Pharmacokinetic-Pharmacodynamic Modelling in Hemophilia A: Relating Thrombin and Plasmin Generation to Factor VIII Activity After Administration of a VWF/FVIII Concentrate

BACKGROUND

Hemophilia A patients are treated with factor (F) VIII prophylactically to prevent bleeding. In general, dosage and frequency are based on pharmacokinetic measurements. Ideally, an alternative dose adjustment can be based on the hemostatic potential, measured with a thrombin generation assay (TGA), like the Nijmegen hemostasis assay.

OBJECTIVE

The objective of this study was to investigate the predicted performance of a previously developed pharmacokinetic-pharmacodynamic model for FVIII replacement therapy, relating FVIII dose and FVIII activity levels with thrombin and plasmin generation parameters.

METHODS

Pharmacokinetic and pharmacodynamic measurements were obtained from 29 severe hemophilia A patients treated with pdVWF/FVIII concentrate (Haemate P®). The predictive performance of the previously developed pharmacokinetic-pharmacodynamic model was evaluated using nonlinear mixed-effects modeling (NONMEM). When predictions of FVIII activity or TGA parameters were inadequate [median prediction error (MPE) > 20%], a new model was developed.

RESULTS

The original pharmacokinetic model underestimated clearance and was refined based on a two-compartment model. The pharmacodynamic model displays no bias in the observed normalized thrombin peak height and normalized thrombin potential (MPE of 6.83% and 7.46%). After re-estimating pharmacodynamic parameters, EC50 and Emax values were relatively comparable between the original model and this group. Prediction of normalized plasmin peak height was inaccurate (MPE 58.9%).

CONCLUSION

Our predictive performance displayed adequate thrombin pharmacodynamic predictions of the original model, but a new pharmacokinetic model was required. The pharmacodynamic model is not factor specific and applicable to multiple factor concentrates. A prospective study is needed to validate the impact of the FVIII dosing pharmacodynamic model on bleeding reduction in patients.

The Nijmegen ultra-sensitive Bethesda Assay detects very low-titer factor VIII inhibitors in patients with congenital and acquired hemophilia A

BACKGROUND

An inhibitor can develop in congenital hemophilia A (HA) patients against exogenous infused factor (F)VIII, whereas in acquired HA (AHA) inhibitors initially develop against endogenous FVIII. Inhibitors can be detected with the Nijmegen Bethesda Assay (NBA), which has an international cut-off level of 0.60 Nijmegen Bethesda Units/mL (NBU/mL). Thereby, very low-titer inhibitors may remain undetected.

AIM

To describe the design and validation of the Nijmegen ultra-sensitive Bethesda Assay (NusBA) for the detection of very low-titer inhibitors.

METHODS

The NusBA is a modification of the NBA in which the ratio of patient plasma to normal pooled plasma is changed from 1:1 to 9:1. Analytical validation was performed according to the CLSI EP10 guideline in order to determine trueness and reproducibility. Clinical validation was performed in two cohorts of congenital HA patients (82 adults) with pharmacokinetic data and four AHA patients. The limit of quantitation (LOQ) was determined by measuring plasma samples spiked with inhibitor levels in the low range (0.05-0.80 NBU/mL).

RESULTS

The LOQ for the NusBA was 0.10 NusBU/mL, with a coefficient of variation of 24.2 %. Seven (8.5 %) congenital HA patients had a positive NusBA result, of which only one was detected with the NBA. There was no correlation between NusBA and FVIII half-life. In three of the AHA patients the NusBA remained positive, when the NBA became negative.

DISCUSSION

The NusBA is able to detect very low-titer FVIII inhibitors of ≥0.10 NBU/mL. Thereby, it may have added value in early inhibitor detection and therapy adjustments in patients with congenital HA and AHA.

Aspirin and clopidogrel resistance; a neglected gap in stroke and cardiovascular practice in Iran: a systematic review and meta-analysis

OBJECTIVE

Antiplatelet drugs, such as Aspirin and Clopidogrel (Plavix) are effective in the primary prevention of thromboembolic events. They are commonly used to reduce the risk of recurrence of thromboembolism. The body's hemostatic system responds differently to these drugs in different people. Resistance testing for aspirin and Clopidogrel is now recommended before starting antiplatelet therapy.

METHODS

A systematic literature search was performed on May 12, 2021, using the medical search engines PubMed, Scopus, and Web of Science, and the local databases SID and Magiran. After data extraction, a meta-analysis was performed using Comprehensive Meta-Analysis (CMA2) software. The I2 statistic was used to measure heterogeneity between estimates.

