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1.
J Neuroendocrinol ; 35(6): e13311, 2023 06.
Article in English | MEDLINE | ID: mdl-37345276

ABSTRACT

RECIST 1.1 criteria are commonly used with computed tomography (CT) to evaluate the efficacy of systemic treatments in patients with neuroendocrine tumors (NETs) and liver metastases (LMs), but their relevance is questioned in this setting. We aimed to explore alternative criteria using different numbers of measured LMs and thresholds of size and density variation. We retrospectively studied patients with advanced pancreatic or small intestine NETs with LMs, treated with systemic treatment in the first-and/or second-line, without early progression, in 14 European expert centers. We compared time to treatment failure (TTF) between responders and non-responders according to various criteria defined by 0%, 10%, 20% or 30% decrease in the sum of LM size, and/or by 10%, 15% or 20% decrease in LM density, measured on two, three or five LMs, on baseline (≤1 month before treatment initiation) and first revaluation (≤6 months) contrast-enhanced CT scans. Multivariable Cox proportional hazard models were performed to adjust the association between response criteria and TTF on prognostic factors. We included 129 systemic treatments (long-acting somatostatin analogs 41.9%, chemotherapy 26.4%, targeted therapies 31.8%), administered as first-line (53.5%) or second-line therapies (46.5%) in 91 patients. A decrease ≥10% in the size of three LMs was the response criterion that best predicted prolonged TTF, with significance at multivariable analysis (HR 1.90; 95% CI: 1.06-3.40; p = .03). Conversely, response defined by RECIST 1.1 did not predict prolonged TTF (p = .91), and neither did criteria based on changes in LM density. A ≥10% decrease in size of three LMs could be a more clinically relevant criterion than the current 30% threshold utilized by RECIST 1.1 for the evaluation of treatment efficacy in patients with advanced NETs. Its implementation in clinical trials is mandatory for prospective validation. Criteria based on changes in LM density were not predictive of treatment efficacy. CLINICAL TRIAL REGISTRATION: Registered at CNIL-CERB, Assistance publique hopitaux de Paris as "E-NETNET-L-E-CT" July 2018. No number was assigned. Approved by the Medical Ethics Review Board of University Medical Center Groningen.


Subject(s)
Liver Neoplasms , Neuroendocrine Tumors , Humans , Response Evaluation Criteria in Solid Tumors , Neuroendocrine Tumors/diagnostic imaging , Neuroendocrine Tumors/drug therapy , Retrospective Studies , Tomography, X-Ray Computed , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/drug therapy
2.
Can J Pain ; 2(1): 280-291, 2018.
Article in English | MEDLINE | ID: mdl-35005385

ABSTRACT

BACKGROUND: Young children are at risk for poorly managed pain after surgery, with significant negative consequence to their quality of life and health outcomes. Mobile applications offer a highly accessible, engaging, and interactive medium to improve pain assessment and management; however, they generally lack scientific foundation or support. AIMS: The aims of this study were to describe a successful parent-science partnership in the development and testing of Achy Penguin, a parent-developed iOS app to help assess and manage acute pain in young children, and to evaluate and refine the usability of Achy Penguin in young children with acute postoperative pain. METHODS: Three cycles of iterative usability testing were conducted with 20 4- to 7-year-old children (M = 5.8 years) in hospital who had recently undergone surgery (n = 6-7 children/cycle). Semistructured qualitative interviews were analyzed using simple content analysis. RESULTS: Feedback from children and further integration of evidence-based pediatric pain knowledge led to refinements in app pain assessment and management content, as well as app flow and functionality. Changes improved children's ease of use and understanding and satisfaction by simplifying language in app instructions and content, adding audio and pictorial instructions, and increasing the engagement, interactiveness, immersiveness, and general appeal of pain management strategies. CONCLUSIONS: This article showcases the value of collaborative partnerships between various stakeholders (parents, app developers, and researcher/health care providers) to address gaps in pediatric pain care. The Achy Penguin app shows promise for improving pain assessment and management in young children, although further evaluation of app effectiveness and implementation is warranted.


