Search the Community
Showing results for tags 'predictive'.
Found 3 results
Jefferson Adams posted an article in Celiac Disease Diagnosis, Testing & TreatmentCeliac.com 06/04/2010 - A team of researchers recently set out to assess the positive predictive value of blood test screening for possible cases of celiac disease. The team included Peter Toftedal, Christian Nielsen, Jonas Trolle Madsen, Kjell Titlestad, Steffen Husby, and Søren Thue Lillevang. They are affiliated with the Hans Christian Andersen Children's Hospital, and the Department of Clinical Immunology of Odense University Hospital in Denmark. P. Toftedal and Ch. Nielsen made contributions to the final published article. In deciding which possible celiac disease cases might require duodenal biopsy, doctors rely mainly on tests for celiac disease antibodies, such as immunoglobulin A (IgA) anti-tissue transglutaminase (anti-tTG), IgA endomysium antibody (EMA), IgA and IgG anti-gliadin antibodies (IgA and IgG AGA). For their study, the research team wanted to assess the diagnostic quality of blood testing for possible cases of celiac disease. They did this by performing celiac disease blood tests (IgA and IgG AGA, anti-tTG and EMA) on 11,915 subjects. They then combined the serological data with clinical data and duodenal biopsy results using a unique Danish personal identification number. They found that positive predictive value (PPV) fluctuated in accordance with various combinations of positive celiac disease antibodies. They found the highest predictive value (97.6%) when results for IgA and IgG AGA, anti-tTG and EMA antibodies were all positive. The team used a logistic regression model at initial blood screening to predict the probability of later biopsy-proven celiac disease in relation to concentrations of IgA AGA and anti-tTG. They found that anti-tTG concentrations correlated strongly with EMA positivity, number of additional positive antibodies, and higher PPV. The anti-tTG concentration upon first blood screening for celiac disease was highly informative in relation to EMA positivity, number of additional celiac disease specific antibodies and PPV. Lastly, results for the high-risk patient group showed that anti-tTG and IgA AGA concentrations at initial serological screening accurately predicted probability of future biopsy-proven celiac disease. Source: Clin Chem Lab Med 2010;48:685–91. DOI: 10.1515/CCLM.2010.136
Scott Adams posted an article in Celiac Disease Diagnosis, Testing & TreatmentJ Pediatr 2000;137:356-366. Celiac.com 10/10/2000 - Researchers from the University of Colorado School of Medicine, Denver have determined that transglutaminase (TG) antibodies in asymptomatic children are 70% to 83% predictive of biopsy evidence of celiac disease, and may identify children who are likely to develop the disease, as reported in the September issue of the Journal of Pediatrics. Dr. Edward J. Hoffenberg and colleagues studied 30 asymptomatic children who had a genetic risk for celiac disease to determine the relationships between TG antibody titer, small bowel histology, growth, and clinical features of celiac disease. Using the Marsh System to grade the small bowel histology Dr. Hoffenberg that out of 30 children with a positive TG antibody test result - 21 (70%) had definite (Marsh score 2 or 3) and 4 (13%) had possible (Marsh score 1) biopsy evidence of celiac disease, further, the TG antibody titer correlated with Marsh score.
Vijay Kumar, M.D., Research Associate Professor at the University of Buffalo and President and Director of IMMCO Diagnostics: Not really. It is not true that the serological methods have lower predictive value in children less than two years of age. In all the studies that we did, there was 100% correlation of the EMA to the disease activity irrespective of the age. Karoly Horvath, M.D., Ph.D., Associate Professor of Pediatrics; Director, Peds GI & Nutrition Laboratory; University of Maryland at Baltimore: There are age dependent changes in several blood parameters during childhood. It is well known that immunoglobulin levels depend on the age of children. E.g. the IgA class immunoglobulins reach the adult level only by 16 years of age, and the blood level of IgA immunoglobulins is only 1/5th of adult value below two years of age. A large study from Europe (Brgin-Wollf et al. Arch Dis Child 1991;66:941-947) showed that the endomysium antibody test is less specific and sensitive in children below two years of age. They found that the sensitivity of the EmA test decreased from 98% to 88% in children younger than 2 years of age. It means that 12% of their patients with celiac disease, who were younger than two years of age, did not have an increase in their endomysium antibody levels.