FIGURE 4

AD in APOC1(+/+) mice: mast cells and IgE. Mice were killed at different ages starting at an age of 6 weeks, and tissue sections were evaluated with respect to the number of (a) mast cells or (c) IgE⁺ cells. Individual APOC1(+/+) mice are indicated with filled circles. Heterozygous APOC1(+/-) mice (triangles) or -/- wild-type mice (open circles), which do not develop AD, are included as controls. (b) IgE levels were tested by ELISA as described in Materials and Methods. For each individual mouse, three non-serial sections were evaluated (10 sequential microscopic views per section). Each symbol represents an individual mouse with the mean number of cells per microscopic view at a 400 magnification. (c) Number of IgE⁺ cells was determined and for each individual mouse it was plotted against the corresponding serum value. For statistical analysis, data obtained in 5- and 6-week-old mice were combined; the same was done for 8- and 9-week-old mice. The Kruskal–Wallis test showed significant differences for mast cells (P<0.00001) and for IgE (P<0.01). At all time points, numbers of mast cells were significantly increased (Mann–Whitney U-test, P<0.01), as compared to wild-type mice or APOC1(+/-) mice. Differences as compared to week 5/6 are indicated in the figure.