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Protocol - Celiac Sprue - Assay

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Protocol Name from Source:

This section will be completed when reviewed by an Expert Review Panel.

Availability:

Publicly available

Description:

This protocol uses two-step serologic testing of serum to determine the presence of antihuman recombinant tissue transglutaminase (TTG) and endomysial antibody (EMA). When both tests are positive, the subject is notified that they are positive for celiac sprue. The test is most accurate if patients have not been on a gluten-free diet in the weeks leading up to the assay, as a gluten-free diet may cause the serologic assays to normalize in many patients.

Protocol:

Exclusion Criteria

Persons will be excluded from this component if they:

  • report that they have hemophilia, or
  • report that they have received cancer chemotherapy in the last 4 weeks.

SP= Sample Person.

1. Do you have hemophilia?

[ ] 1 Yes

[ ] 2 No

[ ] 7 Refused

[ ] 9 Don't Know

If the SP answers "Yes," the SP is excluded from the blood draw.

If SP answers "No" or "Don't Know," blood is drawn from the SP.

2. Have you received cancer chemotherapy in the past 4 weeks, or do you anticipate such therapy in the next 4 weeks?

[ ] 1 Yes

[ ] 2 No

[ ] 7 Refused

[ ] 9 Don't Know

If the SP answers "Yes," the SP is excluded from the blood draw.

If SP answers "No" or "Don't Know," blood is drawn from the SP.

Note from the Gastrointestinal WG: The investigator should record the reason a person is excluded from the blood draw.

Venipuncture Procedures

Venipuncture should generally be performed using the median cubital, cephalic, or basilic veins in the left arm unless this arm is unsuitable. If the veins in the left arm are unsuitable, look for suitable veins on the right arm. If the veins in the antecubital space on both arms are not suitable, then look for veins in the forearm or dorsal side of the hand on the left arm/hand and then the right arm/hand.

For a full description of phlebotomy procedures, please refer to Chapter 4 in the downloadable PDF of the 2009–2010 National Health and Nutrition Examination Survey (NHANES) Laboratory Procedures Manual available here: [alink[NHANES_2009-2010_LabManual.pdf|NHANES 2009-2010 Lab Manual]]

Recording the Results of the Venipuncture Procedure

Immediately after completing the venipuncture, record the results of the blood draw, the reasons for a tube not being drawn according to the protocol, and any comments about the venipuncture.

For a full description of blood processing procedures, please refer to Chapter 8 in the downloadable PDF of the 2009–2010 National Health and Nutrition Examination Survey (NHANES) Laboratory Procedures Manual available here: [alink[NHANES_2009-2010_LabManual.pdf|NHANES 2009-2010 Lab Manual]]

The serum processing protocol is displayed in Exhibit 8.6.

Laboratory Assay

Note from the Gastrointestinal WG: Although there is not a standardized assay, there are a number of different kits that are appropriate to measure the concentration of TTG and EMA in serum. Once an assay is chosen for a particular study, the WG recommends that no changes in the protocol be made over the course of the study. To aid comparability, the Gastrointestinal WG recommends that the investigator record the make and manufacturer of equipment used and the repeatability and coefficients of variation for the assay.

Reference Intervals

TTG:
19 Units or less = Negative
20–30 Units = Weak Positive
31 Units or greater = Moderate to Strong Positive

EMA: < 1:10

Personnel and Training Required

A laboratory technician or phlebotomist who is trained and found to be competent (i.e., tested by an expert) in the conduct of bioassays.

Equipment Needs

Phlebotomy supplies, laboratory to perform assays

Requirements

Requirement CategoryRequired
Average time of greater than 15 minutes in an unaffected individualNo
Major equipmentNo
Specialized requirements for biospecimen collectionNo
Specialized trainingNo

Mode of Administration

Self-administered

Life Stage:

Child, Adolescent, Adult

Specific Instructions:

It is important that the patients screened with this laboratory assay are eating a diet that contains dietary sources of gluten in order for the assay to be most accurate. Sources of dietary gluten include the grains wheat, rye, and barley. The Gastrointestinal Working Group (WG) also recommends performing the immunoglobulin A (IgA) and immunoglobulin G (IgG) antibody tests for more sensitivity. The National Health and Nutrition Examination Survey (NHANES) uses red-top tubes to collect 0.5 ml serum for the antihuman recombinant tissue transglutaminase (TTG)/ endomysial antibody (EMA) bioassay. However, the Gastrointestinal Working Group recommends consulting the laboratory that will perform the bioassay regarding the appropriate collection tubes to use.
Research Domain Information

Release Date:

December 13, 2010

Definition

This is a two-step serologic measure to determine whether a person is positive for celiac sprue, also known as gluten-sensitive enteropathy.

