Extrarenal pathological findings. (A-B) Duodenal biopsy. (A) Light microscopy (hematoxylin and eosin staining, original magnification ×400). Crypt atrophy and deposits (arrows) within the basement membranes of the mucosa. (B) IF microscopy (anti-κ fluorescein isothiocyanate conjugate, original magnification ×400). Linear deposits along the basement membranes of the mucosa and around vascular myocytes. (C-D) Liver biopsy. (C) Light microscopy (Masson’s trichrome staining, original magnification ×400). Deposits along sinusoids within Disse spaces. (D) Immunohistochemistry (anti-κ antibody, original magnification ×200). Diffuse linear deposits in Disse spaces. (E-F) Minor salivary gland biopsy. (E) Light microscopy (hematoxylin and eosin staining, original magnification ×200). Deposits along glandular basement membranes and around vascular myocytes (arrows). (F) IF microscopy (anti-κ fluorescein isothiocyanate conjugate, original magnification ×200). Linear deposits along glandular basement membranes. Bars = 50 µm.