Translating patient needs into medical device development: co-design of a photoprotection visor for Xeroderma Pigmentosum using qualitative interviews

INTRODUCTION

People with Xeroderma Pigmentosum (XP) have a heightened sensitivity to ultraviolet radiation (UVR) and are advised to wear photoprotective clothing including a visor covering the face and neck. Photoprotective visors are homemade and predominately worn by children with decreasing frequency as age increases. To improve upon the current design and efficacy we were tasked with developing a prototype visor to meet patients' needs.

METHODS

Adopting a codesign methodology, patients' experiences of wearing a visor and patient and carer views of emerging prototypes were explored during interviews. A thematic analysis was conducted in parallel with data collection and themes were interpreted into design cues; desirable attributes of a visor that would counteract the negative user experiences and meet the requirements described by patients and carers. The design cues guided the iterative development of prototypes by academic engineers.

RESULTS

Twenty-four interviews were conducted with patients and carers. Thematic analysis resulted in the following five themes: Being safe from UVR exposure; self-consciousness; temperature effects; acoustic difficulties; and material properties. The following design cues were developed from the themes respectively; materials and design with high UVR protection; ability to customise with own headwear; ventilation to reduce steaming up; acoustic functionality to enable hearing and speech; foldable, portable, and easy to put on and take off.

CONCLUSIONS

It is important to understand people's experiences of using medical devices to improve their safety, efficiency and user satisfaction. The user experience themes and design cues, informed the iterative development of low fidelity visor prototypes as part of a codesign process. These design cues and responses to the prototypes are guiding commercial manufacturing and regulatory approval. The visor can then be prescribed to patients, providing an equitable service of care.

Whole Exome Sequencing of a Patient with a Milder Phenotype of Xeroderma Pigmentosum Group C

A 17-year-old female Korean patient (XP115KO) was previously diagnosed with Xeroderma pigmentosum group C (XPC) by Direct Sanger sequencing, which revealed a homozygous nonsense mutation in the XPC gene (rs121965088: c.1735C > T, p.Arg579Ter). While rs121965088 is associated with a poor prognosis, our patient presented with a milder phenotype. Hence, we conducted whole-exome sequencing in the patient and her family members to detect coexisting mutations that may have resulted in a milder phenotype of rs121965088 through genetic interaction. Materials and Methods: the whole-exome sequencing analysis of samples obtained from the patient and her family members (father, mother, and brother) was performed. To identify the underlying genetic cause of XPC, the extracted DNA was analyzed using Agilent's SureSelect XT Human All Exon v5. The functional effects of the resultant variants were predicted using the SNPinfo web server, and structural changes in the XPC protein using the 3D protein modeling program SWISS-MODEL. Results: Eight biallelic variants, homozygous in the patient and heterozygous in her parents, were detected. Four were found in the XPC gene: one nonsense variant (rs121965088: c.1735C > T, p.Arg579Ter) and three silent variants (rs2227998: c.2061G > A, p. Arg687Arg; rs2279017: c.2251-6A > C, intron; rs2607775: c.-27G > C, 5'UTR). The remaining four variants were found in non-XP genes, including one frameshift variant [rs72452004 of olfactory receptor family 2 subfamily T member 35 (OR2T35)], three missense variants [rs202089462 of ALF transcription elongation factor 3 (AFF3), rs138027161 of TCR gamma alternate reading frame protein (TARP), and rs3750575 of annexin A7 (ANXA7)]. Conclusions: potential candidates for genetic interactions with rs121965088 were found. The rs2279017 and rs2607775 of XPC involved mutations in the intron region, which affected RNA splicing and protein translation. The genetic variants of AFF3, TARP, and ANXA7 are all frameshift or missense mutations, inevitably disturbing the translation and function of the resultant proteins. Further research on their functions in DNA repair pathways may reveal undiscovered cellular relationships within xeroderma pigmentosum.

