Currently recommended skin scores correlate highly in the assessment of patients with Juvenile Dermatomyositis (JDM).

BACKGROUND: Juvenile Dermatomyositis (JDM) is a rare, chronic, and life-threatening childhood autoimmune disease. Currently, there are recommended, reliable and validated measurement tools for assessment of skin disease activity in JDM including the Disease Activity Score (skinDAS), Cutaneous Assessment Tool (CAT), and the Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI). The Physician's global assessment skin visual analog scale (Skin VAS) is also widely used for skin activity in JDM. For the purpose of comparative international studies, we wanted to compare these tools to the Physician's skin VAS (as a standard) to identify which performs better. OBJECTIVES: We sought to compare the correlations of these scoring tools, and separately assess the responsiveness each tool demonstrates following patient treatment, in order to see if one tool may be preferred. This was determined by assessing how well these tools correlate with each other, and the Physician's skin VAS over time, as well as the responsiveness of each tool after patient treatment. METHODS: Skin scores were recorded at a baseline (first visit after June 1st, 2018) and all follow-up office visits at the Juvenile Dermatomyositis Clinic. Following baseline visits, patients were followed up as clinically indicated. A subset of newly diagnosed patients (inception cohort) was identified. Correlations were assessed at the baseline visit and over time for the whole cohort. The correlations over time were derived using Generalized Estimating Equations (GEEs). Standardized response means with 95% confidence intervals were calculated to test score responsiveness for the nested inception cohort. RESULTS: The skinDAS, CAT and CDASI all correlated highly with each other and with the Physician's skin VAS. The three scoring tools accurately reflected Physician's skin VAS scores over time. In addition, all tools showed moderate to high responsiveness following treatment. CONCLUSION: All studied skin score tools performed well in our study and appear to be useful. Since no tool far outperforms the others, arbitrary consensus will be needed to select a single standard measurement tool for the purposes of efficiency and global comparability.

Assessment of Orofacial Symptoms in Juvenile Idiopathic Arthritis: Validation of a Consensus-Based Short Patient Questionnaire.

OBJECTIVE: To develop, validate, and test the performance of patient-reported outcomes (PROs) in a short patient questionnaire (< 5 minutes in length) in order to assess the multidimensional aspects of orofacial symptoms related to juvenile idiopathic arthritis (JIA) among patients aged ≥ 10 years. METHODS: The study was conducted by an interdisciplinary task force from the Temporomandibular Joint Juvenile Arthritis Working Group. The project consisted of a multiphased approach including the following: (1) conceptual phase with online international survey of 167 healthcare workers, (2) item generation and drafting of preliminary questionnaire(s) (ie, face validity), (3) cognitive script interview and probing (ie, content validity; 16 patients with JIA), (4) assessment of construct validity (ie, convergence and divergence; 53 patients with JIA), (5) test of reliability, and (6) test of clinical performance and psychometric characteristics (95 patients with JIA). RESULTS: In total, 7 PROs were included in the final patient questionnaire: (1) pain frequency, (2) pain intensity, (3) pain location, (4) jaw function, (5) specific questions related to symptoms and dysfunction, (6) changes in face and jaw pain since last visit, and (7) changes in jaw function since last visit. In total, 80% of the patients were able to complete the questionnaire in less than 5 minutes. CONCLUSION: We have developed and validated a short patient questionnaire to assess the multidimensional aspects of JIA-related orofacial symptoms. The PROs included in our questionnaire show acceptable validity and reliability. The questionnaire is applicable to routine monitoring of subjects with JIA, as well as future research studies.

Implementation of Rheumatology Health Care Transition Processes and Adaptations to Systems Under Stress: A Mixed-Methods Study.

