8A4-NP1 cryoglobulin, renal lesions observed in mice kidneys.

(A and B) Light microscopy showing intravascular precipitates not solely in glomerular capillary lumens but also in peritubular capillary and arteriolar lumens. Note the absence of inflammatory reaction. Semi-thin sections, toluidine blue staining (A, original magnification ×400; B, ×1000). (C) Immunofluorescence microscopy with antimouse Ig conjugate (original magnification ×200) showed staining of intravascular cryoglobulin aggregates. (D and E) Electron microscopy showed osmiophilic amorphous precipitates in capillary lumens without crystalline substructure and without any deposits in subendothelials spaces. Note also the amorphous dense bodies in epithelial and endothelial cell cytoplasms (D, original magnification ×2500; E, ×12 000).