Transglutaminase antibodies in children with a genetic risk for celiac disease.

OBJECTIVES: The transglutaminase (TG) antibody test is accurate in identifying celiac disease in symptomatic children. We sought to determine the positive predictive value of this test in asymptomatic children at genetic risk for celiac disease. STUDY DESIGN: Asymptomatic children with a genetic risk for celiac disease were studied to investigate the relationships between TG antibody titer, small bowel histology, growth, and clinical features. Small bowel biopsy histology was graded by using the system of Marsh. RESULTS: 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. TG antibody titer correlated with Marsh score (r = 0.569, P <.01). There was an inverse correlation between Marsh score and height z score (r = -0.361, P =. 05). CONCLUSIONS: In this group of asymptomatic children screened because of a genetic risk, TG antibodies have a positive predictive value of 70% to 83% for biopsy evidence of celiac disease and may identify children before clinical features of celiac disease develop.

Distinction between transient hyperglycemia and early insulin-dependent diabetes mellitus in childhood: a prospective study of incidence and prognostic factors.

We prospectively studied 63 children with transient hyperglycemia to determine their risk of acquiring insulin-dependent diabetes mellitus (IDDM) and to evaluate the predictive value of immunologic markers of prediabetes and of the intravenous glucose tolerance test. Children with transient hyperglycemia were identified by a prospective systematic review of the laboratory reports of a large children's hospital and an office-based pediatric practice and by referral from pediatricians. Transient hyperglycemia occurred in 0.46% of children seen in the children's hospital and in 0.013% of children attending a pediatric office practice. Insulin-dependent diabetes mellitus developed within 18 months of identification in 32% of children in whom transient hyperglycemia was discovered in the absence of a serious illness, compared with 2.3% of children identified during a serious illness (relative risk, 13.9; 95% confidence interval, 1.56 to 123.5). Islet cell antibodies and competitive insulin autoantibodies each had a 100% positive predictive value for IDDM; the negative predictive value of islet cell antibodies and competitive insulin autoantibodies was 96% and 98%, respectively. The stimulated insulin release during an intravenous glucose tolerance test, adjusted for age, had the highest overall accuracy of prediction. All children less than 6 years of age with stimulated insulin release levels < 85 pmol/L (12 microU/ml) subsequently had IDDM, as did an 11-year-old child whose stimulated insulin release level was below the 1st percentile of 170 pmol/L (24 microU/ml). To date, no child whose stimulated insulin release level was above the 5th percentile has had IDDM. We conclude that when transient hyperglycemia occurs during a serious intercurrent illness, the risk of progression to IDDM is low. In contrast, one third of children in whom transient hyperglycemia is identified without a serious illness can be expected to have IDDM within 1 year. A combination of islet cell antibodies, competitive insulin autoantibodies, and stimulated insulin release levels during an intravenous glucose tolerance test can accurately distinguish children with prediabetes from those with presumed benign transient increases in plasma glucose concentrations.