RESULTS

Among the 949 papers, Clopidogrel resistance was assessed in 136 patients and Aspirin resistance in 400 patients. The prevalence of Aspirin resistance was found to be 52.1% and the prevalence of Clopidogrel resistance was found to be 20.5%.

CONCLUSION

It seems that in Iran, the issue of Aspirin and Clopidogrel resistance is suboptimally addressed. This pattern could also occur in other developing countries in the Middle East region.

Significance of heparin induced thrombocytopenia (HIT) in COVID-19: a systematic review and meta-analysis

Heparin-induced thrombocytopenia (HIT) occurs in approximately 3% of patients receiving heparinoids. About 30-75% of patients with type 2 of HIT develop thrombosis as a result of platelet activation. The most important clinical symptom is thrombocytopenia. Patients with severe COVID-19 are among those receiving heparinoids. This meta-analysis performed to picture the current knowledge and results of published studies in this field. Three search engines were searched and 575 papers were found. After evaluation, 37 articles were finally selected of which 13 studies were quantitatively analyzed. The pooled frequency rate of suspected cases with HIT in 13 studies with 11,241 patients was 1.7%. The frequency of HIT was 8.2% in the extracorporeal membrane oxygenation subgroup with 268 patients and 0.8% in the hospitalization subgroup with 10,887 patients. The coincidence of these two conditions may increase the risk of thrombosis. Of the 37 patients with COVID-19 and confirmed HIT, 30 patients (81%) were treated in the intensive care unit or had severe COVID-19. The most commonly used anticoagulants were UFH in 22 cases (59.4%). The median platelet count before treatment was 237 (176-290) x 10³/µl and the median nadir platelet count was 52 (31-90.5) x 10³/µl.

Trend of fluctuations of antithrombin in plasma of patients with COVID-19: a meta-analysis and systematic review

BACKGROUND

Antithrombin is considered as one of the accused markers for the development of thrombosis in patients with COVID-19. Because plasma levels of antithrombin vary in patients with COVID-19, a meta-analysis was performed to determine the trend of antithrombin levels in patients with COVID-19.

RESEARCH DESIGN AND METHODS

A literature search was performed in PubMed, Scopus, and the Web of Science to find papers on antithrombin levels in patients with COVID-19. After removing of duplicate papers, inclusion and exclusion criteria were applied. The full texts of the articles were read to select relevant articles and then to identify the data needed. All meta-analyses were performed using Stata software v16.0.

RESULTS

Testing for differences between subgroups showed a significant difference between ICU and non-ICU patients. Analysis showed a significant decrease in antithrombin level in patients with severe COVID-19. Analysis showed that the mean value of antithrombin level was 89.65% in all patients. The antithrombin level was significantly lower in the non-survivor group (87.52%) than in the survivor group (92.38%).

CONCLUSION

: The determination of antithrombin may be useful to determine the susceptibility of COVID-19 patients to hypercoagulability and to indicate the severity of COVID-19 infection.

Female case with misdiagnosis of hemophilia A who underwent total knee arthroplasty: A case report

A female was diagnosed with hemophilia A. She had undergone bilateral total knee arthroplasty. She had a history of numerous hemorrhages including hemarthrosis. After further investigations, the diagnosis of von Willebrand disease type 2N was confirmed. The differential diagnoses for hemophilia A include von Willebrand disease, rare bleeding disorders, and severe platelet disorders.

Elevated levels of C3 , C4 , and CH50 of the complement system in ICU and non‐ICU patients with COVID ‐19

Purpose

SARS‐CoV‐2 infection has spread in each corner of the world. Many health systems have dealt with it intensively. The complement system is an instrumental component in the inflammatory immune response and plays a role in the activation of blood coagulation. Our understanding of the pathophysiology of SARS‐CoV‐2 is still limited but is constantly expanding. This study aimed to determine changes in the complement system in intensive care unit (ICU) and non‐ICU patients with COVID‐19.

Methods

In a cross‐sectional study, plasma levels of C3, C4, and CH50 were determined in two groups of ICU and non‐ICU patients with COVID‐19 to understand the potential effects of SARS‐CoV‐2 on the innate immune system. The assays of C3 and C4 were conducted using turbidimetry method. The CH50 test was conducted using the functional method.

