Elevated levels of soluble Fc epsilon RII/CD23 and antibodies to Epstein-Barr virus in patients with Sjögren's syndrome.

To clarify how Epstein-Barr virus (EBV) infection is responsible for Sjögren's syndrome (SjS) we measured both IgG and IgM antibodies to viral capsid antigen (VCA) of EBV in the sera of normal healthy subjects and patients with SjS. Anti-VCA IgG was detectable in all controls and patients however, anti-VCA IgG titers in the sera of SjS patients were significantly higher than those of the controls (p < 0.01). No anti-VCA IgM was detected in the sera of controls whereas anti-VCA IgM was detected in the sera from 10 out of the 13 patients with SjS. This suggests that SjS might be associated with EBV. The serum levels of sCD23 (IgE-binding factor) were also measured to assess the differential state in patients with SjS. The sCD23 level of normal individuals was 211.26 +/- 12.01 micrograms/L (value is mean +/- SE), and was 443.77 +/- 71.94 micrograms/L in the 13 patients with SjS. The mean sCD23 level in the 9 patients with SjS without any complication was 360.67 +/- 35.63 micrograms/L. In the patients with SjS, sCD23 levels were significantly higher than those in the normal individuals (p < 0.01).