Circulating rotavirus-specific antibody-secreting cells (ASCs) predict thepresence of rotavirus-specific ASCs in the human small intestinal lamina propria

Rotaviruses are the most important cause of infectious diarrhea in children throughout the world. Protection is most likely mediated by small-intestin al virus-specific IgA. However, neither fecal nor serum virus-specific IgA clearly correlates with protection against challenge. The capacity of rotav irus-specific antibodies and rotavirus-specific antibody-secreting cells (A SCs) in the circulation to predict the presence of ASCs in the intestines o f children was evaluated. Mononuclear cells from intestinal biopsy samples and blood from 21 children were enriched for CD38, a marker of terminally d ifferentiated B cells, and evaluated for the presence of virus-specific and total IgA- and IgG-secreting cells, by ELISPOT assay. Serum virus-specific IgA and IgG levels were determined by ELISA. The ratio of virus-specific t o total IgA-secreting cells in the blood correlated with that found in the small, but not large, intestine. In contrast, serum rotavirus-specific IgA correlated less well with the presence of virus-specific ASCs in the small intestine.