Results

The present study revealed that the C3, C4, and CH50 plasma levels were 142.48 ± 30.38 mg/dL, 32.58 ± 8.78 mg/dL, and 61.74 ± 19.54%, respectively. These results indicate high levels of complement components C3 and C4 and complement function (CH50) in patients with COVID‐19 than normal ranges. Plasma levels of C3, C4, and CH50 were higher in ICU patients than in non‐ICU COVID‐19 groups.

Conclusion

These results indicate that the innate immune system was activated in both ICU and non‐ICU patients in response to SARS‐CoV‐2 infection. Further studies with a larger number of COVID‐19 patients and additional testing of complement components (C3a and C5a) may reveal the role of COVID‐19 infection in the activation of the complement system.

Hemostatic System (Fibrinogen Level, D-Dimer, and FDP) in Severe and Non-Severe Patients With COVID-19: A Systematic Review and Meta-Analysis

SARS-CoV-2 in COVID-19 triggers abnormalities in coagulation parameters that can contribute to thrombosis. The goals of this research were to determine the levels of fibrinogen, D-dimer and FDP in COVID-19 patients. Following a systematic study, among 1198 articles, 35 studies were included in the meta-analysis of fibrinogen levels in both severe and non-severe groups. The funnel plot, Egger’s regression asymmetry test, and Begg’s test used to measure the bias of publications. All meta-analysis performed by comprehensive meta-analysis version 2 (CMA2). The pooled findings of fibrinogen levels revealed a significant rise in fibrinogen levels in severe COVID-19 than non-severe patients with COVID-19. The D-dimer and FDP levels were significantly higher in severe patients than non-severe patients with COVID-19 were. The levels of fibrinogen, D-dimer, and FDP have increased significantly in ICU patients compared to non-ICU patients. Although, levels of clotting parameters do not always correlate with the severity of disease, these findings showed the diagnostic importance for fibrinogen, D-dimer, and FDP in COVID-19. The presence of a continuous rise in serial measurements of fibrinogen, D-dimer, and FDP may predict that patients with COVID-19 may become critically ill.

Determining causes of death among individuals with haemophilia in Afghanistan

INTRODUCTION

Haemophilia is a well-known bleeding disorder that affects people worldwide. The main therapeutic strategy is regular infusion of exogenous factor VIII to ensure an optimal haemostatic standard. Morbidity and mortality of individuals with haemophilia has decreased in developing countries due to improvement in early detection, advanced treatments, and comprehensive population outreach efforts. However, individuals with bleeding disorders in developing countries like Afghanistan do not have access to such therapeutic facilities.

AIMS

The goals of this study were to determine the causes of death and findings related to death among in individuals with bleeding disorders in Afghanistan.

METHODS

This study conducted as a retrospective cross-sectional study of 387 individuals with bleeding disorders (mainly haemophilia) in Afghanistan.

RESULTS

All registered individuals with bleeding disorders in Afghanistan were interviewed by telephone. Among the 387 individuals with bleeding disorders, there were 136 deaths. Most deaths occurred in individuals aged 1-15 years (66.2%). Intracranial haemorrhage was the leading cause of death in individuals with haemophilia A and B.

CONCLUSION

These findings revealed that supply of coagulation factor concentrates, facilities for haemostasis diagnosis, and trained haematologists is inadequate in Afghanistan.

High levels of Von Willebrand factor markers in COVID-19: a systematic review and meta-analysis

The SARS-CoV-2 virus has spread to all corners of the world. Thrombosis is the cause of organ failure and subsequent death in COVID-19. The pathophysiology of thrombosis in COVID-19 needs to be further explored to shed light on its downside. For this reason, this meta-analysis of Von Willebrand Factor profile (VWF: Ag, VWF: activity, VWF: RCo), ADAMTS-13, and factor VIII levels in COVID-19 was performed. To obtain data on the status of the aforementioned hemostatic factors, a systematic literature review and meta-analysis were performed on COVID-19. After reviewing the evaluation of 348 papers, 28 papers included in the meta-analysis, which was performed using STATA. The analysis showed an increase in VWF: Ag levels in COVID‐19 patients. VWF: Ac was higher in all COVID-19 patients, while it was lower in the COVID‐19 ICU patients. The pooled mean of VWF: RCO in all patients with COVID-19 was 307.94%. In subgroup analysis, VWF: RCO was significantly higher in ICU patients than in all COVID-19 patients. The pooled mean of ADAMTS-13 activity was 62.47%, and 58.42% in ICU patients. The pooled mean of factor VIII level was 275.8%, which was significantly higher in ICU patients with COVID-19 than all patients with COVID-19. Levels of VWF: Ag, VWF: activity, VWF: ristocetin, and factor VIII are increased in patients with COVID-19. The elevated levels in ICU patients with COVID-19 suggest that these markers may have prognostic value in determining the severity of COVID-19. New therapeutic programs can be developed as a result.

