IgA immune response patterns to gliadin in serum.
The incidence, titer and molecular size of anti-gliadin (GL) IgA were analyzed in sera from children with celiac disease (CD, n = 66), hospitalized control children (n = 64) and children with other malabsorption disorders (n = 103). Anti-GL IgA was assessed by solid-phase radioimmunoassay, and its molecular size was analyzed by sucrose density gradient ultracentrifugation. The median anti-GL IgA titer was significantly higher in untreated CD than in the other groups, with some overlap. Whereas 57% of anti-GL IgA were polymeric IgA (pIgA) in acute CD, only 17% were pIgA in children with other malabsorption disorders. These anti-GL pIgA consisted mainly of dimers with in some children, a low proportion of anti-GL secretory IgA (SIgA). A large proportion of anti-GL pIgA was associated with high total serum IgA. After the onset of a gluten-free diet (GFD), anti-GL pIgA disappeared more quickly from serum than mIgA. During the gluten challenge test, anti-GL IgA comprised 20% pIgA when they reappeared in serum, but 59% pIgA at the end of the test. The presence of anti-GL pIgA in serum seems related to chronic exposure to gluten of CD patients with a flat intestinal mucosa. These serum pIgA antibodies could result from a spillover from the intestinal mucosal synthesis into the circulation.
Mascart-Lemone
F
F
Department of Immunology, Saint-Pierre Hospital, Free University of Brussels, Belgium.
Cadranel
S
S
Van den Broeck
J
J
Dive
C
C
Vaerman
J P
JP
Duchateau
J
J
D000888:Antibodies, Anti-Idiotypic / Q000032:analysis; D000917:Antibody Formation; D002446:Celiac Disease / Q000097:blood / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D005903:Gliadin / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology*; D007071:Immunoglobulin A, Secretory / Q000032:analysis; D007223:Infant; D007700:Kinetics; D008970:Molecular Weight; D010940:Plant Proteins / Q000276:immunology*
D000888:Antibodies, Anti-Idiotypic; D007070:Immunoglobulin A; D007071:Immunoglobulin A, Secretory; D010940:Plant Proteins; D005903:Gliadin