Decreased numbers of circulating plasmablasts and differences in IgA1-plasmablast homing to skin in coeliac disease and dermatitis herpetiformis.

The two clinical phenotypes of gluten enteropathy, coeliac disease (CD) and dermatitis herpetiformis (DH), were characterized for numbers and homing profiles of circulating final effector B cells, plasmablasts, identified as immunoglobulin (Ig)-secreting cells (ISC). In CD, the numbers of ISC were approximately 50% lower than in DH or controls. ISC expressed peripheral lymph node homing receptor (HR), L-selectin, less frequently in CD (54%) and DH (52%) patients than in controls (70%). The expression of gut mucosal HR, alpha(4)beta(7), was less frequent in CD (42%) than in DH (65%) or controls (60%). In DH, but not in CD or controls, a higher proportion of IgA1-ISC (40%) than IgA2-ISC (25%) expressed the skin HR, cutaneous lymphocyte-associated antigen. In gluten enteropathy circulating plasmablasts are more mature, but decreased in number, and have distorted homing profiles. Differential IgA1-plasmablast homing could be associated with the development of skin rash with IgA1-deposits in DH but not in CD.