Serum Cortisol Levels in Lichen Planus: A Systematic Review with Meta-Analysis.

Lichen planus (LP) is an autoimmune, mucocutaneous, T-cell mediated chronic inflammatory disease that involves the oral mucosa. The prevalence of LP is 0.04-2% in general population with a female predilection. Patients with skin lesions also manifest oral lesions predominantly and about 25% present with only oral lesions. The aim of the systematic review is to analyze the serum cortisol levels in LP patients to elucidate the role of cortisol in pathogenesis of the lesion. A comprehensive search was done using electronic data bases such as PUBMED, EMBASE, SCIENCE DIRECT, COCHRANE, GOOGLE, manual search, and back references of the articles were extracted. A total of seven relevant articles were reviewed and analyzed. Electronic database and manual search identified 55 articles. Out of which, 33 were excluded after reading titles and removing duplication and 23 studies were evaluated in detail after reading the abstract and full text. A final of seven studies were included based on the inclusion criteria to meet the research question. All the studies analyzed the serum cortisol levels in LP patients and also in healthy subjects. Within the limitations of this review, it can be inferred that Cortisol is an established stress hormone and Serum cortisol estimation could be an important indicator in identifying susceptible oral lichen planus patients. Copyright:

Introduction

Lichen planus (LP) is an autoimmune, mucocutaneous, T-cell-mediated chronic inflammatory disease that involves the oral mucosa.[1] The prevalence of LP is 0.04–2% in general population with a female predilection. Patients with skin lesions also manifest oral lesions predominantly and about 25% present with only oral lesions. Oral lichen planus (OLP) is classified into 5–6 types based on clinical presentations such as reticular plaque-like, bullous, papular, erythematous, and ulcerative. Burning sensation and pain at the lesion site are the characteristic symptoms of LP, which has a tendency to increase on intake of spicy foods.[2]

The etiology of LP remains unknown except for T-cell-mediated chronic inflammation, and a postulation of myriad of antigen-specific and nonspecific hypotheses have been suggested.[3] LP may also be caused by various triggering factors that are internal factors like heat shock proteins, psychological factor, and genetic factors and external factors like dental restorative materials, medications, and idiopathic factors. CD8+T cells induce apoptosis of basal keratinocytes apoptosis, which is induced by expression of the putative antigen on the surface of keratinocytes by recognizing the body's own peptides as antigens or at the early stage. Cell-mediated immune response, non-specific immune response, chemokines, and autoimmune hypothesis are the main mechanisms that are involved in the pathogenesis of OLP.[4]

Cortisol (21 carbon glucocorticoid) is secreted by the adrenal cortex and it influences metabolism, vascular responsiveness, cognition, immunoregulation, behavior, and pathological conditions such as inflammatory autoimmune disorders. Hence, it can be used to assess the stress levels in human beings. Increased cortisol levels cause changes in the hypothalamus–pituitary–adrenal axis when there is persistent anxiety. Morning cortisol levels are higher than cortisol levels at night. Serum cortisol evaluation results in total cortisol levels whereas salivary cortisol levels are also a reliable indicator.[5]

LP severity is strongly associated with psychological stress that might increase their somatic symptoms.[6] Serum cortisol level is used as an indicator in anxiety evaluation studies as a result of increased cortisol levels particularly during stress and anxiety situations. Physiological effects like pain, metabolic and endocrine changes also elevate the serum cortisol levels. Hence, serum cortisol is also known as the stress hormone. Stress and anxiety constitute as one of the major causative agents for LP because of their effects on the human immune system.[1]

Therefore, the main aim of the systematic review is to analyze the serum cortisol levels in LP patients to elucidate the role of cortisol in pathogenesis of the lesion.

Materials and Methods

This review was done in accordance with guidelines given by Cochrane Handbook of Systematic Review.

Inclusion criteria

Original research on Serum Cortisol levels in OLP patients

Studies where the serum samples were obtained from the patients

Studies where samples collected from patients manifested the lesion in active state.

Studies done on blood samples

Studies in English language were included

Studies that used Statistical Package for Social Sciences (SPSS) for statistical analysis.