Contexte: Les jeunes enfants sont à risque d'une mauvaise prise en charge de leur douleur après une chirurgie, ce qui entraîne des conséquences négatives sur leur qualité de vie et leurs issues de santé. Les applications mobiles sont un médium très accessible, convivial et interactif pour améliorer l'évaluation et la prise en charge de la douleur. Toutefois, elles n'ont généralement pas de soutien ou de fondements scientifiques.Buts: Décrire un partenariat parent-science réussi qui avait pour but de développer et de tester Achy Penguin, une application iOS développée avec l'aide des parents pour faciliter l'évaluation et la prise en charge de la douleur aigue chez les jeunes enfants, ainsi que pour évaluer et perfectionner la facilité d'utilisation de Achy Penguin chez les jeunes enfants souffrant de douleur postopératoire aiguë.Méthodes: Trois cycles itératifs de tests portant sur la facilité d'utilisation ont été menés auprès de 20 enfants âgés de quatre à sept ans (M = 5,8 ans) à l'hôpital qui avaient été soumis à une chirurgie récemment (n = 6 ­ 7 enfants/cycle). Des entrevues qualitatives semi-structurées ont été analysées à l'aide d'une analyse de contenu simple.Résultats: La rétroaction provenant des enfants et une plus grande intégration des connaissances en matière de douleur pédiatrique fondées sur des données probantes ont donné lieu à une amélioration du contenu sur l'évaluation et la prise en charge de la douleurConclusions: Cet article démontre la valeur des partenariats collaboratifs entre différentes parties prenantes (parents, développeurs d'applications, chercheurs et prestataires de soins de santé) afin de combler les lacunes existantes dans les soins pédiatriques pour traiter la douleur. L'application Achy Penguin est prometteuse pour améliorer l'évaluation et la prise en charge de la douleur chez les jeunes enfants, bien qu'une évaluation plus poussée de son efficacité et de sa mise en oeuvre soit nécessaire.

3.
Gland Surg ; 7(6): 576-595, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30687630

ABSTRACT

Radiation therapy (RT) is an important component of breast cancer treatment that reduces local recurrence and improves survival after breast conservation. Breast conservation rates have increased significantly since the late 1980s and techniques have improved with greater awareness of the impact of radiation on the heart. An overview of randomized controlled trials of breast conservation using standard whole breast irradiation, whole breast hypofractionation, accelerated partial breast irradiation (APBI) and intraoperative radiation are reviewed. Selection criteria for breast conservation and the utility of adding a boost dose to the primary tumor site are reviewed. Modern dose constraints are documented and 10 different radiation techniques from the 1980s through to modern volumetric modulated arc therapy (VMAT) are compared for a patient where the breast and internal mammary nodes are treated. A radiation boost reduces the risk of a recurrence for most, but not all patients. Short courses of RT over 3-4 weeks are generally as effective as longer courses. Short-term follow-up of trials of APBI show promise for selected good prognosis subgroups. The role of intraoperative radiation remains controversial. In the last 30 years, there have been significant advances in radiation techniques. Modern radiotherapy equipment and techniques will reduce complications and improve survival rates.

4.
Eur J Paediatr Neurol ; 21(1): 202-213, 2017 Jan.
Article in English | MEDLINE | ID: mdl-28017556

ABSTRACT

BACKGROUND: Early onset dystonia (dyskinesia) and deafness in childhood pose significant challenges for children and carers and are the cause of multiple disability. It is particularly tragic when the child cannot make use of early cochlear implantation (CI) technology to relieve deafness and improve language and communication, because severe cervical and truncal dystonia brushes off the magnetic amplifier behind the ears. Bilateral globus pallidus internus (GPi) deep brain stimulation (DBS) neuromodulation can reduce dyskinesia, thus supporting CI neuromodulation success. METHODS: We describe the importance of the order of dual neuromodulation surgery for dystonia and deafness. First with bilateral GPi DBS using a rechargeable ACTIVA-RC neurostimulator followed 5 months later by unilateral CI with a Harmony (BTE) Advanced Bionics Hi Res 90 K cochlear device. This double neuromodulation was performed in series in a 12.5 kg 5 year-old ex-24 week gestation-born twin without a cerebellum. RESULTS: Relief of dyskinesia enabled continuous use of the CI amplifier. Language understanding and communication improved. Dystonic storms abated. Tolerance of sitting increased with emergence of manual function. Status dystonicus ensued 10 days after ACTIVA-RC removal for infection-erosion at 3 years and 10 months. He required intensive care and DBS re-implantation 3 weeks later together with 8 months of hospital care. Today he is virtually back to the level of functioning before the DBS removal in 2012 and background medication continues to be slowly weaned. CONCLUSION: This case illustrates that early neuromodulation with DBS for dystonic cerebral palsy followed by CI for deafness is beneficial. Both should be considered early i.e. under the age of five years. The DBS should precede the CI to maximise dystonia reduction and thus benefits from CI. This requires close working between the paediatric DBS and CI services.


