Patients with Primary Sjögren's Syndrome Treated for Two Months with Evening Primrose Oil

Abstract

Twenty-four female and 4 male patients, all fulfilling the Copenhagen criteria for primary Sjögren's syndrome (primary SS), were treated for 8 weeks with evening primrose oil (Efamol). Efamol is a seed oil which consists primarily of the n-6 essential fatty acids (EFA): cis-linoleic acid and gammalinolenic acid (GLA).

The investigation was carried out as a randomized, double-blind, placebo-controlled, cross-over trial in order to determine whether long-term treatment of patients with primary SS with Efamol would improve the ocular and oral clinical status, and whether the levels of EFA in plasma and erythrocytes increase during Efamol treatment. The objective ocular status, evaluated by a combined ocular score, including the results from Schirmer-I test, break-up time and van Bijsterveld score, improved significantly during Efamol treatment when compared with Efamol start-values (p< 0.05), but not when compared with placebo values (p< 0.2). The GLA metabolite and prostaglandin-E₁ (PGE₁) precursor dihomogammalinolenic acid (20: 3n6, DGLA) increased both in plasma (p< 0.001) and in erythrocytes (p< 0.001) during treatment with Efamol. No correlations between objective ocular and oral status and DGLA values in plasma or erythrocytes were found.