Serological Markers and HLA-DQ2 Haplotype Among First-Degree Relatives of Celiac Patients

Serologic markers, HLA-DQ2 haplotype, andclinical features suggestive of celiac disease werestudied to assess their diagnostic value in amulticentric study to detect celiac disease in 675first-degree relatives of 227 celiac probands. SerumIgA-class anti-endomysium and IgA-class anti-gliadinantibodies were positive in 5.8% and 1.9% of relatives,respectively. HLA-DQ2 haplotype was present in 64% of relatives, and the overall rate of celiacdisease diagnosed by intestinal biopsy was 5.5% . Thefrequency of HLA-DQ2 in the celiac patients and controlswas 93% and 18% , respectively. The most frequent clinical features — diarrhea, anemia,food intolerance, and growth retardation — werenot present in one third of the celiac diseaserelatives. We conclude that the assessment of IgA-classanti-endomysium antibodies alone seems a reasonable approachfor screening celiac disease in relatives and cannot bereplaced by an accurate clinical anamnesis. HLA-DQ2haplotype may identify the population with a high genetic susceptibility to celiacdisease.