Exclusion criteria

Papers where full texts could not be retrieved were excluded.

Case reports, case series, letters to editors, short communications, poster, conference proceedings, and review articles were excluded.

Studies on nonhuman and salivary samples were excluded.

The search strategy was in accordance with the Cochrane guidelines for systematic reviews. Articles relevant to the search strategy were identified from search data bases of PUBMED, EMBASE, SCIENCE DIRECT, COCHRANE, and GOOGLE from the year 2010 till January 2021. The article search included only those from the English literature. Hand search were also done to obtain the relevant articles of our interest. The title of the articles and abstracts were reviewed. The full text of selected articles were retrieved and further analyzed.

Statistical analysis

Review Manager (RevMan) version 5.4.1 was used for statistical analysis. The Standard Mean Difference for each study was meta-analyzed. The outcome measure is plotted in forest plot. The Standard Mean Difference with 95% Confidence Interval was calculated and pooled in meta analysis. Figure 1 gives the PRISMA flow diagram for the included studies.

Figure 1

Figure depicting the PRISMA flowchart of the included studies

Results

On analysis of seven studies, 100% of them were case-control studies, which analyzed the serum cortisol levels in OLP patients and control group. About 57.14% (four studies) estimated the serum cortisol levels by using Electrochemiluminescence method, whereas the remaining methods were ELISA in one study (14.28%), Chemiluminescence method in another study (14.28%), and Enhanced Lanthanide Fluoroimmunoassay in yet another study (14.28%). All the studies (100%) stated that the serum cortisol levels were significantly higher in OLP group compared to the healthy controls. The included studies are summated in Table 1 and the characteristics of the excluded studies are given in Table 2.

Table 1

Summation of the included studies

Author	Method used	Statistical analysis	P	Results
Shishir Shetty et al.	Electrochemiluminsence	Student’s t-test	P<0.001	Serum cortisol levels were higher in oral lichen planus patients and it could be a predictor for erosive nature of lichen planus.
Daniela Mirlcescu et al.	ELISA	Student’s t-test	P<0.001	Serum cortisol levels were statistically higher in OLP patients than healthy subjects
Priyadharshini Kartikeyan et al.	Electrochemiluminsence	Independent t-test	P=0.000	Significant rise in the serum cortisol levels in OLP patients
Muhaseena et al.	Electrochemiluminsence	t test	P<0.001	Elevated serum cortisol levels in olp patients is a clear indicator of stress in etiology of the lesion
Alhakam Ibrahim et al.	Enhanced lanthanide fluoroimmunoassay	t test	P=023	Mean of serum cortisol was higher in LP patients compared to the control group
Sam Jose et al.	Electrochemiluminsence	Student’s t-test	P<0.05	Different mean values for morning and evening serum cortisol levels in each groups
Nallan CSK Chaitanya	Chemiluminsence	Unpaired t-test	P<0.001	Anxiety is one of the associated factors in causation and prognosis of OLP.

