Neutrophils are the most common type of white blood cell. They are found in large numbers at the site of inflammation in RA and inflammatory bowel disease. They have a number of pro-inflammatory effects.
Neutrophils make a molecule called leukotriene B4 (LTB4) which plays a critical role in promoting inflammation. The starting material they use is a polyunsaturated fatty acid called arachidonic acid, which in turn is derived from the types of polyunsaturated fatty acids found in land-based plants and animals.
Marine plants and animals contain quite different fatty acids from their land-based equivalents, for example eicosapentaenoic acid and docosahexaenoic acid. These fatty acids can take the place of arachidonic acid in the neutrophil's LTB4 manufacturing process, resulting in slightly different end products. These products have a less inflammatory effect than LTB4 itself.
Dr Sperling and his colleagues have shown that dietary eicosapentaenoic acid reduces the production of LTB4 by neutrophils, both from healthy donors and patients with inflammatory disorders.
In addition, a diet rich in eicosapentaenoic acid and other marine-derived fatty acids has been shown to have other beneficial effects on neutrophil activity: neutrophils are less likely to migrate to the site of inflammation, and to release other molecules and enzymes which cause damage at the site of inflammation.
A number of studies have shown that diets enriched in marine fish oils have a modest beneficial effect in patients with diseases such as RA and inflammatory bowel disease. Dr Sperling's results suggest that this is because of the calming effect these oils have on neutrophil activity.
1. Dr Sperling will be speaking in the Lipids and the immune system workshop on Friday 5 December 1997. The BSI 5th Annual Congress will be held at the Brighton Centre, Brighton, UK from 2-5 December.
2. Dr Sperling can be contacted at Dr R I Sperling, Department of Rheumatology and Immunology, Brigham and Women's Hospital, Boston, MA 02115, USA Tel: 508 824 3872 Fax: 508 824 1760
3. There will be a press office at the meeting in operation from 9am on Tuesday 2 December. Tel. +44 1 273 724 320 / 0378 406 416 Journalists are welcome to attend but are asked to contact Kirstie Urquhart in advance to register.
4. Before the meeting Kirstie can be contacted on +44 181 875 2402 / firstname.lastname@example.org