Parvovirus 4 in Individuals with Severe Hemophilia A and Matched Control Group

Background: Hemophilia is a well-known bleeding disorder with worldwide distribution. Replacement therapy, using plasma-derived or recombinant coagulation factors, comprises a gold standard regimen for the treatment. Regardless of the advancements made in viral inactivation methods in the production of plasma-derived coagulation factors, the possibility of transmission of new viral infections remained as a noticeable concern yet. The aim of the current study was to investigate the status of parvovirus 4 (PARV4) in severe hemophilia A, von Willebrand disease (vWD), and healthy control. Materials and Methods: In the current case-control study, 76 patients with hemophilia and vWD and 60 individuals from their family members entered the study. Nested PCR used to determine the presence of PARV4 in study subjects (76 cases). To characterize the PARV4 genotype, positive samples subjected to sequencing and phylogenetic analysis. Results: PARV4 genome detected in 11 (14.47%) patients with bleeding disorders. Among whom, nine patients (14.75%) were with severe hemophilia A and two (13.33%) patients with vWD. Only five healthy controls (8.33%) were positive for PARV4. All PARV4 sequences were found to be genotype 1. Conclusion: PARV4 infection in patients with hemophilia and vWD was higher than the control group. While detection of PARV4 DNA in patients with bleeding disorders may not necessarily reflect a clinical urgency, future investigations are needed to define the clinical significance of PARV4. It seems the detection of the virus immune signature of PARV4 infection, particularly in the context of acute and persistent infections, needs to focus on cellular and tissue targets.

Consanguineous marriage and rare bleeding disorders

Introduction: Rare bleeding disorders (RBDs) are a heterogeneous group of bleeding disorders. Consanguineous marriage is the favorite partnership in many communities among a population of more than a billion. Consanguineous marriages allow the defective recessive genes in RBDs to remain in the family. Clinical approach to RBDs is not as straightforward as typical bleeding disorders, which are secondary to scarcity and variation of RBDs. However, in many developing countries, the limitations of diagnostic facilities, the supply of therapeutic coagulation concentrates, health budgets, and optimal health-care infrastructures may intensify the clinical practice of RBDs.Areas covered: The author addresses the role of consanguineous marriage in the incidence of RBDs and what preventive steps can be considered to minimize the incidence of RBDs. A literature review of PubMed and google Scholar was conducted in November of 2020 using the relevant keywords.Expert opinion: This review addresses the prevalence of consanguineous marriages in Middle Eastern countries and the various reasons behind the coexistence of consanguineous marriage with RBDs. Finally, prevention steps that may be considered by health-care systems to minimize the incidence of rare bleeding disorders have been discussed. Health-care systems should train partners with the intention of consanguineous marriage on the downside of consanguinity.

Clinical Care of Bone Health in Patients on the Immune Tolerance Induction's Protocols With an Immunosuppressive Agent for Inhibitor Eradication in Hemophilia

Nowadays, the development of factor VIII and IX inhibitors in patients with hemophilia is considered as the most challenging in the treatment of hemophilia. Immune tolerance induction (ITI) therapy is an approach for eradication of inhibitors. Some ITI protocols are routinely in use for the eradication of inhibitors in patients with hemophilia. Moreover, such a therapeutic regimen may facilitate the tendency to reduced bone density in patients with inhibitor. This study scheduled to investigate whether that predisposing role of ITI protocols with an immunosuppressive agent has considered or not. By a literature review, published ITI protocols in hemophilia with inhibitors were evaluated. Among them, 51 papers found and studied thoroughly. None of them had performed the bone mineral examination in patients with hemophilia and inhibitor under treatment. Since there are 2 coexisting facilitating factors in these protocols, considering the bone mineral density study for patients with inhibitor who are undergoing ITI protocols with an immunosuppressive agent is recommended.

Mining of mortality-related findings in rare bleeding disorders: a retrospective study from two centers

BACKGROUND

Rare bleeding disorders include inherited coagulation disorders except for von Willebrand disease and hemophilia A and B. These disorders affect both men and women worldwide and mainly have an autosomal recessive pattern of inheritance. Given the paucity of cases of rare bleeding disorders, there are limited data regarding some topics among bleeding disorders.

METHODS

This retrospective study from 2005-2019 collected demographic data and the causes of death among cases with rare bleeding disorders from 2 provinces of Iran.

