TY - CHAP
T1 - Feasibility and acceptability of islet autoantibody testing by home capillary blood sampling
AU - Liu, Yuk-Fun
AU - Rafkin, Lisa
AU - Matheson, Della
AU - Steck, Andrea K.
AU - Yu, Liping
AU - Henderson, Courtney
AU - David, Boulware
AU - Bingley, Polly
PY - 2016/6/1
Y1 - 2016/6/1
N2 - Offering a simple and effective method for islet autoantibody (AAb) screening carried out at home could facilitate recruitment into large-scale type 1 diabetes (T1D) prevention studies. We evaluated the feasibility of self-collection of capillary blood samples (CBS) in relatives of individuals with T1D, enrolled via the TrialNet Pathway to Prevention Study. Sample collection kits were sent with instructions (also available as an online video) and a questionnaire. A minimum blood volume of 200µl was requested for detection of serum AAb to glutamic acid decarboxylase (GADA), islet antigen 2 (IA-2A) and insulin (IAA), with zinc transporter 8 (ZnT8A) tested if any of these AAb were positive. Successful collection was defined as sufficient volume and quality to allow definitive AAb results, including confirmation of positive results by repeat assay.
In 245 individuals who returned samples, median age was 12 (range 1-49) years with 51% males, 33% ≤ 8 years, 41% 9-18 years and 26% >18 years. At time of analysis, 194 (97%) samples were considered successful for GADA and IA-2A screens, 163 (82%) for IAA and 162 (81%) for a complete AAb screen. Upper 90% confidence bounds for failures rates were 5.2% for combined GADA, IA-2A and ZnT8A assays, and 22.5% for IAA assay.
In 216 questionnaires completed by adults, for themselves or on behalf of a child, 93 individuals (43%) considered CBS collection uncomfortable or painful. Nonetheless, 178 families (82%) preferred home CBS over outpatient venous sampling, 89% ≤8 years; 83% aged 9-18 years and 74% >18 years. The perceived difficulty of collecting CBS did not affect failure rate.
Home collection of CBS for islet autoantibody testing is feasible and considered preferable to venous testing by families of people with T1D. Although, using current assays, some individuals with IAA alone may be missed, the method promises sensitive detection of GADA, IA-2A and ZnT8A and therefore of high risk, multiple AAb positive relatives potentially eligible for prevention trials.
AB - Offering a simple and effective method for islet autoantibody (AAb) screening carried out at home could facilitate recruitment into large-scale type 1 diabetes (T1D) prevention studies. We evaluated the feasibility of self-collection of capillary blood samples (CBS) in relatives of individuals with T1D, enrolled via the TrialNet Pathway to Prevention Study. Sample collection kits were sent with instructions (also available as an online video) and a questionnaire. A minimum blood volume of 200µl was requested for detection of serum AAb to glutamic acid decarboxylase (GADA), islet antigen 2 (IA-2A) and insulin (IAA), with zinc transporter 8 (ZnT8A) tested if any of these AAb were positive. Successful collection was defined as sufficient volume and quality to allow definitive AAb results, including confirmation of positive results by repeat assay.
In 245 individuals who returned samples, median age was 12 (range 1-49) years with 51% males, 33% ≤ 8 years, 41% 9-18 years and 26% >18 years. At time of analysis, 194 (97%) samples were considered successful for GADA and IA-2A screens, 163 (82%) for IAA and 162 (81%) for a complete AAb screen. Upper 90% confidence bounds for failures rates were 5.2% for combined GADA, IA-2A and ZnT8A assays, and 22.5% for IAA assay.
In 216 questionnaires completed by adults, for themselves or on behalf of a child, 93 individuals (43%) considered CBS collection uncomfortable or painful. Nonetheless, 178 families (82%) preferred home CBS over outpatient venous sampling, 89% ≤8 years; 83% aged 9-18 years and 74% >18 years. The perceived difficulty of collecting CBS did not affect failure rate.
Home collection of CBS for islet autoantibody testing is feasible and considered preferable to venous testing by families of people with T1D. Although, using current assays, some individuals with IAA alone may be missed, the method promises sensitive detection of GADA, IA-2A and ZnT8A and therefore of high risk, multiple AAb positive relatives potentially eligible for prevention trials.
KW - islet autoantibodies
KW - capillary blood sampling
UR - http://diabetes.diabetesjournals.org/content/65/Supplement_1
M3 - Meeting abstract
VL - 65
BT - Diabetes
ER -