Immune Modulation by Parenteral Fish Oil in Patients With Crohn's Disease

Modulation of Immune Function by Parenteral Fish Oil in Patients With Crohn's Disease and High Inherent Tumor Necrosis Factor-alpha Production: a Randomized, Single Blinded, Cross-over Study

To evaluate the effects of infusion of a Fish oil-based lipid emulsion on TNF-α production and other relevant immune functions. A soybean oil emulsion, rich in the omega-6 polyunsaturated fatty acid linoleic acid, will serve as control.

Rationale: Fish oil (FO), rich in omega-3 polyunsaturated fatty acids, exerts a range of anti-inflammatory actions that render it a potential therapeutic agent to treat Crohn's disease, a chronic inflammatory disease that primarily affects the bowel. Recent evidence suggests that a lack of effect in previous studies might be due to the fact that genetic background was not taken into account. For instance, a study in healthy subjects showed that production of the pro-inflammatory cytokine Tumor Necrosis Factor-alpha (TNF-α) following FO supplementation decreased in individuals within the highest tertile of pre-supplementational TNF-α production, remained unaltered in the middle tertile, and increased in the lowest tertile of pre-supplementational TNF-α production. TNF-α plays a pivotal role in the pathogenesis of Crohn's disease, hence the treatment with anti-TNF-α agents. Based on these notions, and because FO supplementation via the enteral route is strongly dose limited due to fat-induced side effects such as diarrhea, we hypothesize that parenteral FO supplementation might be beneficial in those patients with Crohn's disease with a high inherent TNF-α production. Study design: Single center, randomized, single blinded, lipid-controlled, cross-over pilot trial. Study population: Adult patients with Crohn's disease with previous bowel surgery, currently in remission (without the need for immunosuppressive drugs) and with a high inherent TNF-α production. Intervention: First, patients with a high inherent TNF-α will be identified by assessment of TNF-α production in a group 100 patients who meet in- and exclusion criteria. Patients within the highest tertile will be classified as high producers. Next, 5 patients within the highest tertile will be randomized to receive intravenous administration of 20% (w/v) lipid-control (Intralipid®), and, after crossing over, 10% (w/v) fish oil emulsion (Omegaven®), or vice-versa for 1 hour on three consecutive days at a dose of 0.2 g/kg bodyweight /hr. Study parameters will be assessed in blood drawn prior to the first infusion (T=0) and 1 (T=4) and 8 days (T=11) after the third infusion. Between the two treatment arms, there will be a wash-out interval of at least 2-3 weeks. Main study parameters/endpoints: Early (T=day 4) and late (T=day 11) effects of infusions on TNF-α production by whole blood cultures. Secondary outcomes: effect on leukocyte counts, leukocyte functions and on (anti-)oxidant status, the occurrence of oxidative damage and analysis of specific Single Nucleotide Polymorphisms (SNPs) related to TNF-α production.

intravenous administration 10% (w/v) fish oil emulsion (Omegaven) for 1 hour on three consecutive days at a dose of 0.2 g/kg bodyweight/hr.

intravenous administration of 20% (w/v) lipid-control (Intralipid®), for 1 hour on three consecutive days at a dose of 0.2 g/kg bodyweight/hr.

whole blood cultures are stimulated with 1 ng/ml lipopolysaccharide for 4 hours. TNF-alpha levels are measured in the supernatant with an enzyme-linked immunosorbent assay. Differences are compared by paired t-test or wilcoxon signed rank test.

Change in expression of cell surface markers on neutrophils and monocytes (CD11, CD66, CD62 and CD63) by immune fluorescent staining and subsequent flowcytometric analysis. Between day 0 and day 4 patients receive on intralipid or omegaven 3 consecutive days. Differences are compared by paired t-test or wilcoxon signed rank test

Change in expression of cell surface markers on neutrophils and monocytes (CD11, CD66, CD62 and CD63) by immune fluorescent staining and subsequent flowcytometric analysis. Differences are compared by paired t-test or wilcoxon signed rank test.

whole blood cultures are stimulated with 1 ng/ml lipopolysaccharide for 24 hours. Interleukin (IL)-1B, Il-6 and IL-10 levels are measured in the supernatant with an enzyme-linked immunosorbent assay. Differences are compared by paired t-test or wilcoxon signed rank test.

whole blood cultures are stimulated with 1 ng/ml lipopolysaccharide for 24 hours. Il-1B, Il-6 and IL-10 levels (pg/ml ) are measured in the supernatant with an enzyme-linked immunosorbent assay . Differences are compared by paired t-test or wilcoxon signed rank test.

to evaluate fatty acid incorporationDifferences are compared by paired t-test or wilcoxon signed rank test.

whole blood cultures are stimulated with 1 ng/ml lipopolysaccharide for 4 hours. TNF-alpha levels are measured in the supernatant with an enzyme-linked immunosorbent assay. Differences are compared by paired t-test or wilcoxon signed rank test.

Oxidative stress will be measured by both lipid and protein peroxidation and antioxidant capacity. Differences are compared by paired t-test or wilcoxon signed rank test.

Oxidative stress will be measured by both lipid and protein peroxidation and antioxidant capacity. Differences are compared by paired t-test or wilcoxon signed rank test.

Inclusion Criteria: Adult patients with Crohn's disease with previous bowel surgery, currently in remission (without the need for immunosuppressive drugs) and with a high inherent TNF-α production. Exclusion Criteria: Patients with other active inflammatory / immune mediated underlying diseases Smoking > 5 cigarettes a day Diet with >2 portions of fatty fish (tuna, salmon, mackerel, herring, and trout) a week History of metabolic disorder (especially diabetes or lipid disorders) Crohn's disease activity, including the presence of active fistulas On need for medical (other than 5-aminosalicylic acid preparations) or surgical treatment for Crohn's disease activity Use of non-steroidal anti-inflammatory drugs or aspirin C-reactive protein levels of >10 mg/l History of venous or arterial thrombosis Active malignancy Presence of severe pulmonary, cardiovascular, renal, liver, coagulation or hematological disease Pregnancy or lactation Age <18 yrs Allergy for one of the following components: fish, chicken, eggs or soy beans