Controversies in the laboratory diagnosis of celiac disease in children; new haplotypes discovered.

The latest consensus on celiac disease in 2008, under the auspices of the International Societies of Pediatric Gastroenterology, Hepatology and Nutrition, shows that HLA DQ2/DQ8 typing indicates the highest negative predictive value for celiac disease, which would exclude the diagnosis of celiac disease. In Romania, there are no studies on the implication of HLA-DQ2/DQ8 in celiac disease in children. The aim of our study was to analyze the significance of genetic tests, with a focus on negative HLA-DQ2/DQ8 cases, as well as to determine the main haplotypes involved in celiac disease in children. We tested in 37 children with old celiac disease, confirmed based on the presence of intestinal villi changes on duodenal biopsy, the IgA anti-tissue transglutaminase antibodies (TgA-IgA) by ELISA and the IgA anti-endomysium antibodies (EmA-IgA) by indirect immunofluorescence, compared to HLA-DQ2/DQ8 typing by polymerase chain reaction (PCR). In 25 children, the determined HLA haplotypes predominantly belonged to DQ2, and in 3 children we report the presence of a new haplotype, DR3-DQ2/DR4-DQ8, formed by pattern 1, DR3-DQ2-the DQA1*0501 and DQB1*0201 alleles, and pattern 5, DR4-DQ8-the DQA1*0301 and DQB1*0302 alleles. In 9 children, genetic tests were negative for celiac disease. The identification of HLA-DQ2/DQ8 provides additional data in the diagnosis of celiac disease, but a rigid algorithm in the diagnosis of celiac disease has no practical applicability.