Essential fatty acid and prostaglandin metabolism in Sjögren's syndrome, systemic sclerosis and rheumatoid arthritis.

Evidence from biochemical studies and from experimental animals indicates that abnormalities of essential fatty acid (EFA) and eicosanoid metabolism could lead to salivary and lacrimal gland atrophy and to immunological and cardio-vascular defects. Measurements of EFA levels in erythrocytes from patients with primary Sjögren's syndrome have shown that abnormalities are indeed present. Controlled clinical trials of supplementation with gamma-linolenic acid (GLA) as evening primrose oil (Efamol) in both primary Sjögren's syndrome and systemic sclerosis have given positive results. There are strong arguments to indicate that sophisticated manipulation of EFA metabolism may have a role to play, not only in Sjögren's syndrome but also in other rheumatological disorders.