RESULTS

Overall, 5 deaths were reported, including 3 cases with factor V deficiency, a case with factor XIII deficiency, and a case with combined factor V and factor VIII deficiencies. The main causes of death were bleeding in the central nervous system (2 cases; 1 with factor V deficiency and 1 with combined factor XIII deficiency). Post-partum hemorrhage was the cause of death in a woman with factor V deficiency while anaphylaxis shock was the cause of death in the case with combined factor V and factor VIII deficiencies. A woman with factor V deficiency died from an internal bleeding episode.

CONCLUSION

Gathering data on the causes of death in rare bleeding disorders through worldwide registries can be helpful for the management of this rare group of bleeding disorders.

D-dimer level in COVID-19 infection: a systematic review

INTRODUCTION

COVID-19 disease has spread worldwide from December 2019 to the present day; the early stage of this disease can be associated with high D-dimer, prolonged PT, and elevated levels of fibrinogen, indicating activation of coagulation pathways and thrombosis. In this article, we analyze the levels of D-dimer in patients with COVID-19.

AREA COVERED

In the current study, three databases, PubMed, Scopus, Web of Science, searched using related keywords and information extracted from articles such as location, sample size, gender, age, coagulation test values, patient results, and disease severity.

EXPERT OPINION

D-dimer level is one of the measures used in patients to detect thrombosis. Studies have reported an increase in D-dimer and fibrinogen concentrations in the early stages of COVID-19 disease a 3 to 4-fold rise in D-dimer levels is linked to poor prognosis. In addition, underlying diseases such as diabetes, cancer, stroke, and pregnancy may trigger an increase in D-dimer levels in COVID-19 patients. Measuring the level of D-dimer and coagulation parameters from the early stage of the disease can also be useful in controlling and managing of COVID-19 disease.

Is the Detection of Factor IX Inhibitors in Hemophilia B Orphan than Factor VIII Inhibitors in Hemophilia A? A Concise, Systematic Review

OBJECTIVE

Development of inhibitors in hemophilia A and B comprise significant challenge for patients, hematologists, and health provider systems. It has recommended by the World Federation of Hemophilia (WFH) to check inhibitors every 3-4 months. The incidence of inhibitor in hemophilia B is lower than hemophilia A. Here, it tried to unravel whether the detection of inhibitors in hemophilia B neglected compared to hemophilia A or not?

METHODS

A comprehensive review carried out using six international and local medical search engines on published contributions about inhibitors in hemophilia A and B in Iran.

RESULTS

From 699 titles, 12 relevant papers were selected. The mean of factor VIII inhibitors in hemophilia A was 14.8%. The mean of factor IX inhibitors in hemophilia B was 6%. The minimum and maximum reported percentages of factor VIII inhibitors were 4% and 19.6%, while the minimum and maximum of reported percentages of factor IX inhibitors were 0% and 11.8%, respectively. The inhibitors in hemophilia A had reported in 6 papers. One paper had covered the inhibitors in hemophilia B. There were five papers on inhibitors in both hemophilia A and B. The comparison between the reported patients showed that 3020 patients with hemophilia A and 314 patients with hemophilia B had studied.

CONCLUSION

Consistent with the lower frequency of hemophilia B and the lower development of inhibitors in hemophilia B compared to hemophilia A, it was concluded that hemophilia B had not neglected in Iran. It seems to be rational that each country, check rates of detection of inhibitors in hemophilia B to identify whether it has neglected or not.

Is It Rational to Study Coagulations Test Routinely before Operations and Invasive Procedure: Single Center Retrospective Study

This article is a Letter to the Editor and does not include an Abstract.

The Most Common Allergenic Tree Pollen Grains in the Middle East: A Narrative Review

Allergy is becoming a major disease burden globally. Pollens are considered as the main component of aeroallergens that lead to rhinitis and asthma. Due to the lack of a comprehensive investigation on most allergic pollens of trees in the Middle East, the present study aimed to conduct a comprehensive literature review on this topic. The main goal of the study was to provide a checklist for allergists and patients to easily identify the commonest allergic pollens in their locality. The present review provides a broad range of information on the types and geographic locations of the most common allergic pollens of trees in each studied country. In general, among the 23 studied countries, palm and mesquite trees were the common producers of pollen allergen in the Persian Gulf region. Olive tree is common in Turkey, Palestine, and Israel, whereas sycamore tree is the common allergen pollen in Iran. Considering the uneven geographical distribution of these trees in the world, allergists are unable to accurately select the appropriate extracts for the skin prick test based on the information from the neighboring countries. This scenario becomes more complicated if one adds the imported ornamental trees in the picture.

