CK16, Skin Damage

Cytokeratin-16 is a type I cytoskeletal protein. It is used as a marker for epidermal hyperplasia, a characteristic which is associated with various inflammatory skin diseases such as atopic dermatitis and psoriasis, see [1]. In contrast, CK16 protein expression in normal epidermis is very low or absent.

This protocol can be used for quantifying the epidermal expression of CK16. It divides the CK16 staining intensity into four categories: no staining (negative), low staining intensity (1+), medium staining intensity (2+), and high staining intensity (3+). An intensity score is calculated based on the categories.

Figure 1

Part of epidermis stained with CK16

Figure 2

Manual outline of epidermis

Figure 3

>CK16 staining intensity categorization within the epidermis with exclusion of nuclei

Figure 4

Microscopic view of epidermis stained with CK16

Figure 5

Microscopic view of analyzed image

Details

Quantitative Output variables

The output variables obtained from this protocol are:

Total area of the epidermis excluding nuclei [μm²]
Percentage of the epidermis area (excluding nuclei) with negative staining intensity
Percentage of the epidermis area (excluding nuclei) with 1+ staining intensity
Percentage of the epidermis area (excluding nuclei) with 2+ staining intensity
Percentage of the epidermis area (excluding nuclei) with 3+ staining intensity
Intensity score (inspired by the H score) defined as: 1 x (Percentage of 1+ staining intensity) + 2 x (Percentage of 2+ staining intensity) + 3 x (Percentage of 3+ staining intensity)

Workflow

Step 1: Manually outline the epidermis

Step 2: Load and run the APP “10152 – CK16, Skin damage” for the quantification of CK16 staining intensity

Methods

The nuclei present in the epidermis are detected using a polynomial blob filter on a blue-enhancing feature image. The detection allows for exclusion of the nuclei before quantifying the CK16 staining intensity. A feature image, which revolves around red staining, is used for quantification of CK16 intensity. The intensity is divided into four groups ranging from negative (no staining) to strongly positive (3+) based on a threshold classifier and morphological post-processing steps is used for slight smoothing of the stain to handle grainy areas.

Staining Protocol

There is no staining protocol available.

Keywords

CK16, Skin, Skin damage, Dermatology, Digital pathology, Image analysis, IHC

References

LITERATURE
1. De Jong, G. J., High Expression Levels of Keratinocyte Antimicrobial Proteins in Psoriasis Compared with Atopic Dermatitis, J. Invest Dermatol. 2005, 126 (6), 1163-1173.