Xeroderma Pigmentosum: General Aspects and Management

Xeroderma Pigmentosum (XP) is a rare genetic syndrome with a defective DNA nucleotide excision repair. It is characterized by (i) an extreme sensitivity to ultraviolet (UV)-induced damages in the skin and eyes; (ii) high risk to develop multiple skin tumours; and (iii) neurologic alterations in the most severe form. To date, the management of XP patients consists of (i) early diagnosis; (ii) a long-life protection from ultraviolet radiation, including avoidance of unnecessary UV exposure, wearing UV blocking clothing, and use of topical sunscreens; and (iii) surgical resections of skin cancers. No curative treatment is available at present. Thus, in the last decade, in order to prevent or delay the progression of the clinical signs of XP, numerous strategies have been proposed and tested, in some cases, with adverse effects. The present review provides an overview of the molecular mechanisms featuring the development of XP and highlights both advantages and disadvantages of the clinical approaches developed throughout the years. The intention of the authors is to sensitize scientists to the crucial aspects of the pathology that could be differently targeted. In this context, the exploration of the process underlining the conception of liposomal nanocarriers is reported to focus the attention on the potentialities of liposomal technology to optimize the administration of chemoprotective agents in XP patients.

Improving photoprotection in adults with xeroderma pigmentosum: personalisation and tailoring in the 'XPAND' intervention

BACKGROUND

Individualised behaviour change interventions can result in greater effects than one-size-fits-all approaches. Factors linked to success include dynamic (vs. static) tailoring, and tailoring on behaviour, multiple theoretical variables, and participant characteristics. XP is a very rare (∼100 UK patients) genetic disease, involving an inability to repair ultraviolet radiation (UVR)-induced damage, resulting in skin cancers and eye damage from an early age, and mean life expectancy of 32-years. Management involves rigorous UVR photoprotection, which is often inadequate, and no interventions have been published. UK-based care is personalised and delivered by a multidisciplinary team at the National XP Service in London. Following an intensive, mixed-methods formative phase with patients diagnosed with XP (n-of-1, qualitative interviews, objective UVR measurement, cross-sectional survey) and relevant stakeholder consultation (clinical and patient/public teams), the 'XPAND' intervention was developed. This paper describes the comprehensive and novel tailoring and personalisation processes used to deliver the intervention.

METHODS

XPAND consists of core and personalised modules targeting cue-based (time of day, weather, symptoms), belief-based (motivation, priority), self-regulatory (effort, barriers, planning), and emotional (stress, self-consciousness, mental exhaustion) factors, social support, disclosure, habit, and willingness, using appropriately-matched BCTs. A-priori, phase I data and a baseline profiling questionnaire (data sources) were used to allocate modules to participants ('personalisation') and to adapt module content ('tailoring'). Iterative decisions about delivery were based on patient response to feedback, identification of additional barriers (e.g. reasons for varying protection across contexts), and emergence of new barriers as improvements in protection were attempted or achieved (e.g. appearance concerns).

CONCLUSIONS

Dynamic multi-level personalisation and tailoring based on mixed-methods in XPAND allowed for insights and decision-making not possible with cross-sectional quantitative or qualitative methods alone. Data collection and allocation/adaptation methods may be of use in other rare conditions where small patient numbers mean that within-participant, individual-level delivery is well-suited and feasible.

Novel variants in POLH and TREM2 genes associated with a complex phenotype of xeroderma pigmentosum variant type and early-onset dementia

BACKGROUND

Xeroderma pigmentosum (XP) is a rare, genetically heterogeneous, autosomal recessive disorder caused by defects in the genes involved in repairing DNA damaged by ultraviolet radiation. These defects lead to a propensity to develop skin cancer at early ages as a hallmark, and progressive neurological degeneration can be observed in around 25% of patients. Eight clinically heterogeneous groups have been identified so far (XPA to XPG and XPV). Xeroderma pigmentosum variant type (XPV) is associated with pathogenic variants in POLH on chromosome 6, and no neurological dysfunction has been seen in these cases. However, on the same chromosome, it has been shown that TREM2 is associated with some types of dementia, particularly in patients with a behavioral variant frontotemporal phenotype.

