An immunohistochemical study of cytokeratins in skin-limited amyloidosis

Keratinic amyloid deposition in canine hair follicle tumors

Keratinic primary localized cutaneous amyloidosis is a disease in humans; however, no similar condition has been reported in animals. This study aimed to investigate cutaneous keratinic amyloid deposition in dogs and elucidate its etiology. Canine hair follicle tumor tissues were histopathologically analyzed. Immunohistochemistry and mass spectrometry-based proteomic analyses were performed to identify precursor protein candidates. Structural prediction and in vitro fibrillization analyses were conducted to determine the amyloidogenic region and gene sequencing analysis was performed to assess mutations. Of the 266 samples, 16 had amyloid deposition. Amyloid deposits were found in the stroma of tumors and in the margins of keratin debris and around normal hair follicles. Cytokeratin 5 (CK5) was identified as a precursor protein candidate. C-terminal truncation of CK5 was observed in amyloid deposits, and the truncation sites varied depending on the deposition pattern. There was a significantly higher incidence of amyloid deposition in Shiba dogs, and CK5 amino acid polymorphisms were identified in these dogs. A part of the C-terminal region of both canine and human CK5 exhibited highly amyloidogenic properties in vitro. This study revealed the existence of cutaneous keratinic amyloid deposition in animals and identified CK5 as an amyloid precursor protein, providing novel insights into understanding the etiology of cutaneous amyloidosis.

Amyloid and Amyloid-Like Aggregates: Diversity and the Term Crisis

Active accumulation of the data on new amyloids continuing nowadays dissolves boundaries of the term "amyloid". Currently, it is most often used to designate aggregates with cross-β structure. At the same time, amyloids also exhibit a number of other unusual properties, such as: detergent and protease resistance, interaction with specific dyes, and ability to induce transition of some proteins from a soluble form to an aggregated one. The same features have been also demonstrated for the aggregates lacking cross-β structure, which are commonly called "amyloid-like" and combined into one group, although they are very diverse. We have collected and systematized information on the properties of more than two hundred known amyloids and amyloid-like proteins with emphasis on conflicting examples. In particular, a number of proteins in membraneless organelles form aggregates with cross-β structure that are morphologically indistinguishable from the other amyloids, but they can be dissolved in the presence of detergents, which is not typical for amyloids. Such paradoxes signify the need to clarify the existing definition of the term amyloid. On the other hand, the demonstrated structural diversity of the amyloid-like aggregates shows the necessity of their classification.

Comparison of Immunostaining with Hematoxylin-Eosin and Special Stains in the Diagnosis of Cutaneous Macular Amyloidosis

Background

Although macular amyloidosis is a relatively rare disease, it is a common cutaneous disease in Asia and the Middle East. On hematoxylin and eosin (H&E) stained slides, early lesions could easily be missed without the use of special stains and/or immunohistochemistry.

Methods

We enrolled 42 patients with the clinical impression of macular amyloidosis who had undergone two 4-mm punch biopsies from 2015 to 2016 at a dermatology clinic affiliated to Shiraz University. Besides, 14 cases with a clinical diagnosis other than macular amyloidosis were selected as the negative control group. Congo red, crystal violet, and immunohistochemical (IHC) staining of CK5 and high molecular weight keratin (HMWK) were performed for each specimen.

Results

H&E slides showed globular depositions in 15 (35.7%) out of 42 patients. None of the patients showed apple-green birefringence with Congo red stain. Evaluation of crystal violet stained sections revealed purplish violet amyloid deposits in 15 (35.7%) patients. IHC study showed expression of CK5 in 52.4% and HMWK in 50% of the patients, which was not a significant difference (p = 0.715). The findings of both IHC markers had a significant difference with H&E stains (p = 0.039) and crystal violet (p = 0.008). Additionally, we found that two punch biopsies from two sites in the involved area did not have a significant preference over one punch biopsy. All of the cases in the control group were negative for amyloid deposition in H&E, special stains, and IHC stained slides as expected.

Conclusions

IHC evaluation using CK5 and HMWK might be a useful tool for diagnosing macular amyloidosis.

Clinicopathological evaluation of patients with rippled pattern pigmentation of the skin: A single-center study

The aim of the present study was to investigate the clinical association between rippled pattern pigmentation and the positivity of histopathological analysis for amyloid. A total of 50 patients (90% women) with rippled pattern pigmentation referring to Dermatology Clinic of Shahid Faghihi Hospital, Shiraz, Iran, in 2015 participated in this study. Two biopsies were performed for all the cases from the most frequently affected sites. The specimens were evaluated for amyloid deposits with hematoxylin-eosin (H&E), Congo red (CR), and crystal violet (CV) stains. The upper back was the most frequently affected area in the patients. Family history (28%), atopy (14%), pruritus as a common finding (86%), and history of friction (54%) were positive. The prevalence of disease was higher in patients with skin photo Type 3. Amyloid deposit was not detected in most patients by these stains. No statistically significant difference was found between the amyloid positive cases stained with H&E, CR, and CV (p-value > 0.05). Only the difference in positive results between biopsy number 2 and the total biopsy (1 and 2) was significant (p-value < .05). In conclusion, it seems that it is useful to increase the number of biopsies and other more sensitive staining methods to detect small focal amyloid deposits.