OBJECTIVES: Despite poor health care transition outcomes among young adults with pediatric rheumatic diseases, adoption of transition best practices is low. We sought to understand how structured transition processes were operationalized within pediatric rheumatology practices and what factors were perceived to enable adaptations during a global pandemic. METHODS: We conducted a mixed methods study of team leaders' experiences during an interim analysis of a pilot project to implement transition policy discussions at sites in the Childhood Arthritis and Rheumatology Research Alliance Transition Learning Collaborative. We combined quantitative assessments of organizational readiness for change (9 sites) and semistructured interviews of team leaders (8 sites) using determinants in the Exploration, Preparation, Implementation, Sustainment Framework. RESULTS: Engagement of nursing and institutional improvement efforts facilitated decisions to implement transition policies. Workflows incorporating educational processes by nonphysicians were perceived to be critical for success. When the pandemic disrupted contact with nonphysicians, capacity for automation using electronic medical record (EMR)-based tools was an important facilitator, but few sites could access these tools. Sites without EMR-based tools did not progress despite reporting high organizational readiness to implement change at the clinic level. Lastly, educational processes were often superseded by acute issues, such that youth with greater medical/psychosocial complexity may not receive the intervention. CONCLUSION: We generated several considerations to guide implementation of transition processes within pediatric rheumatology from the perspectives of team leaders. Careful assessment of institutional and nursing support is advisable before conducting complex transition interventions. Ideally, new strategies would ensure interventions reach youth with high complexity.

Pediatric to Adult Transition Literature: Scoping Review and Rheumatology Research Prioritization Survey Results.

The transition from pediatric to adult care is the focus of growing research. It is important to identify how to direct future research efforts for maximum effect. Our goals were to perform a scoping review of the transition literature, highlight gaps in transition research, and offer stakeholder guidance on the importance and feasibility of research questions designed to fill identified gaps. The transition literature on rheumatic diseases and other common pediatric-onset chronic diseases was grouped and summarized. Based on the findings, a survey was developed and disseminated to pediatric rheumatologists and young adults with rheumatic diseases as well as their caregivers. The transitional care needs of patients, healthcare teams, and caregivers is well described in the literature. While various transition readiness scales exist, no longitudinal posttransfer study confirms their predictive validity. Multiple outcome measures are used alone or in combination to define a successful transition or intervention. Multimodal interventions are most effective at improving transition-related outcomes. How broader health policy affects transition is poorly studied. Research questions that ranked highest for importance and feasibility included those related to identifying and tracking persons with psychosocial vulnerabilities or other risk factors for poor outcomes. Interventions surrounding improving self-efficacy and health literacy were also ranked highly. In contrast to healthcare teams (n = 107), young adults/caregivers (n = 23) prioritized research surrounding improved work, school, or social function. The relevant transition literature is summarized and future research questions prioritized, including the creation of processes to identify and support young adults vulnerable to poor outcomes.

Translating research into practice-implementation recommendations for pediatric rheumatology; Proceedings of the childhood arthritis and rheumatology research alliance 2020 implementation science retreat.

The translation of research findings into clinical practice is challenging, especially fields like in pediatric rheumatology, where the evidence base is limited, there are few clinical trials, and the conditions are rare and heterogeneous. Implementation science methodologies have been shown to reduce the research- to- practice gap in other clinical settings may have similar utility in pediatric rheumatology. This paper describes the key discussion points from the inaugural Childhood Arthritis and Rheumatology Research Alliance Implementation Science retreat held in February 2020. The aim of this report is to synthesize those findings into an Implementation Science Roadmap for pediatric rheumatology research. This roadmap is based on three foundational principles: fostering curiosity and ensuring discovery, integration of research and quality improvement, and patient-centeredness. We include six key steps anchored in the principles of implementation science. Applying this roadmap will enable researchers to evaluate the full range of research activities, from the initial clinical design and evidence acquisition to the application of those findings in pediatric rheumatology clinics and direct patient care.

Electronic forms for patient reported outcome measures (PROMs) are an effective, time-efficient, and cost-minimizing alternative to paper forms.

BACKGROUND: Patient reported outcome measures (PROMs) provide valuable insight on patients' well-being and facilitates communication between healthcare providers and their patients. The increased integration of the technology within the healthcare setting presents the opportunity to collect PROMs electronically, rather than on paper. The Childhood Health Assessment Questionnaire (CHAQ) and Quality of My Life (QoML) are common PROMs collected from pediatric rheumatology patients. The objectives of this study are to (a) determine the equivalence of the paper and electronic forms (e-form) of CHAQ and QoML questionnaires; (b) identify potential benefits and barriers associated with using an e-form to capture PROMs; and (c) gather feedback on user experience. METHODS: Participants completed both a paper and an e-form of the questionnaires in a randomized order, following which they completed a feedback survey. Agreement of the scores between the forms were statistically analyzed using the intraclass correlation coefficient (ICC) (95 % Confidence Interval (CI)) and bias was assessed using a Bland-Altman plot. Completion and processing times of the forms were compared using mean and median measures. Quantitative analysis was performed to assess user experience ratings, while comments were qualitatively analyzed to identify important themes. RESULTS: 196 patients participated in this project. Scores on the forms had high ICC agreement > 0.9. New patients took longer than returning patients to complete the forms. Overall, the e-form was completed and processed in a shorter amount of time than the paper form. 83 % of survey respondents indicated that they either preferred the e-form or had no preference. Approximately 10 % of respondents suggested improvements to improve the user interface. CONCLUSIONS: E-forms collect comparable information in an efficient manner to paper forms. Given that patients and caregivers indicated they preferred completing PROMs in this manner, we will implement their suggested changes and incorporate e-forms as standard practice for PROMs collection in our pediatric rheumatology clinic.