Table 2

Characteristics of the excluded studies

Citation	Year	Reason For Exclusion
Catherine M Flaitz et al.	2011	Does not satisfy our inclusion criteria. It was a case report.
Mutafchieva et al.	2018	Does not satisfy our inclusion criteria. Study was a review article.
Cerqueira JDM et al.	2018	Does not satisfy our inclusion criteria. Study was a review article.
Vilar-Villanueva et al.	2019	Does not satisfy our inclusion criteria. Study was a questionnaire study.
Paswach Wiriyakijja et al.	2019	Does not satisfy our inclusion criteria. Study was a questionnaire study.
Malgorzata Radwan-Oczko et al.	2018	Does not satisfy our inclusion criteria. Study was a questionnaire study.
Assane Diop et al.	2020	Does not satisfy our inclusion criteria. Study was an epidemiological study
Giardi C et al.	2011	Does not satisfy our inclusion criteria. Study was done using salivary cortisol levels
Chen HX et al.	2017	Does not satisfy our inclusion criteria. Study was a questionnaire study
Lopez-Jornet P et al.	2016	Does not satisfy our inclusion criteria. Study was done using salivary cortisol levels
Kurosh Mohamadi Hasel et al.	2013	Does not satisfy our inclusion criteria. Study was done without a control group
Routary S et al.	2020	Does not satisfy our inclusion criteria. Not an original article
Lidia Gavic et al.	2014	Does not satisfy our inclusion criteria. Study was a questionnaire study
Milos Cankovic et al.	2015	Does not satisfy our inclusion criteria. Study was a questionnaire study
Madiha Rana et al.	2015	Does not satisfy our inclusion criteria. Study was a questionnaire study
Kruna Valter et al.	2013	Does not satisfy our inclusion criteria. Study was a questionnaire study
Alshahrani S et al.	2014	Does not satisfy our inclusion criteria. Study was a questionnaire study
Yan Zhang et al.	2011	Does not satisfy our inclusion criteria. No data available.
Isil Cakmak Karaer et al.	2020	Does not satisfy our inclusion criteria. Study was done in recurrent aphthous stomatitis group
Kathrina et al.	2020	Does not satisfy our inclusion criteria. Study was based on bone turnover in saliva
Daniel Pietzrak et al.	2018	Does not satisfy our inclusion criteria. Study was done based on psoriasis
Jenna L Riis	2018	Does not satisfy our inclusion criteria. Study was based on uric acid measurement in saliva
Lorena Maetinez et al.	2020	Does not satisfy our inclusion criteria. It is a chapter on identification of salivary biomarkers
Lucia Corina Dima Cozma et al.	2017	Does not satisfy our inclusion criteria. Study was based on cardiovascular dysfunction
Seung Ki Min	2017	Does not satisfy our inclusion criteria. Study was based on oral cancer cells
Yvette Z Szabo	2021	Does not satisfy our inclusion criteria. Study was based on salivary markers of inflammation
Ioana Tiua Gug et al.	2019	Does not satisfy our inclusion criteria. Study was based on salivary biomarkers detection
Sveučilište u Zagrebu et al.	2018	Does not satisfy our inclusion criteria. Study was not English language
Zahra Karimzadeh et al.	2020	Does not satisfy our inclusion criteria. Study was based on cancer proteins
Tetiana V Melnyk et al.	2019	Does not satisfy our inclusion criteria. Study was based on endotoxicosis and endogeneous toxication in LP patients.
Wei wei et al.	2017	Does not satisfy our inclusion criteria. Study was based on inhomogeneous expression profile of Th1/Th2 related cytokines
Chuanxia Lu et al.	2013	Does not satisfy our inclusion criteria. Study was based on intralesional betamethasone in OLP
Larshoffman	2016	Does not satisfy our inclusion criteria. Study was based on renal effects of anti PD 1 therapy
Mohammed - Hossein et al.	2020	Does not satisfy our inclusion criteria. Study was based on multiple sclerosis
Milad Alikhani et al.	2014	Does not satisfy our inclusion criteria. Study was based on geographic tongue
Zwkayi Kutluby et al.	2019	Does not satisfy our inclusion criteria. Study was based on color of skin
Jessica Wang et al.	2015	Does not satisfy our inclusion criteria. Study was a critical review
Quieroz et al.	2018	Does not satisfy our inclusion criteria. Study was based on recurrent aphthous ulcer
Fabianne Furtado et al.	2012	Does not satisfy our inclusion criteria. Study was based on keloid recurrence
Lais Morandini Rodrigues et al.	2019	Does not satisfy our inclusion criteria. Study was based on salivary levels for burning mouth syndrome
Lorena Da Ros Goncalves et al.	2010	Does not satisfy our inclusion criteria. Study was based on protein composition of unstimulated saliva
Annamaris Giraldi et al.	2013	Does not satisfy our inclusion criteria. Study was based on female sexual arousal disorders
Drew Taylor et al.	2016	Does not satisfy our inclusion criteria. Study was based on polymorphic eruption of pregnancy
A Ascierto	2020	Does not satisfy our inclusion criteria. It was a clinical trial.
Florence E Roufosse et al.	2013	Does not satisfy our inclusion criteria. Study was based on treatment for hypereosionophilic syndromes

Meta-analysis was done for all the seven included studies. The pooled Standard Mean difference using random effect analysis of serum cortisol levels in OLP patients compared with the control group was 0.75 μg/dl (95% CI: 0.52,0.98) with I2 = 94%, where I2 represents the heterogeneity of the studies. Results for the meta analysis are tabulated in Table 3 and Figure 2.