Subject(s)
Athetosis/rehabilitation , Cerebellum/abnormalities , Cerebral Palsy/rehabilitation , Chorea/rehabilitation , Cochlear Implantation/instrumentation , Deafness/rehabilitation , Deep Brain Stimulation/instrumentation , Diseases in Twins/rehabilitation , Dystonia/rehabilitation , Globus Pallidus/physiopathology , Infant, Premature, Diseases/rehabilitation , Cerebral Palsy/physiopathology , Child , Child, Preschool , Chorea/physiopathology , Cochlear Implantation/rehabilitation , Combined Modality Therapy , Deafness/physiopathology , Diseases in Twins/physiopathology , Dystonia/physiopathology , Female , Follow-Up Studies , Humans , Infant , Infant, Newborn , Infant, Premature, Diseases/physiopathology , Male , Treatment Outcome
5.
Child Neuropsychol ; 22(3): 255-75, 2016.
Article in English | MEDLINE | ID: mdl-25704232

ABSTRACT

There is a limited amount of research that examines social-emotional functioning in children with Fetal Alcohol Spectrum Disorder (FASD), and the majority of it relies on parent and teacher reports of social impairments. Because these provide broad measures of social function, they fail to elucidate the underlying specific skills with which this group of children has difficulty. The current study examines emotion-recognition abilities in children with FASD, as it plays a central role in social interaction. Participants were 22 children with diagnosed FASD (ages 8-14), and age- and gender-matched typically developing controls. Tasks included measures of emotion recognition from three nonlinguistic modalities: facial expressions, emotional tone of voice, and body positioning and movement. Participant's parents completed measures of adaptive and behavioral function that were related to children's performance on aspects of emotion recognition. Overall, the results show that children with FASD have more difficulties with emotion recognition than typically developing age-matched peers, but these difficulties may not be clinically significant (e.g., smaller effect size) or may be specific to the age of the individual exhibiting the emotion (i.e., child vs. adult). These results are discussed in the context of previous studies.


Subject(s)
Cognition/physiology , Emotions/physiology , Fetal Alcohol Spectrum Disorders/psychology , Social Behavior , Adolescent , Case-Control Studies , Child , Female , Humans , Male , Neuropsychological Tests , Parents , Patient Positioning , Pregnancy
6.
Dev Med Child Neurol ; 58(2): 145-53, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26616635

ABSTRACT

AIM: Hyperkinetic movement disorders (HMDs) can be assessed using impairment-based scales or functional classifications. The Burke-Fahn-Marsden Dystonia Rating Scale-movement (BFM-M) evaluates dystonia impairment, but may not reflect functional ability. The Gross Motor Function Classification System (GMFCS), Manual Ability Classification System (MACS), and Communication Function Classification System (CFCS) are widely used in the literature on cerebral palsy to classify functional ability, but not in childhood movement disorders. We explore the concordance of these three functional scales in a large sample of paediatric HMDs and the impact of dystonia severity on these scales. METHOD: Children with HMDs (n=161; median age 10y 3mo, range 2y 6mo-21y) were assessed using the BFM-M, GMFCS, MACS, and CFCS from 2007 to 2013. This cross-sectional study contrasts the information provided by these scales. RESULTS: All four scales were strongly associated (all Spearman's rank correlation coefficient rs >0.72, p<0.001), with worse dystonia severity implying worse function. Secondary dystonias had worse dystonia and less function than primary dystonias (p<0.001). A longer proportion of life lived with dystonia is associated with more severe dystonia (rs =0.42, p<0.001). INTERPRETATION: The BFM-M is strongly linked with the GMFCS, MACS, and CFCS, irrespective of aetiology. Each scale offers interrelated but complementary information and is applicable to all aetiologies. Movement disorders including cerebral palsy can be effectively evaluated using these scales.