Exploring Pediatric Tele-Rheumatology Practices During COVID-19: A Survey of the PRCOIN Network.

Healthcare providers were rapidly forced to modify the way they practiced medicine during the coronavirus disease 2019 (COVID-19) pandemic. Many providers transitioned from seeing their patients in person to virtually using telemedicine platforms with limited training and experience using this medium. In pediatric rheumatology, this was further complicated as musculoskeletal exams typically require hands-on assessment of patients. The objective of this study was to examine the adoption of telemedicine into pediatric rheumatology practices, to assess its benefits and challenges, and to gather opinions on its continued use. A survey was sent to the lead representatives of each Pediatric Rheumatology Care and Outcomes Improvement Network (PR-COIN) site to collect data about their center's experience with telemedicine during the COVID-19 pandemic. Quantitative data were analyzed using descriptive statistics, and qualitative data were thematically analyzed. Responses were received from the majority [19/21 (90%)] of PR-COIN sites. All respondents reported transitioning from in-person to primarily virtual patient visits during the COVID-19 pandemic. All centers reported seeing both new consultations and follow-up patients over telemedicine. Most centers reported using both audio and video conferencing systems to conduct their telemedicine visits. The majority of respondents [13/19 (68%)] indicated that at least 50% of their site's providers consistently used pediatric Gait Arms Legs and Spine (pGALS) to perform active joint count assessments over telemedicine. Over half of the centers [11/19 (58%)] reported collecting patient-reported outcomes (PROs), but the rate of reliably documenting clinical components varied. A few sites [7/19 (37%)] reported performing research-related activity during telemedicine visits. All centers thought that telemedicine visits were able to meet providers' needs and support their continued use when the pandemic ends. Benefits reported with telemedicine visits included convenience and continuity of care for families. Conversely, challenges included limited ability to perform physical exams and varying access to technology. Pediatric rheumatology providers were able to transition to conducting virtual visits during the COVID-19 pandemic. Healthcare providers recognize how telemedicine can enhance their practice, but challenges need to be overcome in order to ensure equitable, sustainable delivery of quality and patient-centered care.

Differences in Healthcare Transition Views, Practices, and Barriers Among North American Pediatric Rheumatology Clinicians From 2010 to 2018.

OBJECTIVE: Since 2010, the rheumatology community has developed guidelines and tools to improve healthcare transition. In this study, we aimed to compare current transition practices and beliefs among Childhood Arthritis and Rheumatology Research Alliance (CARRA) rheumatology providers with transition practices from a provider survey published in 2010. METHODS: In 2018, CARRA members completed a 25-item online survey about healthcare transition. Got Transition's Current Assessment of Health Care Transition Activities was used to measure clinical transition processes on a scale of 1 (basic) to 4 (comprehensive). Bivariate analyses were used to compare 2010 and 2018 survey findings. RESULTS: Over half of CARRA members completed the survey (202/396), including pediatric rheumatologists, adult- and pediatric-trained rheumatologists, pediatric rheumatology fellows, and advanced practice providers. The most common target age to begin transition planning was 15-17 years (49%). Most providers transferred patients prior to age 21 years (75%). Few providers used the American College of Rheumatology transition tools (31%) or have a dedicated transition clinic (23%). Only 17% had a transition policy in place, and 63% did not consistently address healthcare transition with patients. When compared to the 2010 survey, improvement was noted in 3 of 12 transition barriers: availability of adult primary care providers, availability of adult rheumatologists, and pediatric staff transition knowledge and skills (P < 0.001 for each). Nevertheless, the mean current assessment score was < 2 for each measurement. CONCLUSION: This study demonstrates improvement in certain transition barriers and practices since 2010, although implementation of structured transition processes remains inconsistent.