Table 3

Depiction of meta-analysis

Author and year	Lichen planus			Control			Standard mean difference Random effects
	Mean	SD	Total	Mean	SD	Total
Shishir Shetty-2010	12.16	3.55	30	7.21	1.62	10	1.52 [0.72,2.31]
Daniela- 2015	9.08	1.05	20	3.17	0.63	20	6.69 [5.03,8.35]
Muhaseena-2016	9.26	2.34	26	6.87	2.4	26	0.99 [0.41,1.57]
Priyadarshini-2016	20.87	6.85	30	10.46	4.17	30	1.81 [1.20,2.42]
Sam Jose-2019	4.76	26.63	30	19.53	11.71	30	-0.71 [-1.23,-0.19]
Nallan CSK Chaitanya-2020	13.02	3.70	30	10.16	3.51	30	0.78 [0.26,1.31]
Alkaham Ibrahim-2020	194.4	85.1	32	171.4	60.9	30	0.31 [-0.20,0.81]
Pooled Standard Mean difference using random effects							0.75 [0.52,0.98]

Figure 2

Forest plot depicting the meta analysis

Discussion

LP is a T-cell-mediated chronic inflammatory autoimmune disease that affects the oral cavity and skin, and predominantly in women. The age of onset for OLP is between the third and the sixth decades of life.[7] Though the etiology of OLP is still hypothetical, many factors have known to contribute for the pathogenesis of the lesion. Amin et al.,[16] stated that tobacco usage can be a contributing factor for pathogenesis of OLP as it increases the expression of inflammatory mediators like TLR-2 and CD-34.

Health is defined as the complete mental, physical, and social well-being of an individual and not merely the absence of a disease. Stress/anxiety can be defined as a reaction to any adverse stimulus, physical/mental, or emotional that disturbs the homeostasis of an individual.[8] Poor quality of life might induce stressful events in life, which is an established risk factor for the etiology of the lesion.[9]

Cortisol (21- carbon glucocorticoid) is secreted by the adrenal cortex and plays an important role in the regulation of fats, proteins, water metabolism, carbohydrates, maintaining vascular reactivity, and also regulation of blood vessels. It affects both the sensitivity of the central nervous system and stress response in humans. Serum cortisol levels are elevated during stressful events and it is an established biomarker for assessment of stress. Hence, it can aid in understanding the pathogenesis of OLP.[10]

This systematic review analyzed a total of seven relevant articles in which serum cortisol levels were comparatively evaluated for 176 healthy individuals with 198 LP patients.[1510] About 33.32% of the articles evaluated serum cortisol levels for recurrent aphthous ulcer and periodontal diseases for the study population. As it didn't meet the inclusion criteria, it has been excluded.

About 57.14% estimated the serum cortisol levels by using Electrochemiluminescence method,[13510] whereas the remaining methods were ELISA in one study (14.28%),[11] Chemiluminescence in another study (14.28%),[12] and Enhanced Lanthanide Fluoroimmunoassay in yet another study (14.28%).[13] All the seven studies (100%) analyzed serum cortisol levels in both LP and control group, which resulted in statistically higher serum cortisol levels than the control group.

Among the seven studies, three studies (42.85%) conducted a questionnaire evaluation to assess the anxiety/depression of the subjects included in the study. Two studies (28.57%) administered Hospital Anxiety Depression Score Questionnaire (HADS)[310] to evaluate the psychiatric status of the patients whereas one study (14.28%) administered the Depression Anxiety Stress Scale (DASS). The mean values of the questionnaire were higher in OLP patients compared to healthy subjects in all three studies.

