Acne vulgaris (AV) is the commonest immune-mediated skin problem affecting 9.4% people worldwide but still considered as non-curable (Liaqat et al., 2021; Alanazi et al., 2018). Acne ranks as the eighth most frequently seen sickness (Kaleta et al., 2020; Tan and Bhate, 2015). This self-limiting externally visible polymorphic disorder is commonly known as acne (Franik et al., 2018; Rahman et al., 2012). Acne affects pilosebaceous follicles and is chronic inflammatory (Endres et al., 2021; Sobhan et al., 2020). This externally visible disease has multiple etiologies (Shah et al., 2021; Franik et al., 2018). It is also a prevalent symptom in the course of hormone disorders (Rahman et al., 2012). Increased sebum production plays a major role in acne outcome (Sobhan et al., 2020). Acne primarily manifests as comedones (closed & open comedones) which are non-inflammatory (Lynn et al., 2016). The breakage of comedone components into the dermis causes inflammatory (nodules, pustules & papules) acne (Shah and Parmar, 2015; Salma et al., 2023). 

It mostly affects the face, with smaller amounts also occurring on the back, neck and chest (Rahman et al., 2012). There exist three distinct age groups of individuals with acne vulgaris: preadolescent, adolescent and post-adolescent or adult acne (Shah et al., 2021). Acne between 12–25 years of age is adolescent acne (Skroza et al., 2018). The GBD (Global Burden of Disease) report states that acne affects 85% teenagers worldwide (Sobhan et al., 2020). It often resolves in early adulthood (Lynn et al., 2016). Significant acne lesions still persist in 12% women and in 3% men until the age of 40s (Bogino et al., 2014). Its progress is unpredictable, and recurring flare-ups are typical (Shah and Parmar, 2015). Acne that appears above 25 years of age is referred to as post-adolescent or adult acne (Khunger and Kumar, 2012). It needs to be medicated and continues longer (Endres et al., 2021; Vergou et al., 2011). There are two distinct varieties of adult acne based on the time it first appears: persistent and late-onset acne (Skroza et al., 2018). Persistent acne is a continuation or relapse of adolescent acne into adulthood and middle age (Shah et al., 2021). Late-onset type develops initially after reaching the age of 25 or more who have not been experienced acne vulgaris previously (Kutlu et al., 2022; Khunger and Kumar, 2012). 

The main enzyme responsible for catalyzing the coupling reaction and iodination reactions involved in the production of thyroid hormone is thyroid peroxidase (TPO) enzyme (Kapoor et al., 2022). TPO-Ab is produced against TPO enzyme (Sridevi et al., 2018) and is located intracellularly (Fröhlich and Wahl, 2017). TPO-Ab, a member of thyroid autoantibody is most frequently assessed in population surveys (Li et al., 2008; Ghoraishian et al., 2006). This polyclonal antibody is heterogeneous (Kapoor et al., 2022; Fröhlich and Wahl, 2017) and is known as the anti-microsomal antibody historically (Sridevi et al., 2018). They are mostly IgG (Kapoor et al., 2022), although some are IgA (Fröhlich and Wahl, 2017). TPO-Ab directly causes the demise of thyroid cells (Amouzegar et al., 2017). They are sensitive indicator of AITD and thyroid disorders and judgement of treatment efficacy (Ghoraishian et al., 2006).  

Study place

The study was conducted at the Department of Physiology, Dhaka medical college, Dhaka, Bangladesh, from January 2022 to December 2022. 

Ethical approval of the study protocol

The study protocol was approved by Ethical Review Committee and Research Review Committee of Dhaka Medical College, Dhaka, Bangladesh. 

Selection criteria of the subjects 

Inclusion criteria of case 

Both genders with normal BMI and clinically identified acne vulgaris case (seborrhea which inclu-des comedones, pustules, papules, oily skin, nodules, and scarring) between the ages of 15 and 45 met the inclusion criteria. 