METHODS

Gene mutational analysis was performed by whole-exome sequencing.

RESULTS

We report a case of a Caucasian woman with XP that developed behavioral and cognitive impairment at age 37. Whole-exome sequencing identified novel homozygous variants in POLH c.638C>G (p.Ser213*) and TREM2 c.154C>T (p.Arg52Cys), classifying the patient as XPV and suggesting that her frontotemporal dementia phenotype could be related to the variant in TREM2.

CONCLUSION

This paper describes a rare case of a patient with two novel variants in the same chromosome associated with XPV and early-onset dementia.

Forms, interactions, and responses to social support: A qualitative study of support and adherence to photoprotection amongst patients with Xeroderma Pigmentosum

OBJECTIVES

Social support influences adherence to treatment in chronic illness, but there is uncertainty about its facilitators and constraints. This study explored the forms, processes, and responses associated with mobilization of informal support across three life contexts amongst patients with Xeroderma Pigmentosum (XP), a condition requiring rigorous photoprotection to reduce cancer risks.

DESIGN

Qualitative interview study.

METHODS

A total of 25 adults with XP participated in semi-structured interviews conducted face to face. An inductive thematic analysis was applied using a framework approach.

RESULTS

Practical support, involving both assistance with recommended photoprotection and adjusting daily activities to reduce exposure, was the key form of support provided by family and friends. However, responses to this support differed with two groups identified based on the relative priority given to photoprotection in daily life and processes of disclosure. For 'positive responders', support aligned with their own priorities to photoprotect, conveyed feelings of being cared-for and was facilitated by talking openly. In contrast, for 'negative responders' support conflicted with their priority of living 'normally' and their limited disclosure hindered receipt of helpful support in personal, clinic, and work interactions. Fears of workplace stigma also reduced disclosure amongst participants open in other contexts.

CONCLUSIONS

Practical support conveyed psychosocial support with positive effects on adherence. This suggests the traditional separation into practical and emotional support is overly simplistic, with measures potentially missing important aspects. Interactional processes contribute to the effects of support, which can be addressed by targeting disclosure, stigma, and other barriers at individual and organizational levels. Statement of contribution What is already known on this subject? Social support can be both a facilitator and a hindrance to treatment adherence. Practical support is identified as the most important form of support in the context of adherence. The processes of support underpinning its relationship to adherence are unclear. What does this study add? Variations in the provision and impacts of support are influenced by participants' disclosure and attitudes to photoprotection, with two key groups comprising 'positive responders' and 'negative responders'. The influence of emotional support on adherence may be underestimated through neglect of the ways in which practical support often conveys feelings of being valued and cared-for. Barriers to mobilizing effective adherence support extends across life spheres, with fears of stigma and discrimination in work settings highlighting the need to intervene at individual and organizational levels.

Macular and Retinal Nerve Fibre Layer Thinning in Xeroderma Pigmentosum: A Cross-sectional Study

The purpose of this study was to evaluate retinal thickness in different Xeroderma Pigmentosum (XP) complementation groups using spectral-domain optical coherence tomography (SD-OCT). This was a cross-sectional pilot study of 40 patients with XP. All patients had healthy-looking retinae and optic nerves on slit lamp biomicroscopy, and subtle or no neurological deficits. Patients were divided into two groups based on the known tendency for neurodegeneration associated with certain XP complementation groups. A third control group was obtained from a normative database. Using SD-OCT, we compared peripapillary retinal nerve fibre layer (pRNFL) and macular thickness between the groups. XP patients with a known tendency for neurodegeneration were found to have a statistically significant reduction in both pRNFL (p < 0.01) and macular thickness (p < 0.001) compared with healthy controls. In contrast, there was no statistically significant difference between pRNFL and macular thickness in XP patients not expected to develop neurodegeneration compared to the same control group. When both XP groups were compared, a statistically significant reduction in total pRNFL (p = 0.02) and macular thickness (p = 0.002) was found in XP patients predisposed to neurodegeneration. Our results suggest that pRNFL and macular thickness are reduced in XP patients with a known tendency for neurodegeneration, even before any marked neurological deficits become manifest. These findings demonstrate the potential role of retinal thickness as an anatomic biomarker and prognostic indicator for XP neurodegeneration.

