Search

Studies in autoimmune-prone NZB/W F1 mice have demonstrated that the amount of dietary fat can affect autoantibody production and the disease course of autoimmune diseases. Anti-cardiolipin antibodies have been found to play a major role in thrombus formation and the increase of abortion rate in both human lupus patients and murine lupus. The present study investigated further the effect of dietary fat on lipid and anti-cardiolipin antibody production in autoimmune-prone mice. Two groups of NZB/W F1 mice were fed on diets containing 200 g dietary fat/kg and 50 g dietary fat/kg respectively, the fat being composed of equal amounts of lard and soyabean oil. Serum levels of lipids, immunoglobulin (Ig) anti-single stranded DNA and anti-cardiolipin antibodies were followed regularly every month and mice were killed for in vitro experiments after 5 months on the experimental diets. The results showed that serum triacylglycerol concentration was lower in mice fed on the high-fat diet than in those fed on 50 g fat/kg. There was no significant difference in hepatic lipid contents; however, the fatty acid contents were different between these two groups. Hepatic linoleic acid (18:2n−6) and arachidonic acid (20:4n−6) concentrations were higher in mice fed on the high-fat diet. There were no significant differences in serum IgM concentrations or IgM anti-cardiolipin antibody levels between these two groups. However, IgG anti-cardiolipin antibody levels were higher in mice fed on the high-fat diet at the age of 3–4 months. Total serum IgG concentration was noted to be higher, but in contrast, serum IgA was lower, in the high-dietary-fat group. These findings suggest that high dietary fat may affect lipid metabolism and autoantibody levels in autoimmune diseases [ABSTRACT FROM PUBLISHER]

To elucidate further the influences of dietary fat on autoimmune diseases, two groups of NZB/W F1 mice were fed with diets containing 200 g dietary fat/kg and 50 g dietary fat/kg (control) respectively. The difference in energy intake between these two groups was compensated with carbohydrate. Mice were bled regularly every month and some of them were killed for in vitro experiments after 5 months experimental diets. Higher immunoglobulin (Ig)M and IgG anti-double stranded DNA antibody levels, shortened life span and worsened proteinuria were noted in mice fed on the high-fat diet compared with those fed on 50g dietary fat/kg. Phenotypic analyses of spleen cells and peritoneal exudate cells showed that the percentage of CD5+ B cells and the mean fluorescent intensity of major histocompatibility molecules on the surface of both types of cells were higher in mice fed on the high-fat diet. In general, higher type 2 T-helper cell activity was noted in mice fed on the high-fat diet. In addition, cytokines such as interleukin-6, tumour necrosis factor-α and prostaglandin E2 (PGE2) produced by lipopolysaccharide-stimulated peritoneal exudate cells were also higher in the high-dietary-fat group. These studies suggest that high dietary fat and its related PGE2 level might have a critical effect on the frequency of CD5+ B cells, cytokine production, macrophage function and subsequent autoimmune regulation in autoimmune mice. [ABSTRACT FROM PUBLISHER]