Purpose

The purpose of this measure is to determine the presence of celiac disease, an intolerance to dietary glutens that has protean manifestations. Surveys in other countries have found celiac sprue in about 0.5 percent to 1.0 percent of the population. Celiac sprue may well be as common in the United States, but it has not been adequately examined.

Selection Rationale

The National Health and Nutrition Examination Survey (NHANES) 2009-2010 protocol was selected as the best practice methodology and is one of the most widely used research protocols.

Language

English

Standards

StandardNameIDSource
Common Data Elements (CDE)Serum Celiac Disease Assay Laboratory Finding Result3163027CDE Browser
Logical Observation Identifiers Names and Codes (LOINC)Celiac sprue assay proto62957-6LOINC

Process and Review

This section will be completed when reviewed by an Expert Review Panel.

Source

Centers for Disease Control and Prevention (CDC). National Center for Health Statistics (NCHS). National Health and Nutrition Examination Survey Questionnaire. Laboratory Procedures Manual. Hyattsville, MD: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, 2009-2010.

General References

Dieterich, W., Ehnis, T., Bauer, M., Donner, P., Volta, U., Riecken, E. O., & Schuppan, D. (1997). Identification of tissue transglutaminase as the autoantigen of celiac disease. National Medicine, 3(7), 797–801.

Dieterich, W., Laag, E., Schopper, H., Volta, U., Ferguson, A., Gillett, H., Riecken, E. O., & Schuppan, D. (1998). Autoantibodies to tissue transglutaminase as predictors of celiac disease. Gastroenterology, 115(6), 1317–1321.

Green, P. H., Rostami, K., & Marsh, M. N. (2005). Diagnosis of coeliac disease. Best Practice and Research Clinical Gastroenterology, 19(3), 389–400.

Protocol ID:

190301

Variables:

Export Variables
Variable NameVariable IDVariable DescriptionVersiondbGaP Mapping
PX190301_HemophiliaPX190301010000Do you have hemophilia?4Variable Mapping
PX190301_ChemotherapyPX190301020000Have you received cancer chemotherapy in the past four weeks or do you anticipate such therapy in the next four weeks?4N/A
PX190301_Exclusion_CriteriaPX190301030000Exclusion Criteria4N/A
PX190301_Blood_Draw_DonePX190301040100Was blood drawn?4Variable Mapping
PX190301_Blood_Draw_SamplePX190301040200Was full sample obtained?4Variable Mapping
PX190301_Blood_Draw_CommentsPX190301040300Record any comments about the blood draw, including any reasons for the tube not being drawn according to the protocol.4Variable Mapping
PX190301_Sample_CommentsPX190301050000Record any comments about the sample during processing.4Variable Mapping
PX190301_Assay_Type_TTGPX190301060000Record the type of assay used to perform the determination of tissue transglutaminase antibody.4N/A
PX190301_Equipment_Make_TTGPX190301070100Make of the equipment used to perform the determination of tissue transglutaminase antibody4N/A
PX190301_Equipment_Manufacturer_TTGPX190301070200Manufacturer of the equipment used to perform the determination of tissue transglutaminase antibody.4N/A
PX190301_Assay_Repeatability_TTGPX190301080000Repeatability of the assay for tissue transglutaminase antibody4N/A
PX190301_Coefficient_Of_Variation_TTGPX190301090000Coefficient of variation for the assay for tissue transglutaminase antibody4N/A
PX190301_TTG_Assay_ResultsPX190301100000Results of tissue transglutaminase antibody assay4N/A
PX190301_Assay_Type_EMAPX190301110000Record the type of assay used to perform the determination of endomysial antibody titer4N/A
PX190301_Equipment_Make_EMAPX190301120100Make of the equipment used to perform the determination of endomysial antibody antibody titer4N/A
PX190301_Equipment_Manufacturer_EMAPX190301120200Manufacturer of the equipment used to perform the determination of endomysial antibody antibody titer4N/A
PX190301_Assay_Repeatability_EMAPX190301130000Repeatability of the assay for endomysial antibody titer4N/A
PX190301_Coefficient_Of_Variation_EMAPX190301140000Coefficient of variation for the assay for endomysial antibody titer4N/A
PX190301_EMA_Assay_ResultsPX190301150000Results of endomysial antibody antibody titer4N/A