Dietary fatty acids and immune reactions in synovial tissue.

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Eur J Med Res. 2003 Aug 20;8(8):381-7.

Dietary fatty acids and immune reactions in synovial tissue.

Adam O.

Walther-Straub Institute, Ludwig-Maximilians-University Munich, Germany.

olafadam@...

Inflammation of the synovial membrane in rheumatoid arthritis is

mediated by specialized cells necessary for immune response. The most

prominent features are the accumulation of mononuclear phagocytes,

lymphocytes and leukocytes in the proliferating tissue. Pro-inflammatory and

proliferative signals are transmitted to the bone marrow and to the synovial

membrane. The result is a monoclonal stimulation of specific cell lines, and

synovial proliferation in the inflamed joint. Angiogenesis, synovial

hypertrophy, and increased perfusion facilitate the accumulation of

inflammatory cells. Components of the autoimmune reaction are described in

the international system of classification, the CD-System (cluster of

differentiation). Pro-inflammatory signals are mediated by metabolites of

arachidonic acid. Prostaglandins, leukotrienes, lipoxines and hydroxy fatty

acids, derived from this PUFA, stimulate the formation and the activity of

adhesion molecules (integrines), cytokines (gamma-interferon, interleukin-1,

interleukin-6, tumor-necrosis factor), chemokines (interleukine-8,

macrophage-chemotactic peptide, RANTES and colony -stimulating factors

((CSF, granulocytes/ monocytes-CSF, Multi-CSF (= IL-3)). Dietary means to

mitigate inflammation comprise reduction of arachidonic acid, and increased

intake of eicosapentaenoic acid and antioxidants. In the literature 12

randomized, placebo-controlled double-blind studies, fulfilling

GCP-criteria, demonstrate a moderate but consistent improvement of clinical

findings and laboratory parameters in patients with RA. A dose-response

relationship was established up to an daily dose of 2.6 gram fish oil,

equivalent to about 1.6 gram EPA. In these experiments EPA was the omega-3

fatty acid responsible for improvement, with distinct effects on inhibition

of cytokines formation (IL-1 to IL-6, IL-8, TFN-alpha, GM-CSF), decreased

induction of proinflammatory adhesion molecules (selectines, intercellular

adhesions molecule-1 (ICAM-1)), and degrading enzymes (e.g. phospholipase

A2, cyclooxygenase-2, inducible NO-synthetase). Only one study reports the

relevance of the background diet. From this study it became apparent that

reduction of dietary arachidonic acid improves the incorporation and the

clinical benefit of EPA.

PMID: 12915334 [PubMed - indexed for MEDLINE]