Bone Density Status in Bleeding Disorders: Where Are We and What Needs to Be Done?

Bleeding disorders, including hemophilia, can be seen in every ethnic population in the world. Among various bleeding disorders, reduced bone density has been addressed in hemophilia A. In recent years, there has been an increasing interest in addressing osteopenia and osteoporosis in hemophilia A. There is little or no study about the possible susceptibility of other individuals with bleeding disorders to reduced bone density. Questions have been raised about the role of blood coagulation factors in bone mineralization. This review provides new insight and ideas for further survey in the field of bleeding disorders and reduced bone density.

Common solvents for making extraction of allergenic proteins from plants' pollens for prick tests and related factors: a technical review

Collecting information on influencing factors in developing consistent and high-quality extracts results in accurate diagnosis and effective treatment of type I allergy (IgE mediated). Furthermore, considering that a large number of allergens are currently in practice, any attempt to develop a more effective procedure for preparing extract may be useful. Nowadays, different saline solvents, temperature, incubation time, and PH are being incorporated for preparing allergen extracts. The objective of the current study was to clear and address the commonest of solvent buffers and allied conditions for making extracts of pollens of grasses, trees, and weeds. The literature review was done in Jan 2016 on PubMed and Google Scholar medical search engines without any time limitation. After reading abstracts of 87 articles, finally 37 relevant papers were selected and their full texts were retrieved. In conclusion, 24 full-text papers were recognized appropriate and chosen. The extracted information for papers has been described fully in the text. On the basis of these data, PBS buffer with PH 7.4, temperature of 4 °C and with overnight incubation time, may be the optimized condition in order to have a proper extract for carrying out skin prick tests.

Causes of Death Among 379 Patients With Hemophilia: A Developing Country's Report

There are steps to achieve an optimum life for patients with hemophilia in developing countries, and awareness of the pattern of death in patients with hemophilia is a prerequisite for any health-care program. Owing to the lack of any data on the pattern of death in patients with hemophilia from developing countries, the current study was done to address common causes of death, and the spectrum of causes of death among individuals with hemophilia A and B. To address the pattern of death in northeast of Iran, we retrospectively collected demographic data regarding deceased patients with hemophilia A and B. Overall, among 379 people with hemophilia A and B, there were 46 deaths. Thirty-two deaths happened in the severe forms of the diseases. The obtained results show the patterns of death in the patients studied are not as parallel as some reports from the developed countries. Traumatic and spontaneous bleeding events were the main causes of death. The trend of death shows a decrease in the current decade post better therapeutic facilities. Evaluation of causes of death in hemophilia can be a useful indicator for managing the efficacy of health care in the current patients.

A close insight to factor VIII inhibitor in the congenital hemophilia A

INTRODUCTION

Hemophilia A (HA) has an X-linked pattern of inheritance and is the most common of the hemorrhagic disorders. HA is caused by a decreased or deficiency of the functional clotting factor VIII (FVIII) and effects 1 in 5000-10,000 male births. The common treatment for hemophilia is replacement therapy by plasma-derived or recombinant FVIII. Approximately 20-30% of people with a severe type of HA develop an inhibitor and this phenomenon is the main challenge in the management of these patients. Genetic factors and environmental determinants contribute to inhibitor development. Here, the roles of various genetic and environmental factors such as the type of FVIII concentrate used, the number of exposure days, and peak treatment time will be discussed in detail. It seems this information is helpful for hematologists.

AREAS COVERED

A literature review was done in January 2016 on PubMed and Scopus using the following keywords:' h(a)emophilia A & factor VIII inhibitor', 'h(a)emophilia A & factor VIII alloantibody', 'h(a)emophilia A & inhibitor'. There was no time limitation; however, there was an English language limitation placed on the articles selected. Expert commentary: Influential genetic and environmental factors in developing inhibitors have been discussed. Most of the risk factors are related to previously untreated patients with hemophili.

Desmopressin acetate as a haemostatic elevator in individuals with combined deficiency of factors V and VIII: a clinical trial

ESSENTIALS: Combined factor V (FV) and factor VIII (FVIII) deficiency (CF5F8D) is an autosomal recessive coagulation disorder. Desmopressin acetate (DDAVP) was intravenously infused in 20 adult patients with CF5F8D. DDAVP can enhance FVIII levels but has no effect on FV levels in patients with CF5F8D. DDAVP can be substituted for FVIII concentrates in patients with CF5F8D.

