Implications of long-term medication of oral steroids and antimalarial drugs in primary Sjögren's syndrome

Abstract

Background: Immunomodulating drugs are commonly used in treating patients with autoimmune diseases but with very different outcomes. We aimed to investigate differences in cytokine and autoantibody levels with regard to patient characteristics in patients with primary Sjögren's syndrome (pSS) receiving oral steroids or antimalarial drugs (AM) after a longer period of time.

Methods: Serum samples from 141 patients fulfilling the revised EU-US criteria and 99 healthy controls were analysed for 25 cytokines and 8 autoantibodies.

Results: AM-patients had lowered levels of IL-5, IL-10, IL-13 and IFN-γ, though non-significantly. Use of prednisolone was associated with reduced levels of IL-15, IL-2, IL-4, IL-12p40, TNF-α, MIP-1α and MIP-1β (p<0.05), and a trend towards decreased levels of IL-1RA and IL-1β was observed. No associations were seen between AM and antibody levels. Significantly higher protein levels of anti-Ro-52 and anti-Ro-60 were observed in the patients taking prednisolone (p<0.05). The proportion of patients positive for anti-Ro-52 and anti-La-48 did not differ significantly in the groups taking and not taking prednisolone, but a difference was seen for anti-Ro-60 (p<0.05).

Conclusions: Prednisolone is a potent anti-inflammatory and immunosuppressive drug commonly used in autoimmune diseases. Our study shows that oral steroids are associated with reduced levels of several pro-inflammatory cytokines, but increased levels of pSS specific autoantibodies. The association between steroid use and increased antibody levels is not readily explained by known steroid effects, and should therefore be confirmed in further studies. Lower levels of pro-inflammatory cytokines indicate a beneficial effect of oral steroids in this patient group.