Efficacy of anti-programmed cell death-1 immunotherapy for skin carcinomas and melanoma metastases in a patient with xeroderma pigmentosum

Xeroderma pigmentosum (XP) is an orphan disease of poor prognosis. We report one case of parallel efficacy with anti-programmed cell death-1 (PD-1) antibody on both melanoma and skin carcinoma in a patient with XP. A 17-year-old patient presented with metastatic melanoma and multiple nonmelanoma skin cancers. He was treated with pembrolizumab, a monoclonal anti-PD-1 antibody, at a dose of 2 mg kg^-1 , every 3 weeks. Parallel therapeutic efficacy of anti-PD-1 was observed in metastatic melanoma and skin carcinomas, and maintained at week 24. This observation suggests anti-PD-1 may be considered in patients with XP and metastatic melanoma in addition to advanced nonmelanoma skin cancer.

Experiences of stigma over the lifetime of people with xeroderma pigmentosum: A qualitative interview study in the United Kingdom

This study explored experiences of stigma in 25 adults with xeroderma pigmentosum. Analysis of semi-structured interviews revealed the changing nature of stigma over the lifetime. Bullying occurred in childhood, whereas adults were questioned about both their photoprotection and skin damage, often resulting in internalised feelings of stigma. Resilience and rejection of feelings of stigma increased with age and experiences of stigma differed across cultures. Findings indicate a need to develop social skills training to help people reject feelings of stigma. Future research should explore perspectives of families, friends and formal institutions and their potential to cause or reduce feelings of stigma.

Modeling xeroderma pigmentosum associated neurological pathologies with patients-derived iPSCs

Xeroderma pigmentosum (XP) is a group of genetic disorders caused by mutations of XP-associated genes, resulting in impairment of DNA repair. XP patients frequently exhibit neurological degeneration, but the underlying mechanism is unknown, in part due to lack of proper disease models. Here, we generated patient-specific induced pluripotent stem cells (iPSCs) harboring mutations in five different XP genes including XPA, XPB, XPC, XPG, and XPV. These iPSCs were further differentiated to neural cells, and their susceptibility to DNA damage stress was investigated. Mutation of XPA in either neural stem cells (NSCs) or neurons resulted in severe DNA damage repair defects, and these neural cells with mutant XPA were hyper-sensitive to DNA damage-induced apoptosis. Thus, XP-mutant neural cells represent valuable tools to clarify the molecular mechanisms of neurological abnormalities in the XP patients.

Generation of Xeroderma Pigmentosum-A Patient-Derived Induced Pluripotent Stem Cell Line for Use As Future Disease Model

Xeroderma pigmentosum group A (XP-A) is a genetic disorder in which there is an abnormality in nucleotide excision repair that causes hypersensitivity to sunlight and multiple skin cancers. The development of central and peripheral neurological disorders not correlated to ultraviolet light exposure is associated with XP-A. The genes responsible for XP-A have been identified and a XPA knockout mouse has been generated. These knockout mice exhibit cutaneous symptoms, but they do not show neurological disorders. The mechanism of pathogenesis of neurological disorders is still unclear and therapeutic methods have not been established. Therefore, we generated XP-A patient-derived human induced pluripotent stem cells (XPA-iPSCs) to produce in vitro models of neurological disorders. We obtained iPSC lines from fibroblasts of two patients carrying different mutations. Drugs screened using XPA-iPSC lines can be helpful for treating XP-A patients in Japan. Additionally, we revealed that these iPSCs have the potential to differentiate into neural lineage cells, including dopaminergic neurons, which decrease in XP-A patients. Our results indicate that expression of the normal XPA gene without mutations is not required for generation of iPSCs and differentiation of iPSCs into neural lineage cells. XPA-iPSCs may become useful models that clarify our understanding of neurological pathogenesis and help to establish therapeutic methods.