Patient and caregiver engagement in research: factors that influence co-enrollment in research.

BACKGROUND: Recruitment of pediatric participants in studies is difficult due to the vulnerability of this population and the scarcity of certain conditions. Co-enrolling in multiple studies is a strategy that may help overcome this problem. Although anecdotal evidence suggests that co-enrollment may increase patient and caregiver burden, few studies have been conducted from the patient perspective. The objective of this quality improvement project was to elicit patient and caregiver opinions on co-enrolling in multiple research studies. METHODS: Patients and caregivers attending the rheumatology clinic at The Hospital for Sick Children were invited to participate in a semi-structured interview or focus group session. Participants were asked to respond to ten prompts, organized into five categories: experience in clinical research, multiple studies, study selection, study timing and other comments. Sessions were recorded, transcribed and analyzed using NVivo 10 to identify common themes. RESULTS: Overall, eighteen caregivers and two patients were included in the study. Participants felt that the level of study involvement, rather than the number of studies, was the biggest factor affecting their decision to participate. Another factor commonly identified was the competing demands of participants' work and family life. Participants indicated that they generally preferred to be informed about all study opportunities and liked to receive this information prior to their appointments. Once informed, they preferred to be approached by the research team while they were waiting for their appointment. CONCLUSION: Patients and caregivers are open to the concept of co-enrolling in multiple research studies. There are multiple factors which influence decisions to co-enroll in studies including the demands of the study and personal limitations. These findings will help guide the design and practices of future research.

A wearable activity tracker intervention for promoting physical activity in adolescents with juvenile idiopathic arthritis: a pilot study.

BACKGROUND: Children and adolescents with juvenile idiopathic arthritis (JIA) are less physically active than their healthy peers and are at high risk of missing out on the general health benefits of physical activity. Wearable activity trackers are a promising option for intervening in this population with potential advantages over traditional exercise prescriptions. The objectives of this study were to: (1) determine the feasibility of a wearable activity tracker intervention in adolescents with JIA; and (2) estimate the variability in response to a wearable activity tracker intervention on the physical activity levels of adolescents with JIA. METHODS: Participants aged 12-18 years with JIA were recruited during their routine rheumatology clinic visits at a tertiary care hospital. Participants completed the 3-Day Physical Activity Recall self-reported questionnaire at baseline, 1 week and 5 week follow-up. At the 1 week follow up, participants were instructed to start wearing an activity tracker for 28 consecutive days. Participants completed a feasibility questionnaire at their end of study visit. Participant demographics, adherence rates and feasibility outcomes were summarized using descriptive statistics. The effect of wearing a tracker on moderate-to-vigorous physical activity (MVPA) and total metabolic equivalents (METs) per day were analyzed using a paired t-test. RESULTS: Twenty-eight participants (74% female; median age 15.1, range 12.8-18.6) were included in the analysis. All of the participants were able to synchronize the activity tracker to a supported device, use the activity tracker correctly and complete the study measurements. On average, participants had activity logged on their smartphone application for 72% of the intervention period. The standard deviation of the change in mean METs/day was 12.148 and for mean MVPA blocks/day was 3.143 over the study period. CONCLUSION: Wrist worn activity tracking is a feasible intervention for adolescent patients with JIA. More research is needed to examine the effect of activity tracking on physical activity levels. TRIAL REGISTRATION: Not an applicable clinical device trial as per the criteria listed on ClinicalTrials.gov as the primary objective is feasibility.

The effect of distant reiki on pain in women after elective Caesarean section: a double-blinded randomised controlled trial.

