Laura Watts

ERAP1 association with ankylosing spondylitis is attributable to common genotypes rather than rare haplotype combinations.

Significance Ankylosing spondylitis (AS) is a common inflammatory arthritis of the spine. It is associated with two genes involved in antigen processing and presentation to the immune system, HLA-B*27 and ERAP1 (endoplasmic reticulum aminopeptidase 1), which act synergistically in AS. Previous reports have suggested that rare ERAP1 variants associated with dramatically altered antigen processing function are responsible. In contrast, we show here conclusively that it is common variants of ERAP1 that are mainly responsible for protection/susceptibility in AS rather than rare ERAP1 variants and/or unusual combinations of ERAP1 variants. This has important potential implications for future studies addressing the development of ERAP1 inhibitors as new treatments not only for AS but also in other diseases genetically associated with ERAP1. We investigated the proposal that ankylosing spondylitis (AS) is associated with unusual ERAP1 genotypes. ERAP1 haplotypes were constructed for 213 AS cases and 46 rheumatoid arthritis controls using family data. Haplotypes were generated from five common ERAP1 single nucleotide polymorphisms (SNPs)—rs2287987 (M349V), rs30187 (K528R), rs10050860 (D575N), rs17482078 (R725Q), and rs27044 (Q730E). Haplotype frequencies were compared using Fisher’s exact test. ERAP1 haplotypes imputed from the International Genetics of AS Consortium (IGAS) Immunochip study were also studied. In the family study, we identified only four common ERAP1 haplotypes (“VRNQE,” “MKDRQ,” “MRDRE,” and “MKDRE”) in both AS cases and controls apart from two rare (<0.5%) previously unreported haplotypes. There were no examples of the unusual ERAP1 haplotype combination (“*001/*005”) previously reported by others in 53% of AS cases. As expected, K528-bearing haplotypes were increased in the AS family study (AS 43% vs. control 35%), due particularly to an increase in the MKDRQ haplotype (AS 35% vs. control 25%, P = 0.01). This trend was replicated in the imputed Immunochip data for the two K528-bearing haplotypes MKDRQ (AS 33% vs. controls 27%, P = 1.2 × 10–24) and MKDRE (AS 8% vs. controls 7%, P = 0.004). The ERAP1 association with AS is therefore predominantly attributable to common ERAP1 haplotypes and haplotype combinations.

Health-related quality of life and a cost-utility simulation of adults in the UK with osteogenesis imperfecta, X-linked hypophosphatemia and fibrous dysplasia.

BackgroundHealth-related quality of life of adults with osteogenesis imperfecta (OI), fibrous dysplasia (FD) and X-linked hypophosphatemia (XLH) remains poorly described. The aim of this study was to describe the HRQoL of adults with osteogenesis imperfecta, fibrous dysplasia and X-linked hypophophataemia and perform a cost-utility simulation to calculate the maximum cost that a health care system would be willing to pay for a hypothetical treatment of a rare bone disease.ResultsParticipants completed the EQ-5D-5 L questionnaire between September 2014 and March 2016. For the economic simulation, we considered a hypothetical treatment that would be applied to OI participants in the lower tertile of the health utility score.A total of 109 study participants fully completed the EQ-5D-5 L questionnaire (response rate 63%). Pain/discomfort was the most problematic domain for participants with all three diseases (FD 31%, XLH 25%, OI 16%).The economic simulation identified an expected treatment impact of +2.5 QALYs gained per person during the 10-year period, which led to a willing to pay of £14,355 annually for a health care system willing to pay up to £50,000 for each additional QALY gained by an intervention.ConclusionsThis is the first study to quantitatively measure and compare the HRQoL of adults with OI, FD and XLH and the first to use such data to conduct an economic simulation leading to healthcare system willingness-to-pay estimates for treatment of musculoskeletal rare diseases at various cost-effectiveness thresholds.

