Nano-evidence for joint microbleeds in hemophilia patients

The concept of joint microbleeding in hemophilia patients was first proposed over 10 years ago. This was based on unexpected abnormalities found in medical imaging studies of asymptomatic joints. Since then, there have been no published studies confirming the presence of joint microbleeds. This critique will review the evidence for and against joint microbleeding in hemophilia patients and the potential implications.

Fresh frozen plasma: the most commonly prescribed hemostatic agent

Although fresh frozen plasma (FFP) is one of the most commonly prescribed therapies in clinical practice throughout the world today, there is little medical evidence available supporting its use. Recent guidelines have called for limiting FFP transfusions. Despite this, FFP use does not seem to be decreasing. The reasons for this are likely to be multifactorial, and may be based on ideas regarding medical practices dating back to Galen and Hippocrates. A review of the history of the development of FFP may shed some light on current clinical practice and guide the direction of future investigations and therapies.

Prevalent inhibitors in haemophilia B subjects enrolled in the Universal Data Collection database

Several risk factors for inhibitors have recently been described for haemophilia A. It has been assumed that similar risk factors are also relevant for haemophilia B, but there is limited data to confirm this notion. The aim of this study was to determine the prevalence of and risk factors associated with inhibitors in haemophilia B. The database of the Universal Data Collection (UDC) project of the Centers for Disease Control for the years 1998-2011 was queried to determine the prevalence of inhibitors in haemophilia B subjects. In addition, disease severity, race/ethnicity, age, factor exposure and prophylaxis usage were evaluated to determine their impact on inhibitor prevalence. Of the 3785 male subjects with haemophilia B enrolled in the UDC database, 75 (2%) were determined to have an inhibitor at some point during the study period. Severe disease (OR 13.1, 95% CI 6.2-27.7), black race (OR 2.2, 95% CI 1.2-4.1), and age <11 years (OR 2.5, 95% CI 1.5-4.0) were found to be significantly associated with having an inhibitor. There was insufficient data to determine if type of factor used and prophylaxis were associated with inhibitors. Inhibitors in haemophilia B are much less prevalent than haemophilia A, especially in patients with mild disease. Similar factors associated with inhibitors in haemophilia A also seem to be present for haemophilia B. The information collected by this large surveillance project did not permit evaluation of potential risk factors related to treatment approaches and exposures, and additional studies will be required.

The use of a single von Willebrand factor-containing, plasma-derived FVIII product in hemophilia A immune tolerance induction: the US experience

BACKGROUND

Inhibitors are a serious complication for patients with severe hemophilia A. Immune tolerance induction (ITI) is the primary method for eradicating these inhibitors. The role of type of concentrate and in particular the use of von Willebrand factor-containing, plasma-derived factor VIII (VWF/pd-FVIII) concentrate in primary or rescue ITI remains unclear.

OBJECTIVES

To report retrospective collection of data on the use of a single VWF/pd-FVIII concentrate in primary and rescue ITI.

METHODS

Retrospective chart review of hemophilia A inhibitor patients at 11 US institutions who received VWF/pd-FVIII concentrate in primary or rescue ITI.

RESULTS

Primary ITI was carried out in eight inhibitor patients with a 75% complete and partial success. Secondary ITI was carried out in 25 inhibitor patients, with 52% attaining complete or partial success.

CONCLUSIONS

This report represents the largest group of primarily pediatric, high-titer inhibitor patients treated with a single VWF/pd-FVIII concentrate. It adds retrospective data to the use of VWF-containing plasma-derived factor VIII concentrate in primary and rescue ITI, particularly in those patients with characteristics of poor response to ITI.

Incidental finding of a papillary fibroelastoma on the aortic valve in 16 slice multi-detector row computed tomography

Papillary fibroelastoma (PFE) is a benign, rare, gelatinous tumour derived from the endocardium, primarily the cardiac valves, which is usually diagnosed by high resolution echocardiography. Although rarely clinically symptomatic, PFEs have a potential for coronary ischaemia, systemic embolisation with neurologic symptoms, and sometimes valvar dysfunction. There are reports of coronary occlusion and even sudden cardiac death due to a ball valve phenomenon on the coronary ostia. This report describes the characteristics of a PFE with multidetector 16 slice computed tomography and 1.5 Tesla cardiac magnetic resonance imaging.

Combination therapy with ribavirin and interferon in a cohort of children with hepatitis C and haemophilia followed at a pediatric haemophilia treatment center

Nearly all children with bleeding disorders who received factor concentrates prior to the late 1980s were infected with hepatitis C. Treatment of adults infected with hepatitis C with combination therapy consisting of ribavirin and interferon has shown sustained response rates of 30-60%. Little data is available on the response of children infected with hepatitis C treated with combination therapy, especially those with bleeding disorders. We wish to report a single paediatric haemophilia treatment center's results of treatment of adolescents with haemophilia and hepatitis C infection with combination therapy. All patients followed at the haemophilia treatment center with hepatitis C, who were human immunodeficiency virus (HIV) negative and had a measurable hepatitis C viral load were eligible. Study patients received at least 6 months of 3 MU interferon-alpha via subcutaneous injection three times per week and 1000 mg day(-1) of ribavirin. Eleven patients agreed to participate in the study. Three patients had an un measurable viral load after 6 months of combination therapy. All three completed 12 months of medication and continued to remain free of hepatitis C for 12 months after discontinuation of therapy. Side-effects of combination therapy were significant but tolerable. The sustained response rate in this study is similar to the historical response rate seen in adults but less than the other reported response rates seen in children treated with combination therapy. Given the toxicity of combination therapy, and natural history of hepatitis C infection in children, consideration of a liver biopsy to evaluate disease progression prior to considering antiviral medications is warranted.

Maintenance of functional equivalence during paralogous Hox gene evolution

Biological diversity is driven mainly by gene duplication followed by mutation and selection. This divergence in either regulatory or protein-coding sequences can result in quite different biological functions for even closely related genes. This concept is exemplified by the mammalian Hox gene complex, a group of 39 genes which are located on 4 linkage groups, dispersed on 4 chromosomes. The evolution of this complex began with amplification in cis of a primordial Hox gene to produce 13 members, followed by duplications in trans of much of the entire unit. As a consequence, Hox genes that occupy the same relative position along the 5' to 3' chromosomal coordinate (trans-paralogous genes) share more similarity in sequence and expression pattern than do adjacent Hox genes on the same chromosome. Studies in mice indicate that although individual family members may have unique biological roles, they also share overlapping functions with their paralogues. Here we show that the proteins encoded by the paralogous genes, Hoxa3 and Hoxd3, can carry out identical biological functions, and that the different roles attributed to these genes are the result of quantitative modulations in gene expression.