INTRODUCTION: Approximately 25% of all babies in North America are delivered via Caesarean section (C-section). Though a common surgical procedure, C-section recovery can be painful. Opioids, specifically codeine, are commonly used to ease pain; however, its active metabolite, morphine, passes into breast milk, and may produce unwanted side effects in neonates; therefore, alternatives to opioids are being sought. Reiki is an ancient Japanese form of healing where practitioners transfer healing energy through light touch and positive healing intention. Although 1.2 million Americans use reiki to reduce pain or depression, there is a lack of strong evidence supporting its effectiveness. A recent systematic review showed existing studies to be of poor methodological quality, with the common limitation of lack of blinding. To overcome this issue, the authors used distant reiki to assess its effectiveness in reducing pain following an elective C-section. METHODS: In this randomised, double-blinded study, women who underwent an elective C-section were allocated to either usual care (control, n=40) or three distant reiki sessions in addition to usual care (n=40). Pain was assessed using a visual analogue scale (VAS). The primary endpoint was the Area Under the VAS-Time Curve (AUC) for days 1-3. Secondary measures included: the proportion of women who required opioid medications and dose consumed, rate of healing and vital signs. RESULTS: AUC for pain was not significantly different in the distant reiki and control groups (mean ± SD; 212.1 ± 104.7 vs 223.1 ± 117.8; p=0.96). There were no significant differences in opioid consumption or rate of healing; however, the distant reiki group had a significantly lower heart rate (74.3 ± 8.1 bpm vs 79.8 ± 7.9 bpm, p=0.003) and blood pressure (106.4 ± 9.7 mmHg vs 111.9 ± 11.0 mmHg, p=0.02) post surgery. CONCLUSION: Distant reiki had no significant effect on pain following an elective C-section. Clinical Trial Registration Number ISRCTN79265996.

Rates of fetal alcohol exposure among newborns in a high-risk obstetric unit.

Meconium fatty acid ethyl esters (FAEEs) are sensitive and specific biomarkers for prenatal alcohol exposure (PAE) in pregnancy. We recently reported a 2.5% rate of FAEE positive meconium in a general population sample of infants born in the region of Grey-Bruce, Ontario. Women in this region with high-risk pregnancies are transferred to a tertiary care facility in London, Ontario. The objective of this study was to determine, in a population-based sample, whether high-risk pregnancies are associated with an increased risk of in utero alcohol exposure. Grey-Bruce residents transferred to the high-risk obstetric unit of St. Joseph's Health Care in London, Ontario were identified and consented to this anonymous prevalence study. Meconium was collected and analyzed for FAEE using gas chromatography with mass spectrometry. The prevalence of FAEE positive meconium was compared with the population-based prevalence in the Grey-Bruce. Fifty meconium specimens were collected from August 1, 2006 to July 31, 2007. Fifteen (30%) specimens tested positive for FAEE. The results indicate that infants born in the high-risk obstetric unit had a 12-fold higher risk of screening positive for second and third trimester alcohol exposure compared with infants born in the general population of Grey-Bruce (relative risk=12.04, 95% confidence interval=6.40-22.65, P<.0001). These results suggest that the high-risk pregnancies should be screened for PAE and followed-up for potential diagnosis of fetal alcohol spectrum disorder.

Alcohol content in declared non-to low alcoholic beverages: implications to pregnancy.

BACKGROUND: Alcohol consumption in pregnancy may result in serious adverse fetal outcome. Non- or low alcoholic wines and beers may be a risk-reduction strategy to help alcohol-dependent individuals to prevent or limit ethanol consumption. The objective of this study was to quantify ethanol concentrations in Canadian beverages claiming to contain no or low alcohol content. METHODS: Forty-five different beverages claiming to contain no or low alcohol content in the Canadian market were tested for ethanol concentration using gas chromatography. RESULTS: Thirteen (29%) of the beverages contained ethanol levels higher than the declared concentration on their label. Six beverages claiming to contain no alcohol were found to contain greater than 1% ethanol. CONCLUSION: Pregnant women seeking replacement to alcoholic beverages may be misled by these labels, unknowingly exposing themselves and their unborn babies to ethanol.

Periconceptional folic acid supplementation: a new indication for therapeutic drug monitoring.

The role of periconceptional folic acid supplementation in the prevention of neural tube defects (NTDs) has been well established. Maternal red blood cell (RBC) folate concentration is inversely associated with NTD risk, and concentrations above 906 nmol/L are associated with a low risk of NTDs. Current guidelines call for a minimum of 0.4 mg of folic acid per day for all women who could become pregnant and higher levels of supplementation for women with a family history of NTDs or risk factors associated with NTDs. However, there is variability in supplement adherence and lack of knowledge of conditions that may elevate folate requirements or NTD risk. Therefore, guidance provided to the population as a whole may be inappropriate for individual women. Current data show that a significant proportion of women of childbearing age have RBC folate concentrations below 906 nmol/L, rendering a higher-than-baseline risk for NTDs. Therapeutic drug monitoring (TDM) of RBC folate could be used to identify these women and to help them improve their folate status, thus reducing their risk for having a child with an NTD.This review describes the evolution of the evidence for TDM of RBC folate and preliminary experience with TDM in a population of 12 women who were planning a pregnancy and who were being treated with an atypical antipsychotic.

