Arg) and about 210 kd (dA13). Cell lysates contained pro-VWF forms of Cys1149Arg and dA13. Immunoprecipitation with an antidomain A1 antibody recovered both subunits in heterodimers, and subunit ratios were consistent with random dimerization. Similar results were obtained for cotransfection of Cys1149Arg and dA1. Normal VWF has a Cys1149-Cys1169 intrachain bond. When cotransfected with normal VWF, Cys1149Arg or the double mutant Cys1149Arg+Cys1169Ser caused a similar decrease in VWF secretion, suggesting that an unpaired Cys1169 does not explain the intracellular retention of Cys1149Arg. VWF Cys1149Arg was not secreted from BHK cells but was degraded intracellularly within about 4 hours, and the proteasome inhibitor lactacystin delayed its clearance more than 16 hours. Thus, dominant von Willebrand disease type 1 may be caused by heterodimerization of mutant and normal subunits in the endoplasmic reticulum followed by proteasomal degradation in the cytoplasm. A similar dominant negative mechanism could cause quantitative deficiencies of other multisubunit proteins.

Localization of disulfide bonds in the cystine knot domain of human von Willebrand factor

von Willebrand factor (VWF) is a multimeric glycoprotein that is required for normal hemostasis. After translocation into the endoplasmic reticulum, proVWF subunits dimerize through disulfide bonds between their C-terminal cystine knot-like (CK) domains. CK domains are characterized by six conserved cysteines. Disulfide bonds between cysteines 2 and 5 and between cysteines 3 and 6 define a ring that is penetrated by a disulfide bond between cysteines 1 and 4. Dimerization often is mediated by additional cysteines that differ among CK domain subfamilies. When expressed in a baculovirus system, recombinant VWF CK domains (residues 1957-2050) were secreted as dimers that were converted to monomers by selective reduction and alkylation of three unconserved cysteine residues: Cys(2008), Cys(2010), and Cys(2048). By partial reduction and alkylation, chemical and proteolytic digestion, mass spectrometry, and amino acid sequencing, the remaining intrachain disulfide bonds were characterized: Cys(1961)-Cys(2011) (), Cys(1987)-Cys(2041) (), Cys(1991)-Cys(2043) (), and Cys(1976)-Cys(2025). The mutation C2008A or C2010A prevented dimerization, whereas the mutation C2048A did not. Symmetry considerations and molecular modeling based on the structure of transforming growth factor-beta suggest that one or three of residues Cys(2008), Cys(2010), and Cys(2048) in each subunit mediate the covalent dimerization of proVWF.

CD4 but not CD8 is comodulated with the T-cell antigen receptor (TCR) after activation of a CD4+ CD8+ human leukemia line with staphylococcal enterotoxin

Recent studies support the possibility of an interaction between CD4/8 and the TCR complex. To determine if there is specificity in this interaction, we have studied the comodulation of CD4/8 with the CD3/TCR complex on a CD4+ CD8+ human leukemic T-cell line stimulated with staphylococcal enterotoxin A (SEA) bound to Raji cells. FACS analysis revealed that CD3 and the TCR were modulated from the surface. CD4 and not CD8 was comodulated with the T-cell receptor complex, supporting the existence of a docking site on the TCR with selectivity for CD4 or CD8 but not both. Fewer than 45 SEA molecules per presenting cell led to detectable comodulation. The ratio of %CD4/%TCR modulation varied with both time and the amount of SEA used for stimulation. ConA or PHA induced modulation of CD3 but, unlike SEA, failed to induce IL-2 secretion, suggesting multiple pathways and states of T-cell activation. Our findings also suggest that some human T leukemic lines can respond to antigen.

Effect of vitamin A treatment on the immune reactivity of patients with systemic lupus erythematosus

Treatment of patients suffering from systemic lupus erythematosus with vitamin A (100,000 U daily for 2 weeks) resulted in an enhancement of antibody-dependent cell-mediated cytotoxicity, natural killer cell activity and blastogenic response to plant mitogens and interleukin-2 (IL-2).

Independence of depressed lectin-dependent cell-mediated cytotoxicity from interleukin 2 production in patients with systemic lupus erythematosus

The relationship of lectin-dependent cell-mediated cytotoxicity (LDCC) to interleukin-2 (IL-2) production was studied in healthy subjects and in patients with systemic lupus erythematosus (SLE). Profoundly depressed levels of LDCC were elicited by peripheral blood mononuclear cells (PBMC) from nine patients with active SLE in comparison to LDCC from seven controls, and eleven inactive SLE donors, using 3H-TdR-prelabelled adherent HEP-2 cells as targets in a 24 h assay with 25 micrograms/ml Con A. In parallel experiments, no individual correlation was found between LDCC activity and IL-2 production for healthy or SLE subjects. Further, no major differences were detected in IL-2 release when the three groups of donors were compared, a tendency observed at the Con A doses (5 and 25 micrograms/ml) and incubation times (24, 48, and 72 h) used to induce IL-2 production. In additional studies, impaired Con A-induced blastogenesis was noted for PBMC from active SLE patients in comparison to the PBMC from the controls or patients with inactive SLE. While strong individual correlation was obtained between blastogenesis and IL-2 secretion in controls and patients with inactive SLE, no such relationship was found in patients with active SLE. While addition of exogenous IL-2 to the cytotoxicity assay considerably enhanced LDCC by healthy donors it failed to improve LDCC by patients with active SLE. These data suggest that depressed LDCC and Con A-induced blastogenesis of patients with active SLE may not be related to impaired IL-2 production but rather to an inherent dysfunction of the effector lymphocytes, including their unresponsiveness to IL-2.