The RUDY study: using digital technologies to enable a research partnership

Patients have extensive experience of their disease that can enhance the design and execution of research leading to significant innovations and efficiencies in the research process. The research community on the whole have been slow to adopt practices that enable patients to become active partners in research. Digital technologies are providing the means to do this more easily and so are increasingly being used to interact with patients and involve them in the design and execution of research. The RUDY (Rare UK Diseases of bone, joints and blood vessels) study’s pioneering approach applies a custom-developed electronic platform where patients can contribute information over time about their disease experience, lifestyle and clinical history. This is combined with a state-of-the-art Dynamic Consent model and a commitment to patient-driven research, to further our understanding of rare diseases. This paper describes the RUDY study and the benefits that have been gained from adopting this partnership approach to research.

Patient experiences of participation in a medical student teaching workshop

Abstract Objectives: To investigate the motivations for and experiences of patients who actively participate in a workshop to teach medical students about chronic disease. Design: Descriptive study using structured telephone or e-mail-based questionnaire exploring the views of ‘patient tutors’ who participate in a ‘living with chronic disease’ workshop. Participants: ‘Patient tutors’ with a chronic medical condition who had participated in at least one ‘living with chronic disease’ workshop for medical students at Oxford University Medical School. Results: Patient motivating factors can be divided into two groups, direct benefits such as companionship or improved knowledge of their condition, and a teaching role involving an altruistic desire to give something back, and wanting to educate the doctors of the future. Importantly, most patients participated multiple times over a number of years despite no remuneration for their time other than expenses. Conclusions: Patients appear highly motivated to educate medical students about chronic disease, due to a combination of personal benefits and an altruistic desire to ‘give something back’. This suggests that they present an invaluable and currently undermobilized resource for the future of medical education.

Chiari malformation, syringomyelia and bulbar palsy in X linked hypophosphataemia.

X linked hypophosphataemia (XLH) is a rare condition with numerous musculoskeletal complications. It may mimic other more familiar conditions, such as vitamin D deficiency, ankylosing spondylitis or diffuse idiopathic skeletal hyperostosis. We describe two cases with Chiari type 1 malformations and syringomyelia, neither of which is well recognised in XLH. The first presented late with the additional complications of spinal cord compression, pseudofracture, renal stones and gross femoroacetabular impingement requiring hip replacement. The second also had bulbar palsy; the first case to be described in this condition, to the best of our knowledge. We wish to raise awareness of the important neurological complications of syringomyelia, Chiari malformation, spinal cord compression and bulbar palsy when treating these patients. We also wish to draw attention to the utility of family history and genetic testing when making the diagnosis of this rare but potentially treatable condition.

The severity of ankylosing spondylitis and responses to anti-tumour necrosis factor biologics are not influenced by the tumour necrosis factor receptor polymorphism incriminated in multiple sclerosis.

Genetic polymorphism (rs1800693) of TNFRSF1A (type 1 tumour necrosis factor receptor) encodes a potentially anti-inflammatory soluble truncated form of the p55 receptor, which is associated with predisposition to multiple sclerosis but protection against ankylosing spondylitis (AS). We analysed 2917 UK Caucasian cases by linear and logistic regression for associations of rs1800693 with disease severity assessed by the Bath Ankylosing Spondylitis measures of disease activity and function (BASDAI, BAS-G and BASFI) and/or responses to anti-TNF therapy. In contrast to predictions, rs1800693 GG homozygotes actually had significantly worse BASDAI (mean 4.2, 95% CI: 4–4.5) than AA homozygotes (mean 3.8, 95% CI: 3.7–4) in both the unadjusted (difference = 0.4, p = 0.006) and adjusted analyses (difference = 0.2–0.5, p = 0.002–0.04 depending on the adjustment model). We found no evidence that rs1900693 predicted functional status (BASFI) or global disease scores (BAS-G), and it exerted no influence on either the intention to treat with or efficacy of anti-TNF treatment.