Celiac Disease (CD) [K90.0]
OMIM number: 212750
Dr. med. Kaimo Hirv, Dr. rer. nat. Barbara Bangol
Celiac disease (CD), in adults also referred to as endemic sprue, is a disease of the small intestine caused by grain proteins leading to lymphocytic infiltration and damage of the intestinal mucosa. Activation of B lymphocytes cause the formation of various celiac specific antibodies, which can be analyzed if celiac disease is suspected. Celiac disease is among the diseases associated most with HLA. Almost every patient suffering from celiac disease carries the HLA class II alleles HLA-DQ2 and/or HLA-DQ8. Only these HLA molecules are capable of presenting gliadin peptides (degradation products of gluten) and to trigger an immunologic response. Approximately 95% of all patients are HLA-DQ2 (DQB1*02, DQA1*05) positive. The majority of the remaining patients carry HLA-DQ8 (DQB1*03:02, DQA1*03). The negative predictive value of HLA testing is therefore almost 100%. The positive predictive value, however, is very low, since approximately 40% of the European population carries these HLA alleles. The ESPGHAN guidelines recommend determination of HLA-DQ2 and DQ8 for patients with unclear diagnosis due to unclear biopsy or serology. If biopsy of the small intestine is not to be carried out in children with strong clinical suspicion of celiac disease and high antibody titers, HLA typing is recommended to add strength to the diagnosis. HLA testing should be carried out in asymptomatic persons who are at an elevated risk of developing celiac disease. If no HLA-DQ2 / DQ8 is detected, no regular serologic monitoring is necessary.