The major component of localized cutaneous amyloids may be derived from
cytokeratin (CK). However, the CK profiles of
primary cutaneous amyloidosis (PCA) and secondary cutaneous
amyloidosis (SCA) remain obscure.
Paraffin-embedded sections of skin tissue from 64 patients with PCA, 111 with SCA and 3 with systemic
amyloidosis were analyzed immunohistochemically using 12 different polyclonal or monoclonal anti-CK
antibodies (34betaE12, MNF116, LP34, AE1/AE3, anti-CK1, CK5, CK6, CK7, CK10, CK14, CK16 and CK17). In addition, frozen skin tissues from 12 patients with PCA were analyzed for comparison with the
paraffin-embedded tissue. In all 64 PCA
paraffin sections, the
amyloid deposits were immunopositive for anti-CK5 antibody and 34betaE12. In all 12 frozen sections of PCA, the
amyloid deposits were immunopositive for anti-CK5 antibody, 34betaE12, MNF116 and LP34, and seven (58.3%), three (25%) and one (8.3%) were immunopositive for anti-CK1, CK14, and CK10
antibodies, respectively. In all SCA sections, the
amyloid deposits were immunopositive for CK5 and 34betaE12. In addition, MNF116 immunolabeled amyloids of all sections from patients with
basal cell carcinoma and trichoepithelioma, and MNF116 and LP34 immunolabeled amyloids of sections from patients with
porokeratosis. Our results indicate that CK5 is the major CK present in the
amyloid deposits of PCA and SCA, and "
amyloid-K" is mainly derived from basal keratinocytes.