OBJECTIVES

Combined factor V (FV) and FVIII deficiency (CF5F8D) is a rare inherited autosomal recessive double-gene disorder most frequently seen in the Middle East. Although affected individuals have deficiency of two coagulation factors (range 5-30%), their bleeding tendencies are similar to patients who have deficiency of a single coagulation factor at the same level. The mainstay of their treatment is infusion of FVIII concentrate and fresh frozen plasma. Here, the effect of intravenous infusion of desmopressin acetate (DDAVP) on elevation of coagulation FV and FVIII was investigated through a clinical trial in May 2015.

PATIENTS AND METHODS

In a registered controlled trial, DDAVP (dosage 0.3 μg kg(-1) ) was intravenously infused into 20 adult patients with CF5F8D over 20 min. After an hour, blood samples were collected and plasma levels of FV and FVIII were measured.

RESULTS AND CONCLUSION

This study revealed that DDAVP can enhance FVIII levels but has no effect on FV plasma concentration in patients with CF5F8D. Based on these findings, FVIII concentrates may be substituted for DDAVP in patients with CF5F8D.

Clinical and laboratory approaches to hemophilia a

Hemophilia A is a worldwide disorder of coagulation system. It is a male disorder, yet females with hemophilia are rarely seen in communities with high rate of consanguineous marriages. The abnormalities in factor VIII gene transfer as an X-linked pattern in the family, affects as many as one-third of patients who had no family history of abnormality and thus the occurrence of a sporadic mutation could be documented. Hemorrhagic symptoms usually correlate with the plasma level of factor VIII and comprise a wide range of hemorrhagic pictures, including from fatal spontaneous bleeding in the brain to ecchymosis of the skin. The coagulation study needs to differentiate between the two types of hemophilia A and B as well as the categorization of the disease severity. In the developing countries, due to limitations in diagnostic hemostasis facilities and a scant number of experts in the field, it is estimated that noticeable numbers of undiagnosed patients with hemophilia A exist. Occasionally, we encounter undiagnosed cases by general physicians while having hemorrhagic symptoms. The purpose of this review is to recap clinical and diagnostic parameters, pitfalls, and interpretation of coagulation assay in hemophilia A. A literature review was done in PubMed and Scopus medical search engines using the keywords "Hemophilia" and "Haemophilia". A time limitation for the publication beyond 1995 and publication in the English language were considered. A total of 94 original articles and chapters of books was selected for the current review. Additionally, a comprehensive and up-to-date information on the clinical and laboratory features for the diagnosis of hemophilia is also presented.

The association between neutrophilic hypersegmentation and iron deficiency with regard to folate status in 16-30 year-old women

INTRODUCTION

Neutrophilic hypersegmentation (NH) is a hematological anomaly that is mainly related to the deficiency of folic acid and/or cobalamin. There are also controversial studies showing that NH relates to iron deficiency anemia (IDA). The aim of this study was to investigate this relationship by comparing two groups: iron deficient (ID) and IDA. The effect of low normal folate level on this relationship was also investigated.

METHODS

In this prospective cohort study, performed in Mashhad, Iran in 2011, ninety 16 - 30 year-old women were selected and divided into three groups, ID, IDA, and control. NH was examined in peripheral blood smears by two experts. CBC was done on a Sysmex K-21 hematologic analyzer. Colorimetric methods were utilized to measure the serum iron and total iron binding capacity. Serum ferritin as well as folate and cobalamin were measured by radioimmunoassay methods. Data was analyzed with SPSS 11.5 software. A p-value < 0.05 was considered to be significant.

RESULTS

Twenty nine ID, thirty IDA, and thirty one control participants were studied. Chi square tests showed statically significant differences in NH values among these three groups (p-value = 0.001), and a correlation between NH and decreased serum iron/ferritin levels (p-value = 0.001). With logistic regression analysis, it was observed that the relation between NH and ID/IDA is due to concomitant low normal folate levels (p-value = 0.044).

CONCLUSIONS

The detection of NH in a peripheral blood smear of patients with ID/IDA is a possible reason for a coexistence of mild folate deficiency. It is suggested that in addition to ID/IDA, latent folate deficiency should be investigated in these patients.

