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Diagnostic tools and technology transfer

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Presentation on theme: "Diagnostic tools and technology transfer"— Presentation transcript:

1 Diagnostic tools and technology transfer
MediCel Workshop

2 In vitro diagnosis of coeliac disease
The serologic in vitro diagnosis of coeliac disease is based on the following tests: tTG DPG AEA AGA In addition, recently, genetic tests have also become available on the market. Elfid

3 Technologies Available technologies can be adapted to any lab size and needs, both in terms of financial and operative resources ELISA tTG, AGA, DPG IFI AEA Dot-Blot tTG, AGA PCR HLA Elfid

4 Tissue transglutaminase
Tissue transglutaminase is the auto-antigen responsible for AEA positivity in coeliac disease. The introduction of tTG is a milestone in the knowledge and in vitro diagnosis of CD. tTG based kits are the reference method for the in vitro diagnosis of coeliac disease Both ELISA and Rapid tests are available Elfid

5 tTG - Elisa kits ELISA tTG IgA is the reference method/test for in vitro diagnosis of coeliac disease Higher sensitivity than AEA IgG should be used in case of Total IgA deficiency mainly Kits on the market show different sensitivity and specificity values depending on the chosen antigen and/or diagnostic approach Need of instrumentation can be limited to an Elisa reader Elfid

6 tTG Workshop 2009 Elfid

7 tTG - Rapid test Negative results Positive results
Sample addition Reading window Red Latex-tTG complex Blue Latex tTG Anti-tTG Other antibodies Negative results Positive results Elfid

8 Rapid tests - Literature

9 Deamidated Gliadin Peptides
Newly introduced in the market More sensitive and specific than AGA Useful in suspected CD patients Limited use in patients with other gastrointestinal disorders Might be a complement to tTG assays in young children Useful in GFD follow-up Elfid

10 Elfid

11 Antiendomysium test Highest specificity Sensitivity lower than tTG
IFA technology normally available in all labs Raising cost of and limited availability of animal substrate HUC is an alternative Elfid

12 Conclusions tTG autoantibodies is still the best test for CD.
tTG autoantibody assays vary greatly qualitatively. IgG tTG are not as reliable as IgA in screening procedures. The introduction of DPG IgG might be helpful in some cases. Children younger than 2 yrs of age GFD follow up Total Serum IgA deficiency Both ELISA and Rapid test are available. Limited need of instrumentation. Elfid

13 Genetic tests and Coeliac Disease
During the last years, many papers have been published about genetics of CD. Both HLA and non-HLA have been extensively studied. An increased number of patients is today subjected to genetic tests. Elfid

14 Present Situation Request of genetic tests for CD is growing up rapidly. Detection of DQ2 a/o DQ8 heterodimers only does no longer meet customers' needs. Knowledge of DR status is now a MUST and is required in medium/small centres dealing with Coeliac Disease, not only reference centres. Elfid

15 What are the requirements ?
Complete HLA status: DQ DR Identification of patients at risk. Possibility to exclude some patients before proceeding to a further testing for risk definition. Elfid

16 What we look for Most common haplotypes associated to Coeliac Disease
Coded by alleles In linkage disequilibrium with DQ2 DQA1*05/DQB1*02 DR3 DQA1*0201/DQB1*02 DR7 DQ8 DQA1*03/DQB1*0302 DR4 DQ7 DQA1*05/DQB1*0301 DR11 Elfid

17 Two level-approach First Level: screening (e.g. Eu-Gen)
DQ 2 and DQ8 Selection of patients requiring additional tests Second level: definition of predisposition (e.g. Eu-Gen Risk) DR (3, 4, 7, 11) and DQ (2, 8) genotypes Complete haplotypes DQB1*02 status Relative risk to develop Coeliac Disease Elfid

18 First level approach DQ2 DQ2/DQ8 DQ8 Non DQ2/8 Inclusion/Exclusion kit
2 mixes containing specific primers for: DQA1*05, DQB1*02, DRB1*04, DQB1*0302. Positive response to any allele: indicates need of further testing Negative response: low or minimal risk. Further tests are not required Mix 4 DQA1*05 DQB1*0302 Mix 6 DQB1*02 DR4 Non DQ2/8 DQ2 DQ8 DQ2/DQ8 Elfid

19 Second level approach 8 mixes with specific primers providing a combined results allowing: Identification of DQ and DR genotypes Definition of complete haplotypes Definition of DQB1*02 status (homo / heterozygosis) if present Definition of relative risk for any tested patient. Elfid

20 Eu-Gen Risk Elfid

21 Genetic test for Coeliac Disease
Technology available Complete information about the patient’s status Easy interpretation of results Experienced technicians are required for proper test performance. Elfid

22 Elfid

23 CD-MEDICS Overall Objectives
Development of disposable microchip for screening of coeliac disease in a portable/hand-held device carrying out multi-analyte tests Simultaneous detection of coeliac disease associated autoantibodies (DPG and tissue transglutaminase) and HLA-DQ2 and DQ8 genes. The device will have embedded communication abilities for result storage and easy follow-up, management and monitoring of the patient’s response to withdrawal of gluten from the diet. Elfid

24 Techniques Applied Elfid 2

25 Clinically Relevant Outcome
Population based screening, and/or screening of high-risk groups and based on the data regarding HLA status, design individually tailored dietary options. Monitoring for adherence to the appropriate gluten-free diet either at their GP’s office, or from their own home, with data being communicated directly to their electronic medical record. Neonatal screening in risk groups to identify newborns who may develop coeliac disease. Elfid

26 Features of the system Standardisation of calibrators
Levels of IgA and IgG anti-tTG antibodies measured in many patient samples. To establish absolute concentrations in terms of ng/mL rather than arbitrary units. IgA and IgG anti-tTG sera of coeliac disease patients to be used as standard calibrator/controls. Clinical evaluation to see if specificity and sensitivity can be improved. Elfid

27 CD MEDICS instrument connectivity
Hospital Information System Laboratory Workstation CD MEDICS Instrument Demographics Requests/ Replies Laboratory Orders / Observations Elfid

28 Thank you for your attention

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