Ermarth et al evaluated pediatric patients for celiac disease (CD). They developed a CART analysis for identifying children at increased risk for the disease. The authors are from the University of Utah.
Patient selection: age <= 18 years
Parameters:
(1) serum IgA antibodies to TTG (tissue transglutaminase)
(2) age in years
(3) sex
|
IgA TTG
|
Age
|
Sex
|
Percent CD
|
|
< 61units
|
NA
|
NA
|
4%
|
|
>= 61
|
>= 8
|
NA
|
92%
|
|
>= 61
|
< 8
|
male
|
79%
|
|
>= 61
|
< 8
|
female
|
86%
|
The serum IgA-TTG was the key diagnostic criteria, especially if persistently high.
Assay: INOVA Diagnostics with upper limit of normal of 19.
ratio of patient's IgA TTG concentration to upper limit of normal (ULN) =
= (patient's serum IgA TTG) / ULN
A ratio <= 1 indicates a very low risk of celiac disease.
A ratio of 2 is associated with a 20% risk of celiac disease (according to Figure 1; the cutoff of 61 units is about 3.2 times the ULN).
A ratio >= 7 is associated with near 100% risk of celiac disease.
Additional risk factors:
(1) trisomy 21 (odds ratio 2.6)
(2) type 1 diabetes (odds ratio 7.5)
Limitations:
• Inability to form IgA would cause a false negative and duodenal biopsy is recommended.
