Langerhans cells in cutaneous tumours: immunohistochemistry study using a computer image analysis system

Density of Langerhans Cells in Nonmelanoma Skin Cancers: A Systematic Review

Langerhans cells (LCs) are bone marrow-derived dendritic cells (DCs) that represent 2-3% of the entire cell population of the human skin, known to have an ability to present antigens to T lymphocytes. Moreover, there is evidence that LCs are probably capable of inducing the local cytotoxic type T-cell-mediated response against the tumour-associated antigens. In the past two decades, a dramatic increase has been noted in the incidence of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). The purpose of this study was to critically assess the results of available studies quantitatively assessing the LCs in nonmelanoma skin cancers and try to establish a conclusion of its possible impact on their future treatment. The PubMed, EMBASE, and the Web of Science databases were searched, which returned 948 citations. After a thorough analysis of full article texts, 30 studies have been chosen, including 11 of the BCC, 12 of the SCC specimens, and 7 analysing both tumour types. There was an overall trend towards slightly higher numbers of LCs in BCC than in SCC; however, these tendencies were discrepant between the studies. We presume that such differences could be caused by various staining techniques with a broad spectrum of specificity, including anti-S100, anti-CD1a, and ATPase activity staining used for LCs identification. We hypothesise that as there is a high inconsistency between the results of the studies, as far as the densities of LCs observed in the specimens are concerned, it seems that the mechanism of the influence of LCs on the antitumoural immune response is complicated. Finally, as at present, there is a paucity of available risk scores for the recurrence or progression of BCC or SCC, the creation of classification stratifying that risk including the density of LCs could bring additional information both for the physician and the patient.

Evaluation of Immunohistochemical Findings and Clinical Features Associated with Local Aggressiveness in Basal Cell Carcinoma

BACKGROUND & OBJECTIVE

Basal cell carcinoma (BCC) is classified into BCC1 or low risk (nodular, superficial type) and BCC2 or high risk (micronodular, morpheaform, infiltrative, and basosquamous types) based on clinical behavior. This study attempts to evaluate immunohistochemical (IHC) findings and clinical features associated with local aggressiveness and recurrence in BCC lesions.

METHODS

This is a cross-sectional descriptive study conducted on 42 paraffin blocks (22 BCC1, 20 in BCC2) at Pathology Department of Afzalipour Teaching Hospital. First, demographic features of the patients were recorded and pathology blocks were classified by two dermatopathologists based on histopathological types of BCC1 and BCC2. Then, primary monoclonal antibodies including CD10, CD1a, SMA, Ki67, CD34, and P53 were utilized for IHC study. We compared BCC1 and BCC2 according to IHC markers, demographic features of patients, and tumoral features.

RESULTS

The mean number of Langerhans cells (LCs) within epidermis above tumor mass was 14+1.92 and 4.7±1.23 in BCC1 and BCC2, respectively; these results show a significant difference between the two groups (P=0.001). P53 was positive in 41.13±6.39% and 74.5 ±6.26% of the tumor cells in BCC1 and BCC2 groups, which was statistically significant (P=0.001). Also, the mean number of blood vessels was 14.40±1.30 and 21.40±1.97 in BCC1 and BCC2, that was statistically significant (P=0.005).

CONCLUSION

Higher numbers of angiogenesis (SMA positive) and positive P53 were observed in BCC2 than BCC1. Also, more active positive CD1a cells were observed in BCC1 compared to BCC2.

Claudin-1 expression decreases with increasing pathological grade in actinic keratosis and may be a marker of high-risk actinic keratosis

BACKGROUND

Actinic keratosis (AK) is a common sun-induced skin disorder that can progress to invasive squamous cell carcinoma. However, there is still no reliable method to predict high-risk AK.

AIM

To identify markers that reflect the biological behaviour of AK and to understand the pathogenesis of AK.

METHODS

In total, 52 patients with AK and 17 site-matched healthy controls (HCs) were enrolled. We evaluated solar elastosis and immunohistochemical features using antibodies to p53, vitamin D receptor (VDR), claudin-1 and Langerin (CD207). Comparisons between AK and HC skin were performed and analyses carried out according to the pathological grade of AK.

RESULTS

We found that in both patients and HCs, solar elastosis increased and Langerhans cell (LC) density decreased with ageing. Solar elastosis and p53 expression were higher and VDR expression was lower in patients than in HCs; however, there was no statistical difference between them in relation to the pathological grade of AK. Claudin-1 expression gradually decreased from HC skin to severe AK, and particularly decreased in areas with epidermal atypia. LC density in severe AK was significantly lower than in HC skin and mild AK, while there was no difference in LC density between HC skin, mild AK and moderate AK.

CONCLUSIONS

Claudin-1 could be a useful marker of the pathological severity of AK. In addition, p53 increases and VDR decreases in AK, not in a gradual manner but in the early steps of carcinogenesis. LC density is relatively maintained in AK until it reaches severe dysplasia.