Inclusion criteria of control

The inclusion criteria for the control group were people who appeared to be in good health and matched by age, BMI and gender of case.

Exclusion criteria 

The study excluded patients with systemic diseases such as thyroid dysfunction, any autoimmune diseases, chronic renal disease, chronic liver disease, cancer, diabetes, subjects unwilling to take part in the study, alcohol users, lactating ladies, pregnant women, smokers and patients under medications for the previous three months or more that impair thyroid function (Birth control pills, dopamine, lithium, bromocriptine, amiodarone and levodopa). 

Study population and design 

A cross-sectional study was carried out in the Department of Physiology, Dhaka medical college, Dhaka, Bangladesh, from January 2022 to December 2022. Calculation of sample size in the cross-sectional study was done by following formula.

                                              n = (z2 pq)/d2 (Pourhoseingholi et al., 2013)

n = the desired sample size

z = Standard normal deviate usually set at 1.96

p = Prevalence of acne vulgaris is 3.9% (Tan and Bhate., 2015)

So, ‘p value will be 0.039. 

Q = 1 - p or 0.961.

n = [(1.96)2 x 0.039 x (1-0.039)] / (0.05)2    

Or, n = 57.59 ~ 58.

Therefore, there were 60 samples in each group and the total sample size was 120. At the commencement of the study, total 120 participants of both genders with age range from 15 to 45 years were enlisted. Among them, 60 acne vulgaris patients were enrolled in group A (Case) and 60 outwardly healthy participants of similar age of male and female having no history of acne or other hormonal disorders were included in group B (control) for comparison. Group A was recruited from Department of Dermatology & Venerology, Dhaka Medical College and Hospital & by personal contact from various regions of Dhaka city according to criteria for exclusion and inclusion. Group B was selected based upon inclusion criteria and exclusion criteria by direct communication from different territories of Dhaka city. A thorough dermatological evaluation was conducted and acne vulgariss categories were determined in group A. Again, group A was further divided into three subgroups: mild acne, moderate acne and severe acne depending on how severe acne was. Acne severity was determined dermatologically by applying clinical standards for acne severity which was as follows: Mild acne – described by the occurrence of either non-inflammatory wound, papulopustular (inflammatory) wound or both; Moderate acne - characterized by  papulopustular lesions, mild scar, accidental nodules or their combination; Severe acne - determined by significant inflammatory lesions, nodules or both, along with wounds; moderate acne that doesnt go away after six months of treatment and acne having a significant negative mental consequence. With all aseptic precautions, from antecubital vein, venous blood was drawn for determination of serum TPO-Ab level. Serum TPO-Ab <60U/mL was considered as normal value. TPO-Ab tests were reported as either positive or negative. TPO-Ab was analyzed in Nuclear Medicine Department of Dhaka Medical College Hospital, Dhaka in Siemens machine from Germany using an ADVIA Centaur XPT system. 

Statistical analysis

By using a computer based statistical program SPSS version 26, statistical analysis was carried out. The continuous variables (quantitative variables) were demonstrated as mean ± SD (mean ± standard deviation), median (IQR) & range and qualitative variables were mentioned as frequency & percentage. To compare the mean of quantitative variables between the two groups, unpaired students t test was executed. Chi-square test was carried out to investigate how two qualitative variables were related to one another. Mann-Whitney test was done for comparing the mean of TPO-Ab in skewed distribution between group A and group B. For comparing TPO-Ab among three subgroups of acne vulgaris, Kruskal-Wallis rank sum test was conducted. To assess the relationship between TPO-Ab and acne vulgaris severity, Spearmans rho correlation coefficient test was carried out. For all statistical tests, p value < 0.05 was accepted as level of significance. 