Subject(s)
Cerebral Palsy/diagnosis , Communication , Dystonia/diagnosis , Hyperkinesis/diagnosis , Motor Skills/physiology , Severity of Illness Index , Adolescent , Adult , Cerebral Palsy/classification , Cerebral Palsy/physiopathology , Child , Child, Preschool , Dystonia/classification , Dystonia/physiopathology , Female , Humans , Hyperkinesis/classification , Hyperkinesis/physiopathology , Male , Young Adult
7.
Clin Rheumatol ; 33(5): 615-21, 2014 May.
Article in English | MEDLINE | ID: mdl-24310107

ABSTRACT

This study was conducted to determine the predictors of foot ulceration occurring in patients with rheumatoid arthritis (RA) without diabetes. A multi-centre case control study was undertaken; participants were recruited from eight sites (UK). Cases were adults diagnosed with RA (without diabetes) and the presence of a validated foot ulcer, defined as a full thickness skin defect occurring in isolation on / below the midline of the malleoli and requiring > 14 days to heal. Controls met the same criteria but were ulcer naive. Clinical examination included loss of sensation (10g monofilament); ankle-brachial pressure index (ABPI); forefoot deformity (Platto); plantar pressures (PressureStat); RA disease activity (36 swollen/tender joint counts) and the presence of vasculitis. History taking included past ulceration/foot surgery; current medication and smoking status. Participants completed the Health Assessment Questionnaire (HAQ) and Foot Impact Scale. A total of 83 cases with 112 current ulcers and 190 ulcer naïve controls participated. Cases were significantly older (mean age 71 years; 95 % confidence interval [CI], 69-73 vs. 62 years, 60-64) and had longer RA disease duration (mean 22 years; 19-25 vs. 15, 13-17). Univariate analysis showed that risk of ulceration increases with loss of sensation; abnormality of ABPI and foot deformity. Plantar pressures and joint counts were not significant predictors. HAQ score and history of foot surgery were strongly associated with ulceration (odds ratio [OR] = 1.704, 95 % CI 1.274-2.280 and OR = 2.256, 95 % CI 1.294-3.932). Three cases and two controls presented with suspected cutaneous vasculitis. In logistic regression modelling, ABPI (OR = 0.04; 95 % CI, 0.01-0.28) forefoot deformity (OR = 1.14; 95 % CI, 1.08-1.21) and loss of sensation (OR = 1.22; 95 % CI, 1.10-1.36) predicted risk of ulceration. In patients with RA, ABPI, forefoot deformity and loss of sensation predict risk of ulceration but, in contrast with diabetes, raised plantar pressures do not predict risk.


Subject(s)
Arthritis, Rheumatoid/complications , Arthritis, Rheumatoid/diagnosis , Foot Ulcer/complications , Foot Ulcer/diagnosis , Aged , Case-Control Studies , Female , Foot Deformities/physiopathology , Humans , Incidence , Male , Middle Aged , Pressure , Quality of Life , Recurrence , Surveys and Questionnaires , Time Factors , United Kingdom
8.
Adv Child Dev Behav ; 45: 39-66, 2013.
Article in English | MEDLINE | ID: mdl-23865112

ABSTRACT

According to recent claims from behavior genetics, executive function (EF) is almost entirely heritable. The implications of this claim are significant, given the importance of EF in academic, social, and psychological domains. This paper critically examines the behavior genetics approach to explaining individual differences in EF and proposes a relational developmental systems model that integrates both biological and social factors in the development of EF and the emergence of individual differences in EF. Problems inherent to behavioral genetics research are discussed, as is neuroscience research that emphasizes the plasticity of the prefrontal cortex. Empirical evidence from research on stress, social interaction, and intervention and training demonstrates that individual differences in EF are experience-dependent. Taken together, these findings challenge the claim that EF is almost entirely genetic but are consistent with an approach that considers biological differences in the context of social interaction.


Subject(s)
Child Development/physiology , Developmental Biology/methods , Executive Function/physiology , Gene-Environment Interaction , Individuality , Interpersonal Relations , Prefrontal Cortex/physiology , Stress, Physiological/physiology , Child , Humans , Systems Theory
9.
Dev Med Child Neurol ; 55(6): 567-74, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23452222