Comparative analysis of extracellular matrix and cellular carbohydrate expression in the sporotrichosis and chromoblastomycosis

This work was based on the analysis of digital images of histochemical profile from subcutaneous lesions in sporotrichosis (ST) and chromoblastomycosis (CM) patients. An additional aim was the detection of carbohydrate expression using lectin histochemical analysis of the different carbohydrates in the fungal cell wall from four different species (Sporothrix schenckii, Fonsecaea pedrosoi, Phialophora verrucosa, and Cladophialophora carrionii) associated with diseases mentioned earlier. Slides from tissue biopsies from ST and CM positive patients (n=10, each) were stained according to routine techniques. Slides were incubated with 25 μg/ml of Con A lectins and WGA conjugated to peroxidase. Digital image analysis was carried out in a workstation using OPTIMAS™ software system. Routine histochemistry results indicated that there is significantly higher collagen deposition and elastic fibers in ST characteristic lesions compared with that found in CM cases. The ST interstitial fibrosis area was larger than in CM lesions. Comparative lectin binding showed a positive and intense lectin staining pattern in the cell wall of S. schenckii, suggesting a higher expression of glucose/mannose and N-acetyl glucosamine in their cell surface as evidenced by Con A and WGA, respectively. However, these lectins were not effective to recognize some carbohydrates moieties in the F. pedrosoi, P. verrucosa, and C. carrionii. Such findings contribute to additional information about specific recognition processes between fungal parasites and their host cell targets may be mediated by the interaction of carbohydrate-binding proteins, such as lectins, on the surface of one type of cell that combine with complementary sugars on the surface of another cells into fibro-connective tissues associated with lesions.

Quantitative study of Langerhans cells in basal cell carcinoma with higher or lower potential of local aggressiveness

BACKGROUNDS

Basal cell carcinoma affects areas of the body that have been exposed to the sun, and this disorder has different clinical and histopathologic presentations. Some of these forms have a higher potential of local aggressiveness, while others have a lower potential. Langerhans cells actively participate in the skin immune system.

OBJECTIVES

To quantitatively evaluate the number of Langerhans cells on the epidermis of basal cell carcinoma with lower and higher potential of local aggressiveness and on adjacent normal epidermis.

METHODOLOGY

The authors divided the sample into two groups with 14 histological slides each: one with basal cell carcinoma with lower potential of local aggressiveness and the other with basal cell carcinoma with higher potential of local aggressiveness. Immunohistochemistry with S-100 protein was used in the identification of Langerhans Cells. Langerhans cells present in 7 microscopic fields were counted using optical microscopy (400X magnification) and Weibel's morphometric grade. The mean for each lamina was obtained. Wilcoxon's statistical test was employed.

RESULTS

In the group with lower potential of local aggressiveness, there was a significant increase in the number of Langerhans cells in the adjacent normal epidermis, as compared with the number of cells in the epidermis superposed to the basal cell carcinoma (pd 0.05). There was no significant statistical difference in the group with higher potential of local aggressiveness (p >0.05).

CONCLUSION

The higher number of Langerhans cells in the normal epidermis adjacent to the tumoral lesion with lower potential of local aggressiveness could indicate greater immunological resistance of the epidermis, thus limiting the aggressiveness of the neoplasm.

[CD1a+ Langerhans cells in the peritumoral epidermis of basal cell carcinoma]

BACKGROUND

Basal cell carcinoma (BCC) is a common malignant tumor and its incidence has risen in recent decades. Research has shown the relationship between ultraviolet (UV) radiation, the skin immune system, and BCC. The role of Langerhans cells (LC) in the immune response to tumors has prompted research into LC density and morphology in response to UV radiation and BCC. However, the data are inconsistent due to differences in research methodology. OBJECTIVE. To study the density and morphology of LCs in the peritumoral epidermis of BCC using immunohistochemistry and image processing software and compare the results with those from the epidermis overlying the tumor.

MATERIAL AND METHODS

Twelve samples from patients with BCC were prepared with a CD1a stain. Areas of epidermis overlying and adjacent to the tumor were defined using light microscopy and the Image J image processing software. The LCs in each area were counted and the cell densities were calculated and compared. Morphological features of LCs were also evaluated in each epidermal areas.

RESULTS

The results showed a lower density of LCs in the epidermis overlying the tumor than in the peritumoral epidermis (p < 0.05). There were also differences in the size, shape, and dendritic pattern of the LCs between the epidermal areas.

CONCLUSIONS

The lower density and fewer morphological changes of LCs in the epidermis overlying BCC may give rise to alterations in the immune response to BCC. Digital image analysis is a reliable method for the morphometric evaluation of LCs.

Age-related changes of claudin expression in mouse liver, kidney, and pancreas

Tight junctions (TJs) play crucial roles in tissue homeostasis and inflammation through their roles in the control of paracellular transport and barrier function. There is evidence that these functions are compromised in older organisms, but the exact mechanisms leading to TJ deterioration are not well understood. Claudin proteins are a family of membrane proteins that constitute the structural barrier elements of TJs and therefore play a major role in their formation and function. Using immunohistochemistry and immunoblotting, we have studied the expression of six different claudin proteins (claudin-1, -2, -3, -4, -5, and -7) in three tissues (liver, kidney, and pancreas) of aging male and female mice. In general, we find an age-dependent decrease in the expression of several claudin proteins in all three tissues observed, although the exact changes are tissue specific. Our findings provide a possible basis for the decrease in tissue barrier function in older organisms.