Journal of Research in Dental

Abstract

Background and aim: Pemphigus vulgaris (PV) is an autoimmune disorder that can clinically manifest as oral mucosal ulcers. Several researchers believe that the level of female sex hormones such as estrogen and progesterone could be effective in the pathogenesis and growth of lesions such as desquamative gingivitis. Studies related to oral ulcers have revealed contradictory results regarding the presence of estrogen in the gingiva and salivary glands. Therefore, the main objective of this research was the evaluation and comparison of estrogen receptor (ER) expression in oral and cutaneous PV.
Materials and Methods: In this cross-sectional study, immunohistochemical staining was performed on 40 Paraffin blocks of oral and cutaneous PV. Staining intensity was investigated. Data were analyzed by Mann-Whitney test, Fisher test and
T-test using SPSS 18 software.
Results: The mean age of the patients equaled 38.3±11.8 and 42.8±11.3 years in oral and cutaneous PV, respectively. The most common sites of ER expression were the buccal mucosa (55%), trunk (21.1%) and scalp (21.1%). Positive ER expression in oral and cutaneous PV was found in 35% and 89.4% of the cases, respectively. Also, there were significant differences in ER expression intensity between cutaneous and mucosal PV (P=0.001). There was no significant correlation between sex, age and ER expression in cutaneous and oral PV
Conclusion: The results of the present study showed that there were significant differences in the intensity of ER expression between cutaneous and mucosal PV.
Key words: Pemphigus Vulgaris, Estrogen receptor, oral lesions.
 

Introduction

 
Pemphigus vulgaris (PV) belongs to the category of blistering dis­eases and affects both skin and mucous membranes. It in­volves the autoantibodies against cell surfaces of keratinocytes, and causes acan­tholysis and blistering (1,2).
PV is considered an auto­immune disease, based on the production of autoanti­bodies such as IgG and IgA against intercellular attachments known as desmosomes (desmoglein 1 and 3) (1, 2).
Thus, according to its etiology, clinical examination of this severe and chronic disease reveals large bullous and/or erosive lesions. Bullas occur as supra-basal clefts in the epidermis and/or epithelium which are susceptible to rupture and erosion. This disease occurs mostly during the fourth and sixth decades of life without any sex predilection (3).
Estrogen is a female sex hormone that regulates various physiological processes in reproductive, mammary and other tissues. Estrogen affects different cells through interaction with estrogen receptors (ERs): ERα and ERβ, which belong to the family of nuclear hormone receptors. (4)
In addition to the regulatory effect on human physiology, estrogen also influences diverse pathophysiological processes including cancer (4-6). It has been proposed that female sex hormones indirectly act on the oral cavity and other tissues by up-regulation of VEGF production in macrophages and endothelial cells (7).
Some researchers have reported that ERα is mostly found in classical target tissues of estrogen such as the mammary gland and endometrium, while ERβ can be found in tissues such as colon and prostate epithelium (8). Valimaa et al. reported that ERα was absent in the buccal mucosa, gingiva and salivary glands, whereas ERβ was found in keratinocytes and acinar and ductal portion of salivary glands. Therefore, they concluded that estrogen can affect oral tissues via ERβ (8). On the other hand, Voutsadakis reported that ERβ shows higher expression levels in benign tumors. Contrariwise, ERα has higher expression levels in malignant tumors (9).
Some authors believe that changes of estrogen levels in blood and saliva leads to changes in oral soft tissues (8,10,11).
It has been suggested that PV may be hormone (estrogen)-mediated and if this hypothesis is confirmed, hormone therapy can be beneficial (5).
Therefore, the present study aimed to evaluate ER expression in patients with oral and cutaneous PV without evaluating specific receptor types due to limited data on the exact location of ERs and the indefinite mechanism of estrogen signaling pathway.
We investigated ER expression in oral and skin lesions of PV, since ERs are present in different tissues such as the gingiva and epithelium, in addition to the classical target tissues, and some researchers believe that change in estrogen levels can cause changes in oral soft tissues.
 

Materials and methods

In this analytical cross-sectional study, 20 Paraffin blocks of oral PV were retrieved from the archives of the oral and maxillofacial pathology department of Qazvin University of Medical Sciences, Iran, by census method. Also, 20 Paraffin blocks of cutaneous PV were retrieved from the archives of Sina hospital, Tabriz, Iran. Hematoxiline & Eosin (H&E)-stained tissue sections of each block were reviewed to confirm the diagnosis. Only the samples with suitable and adequate tissue for sectioning and staining and with complete information regarding age, sex and the anatomical site of the lesion were included in the study. First, 4 µm-thick sections were prepared for immunohistochemical staining. Immunohistochemical technique was performed using Streptavidin-Biotin Complex and ER antibody (DAKO, Carpinteria, USA). Afterwards, the slides were examined under a light microscope and the expression intensity of the cells was determined following the method used by Yih et al, as follows (5):
-: negative
 +: weak
++: moderate
+++: strong
Cells were examined at x400 magnification. Normal testicular tissue with +++ staining intensity was used as a positive control (12). Finally, the data were entered into SPSS 18 software and were analyzed by Mann-Whitney test, Fisher test and T-test.
 

Results

In the present study, 40 paraffin blocks were used as samples, although one of the cutaneous blocks was excluded from the study due to inappropriate processing and loss of texture. Among the 39 samples, 16 cases (41%) were retrieved from males and 23 cases (59%) were retrieved from females. Males and females were almost equally affected by PV. (Table 1) There was no significant correlation between sex and type of PV (oral and cutaneous) (P=0.975).
Table 1: Frequency distribution of PV based on gender

The mean age of the patients affected by oral PV was 38.3±11.8 years. Female (12 cases) to male (8 cases) ratio was 1.5/1. Positive ER expression was found in 7 samples (35%). The most common sites of ER expression were the buccal mucosa (55%) and tongue (20%), respectively. The results revealed no significant correlation between sex and frequency distribution of PV in different parts of the oral cavity (P=0.48).
 
The mean age of the patients affected by cutaneous PV was 42.8±11.3 years. Female (11 cases) to male (8 cases) ratio was 1.3/1. Positive ER expression was found in 13 samples (68.4%). The most common sites of ER expression were the trunk and scalp, with similar frequency (21.1%). The results revealed no significant correlation between sex and frequency distribution of PV in different parts of the skin (P=0.09).
Finally, positive ER expression in cutaneous and oral PV equaled 89.4% and 35%, respectively. There were significant differences in the expression intensity of ER between cutaneous and mucosal PV (P=0.001). Moderate (++) and strong (+++) expression intensities were observed only in cutaneous PV. (Table 2)
Table 2: Marker expression intensity based on PV type