ABSTRACT

AIM: The aim of this study was to examine the impact of dystonia aetiology and duration, contracture, and age at deep brain stimulation (DBS) surgery on outcome in a cohort of children with medically refractory, disabling primary, secondary-static, or secondary-progressive dystonias, including neurodegeneration with brain iron accumulation (NBIA). METHOD: Dystonia severity was assessed using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) motor score at baseline and 6 and 12 months postoperatively in a cohort of 70 consecutive children undergoing DBS between June 2005 and July 2011. RESULTS: Two children (3%) received unilateral DBS for hemidystonia and were excluded and five (7%) developed infections requiring part-DBS removal within 6 months, leaving 63 children (90%) undergoing bilateral DBS for follow-up (34 males, 29 females; mean age at surgery for the whole group 10y 4mo, SD 4y 2mo, range 1-14y). Seventeen children were classified with primary dystonia: mean age 12 years 11 months, SD 4 years 6 months range 4 years 6 months to 17 years 3 months; 28 as having secondary-static dystonia: mean age 10 years 2 months, SD 4 years 9 months (range 3y 3mo-20y); five as having secondary-progressive dystonia: mean age 8 years 11 months, SD 3 years 9 months (range 5y 5mo-13y 1mo); and 13 as having NBIA dystonia: mean age 10 years 2 months, SD 3 years 11 months (range 1-14y). Children with primary dystonias demonstrated greater improvements in BFMDRS motor score than those in the other aetiological categories (Kruskal-Wallis test, p<0.001), which correlated negatively with dystonia duration and more strongly still against the ratio of dystonia duration normalized to age at surgery (DD/AS ratio) at 1 year (Spearman's rank correlation coefficient 0.4752 and -0.599 respectively). A similar significant negative correlation was found in the secondary-static dystonia group between outcome at 1 year and DD/AS ratio (-0.461). Poorer outcome in secondary dystonia coincided with the absence of a period of normal motor development in comparison with the primary dystonia group. A significant improvement in BFMDRS motor score was seen in the NBIA group at 6, but not 12 months (Wilcoxon signed rank test p=0.028, p=0.85 respectively). No reduction in efficacy was seen in children with a musculoskeletal deformity at the time of surgery. CONCLUSION: Response to pallidal DBS in the treatment of dystonia declines with the proportion of life lived with dystonia in primary and secondary dystonia. Other intrinsic factors reduce the median magnitude of reduction in secondary dystonia after DBS. DBS should be offered early, preferably within 5 years of onset, to maximize benefits and reduce the childhood experience of dystonia, including musculoskeletal deformity. Other multidimensional assessments are required to understand how DBS improves the lives of children with dystonia.


Subject(s)
Deep Brain Stimulation/methods , Dystonia/therapy , Dystonic Disorders/therapy , Globus Pallidus , Motor Skills , Adolescent , Child , Child, Preschool , Deep Brain Stimulation/adverse effects , Dystonia/mortality , Dystonia/surgery , Dystonic Disorders/mortality , Female , Humans , Infant , Male , Psychomotor Performance , Severity of Illness Index , Survival Analysis , Time Factors , Treatment Outcome , Young Adult
10.
Lancet ; 380(9859): 2129-43, 2012 Dec 15.
Article in English | MEDLINE | ID: mdl-23245605

ABSTRACT

BACKGROUND: Measurement of the global burden of disease with disability-adjusted life-years (DALYs) requires disability weights that quantify health losses for all non-fatal consequences of disease and injury. There has been extensive debate about a range of conceptual and methodological issues concerning the definition and measurement of these weights. Our primary objective was a comprehensive re-estimation of disability weights for the Global Burden of Disease Study 2010 through a large-scale empirical investigation in which judgments about health losses associated with many causes of disease and injury were elicited from the general public in diverse communities through a new, standardised approach. METHODS: We surveyed respondents in two ways: household surveys of adults aged 18 years or older (face-to-face interviews in Bangladesh, Indonesia, Peru, and Tanzania; telephone interviews in the USA) between Oct 28, 2009, and June 23, 2010; and an open-access web-based survey between July 26, 2010, and May 16, 2011. The surveys used paired comparison questions, in which respondents considered two hypothetical individuals with different, randomly selected health states and indicated which person they regarded as healthier. The web survey added questions about population health equivalence, which compared the overall health benefits of different life-saving or disease-prevention programmes. We analysed paired comparison responses with probit regression analysis on all 220 unique states in the study. We used results from the population health equivalence responses to anchor the results from the paired comparisons on the disability weight scale from 0 (implying no loss of health) to 1 (implying a health loss equivalent to death). Additionally, we compared new disability weights with those used in WHO's most recent update of the Global Burden of Disease Study for 2004. FINDINGS: 13,902 individuals participated in household surveys and 16,328 in the web survey. Analysis of paired comparison responses indicated a high degree of consistency across surveys: correlations between individual survey results and results from analysis of the pooled dataset were 0·9 or higher in all surveys except in Bangladesh (r=0·75). Most of the 220 disability weights were located on the mild end of the severity scale, with 58 (26%) having weights below 0·05. Five (11%) states had weights below 0·01, such as mild anaemia, mild hearing or vision loss, and secondary infertility. The health states with the highest disability weights were acute schizophrenia (0·76) and severe multiple sclerosis (0·71). We identified a broad pattern of agreement between the old and new weights (r=0·70), particularly in the moderate-to-severe range. However, in the mild range below 0·2, many states had significantly lower weights in our study than previously. INTERPRETATION: This study represents the most extensive empirical effort as yet to measure disability weights. By contrast with the popular hypothesis that disability assessments vary widely across samples with different cultural environments, we have reported strong evidence of highly consistent results. FUNDING: Bill & Melinda Gates Foundation.


