Immunoglobulin-producing cells in secretory immune system in patients with selective IgA deficiency.

This study evaluated the class distribution and J chain-positivity of immunoglobulin-producing cells (Ig-PCs) in gastrointestinal mucosa and salivary glands of Japanese patients with selective IgA deficiency. The proportional patterns of gland-associated Ig-PCs showed an increase in not only IgM cells but also IgG cells, most of which were J chain-positive. This may represent a maturation arrest at B cell differentiation, rather than a compensatory phenomenon. No patients showed an increase of IgD cells in salivary glands. This behavior of IgD cells in Japanese patients may reflect associated diseases or ethnic difference in B cell differentiation.