Bleeding disorders and reduced bone density

In recent decays, quality of life and life expectancy of individuals with severe haemophilia A and B have been improved by better quality in treatment and more availability of blood coagulation products. Recently, new concerns have emerged in current groups such as auto-antibody inhibitors to coagulation factors and reduced bone density (RBD). RBD in bleeding disorders is becoming an escalating burden worldwide due to an increased in life expectancy and also in the ageing population with bleeding disorders. Here, we review published papers on bone mineral density of individuals with haemophilia A & B, a rare bleeding disorder entitled combined factor V and VIII deficiency and other rare bleeding disorders. It seems in individuals with bleeding disorders preventive measures including early detection, treatment and adequate physical activity, encouragement to be active in sports and finally anti-osteoporotic therapy must be done.

Successful Use of Factor VIII Concentrate and Fresh Frozen Plasma for Four Dental Extractions in an Individual with Combined Factor V and VIII Deficiency

BACKGROUND: Combined factor V and VIII deficiency (CF5F8D) is a rare autosomal recessive disorder, with an estimated prevalence of about 1:100,000 in the Jewish population. Affected individuals have between 5 and 30% of normal levels of factor V and VIII, whereas the levels of other plasma proteins are not altered. This bleeding disorder has been treated by replacement therapy with plasma infusion and FVIII concentrate as source of factor V and VIII, respectively, depending on the severity of the haemorrhage. CASE REPORT: The individual with CF5F8D was a 22-year-old man with APTT of 51 s (control 33 s), PT of 27 s (control 12 s), factor V of 13%, and factor VIII of 21%. He had four untreatable carious teeth, including the maxillary first premolars and the mandibular first and second right molar. Factor VIII concentrate infusion began 12 h before the first dental extraction procedure and was continued in 8 h intervals. Moreover, 10 ml/kg of fresh frozen plasma were given for compensating factor V deficiency. No remarkable haemorrhage occurred during and after the procedures. The levels of factor V and VIII post procedures were 64 and 75%, respectively. CONCLUSION: It seems that plasma levels of 6075% for both factor V and VIII may be sufficient for major dental procedures.

Acquired hemophilia A: clinical features, surgery and treatment of 34 cases, and experience of using recombinant factor VIIa

Acquired hemophilia A is rare, but life-threatening disorder caused by autoantibody against factor VIII. As it is useful to gather more data on epidemiology, clinical pictures and therapy of it, we evaluated relevant medical findings in 34 acquired hemophiliacs from Dec 1999 to Dec 2007. Eight patients (23.5%) had low titers (<10 Bethesda Unit BU) and 26 patients (76.5%) had high titers of inhibitors (>10 BU). The mean of inhibitors was 548.38 +/- 359.27 SD BU. The most common hemorrhagic symptoms were hematoma 21 (33.33%), ecchymosis 16 (25.39%), hemarthrosis 8 (12.69%), hematuria 6 (9.52%), menorrhagia 4 (6.34%), compartment syndrome 3 episodes (4.76%). The eliminator therapies were recruited according to titers of inhibitor and types of bleeding and it's results were 27 efficient treatments (79.4%), 5 partial efficient treatment (14.7%) and two treatments inefficient (5.9%). Elimination therapy using steroid alone or with combination can terminate complete remission in most cases.

Idiopathic factor VIII inhibitor autoantibody in a man presented after accident

Acquired hemophilia A is a rare but severe autoimmune bleeding disorder caused by autoantibodies against factor VIII activity and is a potentially life-threatening hemorrhagic disorder. The incidence of acquired hemophilia A has been estimated as 1.48 cases per million per year. The overall rate of death from all causes of acquired hemophilia reaches up to 22%. In this article, the authors describe the case of a 55-year-old man who presented with unusual bleeding after an accident and the fluctuation of his hemostatic parameters during 13 months of follow-up. Initially he had 43 Bethesda unit (BU) inhibitor to factor VIII and <1% of factor VIII activity. The patient was given prednisone and azathioprine therapy (30 and 100 mg/day, respectively) for 4 months, but his hemostatic parameters did not improved during this phase. Then, 2 g cyclophosphamide was injected every 2 days, but no remarkable improvement was observed. Nine months later his inhibitor titers were high. The inhibitor and factor VIII concentrations were assessed 11 times during these 13 months, and the mean level of factor VIII inhibitor was 44 BU (with a minimum of 2 BU and a maximum of 103 BU); the minimum and maximum factor VIII concentrations were <1% and 20%, respectively. The patient experienced hemarthroses, severe epistaxis, hematoma, and gastrointestinal bleeding episodes during this phase. His factor VIII concentration spontaneously and gradually improved and increased to 51.5% 8 months after stopping the treatment with undetectable factor VIII inhibitor.