Fig. 3

Immunohistochemical staining of the subcutaneous fat tissue using the patient’s IgG. a: A representative photomicrograph of the fat tissue stained with biotin-conjugated IgG purified from the patient’s serum. Note diffuse staining of pericellular fibers. Bar = 100 μm. b and c: Two representative high-power view fields of the fat tissue stained with the biotin-conjugated IgG purified from the patient’s serum. Bar = 50 μm. In panel b), the arrows indicate the prominent staining of pericellular fibers, and the arrowheads indicate the staining of fiber bundles. In panel c), pericellular staining sometimes shows a membranous pattern. d: A representative photomicrograph of the fat tissue stained with biotin-conjugated IgG purified from a control serum. A view field corresponding to that of panel a) is taken. Bar = 100 μm. e and f: Two representative high-power view fields of the fat tissue stained with the biotin-conjugated IgG purified from the control serum. Bar = 50 μm. Unlike panels b) and c), no diffuse staining of pericellular fibers is observed. Instead, some nuclei are stained (arrowheads). g-i: The same fat tissues were incubated with PBS instead of biotinylated IgG. No staining was observed. Bar = 100 μm (g) or 50 μm