Xeroderma pigmentosum: low prevalence of germline XPA mutations in a Brazilian XP population

Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder characterized by DNA repair defects that cause photophobia, sunlight-induced cancers, and neurodegeneration. Prevalence of germline mutations in the nucleotide excision repair gene XPA vary significantly in different populations. No Brazilian patients have been reported to carry a germline mutation in this gene. In this study, the germline mutational status of XPA was determined in Brazilian patients exhibiting major clinical features of XP syndrome. The study was conducted on 27 unrelated patients from select Brazilian families. A biallelic inactivating transition mutation c.619C>T (p.Arg207Ter) was identified in only one patient with a history of neurological impairment and mild skin abnormalities. These findings suggest that XP syndrome is rarely associated with inherited disease-causing XPA mutations in the Brazilian population. Additionally, this report demonstrates the effectiveness of genotype-phenotype correlation as a valuable tool to guide direct genetic screening.

Site-directed Mutagenesis (Y52E) of POLH Affects Its Ability to Bypass Ultraviolet-induced DNA Lesions in HaCaT Cells

DNA polymerase eta (Pol η) is one of several Y family trans-lesion synthesis (TLS) polymerases in humans and plays an important role in maintaining genome stability after ultraviolet (UV) irradiation, as it carries out error-free TLS at sites of UV-induced lesions. We performed site-directed mutagenesis of human polymerase η gene (Y52E), confirmed by sequencing, then cloned wild-type mutant and POLH genes into the eukaryotic vector pEGFP-N1. After transfecting wild-type and mutant plasmids into HaCaT keratinocytes, we tested for UV induced cis-syn cyclobutane pyrimidine dimer (CPDs) DNA lesions, and analysed cellular viability by MTT cell proliferation assay. The results showed that CPD levels decreased both with empty vector control (EVC), wild-type POLH, and Y52E-POLH over 48 hours post UV irradiation with 0.1 mW/cm2 UVB for 15 minutes (p = 0.025). The rate in CPD reduction of mutant POLH was less than in wild-type POLH. Cell viabilities of all three groups increased over 48 hours after UV irradiation, with the increased rate in the wild-type being higher than for mutant protein (p = 0.046). We conclude that Y52E POLH has reduced capacity to bypass UV induced DNA lesions in HaCaT cells.

UVA1 is skin deep: molecular and clinical implications

Long wavelength UVA1 (340-400 nm) is the main component of terrestrial UVR and is increasingly used in skin phototherapy. Its damage to critical biomolecules such as DNA has been widely attributed to its ability to generate reactive oxygen species (ROS) via other chromophores. However recent studies in vitro and in vivo have shown that UVA1 has a specific ability to generate cyclobutane pyrimidine dimers (CPD), especially thymine dimers (T<>T), and that this is probably due to direct absorption of UVR. The CPD has been implicated in many aspects of skin cancer. Measuring UVB-induced CPD in the epidermis and dermis in vivo shows that, as expected, the skin attenuates UVB. In contrast, our data show that this is not the case with UVA1: in fact there is more damage with increased skin depth. This suggests that the basal layer, which contains keratinocyte stem cells and melanocytes, is more vulnerable to the carcinogenic effects of UVA1 than would be predicted by mouse models. These data support the continuing trend for better UVA1 protection by sunscreens.