Enumeration of IgA producing cells by the enzyme linked immunospot (ELISPOT) technique to evaluate sulphasalazine effects in inflammatory arthritides.

Numbers of IgA producing cells in peripheral blood were determined by the enzyme linked immunospot (ELISPOT) technique in 15 patients with inflammatory arthritides receiving sulphasalazine treatment. The numbers of IgA producing cells decreased significantly after the first three weeks of treatment. In 11 of the patients this decrease persisted, whereas a subsequent increase was seen in the four others; in two of these latter patients this increase coincided with a temporary withdrawal of the sulphasalazine treatment. A reduction of serum concentrations of IgA and haptoglobin was seen after three months' treatment. Eleven of the patients had a subjective improvement in their joint disease during the first three months of treatment. Analysis of circulating cells committed for IgA secretion may constitute one way of assessing gut associated immunity indirectly, and the present data suggest that sulphasalazine has a rapid effect on lymphocytes possibly originating from the gut and that such an effect precedes improvement in laboratory parameters and clinical symptoms in arthritic diseases.