HCDD transgenic mice reproduce human kidney lesions. (A) Immunofluorescence microscopy on DH, DH-CH1⁺, or DH-CH1⁻ kidney sections with an anti-human γHC-fluorescein isothiocyanate. Fluorescence and differential interference contrast are merged. Original magnification, ×400. Note the intense linear staining of tubular and glomerular BMs and in the mesangium of the DH-CH1⁻ kidney. (B) Deposit intensity based on immunofluorescence studies of kidney sections. Each dot represents a score of fluorescence from an individual kidney as described in Materials and Methods. Means ± SEM are shown (n = 6-9 mice in 3 independent experiments; ***P < .001). (C) Electron micrograph of kidney from a DH-CH1⁻ mouse showing finely granular electron-dense deposits along the inner part of the lamina densa of a glomerular-capillary BMs (arrows). Original magnification, ×20 000; scale bar is indicated. (D) Immunoelectron microscopy on kidney from a DH-CH1⁻ mouse (top) and a renal biopsy of the corresponding HCDD patient (bottom). Note the presence of anti–γHC-conjugated gold particles along the BMs in both patient and mice kidneys. Original magnification, ×50 000; scale bars are indicated. (E) Toluidine blue staining showing a faint diffuse thickening of tubular BMs in the outer medulla (left) and glomerular BMs (arrows). Deposits are also observed in the mesangium (star). Original magnification, ×600.