To determine whether oral administration of rebamipide, a mucosal protective agent, is effective in the treatment of Sjögren's syndrome (SS) in the NFS/sld mouse model of the disease.
NFS/sld mice were given daily oral doses of rebamipide (0.3 mg/kg of body weight or 3 mg/kg) or vehicle alone starting from the age of 4 weeks to the age of 8 weeks. The volume of saliva and tears was monitored during and after treatment. After the final dose, histologic features of the tissues, TUNEL+ apoptotic duct cells in affected glands, T cell and cytokine function, and levels of immunoglobulin isotypes and serum autoantibodies were examined.
The 3-mg/kg dose of rebamipide prevented the development of autoimmune lesions. The average volume of saliva in rebamipide-treated mice was significantly higher than that in control mice. We found decreased TUNEL+ apoptotic duct cells in the salivary and lacrimal glands of rebamipide-treated mice as compared with control mice. Rebamipide treatment suppressed the activation of CD4+ T cells and Th1 cytokines (interleukin-2, interferon-gamma) associated with impaired NF-kappaB activity. Production of serum autoantibodies, IgM, and IgG1 was clearly inhibited.
Our findings demonstrate the efficacy of oral administration of rebamipide in the treatment of SS. Rebamipide represents a new therapeutic strategy for the treatment of patients with sicca symptoms caused by SS, as well as for patients with other diseases.