Human umbilical cord as substrate for IgA antiendomysial antibodies allows large scale screening for celiac sprue.

Sera from 800 patients referred to our laboratory for celiac sprue screening were tested for IgA antiendomysial antibodies on human umbilical cord (HUC-EmA) and for IgA and IgG antigliadin antibodies (AGA) on rodent tissue by indirect immunofluorescence. Thirty-three patients (4.1%) were positive for at least one of the two antibodies; IgA HUC-EmA were found in 25 patients, whereas IgA and IgG AGA were detected in 19 and 24 subjects, respectively. Twenty-seven (82%) of the 33 patients with immunological markers showed sub-total or severe partial villous atrophy consistent with celiac sprue, whereas the remaining six cases had normal histological findings. None of 30 antibody-negative biopsied patients showed abnormalities of duodenal mucosa. Of the 27 newly diagnosed celiacs, only 21 (78%) were positive for IgA and/or IgG AGA, whereas IgA HUC-EmA were found in all but two cases (93%). In these two cases, positive only for IgG AGA, celiac sprue was associated with IgA deficiency. Our study proves that the routine use of IgA HUC-EmA increases celiac sprue findings by up to 15% when compared with AGA.