An overall total of 120 subjects of both genders with age range between 15 to 45 years who fulfilled the inclusion criteria were enrolled for this study. Among the recruited participants, group A (case) consisted of 60 acne vulgaris sufferers and group B (control group) included 60 subjects of similar age who appeared healthy having no complaints of acne or other endocrine problems with any visible skin symptoms for comparison. In group A, mean age was 29.32±7.60 years (Table 1). There were 36/60(60%) female and 24/60(40%) male in group A (Table 1 and Fig. 1). In group B, mean age was 31.80±7.79 years and there were 35/60(58.3%) female and 25/60(41.7%) male (Table 1 and Fig. 1). In group A, male and female ratio was 1:1.5 which was 1:1.4 in group B. Male and female ratio in both groups was 1:1.4 (Table 1).  The mean BMI of group A was 22.14±1.44 kg/m2 and group B was 21.64±1.54 kg/m2 (Table 1). No statistically significant (p>0.05) difference was found for age, BMI and gender between group A and group B group (Table 1). Hence, group A and group B were matched for age, BMI and gender.

Table 1: Distribution of sociodemographic characteristics between two groups (N=120).

Results were expressed as mean ± SD for quantitative (continuous) variables and percentage for all categorical variables. Group A =Case and group B = Control. p–values were based on unpaired t-test for all continuous variables and chi-square test for categorical variables.

Fig. 1: Bar diagram showing the distribution of gender in two groups (N=120).

Fig. 2: Pie diagram showing types of AV (%) in group A (case).

Among 60 acne patients of group A, adolescent type of acne was perceived in almost half of the cases 25/60(41.7%). One-third of the cases were persistent type 22/60(36.7%) and only a small percentage was late-onset type of acne 13/60(21.7%) (Fig. 2).

Regarding the acne severity, majority of the population 32/60(53.3%) had severe acne. The prevalence of mild acne was 7/60(11.7%). Around 21/60(35.0%) of the subjects had moderate acne (Table 2).

The mean (±SD) TPO-Ab of group A and group B were 463.80±532.55 U/mL and 184.1±375.1 U/mL and median (IQR) were 122.9 and 40.8 respectively 

(Table 3 and Fig. 3). TPO-Ab levels were observed statistically significantly (p-0.001) increased in group A in comparison to that of group B. TPO-Ab levels were 63.3% (38/60) positive and 36.7% (22/60) negative in group A (Table 3 and Fig. 4). Positive TPO-Ab represented two-third of the acne vulgaris patients. In group B, TPO-Ab levels were positive in 14/60 (23.3.%) and negative in 46/60(76.7%). TPO-Ab levels were statistically significantly (p<0.001) more positive in group A compared with group B (Table 3 and Fig. 4).

 

Table 3: Comparison of TPO-Ab between two groups (N=120).

Results were expressed as mean ± SD for continuous variables. Group A= Case and Group B= Control. 

ap–value was based on Mann-Whitney test and bp–value was based on Chi-square test.

Fig. 3: Bar diagram showing the distribution of TPO-Ab in two groups.

Fig. 4: Bar diagram showing the distribution of TPO-Ab status in two groups.

The level of TPO-Ab was increased with the increased severity of acne participants but the data did not show statistical significance (p-0.585) (Table 4). The median (IQR) value of TPO-Ab level among mild acne was 59.60 (28.0-833.1) U/mL which was almost one and half times higher 90.3 (28.0-1300.0) U/mL for moderate acne and almost 4 times higher 240.5(28.0-1300.0) U/mL for severe acne (Table 4). The prevalence of TPO-Ab was higher in severe type of acne vulgaris than other type of acne vulgaris. But in terms of statistics, it was not significant (p-0.270) (Table 4). TPO-Ab were positive for 3(42.9%), 12(57.1%) and 23(71.9%) of mild, moderate and severe acne respectively (Table 4). TPO-Ab showed positive correlation with the severity of acne vulgaris (r- +0.168) which was not statistically significant (p-0.200) (Fig. 5).

 

Table 4: Comparison between different subgroups of AV based on severity regarding TPO-Ab level and its prevalence in Group A (n=60).