Folic acid: the right dose.

ABSTRACTQUESTION The new Motherisk Guidelines suggest 5 mg/d of folic acid. Why was the dose increased? What is the time frame for taking such a dose?ANSWER Recent data from Ontario reveal that 40% of women of reproductive age still do not achieve therapeutic systemic levels of folate needed to prevent neural tube defects. Compliance is less than optimal among women using prenatal vitamins, rendering many women unprotected against neural tube defects. Taking a higher dose of folate will allow achievement of protective folate levels, even with partial compliance. Five mg of folate should be used daily several months before conception until the end of the first trimester.

Development of Canadian screening tools for fetal alcohol spectrum disorder.

BACKGROUND: Fetal alcohol spectrum disorder (FASD) is the most common cause of neurobehavioural handicap in North America. Screening for FASD may facilitate diagnosis and hence management of these children. We present a variety of screening tools for the identification of children at risk for FASD. METHODS: We critically reviewed and evaluated published and practiced methods for their potential of screening suspected cases, their epidemiological characteristics (sensitivity, specificity, positive and negative predictive values) [Phase I], as well as their feasibility [Phase II]. RESULTS: The following five tools were selected for the FASD screening toolkit: screening fatty acid ethyl esters in neonatal meconium, the modified Child Behaviour Checklist, Medicine Wheel tool, Asante Centre Probation Officer Tool, and maternal history of drinking and drug use. CONCLUSIONS: The toolkit for FASD screening aims at screening different populations, from the newborns to youth and at-risk mothers. It is anticipated that the toolkit will facilitate diagnosis of FASD.

Prenatal supplementation with multivitamins and the incidence of pediatric cancers: clinical and methodological considerations.

Cancer is the second leading cause of death in children. Research has been undertaken to identify risk factors associated with pediatric cancers. Nevertheless one single cause has not been isolated. Recent studies have suggested that prenatal multivitamin consumption may be associated with the prevention of pediatric cancers. It has been shown previously that prenatal multivitamin ingestion is associated with a decrease in congenital anomalies. The following review summarizes the available knowledge associating prenatal multivitamin consumption with the prevention of pediatric cancers.

Increasing folate supplementation for selected groups of Canadian women.

After review of current evidence related to the potential risks and benefits of folic acid supplementation, we conclude that unless clinicians can be assured that pregnant women will reliably use prenatal vitamin supplements containing 0.8-1.1 mg of folate, the prenatal vitamin supplements should be combined with 5 mg of folate.

IFN-{beta} signaling positively regulates tumorigenesis in aggressive fibromatosis, potentially by modulating mesenchymal progenitors.

Aggressive fibromatosis (also called desmoid tumor) is a benign, locally invasive, soft tissue tumor composed of cells with mesenchymal characteristics. These tumors are characterized by increased levels of beta-catenin-mediated T-cell factor (TCF)-dependent transcriptional activation. We found that type 1 IFN signaling is activated in human and murine aggressive fibromatosis tumors and that the expression of associated response genes is regulated by beta-catenin. When mice deficient for the type 1 IFN receptor (Ifnar1-/-) were crossed with mice predisposed to developing aggressive fibromatosis tumors (Apc/Apc1638N), a significant decrease in aggressive fibromatosis tumor formation was observed compared with littermate controls, showing a novel role for type 1 IFN signaling in promoting tumor formation. Type 1 IFN activation inhibits cell proliferation but does not alter cell apoptosis or the level of beta-catenin-mediated TCF-dependent transcriptional activation in aggressive fibromatosis cell cultures. Thus, these changes cannot explain our in vivo results. Intriguingly, Ifnar1-/- mice have smaller numbers of mesenchymal progenitor cells compared with littermate controls, and treatment of aggressive fibromatosis cell cultures with IFN increases the proportion of cells that exclude Hoechst dye and sort to the side population, raising the possibility that type 1 IFN signaling regulates the number of precursor cells present that drive aggressive fibromatosis tumor formation and maintenance. This study identified a novel role for IFN type 1 signaling as a positive regulator of neoplasia and suggests that IFN treatment is a less than optimal therapy for this tumor type.