1987 Volume 10 Issue 1 Pages 24-30
We intended to analyze the mechanism of polyclonal B cell activation in patients with Sjögren's syndrome (SS). We examined the abilities of peripheral blood lymphocytes from SS to respond to B cell stimulatory factors (BSF). Peripheral B cells from SS showed a marked IgG synthesis with BSF alone, in the absence of anti-IgM antibody, measured with Enzyzme Linked Immunosorbent Assay (ELISA). Moreover, SS B cells responded vigorously to the stimulation by BSF associated with anti-IgM antibody compared to normal controls. Furthermore, the hyperactivity of SS B cells to BSF correlated with IgG levels in their sera. By contrast, B cell response to Staphylococcus aureus Cowan 1 (SAC) and expression of B cell differentiation antigens on SS B cells were not different from normal controls.
In addition, one B cell line, spontaneously established from the peripheral blood and positive for EBNA, produced IgG in the culture. It also responded to BSF resulting in augmentation of IgG synthesis.
These data highly suggest that SS B cells are polyclonally activated in vivo and SS B cells have hyperresponsiveness to BSF. These abnormalities might be responsible to perturb immunoregulatory system which result in polyclonal gammopathy and/or production of various autoantibodies in SS.