Concerning the different clinical variants of OLP, two studies (33.33%) reported higher serum cortisol levels in erosive variant of OLP compared to the nonerosive variant. Subsequently, in the two studies, serum cortisol levels were elevated in the non-erosive variant of OLP when compared with the healthy subjects.[110] It can be inferred that higher serum cortisol levels observed in erosive variant of OLP could be due to the association between erosive type of lesions and emotional stress (Lowental U et al. 1995).

The sympathetic and parasympathetic regulation of the autonomous nervous system is altered by stress, which in turn alters the hypothalamic control of endocrine response that is controlled by the pituitary gland. Hormone elevation and autonomic activation plays a pivotal role in cytokine production and immune surveillance mechanism regulation that controls inflammatory process. High activity of lymphocytes, T cells, Langherhans cells, and cyto-toxicity of epithelial cells are seen in LP. Increase in the serum cortisol levels and dysfunction of the hypothalamus–pituitary–adrenal axis (HPA) may cause diseases like LP that affects the human immune system.[3]

Psychological changes can alter immune functions by changing the balance of Th1/Th2 cytokines and elevating the Th2 response, which is directly associated with the development of autoimmune diseases. Previous literatures show that high levels of morning plasma cortisol and low CD3+ T cells were observed in OLP patients, especially in patients with erosive lesions. This could be due to neuro–immune–endocrine relationship in OLP. Elevated cytokines are seen in the saliva of OLP patients with erosive and ulcerative forms of OLP. Evaluation of cytokines in OLP patients could be of important value as it is correlated with malignant transformation.[14] The clinical variants of OLP include reticular, erosive, and bullous like, where elevated serum cortisol levels were associated with erosive type of OLP than the reticular type when compared with healthy subjects. Subsequently, salivary cortisol levels were not as elevated as serum cortisol levels among the clinical variants of OLP.[15]

Meta-analysis for the seven included studies showed a pooled standard mean difference of 0.75 μg/dl (95% CI: 0.52,0.98) by using random effect analysis of serum cortisol levels in OLP patients compared with the control group. Out of the seven included studies, favorability for the OLP group was shown by only two studies (28.57%). The standard mean difference for the studies by Jose et al. (2019)[1] and Alkaham Ibrahim et al. (2020)[13] were -0.71 μg/dl (95%CI: -1.23,-0.19) and 0.31 μg/dl (95% CI: -0.20,0.81), respectively.

The standard mean difference of five studies (71.42%) favoring control group were 1.52 μg/dl (0.72,2.31),[10] 6.69 μg/dl (5.03,8.35),[11] 0.99 μg/dl (0.41,1.57),[3] 0.78 μg/dl (0.26,1.31),[12] and 1.81 μg/dl (1.20,2.42),[5] respectively. Though there was a statistical significant serum cortisol levels in case group than control group, meta analysis of these five studies does not favor the case group. This bias in favorability of the case-control groups could be because of the uneven distribution of sample sizes within them and also due to the different methods used by the studies to assess the serum cortisol levels.

The current review of seven studies clearly indicate that the measurement of serum cortisol levels can be a promising parameter in investigation of OLP as serum cortisol levels reflect an individual's response to stress.[5] Also, serum cortisol levels can also be an indicator for the erosive type of LP as psychological factors are more associated with erosive type of lesions.[1]

Though the current systematic review favor the role of cortisol marker in LP, the meta-analysis results are contradictory that could be because of the factors explained previously. Meta-analysis plays an important role by helping to record the flaws in the studies, assess the strength of an evidence, improve precision of estimates of effect, and pave way to improve the quality of the research.

We acknowledge the presence of limitations within this review. As there was minimal literature evidence on elevated serum cortisol levels in OLP, the number of original articles reviewed is less. In addition, the different methods used to estimate serum cortisol levels and different variants of OLP in the included studies are two important limitations in the present meta-analysis.

Conclusions

Cortisol is an established stress hormone and serum cortisol estimation could be an important indicator in identifying susceptible OLP patients. Understanding the role of stress in OLP pathogenesis will provide a better insight on the progression of the lesion, warranting more research in this area. This review concludes that serum cortisol estimation could be a promising parameter in the detection of OLP.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.