Subject(s)
Disability Evaluation , Health Status , Adolescent , Adult , Aged , Bangladesh , Empirical Research , Female , Health Surveys , Humans , Indonesia , Internet , Male , Middle Aged , Peru , Quality-Adjusted Life Years , Tanzania , United States , Wounds and Injuries , Young Adult
11.
Childs Nerv Syst ; 28(7): 1091-7, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22427261

ABSTRACT

BACKGROUND: The finite life of non-rechargeable batteries powering implantable pulse generators (IPG) necessitates their periodic replacement. Children receiving deep brain stimulation (DBS) may require frequent battery changes over their treatment lifetime. OBJECTIVES: We aimed to determine the battery life of IPGs used in pallidal DBS for the treatment of dystonia in children and young people. METHODS: We make use of a review of case notes of all children and young people undergoing DBS surgery at our institution from June 2005 to May 2010. RESULTS: A total of 54 children and young people underwent surgery on at least one occasion, with a total of 76 IPGs implanted. Replacement IPGs due to battery failure were required in 15 out of 54 (27.8%). The average time to battery failure was 24.5 ± 2.9 months (95% confidence interval), with a range of 13-39 months. Battery life was significantly longer in primary compared to subsequent IPGs. No difference in longevity was seen between different IPG devices. CONCLUSIONS: IPG battery life may be short in children and young people receiving treatment for dystonia. These findings highlight the potential benefits of the recently introduced rechargeable neurostimulators.


Subject(s)
Deep Brain Stimulation/instrumentation , Deep Brain Stimulation/methods , Dystonia/therapy , Electric Power Supplies , Globus Pallidus/physiology , Adolescent , Child , Child, Preschool , Electrodes, Implanted , Female , Follow-Up Studies , Functional Laterality , Humans , Male , Retrospective Studies , Time Factors , Treatment Outcome
12.
J Immunol ; 182(7): 4439-47, 2009 Apr 01.
Article in English | MEDLINE | ID: mdl-19299745

ABSTRACT

We describe a simple iterative approach to augment TCR affinity, which we studied using a myelin oligodendrocyte glycoprotein-specific TCR. We hypothesized that single amino acid modifications in TCR CDR3 could enhance TCR sensitivity through focal interactions with antigenic peptide while minimizing the risk of cross-reactivity observed previously in TCR more broadly mutagenized using in vitro evolution techniques. We show that this iterative method can indeed generate TCR with Ag sensitivity 100-fold greater than the parental receptor and can endow TCR with coreceptor independence. However, we also find that single amino acid mutations in the CDR3 can alter TCR fine specificity, affecting recognition requirements for Ag residues over most of the length of the MHC binding groove. Furthermore, minimal changes in surface-exposed CDR3 amino acids, even the addition of a single hydroxyl group or conversion of a methyl or sulfhydryl moiety to a hydroxyl, can confer modified Ag-specific TCR with new self-reactivity. In vivo modeling of modified TCR through retroviral TCR gene transfer into Rag(-/-) mice confirmed the biological significance of these altered reactivities, although it also demonstrated the feasibility of producing Ag-specific, positively selecting, coreceptor-independent receptors with markedly increased Ag sensitivity. These results affirm the possibility of readily generating affinity-enhanced TCR for therapeutic purposes but demonstrate that minimal changes in TCR CDR3 structure can promote self reactivity and thereby emphasize the importance of caution in validating receptors with even subtle alterations before clinical application.


Subject(s)
Autoimmunity/immunology , Myelin-Associated Glycoprotein/immunology , Receptors, Antigen, T-Cell/genetics , T-Lymphocytes/immunology , Amino Acid Sequence , Animals , Enzyme-Linked Immunosorbent Assay , Flow Cytometry , Interleukin-2/biosynthesis , Mice , Mice, Transgenic , Molecular Sequence Data , Mutation , Myelin Proteins , Myelin-Oligodendrocyte Glycoprotein , Transduction, Genetic
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