LMD/MS based proteomic findings in 10 cases of hepatic amyloidosis and pathological features of ALect2 amyloidosis. (A) LMD/MS read-outs of 2 cases of AL and 8 cases of ALect2 amyloidosis. The proteins identified are listed according to relative abundance based on spectral counts. The first five proteins represent amyloid-associated proteins identified in this cohort, followed by other abundant proteins identified in the deposits. The first two most abundant amyloid-associated proteins (1-2) across the cohort and present in every amyloid type are apolipoprotein E and serum amyloid P-component. The following three proteins (3-5) highlighted by red boxes represent pathogenic proteins identified in these 10 cases. Only one pathogenic protein is present in each case. Rows 1 and 2 represent AL, and rows 3-10 ALect2 amyloidosis. (B-C) Histologic features of ALect2 amyloidosis. There are periportal globular deposits of proteinaceous material (B, arrows) that are strongly Congo-red positive (C, arrows). (B: hematoxylin and eosin, C: Congo red, ×200 original magnification; image acquired using an Olympus DP71 camera and Olympus BX51 microscope.) (D-G) Expression of LECT2 in ALect2 amyloidosis (D-G), normal liver (E), and AL amyloidosis (F). IHC for LECT2 protein labels the globular amyloid deposits in ALect2 amyloidosis (D, arrows and inset), whereas the surrounding hepatic parenchyma is entirely negative. ISH for LECT2 mRNA is negative in normal liver (E, and inset), rare cells are weakly positive in AL amyloidosis (F, and inset), whereas most cells are strongly positive in ALect2 amyloidosis (G and inset; arrow indicates globular amyloid deposits). (D: IHC for LECT2, ×40 original magnification; E-F: ISH for LECT2 mRNA, ×100 original magnification. All images were acquired using an Olympus DP73 camera and Olympus BX51 microscope.)