TAP Device
Research type
Research Study
Full title
A pilot study to assess the feasibility of measuring C-peptide and autoantibodies using a transdermal blood collection device in children and adults with type 1 diabetes
IRAS ID
243484
Contact name
Rachel Besser
Contact email
Sponsor organisation
University of Oxford
Duration of Study in the UK
0 years, 5 months, 1 days
Research summary
Research Summary
Diabetes is the most common chronic disease in childhood after asthma, with over 16,000 children and young people (0-16 years) attending paediatric diabetes centres in England alone (NICE 2004).
Despite advances in our understanding of the condition, many fundamental questions remain unanswered. A key area of interest for the management of paediatric diabetes is in the assessment of an individual’s beta-cell function, and therefore the body’s own ability to secrete insulin. One promising method of assessment of beta-cell function is by measurements of C-peptide(CP)from blood samples.
We need a way of collecting blood that is virtually painless, reliable, safe, provides at least 50 uL of blood and plasma, is self-contained and convenient such that it can be used at home and in the clinic.
A new method of measuring blood has become available, using a ‘TAP’ device. The TAP device is a blood specimen collection device that uses a combination of two technologies, capillary action and vacuum extraction, to obtain 100 μL of capillary whole blood.
Measurement with the TAP device has significant potential benefit for use in diabetes care, allowing a practical, minimally invasive and accurate method of assessing endogenous insulin production (CP) in an outpatient setting. This is particularly relevant to children, where venous blood sampling is a major barrier to recruitment into and ascertainment in research studies, in particular intervention studies close to diagnosis aiming to preserve beta cell function, and which require frequent serial monitoring of CP.
The study will take place at the Oxford Children’s Hospital, The John Radcliffe, as well as the Oxford Centre for Diabetes Endocrinology and Metablism (OCDEM), Churchill Hospital, Oxford.
Venous and TCC samples will be collected (one one occasion) from 60 children and adults with T1D (diagnosed under the age of 30), and 20 healthy, adult, controls.Summary of Results
Abstract
Objective: C-peptide and islet autoantibodies are key type 1 diabetes (T1D) biomarkers, typically requiring venous sampling, which limit their utility. We assessed transdermal capillary blood plasma (TCB) collection as a practical alternative.Research design and methods: Ninety-one individuals (71 T1D, 20 controls; T1D: aged median 14.8years[interquartile range 9.1-17.1]; diabetes duration 4.0years[1.5-7.7]; controls aged 42.2years[38.0-52.1]) underwent a contemporaneous venous and TCB sample for measurement of plasma C-Peptide. T1D participants also provided venous serum and plasma, and TCB plasma for measurement of autoantibodies to glutamate decarboxylase (GADA), islet antigen-2 (IA-2A), and zinc transporter 8 (ZnT8RA/WA). The ability of TCB plasma to detect significant endogenous insulin secretion (venous plasma C-Peptide ≥ 200pmol/L) was compared along with agreement in levels using Bland-Altman. Venous serum was compared with venous and TCB plasma for detection of autoantibodies using established thresholds. Acceptability was assessed by age-appropriate questionnaire.
Results: Transdermal sampling took a mean of 2.35minutes (SD 1.49). TCB C-Peptide showed good agreement to venous plasma (mean venous ln(C-peptide) – TCB ln(C-peptide) = 0.008, 95% CI (-0.23, 0.29), and the measures were highly correlated (r=0.996), with 100%(36/36) sensitivity/100%(50/50) specificity to detect venous C-Peptide ≥200pmol/L. Where venous serum in multiple autoantibody positive TCBl plasma agreed in 22/32 (sensitivity 69%), comparative specificity was 35/36 (97%). TCB was preferred to venous sampling (T1D: 63% vs 7%; 30% undecided).
Conclusions: Transdermal capillary testing for C-Peptide is a sensitive, specific, acceptable and practical alternative to venous sampling, TCB sampling for islet autoantibodies needs further assessment.
REC name
West Midlands - Edgbaston Research Ethics Committee
REC reference
19/WM/0202
Date of REC Opinion
30 Aug 2019
REC opinion
Further Information Favourable Opinion