A national study of pain in the bleeding disorders community: a description of haemophilia pain.

UNLABELLED: The National Pain Study was a prospective, computer-based, descriptive survey of the pain experience of persons with a bleeding disorder conducted in the United States over a 28 month period from 2007 to 2009. The aim of this study was to (i) determine the language used by patients to describe and differentiate acute and persistent pain, (ii) describe pharmacological and non-pharmacological strategies utilized to control pain, (iii) assess the perceived effectiveness of current pain management on quality of life and, (iv) to determine who provides pain management to this population. One thousand, one hundred and four surveys were received. Only the responses of the 764 respondents who reported having hemophilia A or B were evaluated for this paper. Thirty nine percent of participants reported their pain was not well treated. The average acute pain score associated with a bleed reported was 5.97/10 while the average persistent pain score reported was 4.22/10. The most frequently reported word descriptors for acute pain were: throbbing, aching, sharp, tender and miserable. The most frequently reported word descriptors for persistent pain were aching, nagging, tiring, sharp, and tender. The most frequently reported pain strategies for acute and persistent pain included factor, rest, ice, elevation, and compression. Alcohol and illicit drugs were reportedly used to manage both acute pain as well as persistent pain. Primarily, short-acting opioids and acetaminophen were reported to treat both acute and persistent pain. Hematologists and primary care providers provide the majority of pain management for persons with hemophilia (PWH). Quality of life (QOL) scores were lowest in the domains of pain, energy/fatigue and physical problems indicating disruption of QOL. This substantiates under-recognition and under-treatment of pain in the hemophilia population when combined with the 39% of respondents who felt their pain was not well treated and literature in the general pain population of wide spread under-treatment of pain. RECOMMENDATIONS: The NPS is an initial step in recognizing the prevalence and description of pain in PWH. HTC providers should educate themselves in pain management techniques to better serve this population. Further research is necessary to develop specific pain management guidelines for the bleeding disorders population that include multimodal holistic treatment plans.

Assessment of acute and persistent pain management in patients with haemophilia.

A descriptive survey was conducted in Region V-E of the United States to bridge the gap in available information on pain issues in the bleeding disorders population. The aim of this study was to a) determine language used by patients to describe and differentiate acute and persistent pain, b) describe pharmacological and non-pharmacological strategies utilized to control pain, c) determine the providers of pain management to this population and d) evaluate quality of life incorporating the SF-36 QOL tool. A total of 202 surveys were returned. For the purposes of this paper, it was decided to analyse only haemophilia data (n = 114). Average persistent daily pain levels were 5/10 (P < 0.001). The three most common word descriptors for both acute and persistent pain were the same - achy, throbbing and tender; the most utilized pain medications were NSAIDs and acetaminophen. Factor replacement was used for what respondents described as acute pain management 79% of the time and for persistent pain management 38% of the time. Participants described acute and persistent pain with the same pain descriptors leading to the conclusion that patients have difficulty distinguishing between acute and persistent pain. This lack of differentiation was further displayed by the use of factor replacement to treat persistent pain associated with arthritic discomfort (38%) which would be viewed as inappropriate, as well as lack of factor replacement use by 21% of respondents who identified pain as from an acute bleed. Opportunities exist to improve pain management through patient and provider-directed educational programs.

Hereditary haemorrhagic telangiectasia: mutation detection, test sensitivity and novel mutations.

BACKGROUND: Hereditary haemorrhagic telangiectasia (HHT) is a genetic disorder present in 1 in 8000 people and associated with arteriovenous malformations. Genetic testing can identify individuals at risk of developing the disease and is a useful diagnostic tool. OBJECTIVE: To present a strategy for mutation detection in families clinically diagnosed with HHT. METHODS: An optimised strategy for detecting mutations that predispose to HHT is presented. The strategy includes quantitative multiplex polymerase chain reaction, sequence analysis, RNA analysis, validation of missense mutations by amino acid conservation analysis for the ENG (endoglin) and ACVRL1 (ALK1) genes, and analysis of an ACVRL1 protein structural model. If no causative ENG or ACVRL1 mutation is found, proband samples are referred for sequence analysis of MADH4 (associated with a combined syndrome of juvenile polyposis and HHT). RESULTS: Data obtained over the past eight years were summarised and 16 novel mutations described. Mutations were identified in 155 of 194 families with a confirmed clinical diagnosis (80% sensitivity). Of 155 mutations identified, 94 were in ENG (61%), 58 in ACVRL1 (37%), and three in MADH4 (2%). CONCLUSIONS: For most missense variants of ENG and ACVRL1 reported to date, study of amino acid conservation showed good concordance between prediction of altered protein function and disease occurrence. The 39 families (20%) yet to be resolved may carry ENG, ACVRL1, or MADH4 mutations too complex or difficult to detect, or mutations in genes yet to be identified.

SMAD4 mutations found in unselected HHT patients.