Results were expressed as frequency, percentage. p–value obtained by Kruskal-Wallis rank sum test for quantitative variables and Chi-square test for categorical variables.

Fig. 5: Correlation of AV severity with TPO-Ab in group A (Spearmans rho correlation coefficient test).

AV is leveled as the third most as the third most widespread form of skin condition (Kaleta et al., 2020; Lynn et al., 2016). It may reflect an underlying illness (Franik et al., 2018). People of any age, gender or ethnic groups may develop acne. In the current research, mean (±SD) age of case and control were 29.32±7.60 years and 31.80±7.79 years respectively with age range between 15 to 45 years. Sobhan et al. (2020) in Iran stated that the mean ages of participants of acne and control were 24.7±6.3 years and 24.5±5.1 years respectively (age ranged within 15 and 44 years). Another study by Vergou et al. (2011) in Greece displayed that mean age of both groups were 23.6 ± 2.85 years and 25.5 ± 2.78 years respectively. This discrepancy may have resulted from differences in the sample size, ethnicity and methodology. Shah et al. (2021); Liaqat et al. (2021); Bogino et al. (2014) & Rahman et al. (2012) in their study found that acne partakers had mean (±SD) age of 30.12 ± 4.83 years; 24.45±2.90 years, 24.4 ±8.6 years & 22.43± 5.2 years respectively. In dermatology, acne vulgaris is outwardly evident typical skin conditions that affect individuals aged 15 to 40 (Franik et al., 2018). This could be linked to the multifactorial nature of acne. 

The present investigation disclosed that population of acne was dominated by females. Female and male respondents of acne were (36/60, 60%) and (24/60, 40%) respectively. Similar findings were noted by Alshammrie et al. (2020); Sobhan et al. (2020); Kaleta et al., (2020); Shrestha et al. (2019); Alanazi et al. (2018); Skroza et al. (2018); Lynn et al. (2016); & Bogino et al. (2014), who found female preponderance in acne than male. Research reports showing gender differences might suggest that female was more conscious about appearance and visiting hospital to get treatment of acne in comparison to male (Shah et al., 2021; Khunger and Kumar, 2012). On the contrary, Liaqat et al. (2021) in India observed greater incidence of acne in men. The research was limited by a smaller sample size and a small study location (Liaqat et al., 2021).

Acne prevalence in adults and adolescents varies by nation and ethnicity (Bagatin et al., 2014). In the current analysis, among the participants of group A, acne in adolescents was the most frequently encountered age group and perceived almost half of the cases 25/60(41.7%). One-third of acne were persistent acne 22/60(36.7%) and the least frequent was late-onset acne 13/60(21.7%). This age-related variation in acne subtype can be explained by a number of factors (Perkins et al., 2012). Sebum production declines with age, which declines inflammation or there may be age related physiological reduction in inflammation (Perkins et al., 2012). This investigation was in accordance with the findings of Liaqat et al. (2021); Skroza et al. (2018); Alanazi et al. (2018); Bagatin et al. (2014) ; Perkins et al. (2012) who found that acne incidence was higher among adolescents. Adult acne prevalence statistics are mostly based on survey responses and differ depen-ding on how adult acne and acne are defined (Perkins et al., 2012). There is limited data on the number of cases and research of adult acne (Lynn et al., 2016). According to recent surveys, a growing number of adults are suffering with acne (Kaleta et al., 2020; Khunger and Kumar, 2012). However, it is often neglected. Increased clinic/hospital reporting as well as better awareness may help to explain several aspects of increased prevalence of acne in adults (Shah et al., 2021). Additionally, review by Kutlu et al. (2022); Shah et al. (2021); Skroza et al. (2018) & Khunger and Kumar, (2012) reported higher rate of persistent acne among adult types which was consistent with the present analysis. The increasing prevalence of late adolescent acne is currently a worldwide problem (Lynn et al., 2016). 