Bilateral Limbal Keratin-Associated Amyloidosis

Conjunctival amyloid is usually of the immunoglobulin light chain (AL) variety. The authors report an exceptional case of bilateral limbal amyloid deposits that were identified by mass spectrometry as keratin-related specifically regarding to basal keratinocyte keratins 5 and 14. Cytokeratin-related amyloid has been described by immunohistochemical analysis of formalin-fixed cutaneous and mucous membrane lesions but not ocular tissues. The conjunctival lesion in the right eye contained intraepithelial dyskeratotic cells that extended to the surface, causing a lacy leukoplakia on clinical examination. The authors excluded the diagnosis of hereditary benign intraepithelial dyskeratosis in this patient. Collection of patient data and all protected patient health information was compliant with the Health Insurance Portability and Accountability Act.

In vitro amyloidogenic peptides of galectin-7: possible mechanism of amyloidogenesis of primary localized cutaneous amyloidosis

Pathogenesis of primary localized cutaneous amyloidosis (PLCA) is unclear, but pathogenic relationship to keratinocyte apoptosis has been implicated. We have previously identified galectin-7, actin, and cytokeratins as the major constituents of PLCA. Determination of the amyloidogenetic potential of these proteins by thioflavin T (ThT) method demonstrated that galectin-7 molecule incubated at pH 2.0 was capable of binding to the dye, but failed to form amyloid fibrils. When a series of galectin-7 fragments containing β-strand peptides were prepared to compare their amyloidogenesis, Ser(31)-Gln(67) and Arg(120)-Phe(136) were aggregated to form amyloid fibrils at pH 2.0. The rates of aggregation of Ser(31)-Gln(67) and Arg(120)-Phe(136) were dose-dependent with maximal ThT levels after 3 and 48 h, respectively. Their synthetic analogs, Phe(33)-Lys(65) and Leu(121)-Arg(134), which are both putative tryptic peptides, showed comparable amyloidogenesis. The addition of sonicated fibrous form of Ser(31)-Gln(67) or Phe(33)-Lys(65) to monomeric Ser(31)-Gln(67) or Phe(33)-Lys(65) solution, respectively, resulted in an increased rate of aggregation and extension of amyloid fibrils. Amyloidogenic potentials of Ser(31)-Gln(67) and Phe(33)-Lys(65) were inhibited by actin and cytokeratin fragments, whereas those of Arg(120)-Phe(136) and Leu(121)-Arg(134) were enhanced in the presence of Gly(84)-Arg(113), a putative tryptic peptide of galectin-7. Degraded fragments of the galectin-7 molecule produced by limited trypsin digestion, formed amyloid fibrils after incubation at pH 2.0. These results suggest that the tryptic peptides of galectin-7 released at neutral pH, may lead to amyloid fibril formation of PLCA in the intracellular acidified conditions during keratinocyte apoptosis via regulation by the galectin-7 peptide as well as actin and cytokeratins.

Primary cutaneous amyloidosis of the glans penis. Two case reports and a review of the literature

BACKGROUND

Primary cutaneous amyloidosis of the penis is a rare entity.

OBJECTIVES

We describe two cases of primary penile cutaneous amyloidosis presenting as localized lesions on the penis and not associated with systemic amyloidosis.

METHODS

A comprehensive literature review of all published cases.

RESULTS

The rarest form of cutaneous amyloidosis, nodular amyloidosis, is the most frequent presentation of penis-limited cutaneous amyloid with a low incidence of systemic disease progression.

CONCLUSIONS

Although primary nodular amyloidosis is a rare entity it seems to be the most frequent presentation of penile-limited cutaneous disease, with a low incidence of systemic involvement.

Cytokeratin contents of basal cell carcinoma, epidermis overlying tumour, and associated stromal amyloidosis: an immunohistochemical study

Cytokeratins (CKs) are expressed specifically in the cytoplasm of epithelial cells. We investigated the expression of CKs immunohistochemically in basal cell carcinomas (BCCs), epidermis overlying tumour, and skin tumor-associated amyloidosis (STA). Twenty cases of BCC, 11 of which had STA were included to the study. The primary antibodies of CK1-8 (AE3), CK10 (DEK-10), CK14 (LL002), CK17 (E3), CK18 (DC10), CK19 (KS19.1), CK 5/6/18 (LP34), CK8/18 (5D3) were applied to the section immunohistochemically. In BCCs without STA, CK1-8, CK14 and CK17 antibodies were expressed by tumour tissue in all biopsy specimens. In the BCCs with STA, tumour tissue was immunoreactive always with CK1-8 and CK17 antibodies, and commonly immunoreactive with anti-CK 14 antibody. In the epidermis overlying tumour tissue, there was positive immunoreactivity with anti-CK 1-8, CK 5/6/18, CK 10 and CK 14 antibodies in all biopsy specimens. Anti-CK 17 antibody was also positive in 17 biopsy specimens. STA is immunoreactive with anti-CK1-8 in all specimens. There was mild staining with anti-CK5/6/18 and with anti-CK19 whereas no immunoreactivity with anti-CK10 and CK18 antibodies was found. In conclusion, we could not find a significant CK expression difference between BCCs with and without STA. Weak positivity and a few number of CKs were shown in STA when compared with those of BCC and epidermis overlying tumour tissue expressing the more variable CKs. Interestingly, although CKs coexpressed in pairs consisting of one basic and one acidic CK, we detected predominantly basic CKs in STA.

