Improved efficacy by using the pTnT-rhtTG plasmid for the detection of celiac disease specific tissue transglutaminase autoantibodies in radioligand binding assays.

Abstract

BACKGROUND:

Tissue transglutaminase (tTG) autoantibodies are serological markers for celiac disease. The aim was to study the efficacy of the pTnT-rhtTG plasmid and subsequent diagnostic accuracy of tTG autoantibodies for childhood celiac disease using radioligand binding assays.

METHODS:

Coupled in vitro transcription and translation of tTG were performed by pTnT-rhtTG as well as by the pGEMt Easy-rhtTG vectors using the TNT SP6 Coupled Reticulocyte Lysate System in the presence of [³⁵S] methionine. Sera from 190 celiac disease children and 74 controls were measured for tTG autoantibodies in two separate radioligand binding assays using anti-human IgA agarose and protein A sepharose beads for the detection of IgA-tTG and IgG-tTG, respectively.

RESULTS:

Median incorporation of [³⁵S] methionine into the pTnT-rhtTG was 26% compared to 16% for the pGEMt Easy-rhtTG plasmid (p = 0.0016). Using pTnT-rhtTG (as compared to pGEMt Easy-rhtTG), sensitivities were IgA-tTG = 96.3% (95.7%) and IgG-tTG = 95.8% (97.3%) and specificities were IgA-tTG = 91.9% (90.5%) and IgG-tTG = 94.6% (98.4%). According to receiver operator characteristics for the pTnT (pGEMt Easy) assays, area under the curves were IgA-tTG = 98.4% (98.4%) and IgG-tTG = 97.7% (97.2%), respectively.

CONCLUSION:

The pTnT-rhtTG plasmid increased the efficacy of tTG antigen usage without reducing the diagnostic accuracy of IgA-tTG and IgG-tTG for childhood celiac disease. The pTnT-rhtTG plasmid is therefore recommended over the pGEMt Easy-rhtTG for the assessment of IgA-tTG and IgG-tTG using radioligand binding assays.

• Authors: Jennifer Kjellerås, Fariba Vaziri-Sani, Daniel Agardh
• Journal: Scandinavian journal of clinical and laboratory investigation (Scand J Clin Lab Invest) Vol. 71 Issue 8 Pg. 701-4 (Dec 2011) ISSN: 1502-7686 [Electronic] England
• PMID: 21961813 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Anti-Idiotypic
• Antigens, Neoplasm
• Autoantibodies
• Biomarkers
• Staphylococcal protein A-sepharose
• Sulfur Radioisotopes
• anti-IgA
• Sepharose
• Methionine
• Transglutaminases

Topics

• Adolescent
• Antibodies, Anti-Idiotypic (immunology, metabolism)
• Antigens, Neoplasm (blood, immunology)
• Autoantibodies (blood, immunology)
• Biomarkers (blood)
• Case-Control Studies
• Celiac Disease (blood, diagnosis, immunology)
• Cell-Free System (metabolism)
• Child
• Child, Preschool
• Female
• Humans
• Infant
• Male
• Methionine (analysis, metabolism)
• Plasmids (chemistry, immunology)
• Protein Binding
• ROC Curve
• Radioligand Assay
• Reticulocytes (metabolism)
• Sepharose (analogs & derivatives, metabolism)
• Sulfur Radioisotopes (analysis, metabolism)
• Sweden
• Transglutaminases (blood, immunology)
• Young Adult