SEROLOGICAL ANALYSES OF UNAFFECTED PRESUMED GENE CARRIERS OF CELIAC DISEASE: 215

Celiac disease (CD) is known to be familial but its inheritance pattern is not fully understood. Serologic tests are used to identify at risk individuals in CD families. We defined presumed gene carriers for celiac disease as individuals testing negative for IgA endomysial antibody, who have both a CD affected parent, sibling or cousin and a CD affected child. We hypothesized that presumed CD gene carriers would have unique serological profiles. Methods: We measured and compared IgG and IgA tissue transglutaminase (tTG), endomysial antibody (EMA) antigliadin antibody (GA) and total serum IgA in presumed gene carriers, HLA DQ2+ organ donors, and Red Cross blood donors. Results: There were no significant differences in EMA, GA, or IgA tTG levels in controls and presumed carriers. Presumed gene carriers had significantly elevated total serum IgA levels compared to DQ2 and blood donor controls (Table 1). The levels of IgG tTG were also significantly above those of the controls (Table 2).TABLE 1: Serum IgA Levels (mg/dL)TABLE 2: IgG tTG levelsConclusion: Higher total serum IgA levels in CD family members who are presumed gene carriers could be an indication of an accelerated mucosal immune response. The increased IgG tTG levels, indicates a slight tendency towards an immune response to transglutaminase antigen. However, the data clearly indicate that no test is clinically useful in differentiating presumed gene carriers from controls and there does not appear to be a unique serologic pattern differentiating the presumed gene carrier family member.