Acne has a broad range of severity and possible hazard (Tan and Bhate, 2015; Shah and Parmar, 2015). Regarding how severe acne vulgaris is, in the present research, most frequent form of acne was severe acne 32/60(53.3%) which was more than 50% of the population. The prevalence of mild acne and moderate acne was 7/60(11.7%) and 21/60(35.0%) respectively. Variations in the severity of acne in different researches have also been reported. The technique of classification used in a study or severity and frequency of acne may be impacted by the involvement of any underlying diseases. In a study by Endres et al. (2021), it was established that in the auto-immune thyroid disease (AITD) group, severe acne was statistically significantly more common (p< 0.001). Perkins et al. (2012) in an earlier study observed 28% mild acne and 27% clinically severe acne in female between 10-70 years of age. Sobhan et al. (2020) found 9(20%) and 23(51%) of acne had mild and moderate acne respectively. On the other hand, in earlier studies by (Alanazi et al., 2018; Skroza et al., 2018; Bagatin et al., 2014; Vergou et al., 2011) the evaluation of acne severity reviewed that severe acne was the least common type of acne. Shah et al. (2021) observed that majority (72.8%) of patients had grade 2 acne followed by grade 3, 4 and 1 acne respectively. This difference was might be due to the variation in sample size, methods used, ethnicity and clinical examinations by a dermatologist (Bagatin et al., 2014).

Hormonal problems play an important role in development of acne (Franik et al., 2018). The community has a high frequency of thyroid diseases (Shrestha et al., 2019). The current study revealed statistically significant difference (p-0.001) between two groups regarding the presence of TPO-Ab. The mean (±SD) TPO-Ab were 463.80±532.55 U/mL and 184.1±375.1 U/mL in group A and group B respectively. The higher frequency of TPO-Ab in acne versus control supported the potential susceptibility of acne to AITD. TPO-Ab is common in AITD patients (Li et al., 2008). In the current research, TPO-Ab level was documented significantly (p<0.001) more positive in acne 38/60(63.3%) compared with control 14/60(23.3%). Positive TPO-Ab represented two-third of the acne vulgaris patients. According to a study by Chivato et al. (1993), TPO-Ab may be a target for cytotoxic assaults (Shrestha et al., 2019). In similarity to the present observation, research by Stewart and Bazergy, (2017) in Australia recorded 24/130 (18%) positive TPO-Ab in female post adolescent acne in comparison to 4/65 (6%) controls. These results also emphasize the autoimmune background of both the disorders that is acne vulgaris and thyroid dysfunction. Another research conducted by Li et al. (2008) in China revealed that incidence of positive TPO-Ab during the course of 5-years was 2.81%. Endres et al. (2021) in Romania found that 170/236 (72%) patients had elevated serum levels of antithyroid antibodies. 

In the current study, the median value of TPO-Ab level among mild acne, moderate acne and severe acne was 59.60 (28.0-833.1) U/mL, 90.3 (28.0-1300.0) U/mL and 90.3 (28.0-1300.0) U/mL respectively which was not significant statistically (p- 0.585). The study also displayed that TPO-Ab was increased with the increased severity of acne vulgaris but was not statistically significant (p-0.270). Endres et al. (2021) observed that TPO-Ab displayed significantly higher (p-0.007) in severe acne and moderate acne followed by mild acne. Shrestha et al. (2019) documented that 205/768 (26.7%) patients exhibited positive TPO-Ab results, suggesting that about one-fourth of the patients had thyroid autoimmune markers. Their research indicates that the incidence of AITD is increasing. TPO-Ab takes part in the thyroid follicular cells apical membrane to catalyze the production of thyroid hormone and to destroy thyrocytes directly (Amouzegar et al., 2017). TPO-Ab results in reduced synthesis of thyroid hormones (Shimizu et al., 2020). Hypothyroidism is caused by the continuous, gradual loss of thyroid follicular tissue (Shrestha et al., 2019). By inducing a detrimental effect on the thyroid hormone production, TPO-Ab has been exhibited to cause AITD (Shimizu et al., 2020).  TPO-Ab from AITD patients can act as competitive enzyme inhibitors, fix complement and destroy thyroid cells (Fröhlich and Wahl, 2017 & Ghoraishian et al., 2006). 