BACKGROUND: Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant disease exhibiting multifocal vascular telangiectases and arteriovenous malformations. The majority of cases are caused by mutations in either the endoglin (ENG) or activin receptor-like kinase 1 (ALK1, ACVRL1) genes; both members of the transforming growth factor (TGF)-beta pathway. Mutations in SMAD4, another TGF-beta pathway member, are seen in patients with the combined syndrome of juvenile polyposis (JP) and HHT (JP-HHT). METHODS: We sought to determine if HHT patients without any apparent history of JP, who were undergoing routine diagnostic testing, would have mutations in SMAD4. We tested 30 unrelated HHT patients, all of whom had been referred for DNA based testing for HHT and were found to be negative for mutations in ENG and ALK1. RESULTS: Three of these people harboured mutations in SMAD4, a rate of 10% (3/30). The SMAD4 mutations were similar to those found in other patients with the JP-HHT syndrome. CONCLUSIONS: The identification of SMAD4 mutations in HHT patients without prior diagnosis of JP has significant and immediate clinical implications, as these people are likely to be at risk of having JP-HHT with the associated increased risk of gastrointestinal cancer. We propose that routine DNA based testing for HHT should include SMAD4 for samples in which mutations in neither ENG nor ALK1 are identified. HHT patients with SMAD4 mutations should be screened for colonic and gastric polyps associated with JP.

High performance DNA sequencing, and the detection of mutations and polymorphisms, on the Clipper sequencer.

The Visible Genetics Clipper sequencer is a new platform for automated DNA sequencing which employs disposable MicroCel cassettes and 50 microm thick polyacrylamide gels. Two DNA ladders can be analyzed simultaneously in each of 16 lanes on a gel, after labeling with far-red absorbing dyes such as Cy5 and Cy5.5. This allows a simultaneous bidirectional sequencing of four templates. We have evaluated the Clipper sequencer, by cycle-sequencing of an M13 single-stranded DNA standard, and by coupled amplification and sequencing (CLIP) of reverse-transcribed human immunodeficiency virus (HIV-1) RNA standards and clinical patient samples. (i) Limitations of instrument. We have examined basic instrument parameters such as detector stability, background, digital sampling rate, and gain. With proper usage, the optical and electronic subsystems of the Clipper sequencer do not limit the data collection or sequence-determination processes. (ii) Limitations of gel performance. We have also examined the physics of DNA band separation on 50 microm thick MicroCel gels. We routinely obtain well-resolved sequence which can be base-called with 98.5% accuracy to position approximately 450 on an 11 cm gel, and to position approximately 900 on a 25 cm gel. Resolution on 5 and 11 cm gels ultimately is limited by a sharp decrease in spacing between adjacent bands, in the biased reptation separation regime. Fick's (thermal) diffusion appears to be of minor importance on 6 cm or 11 cm gels, but becomes an additional resolution-limiting factor on 25 cm gels. (iii) Limitations of enzymology. Template quality, primer nesting, choice of DNA polymerase, and choice between dye primers and dye terminators are key determinants of the ability to detect mutations and polymorphisms on the Clipper sequencer, as on other DNA sequencers. When CLIP is used with dye-labeled primers and a DNA polymerase of the F667Y, delta(5'--> 3' exo) class, we can routinely detect single-nucleotide mutations and polymorphisms over the 0.35-0.65 heterozygosity range. We present an example of detecting therapeutically relevant mutations in a clinical HIV-1 RNA isolate.

Deletion of RB exons 24 and 25 causes low-penetrance retinoblastoma.

A deletion in the tumor-suppressor gene, RB, discovered by quantitative multiplex PCR, shows low penetrance (LP), since only 39% of eyes at risk in this family develop retinoblastoma. The 4-kb deletion spanning exons 24 and 25 (delta24-25) is the largest ever observed in an LP retinoblastoma family. Unlike the usual RB mutations, which cause retinoblastoma in 95% of at-risk eyes and yield no detectable protein, the delta24-25 allele transcribed a message splicing exon 23 to exon 26, resulting in a detectable protein (pRBdelta24-25) that lacks 58 amino acids from the C-terminal domain, proving that this domain is essential for suppression of retinoblastoma. Two functions were partially impaired by delta24-25-nuclear localization and repression of E2F-consistent with the idea that LP mutations generate "weak alleles" by reducing but not eliminating essential activities. However, delta24-25 ablated interaction of pRB with MDM2. Since a homozygous LP allele is considered nontumorigenic, the pRB/MDM2 interaction may be semi- or nonessential for suppressing retinoblastoma. Alternatively, some homozygous LP alleles may not cause tumorigenesis because an additional event is required (the "three-hit hypothesis"), or the resulting imbalance in pRB function may cause apoptosis (the "death allele hypothesis"). pRBdelta24-25 was also completely defective in suppressing growth of Saos-2 osteosarcoma cells. Targeting pRBdelta24-25 to the nucleus did not improve Saos-2 growth suppression, suggesting that C-terminal domain functions other than nuclear localization are essential for blocking proliferation in these cells. Since delta24-25 behaves like a null allele in these cells but like an LP allele in the retina, pRB may use different mechanisms to control growth in different cell types.