A study of cytokeratin profiles in localized cutaneous amyloids

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.

Cytokeratin expression in lichen amyloidosus and macular amyloidosis

AIM

To understand the role of epidermal cells in the pathogenesis of lichen amyloidosus (LA) and macular amyloidosis (MA).

METHODS

We carried out immunohistochemical investigations on cytokeratins (CKs) in amyloid deposits in formalin-fixed and paraffin-embedded tissue specimens from eight persons with LA and 12 with MA. The primary antibodies of CK1-8 (AE3), CK10 (DEK-10), CK14 (LL002), CK17 (E3), CK18 (DC10), CK19 (KS19.1), CK5/6/18 (LP34) and CK8/18 (5D3) were used in the study.

RESULTS

In amyloid deposits, immunoreactivity with only two monoclonal antibodies (CK1-8 and CK5/6/18) was observed in 14 cases (eight LA and six MA), confirming the hypothesis that epidermal cells participate in amyloid formation of LA and MA.

COMMENTS

All of the CKs detected in amyloid deposits were basic type (type II). It seems plausible either that acidic CKs might be degraded faster than basic types in amyloidogenesis or that paraffin-embedded tissue specimens are less sensitive than frozen tissue sections. The results of our study suggest that when paraffin-embedded specimens are investigated by immunohistochemical methods, CK5 antibody is useful in the diagnosis of LA and MA.

Therapy for immunoglobulin light chain amyloidosis: the new and the old

An accurate diagnosis of amyloidosis and its subtype classification are essential for disease prognostication and treatment. In primary amyloidosis, overall median survival is approximately 2 years and may be less in patients with cardiomyopathy. Current therapy for primary amyloidosis is suboptimal. Controlled studies suggest that treatment with melphalan and prednisone may provide marginal survival benefit. A more aggressive approach such as autologous hematopoietic stem cell transplantation may offer potential for long-term benefit. Although patients undergoing autologous hematopoietic stem cell transplantation are highly selected, response rates can approach 60%, and patients with amyloidosis who respond to treatment have potential for long-term survival. New treatment modalities that were shown to have antitumor activity in multiple myeloma (high-dose dexamethasone and thalidomide) may also be of therapeutic value in primary amyloidosis. Systemic chemotherapy would not be expected to have any beneficial effect on other forms of amyloid and carries significant risk.

Immunohistochemical study of cytokeratins in amyloid deposits associated with squamous cell carcinoma and dysplasia in the oral cavity, pharynx and larynx

The frequency of amyloid deposits associated with squamous cell carcinoma (SCC) and dysplasia in the oral cavity, pharynx and larynx was examined. In addition, the origin of amyloid proteins by immunohistochemical staining with a panel of anticytokeratin monoclonal antibodies was investigated. Amyloid deposits were found in eight of 73 (11.0%) SCC and one of seven (14.3%) dysplasias in the oral cavity, in eight of 22 (36.4%) SCC and zero of two (0%) dysplasias in the pharynx, and in 22 of 37 (59.5%) SCC and four of 10 (40.0%) dysplasias in the larynx. Eight of 12 different cytokeratin (CK) antibodies reacted with these deposits: 34 beta E12 (CK1, -5, -10, -14) reacted with amyloid deposits in 19 of 19 cases (100%), LL002 (CK14) in eight of 18 cases (44.4%), MNF116 (CK5, -6, -8, -17) in eight of 19 cases (42.1%), D5/16B4 (CK5, -6) in five of 18 cases (27.8%), DE-K10 (CK10) in four of 17 cases (23.5%), RCK108 (CK19) in three of 18 cases (16.7%), 34 beta B4 (CK1) in three of 19 cases (15.8%) and AE8 (CK13) in two of 17 cases (11.8%). These antibodies always reacted with the cytoplasm of squamous cell lesions. Amyloid deposits in two cases contained a CK5 and CK14 pair, and in another two cases they contained both a CK5 and CK14 pair, and a CK1 and CK10 pair. Anti-CK antibodies, including OV-TL12/30 (CK7), c-51 (CK8), DC10 (CK18) and IT-Ks20.8 (CK20) did not react with the amyloid deposits. We conclude that the amyloid deposits associated with SCC or dysplasia in the oral cavity, pharynx or larynx were derived from CK of cancer cells and that some amyloid deposits might be assembled by two or more different CK.