An earlier study conducted and published by Vergou et al. (2011) in Greece revealed that median (IQR) values for TPO-Ab in acne and control were 10.00 (0–857) and 12.90 (0–1000) which was not statistically significantly different (p-0.08). 21.50% (23 ⁄ 107) acne and 15.00% (9 ⁄ 60) control exhibited positive TPO-Ab which wasnt significant in statistical terms (p-0.31). Stewart & Bazergy, (2017) observed statistically significant difference (p-0.021) between group A 24/130 (18%) and group B 2/65 (3%) for positive TPO-Ab.  Positive TPO-Ab is correlated with chronic AITD (Ghoraishian et al., 2006). Several studies have reported that TPO-Ab could induce ADCC (antibody-dependent cell-mediated cytotoxicity) (Amouzegar et al., 2017; Li et al., 2008 & Ghoraishian et al., 2006). TPO-Ab is mainly generated by lymphocyte infiltration in the thyroid gland (Stewart and Bazergy, 2017). AITD causes an increase in T lymphocytes in the bloodstream and an invasion of the thyroid gland by CD4+ cells as well as CD8+ T cells. Infiltrated immune cells produce wide variations of cytokines which mediate cytotoxicity thus resulting in the degeneration of thyroid cells (Rajan, 2019). The current study revealed positive correlation of TPO-Ab with the severeness of acne (r- +0.168) which did not have significance in statistical analysis (p-0.200). TPO-Ab causes oxidative stress, which is manifested in the blood by elevated oxygen metabolites, decreased antioxidant potential, and accelerated glycosylation products (Fröhlich and Wahl, 2017). 

Acne vulgaris is generally recognized as a disorder of adolescence. However, the referral of patients aged over 25 years with acne vulgaris is increasing day by day. Thyroid disorders involve all the organ system of the body and as well as skin. Now days, the role of thyroid dysfunction and autoimmunity is strongly suggested in the pathogenesis of acne. Patients with acne vulgaris should be properly evaluated clinically and thorough laboratory investigations must be done for scanning and detection of thyroid disorders in early stage. This may help in accurate treatment of the patients with thyroid abnormalities and prevent of thyroid related comorbidities. There is paucity of researches highlighting the significance of thyroid antibodies for acne vulgaris. The present study was designed to evaluate TPO-Ab in acne vulgaris. After analyzing the results of the study, it can be concluded that women comprised a larger proportion of acne sufferers. The overall incidence of severe acne was statistically considerably higher followed by moderate and mild acne respectively when categorized in accordance with severity. Compared to those with adult acne, adolescents were more likely to have acne vulgaris. Among the post-adolescent or adult subtypes, persistent variety of acne participants were more affected than late-onset acne. There were statistically significantly higher levels of TPO-Ab in acne vulgaris. Serum levels of TPO-Ab were positively correlated with the severity of the acne but it lacked statistical significance. The study will help early detection of thyroid disorder in AV patient and prevention of thyroid related comorbidities. We recommended the estimation of urinary iodine concentration along with serum hormone study. 

U.S.: Contributed in conceptualization, methodology and writing the manuscript. D.B.; and M.R.I.: Contributed in data analysis, investigation, supervision and visualization. U.N.A.; T.M.; J.B.J.; and S.H.: Finally checked the manuscript and editing, data curation, funding acquisition and formal analysis. All the authors who are involved in this research read and approved the manuscript for publication.

With enormous gratitude, we are very grateful to the Department of Physiology and Department of Nuclear Medicine, Dhaka Medical College for their whole hearted cooperation. We also thank the study partici-pants (both acne and control) with enormous gratitude for their collaboration and active participation. 

No competing interests were disclosed by the authors that could be perceived as prejudicing the impartiality of the research reported.