PMC5676379_01
Light microscopy findings. (a) Periodic acid-Schiff stain (PAS) staining showed focal mesangial proliferation (original magnification x400). (b) Periodic acid-methenamine silver (PAM) staining showed thickening of glomerular capillary walls (original magnification x400). (c) Masson trichrome (MT) staining showed red staining in the subepithelial area (original magnification x400).
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Light microscopy showed diffuse thickening of the glomerular capillary walls with focal mesangial proliferation (Figures 1(a) and 1(b)), and red staining was observed in the subepithelial area by Masson's trichrome stain (Figure 1(c)).
Immunofluorescence findings. IgG was strongly positive mainly in the peripheral capillary walls. C3 was also positive in peripheral pattern. In light-chain staining, kappa chain was entirely negative, but lambda chain was positive in the peripheral capillaries (original magnification x400).
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Moreover, only IgG1 among the four subclasses (Binding-Site, Birmingham, UK) and only lambda light chains were detected in the glomerular capillary walls (Figures 2 and 3).
Findings of IgG subclass staining. IgG1 was positive in peripheral granular pattern. On the other hand, IgG2, IgG3, and IgG4 were all negative (original magnification x400).
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Moreover, only IgG1 among the four subclasses (Binding-Site, Birmingham, UK) and only lambda light chains were detected in the glomerular capillary walls (Figures 2 and 3).
Electron microscopic finding. Electron microscopy showed huge electron-dense deposits in subepithelial, intramembranous, and mesangial lesions (original magnification x3,000).
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Granular electron-dense deposits were observed in subepithelial, intramembranous, and mesangial area by electron microscopy (Figure 4).