|Year : 2022 | Volume
| Issue : 2 | Page : 97-102
Immunohistochemical demonstration of interleukin-17 positivity in skin biopsy specimens of patients with chronic plaque psoriasis and its correlation with severity of psoriasis and associated metabolic syndrome and cardiovascular changes
Madivalara Yallappa Suparna1, Praveen Kumar Shanmugam Reddy1, Tharayil Kunneth Sumathy1, Vijaya V Mysorekar2
1 Department of Dermatology, M.S. Ramaiah Medical College, Bengaluru, Karnataka, India
2 Department of Pathology, M.S. Ramaiah Medical College, Bengaluru, Karnataka, India
|Date of Submission||19-Jan-2022|
|Date of Decision||11-Feb-2022|
|Date of Acceptance||11-Mar-2022|
|Date of Web Publication||26-Aug-2022|
Praveen Kumar Shanmugam Reddy
T2, 3rd Main, 2nd Cross, 1st Block, Koramangala, Bengaluru - 560 034, Karnataka
Source of Support: None, Conflict of Interest: None
Background: Psoriasis is a chronic inflammatory disease which can be associated with metabolic syndrome and cardiovascular abnormalities. Objectives: The aim and objective of the study are to demonstrate interleukin-17 (IL-7) positivity in histopathological sections of psoriatic plaques and to correlate with metabolic syndrome and cardiovascular changes. Materials and Methods: Forty-seven patients with chronic plaque psoriasis with body surface area >10% and psoriasis area and severity index (PASI) score >12, in whom skin biopsy showed munro's microabscesses, were evaluated for IL-17 positivity (intensity and proportion) with associated metabolic syndrome according to the National Cholesterol Education Program adult treatment panel III criteria and cardiovascular comorbidities. A co-relation with PASI score was made. IL-17 intensity and proportion were graded with a score ranging from 0 to 3. IBM SPSS version 16.0 was used for statistical analysis and independent t-test and Chi-square test were used for proportion. Results: The mean age of patients was 43 years. A total of 15 (31.9%) female and 32 (68.1%) male patients were enrolled. The mean PASI score was 21.6. Metabolic syndrome was seen in 31 (65.96%) patients. There was statistically significant association with raised diastolic blood pressure in patients with metabolic syndrome (P = 0.042). The total number of patients with IL-17 positivity with metabolic syndrome was 21 (63.6%). Of these, 9 (42.9%) cases showed IL-17 positivity in the munro's microabscess, 14 (66.7%) cases in the rest of the epidermis, and 18 (85.7%) cases in the dermis. Conclusion: In our study, there was no significant difference in IL-7 positivity between patients with or without metabolic syndrome. Further studies need to be done with large sample size to confirm the significance.
Keywords: Chronic plaque psoriasis, immunohistochemistry, interleukin-17, metabolic syndrome
|How to cite this article:|
Suparna MY, Shanmugam Reddy PK, Sumathy TK, Mysorekar VV. Immunohistochemical demonstration of interleukin-17 positivity in skin biopsy specimens of patients with chronic plaque psoriasis and its correlation with severity of psoriasis and associated metabolic syndrome and cardiovascular changes. Clin Dermatol Rev 2022;6:97-102
|How to cite this URL:|
Suparna MY, Shanmugam Reddy PK, Sumathy TK, Mysorekar VV. Immunohistochemical demonstration of interleukin-17 positivity in skin biopsy specimens of patients with chronic plaque psoriasis and its correlation with severity of psoriasis and associated metabolic syndrome and cardiovascular changes. Clin Dermatol Rev [serial online] 2022 [cited 2023 Feb 3];6:97-102. Available from: https://www.cdriadvlkn.org/text.asp?2022/6/2/97/354745
| Introduction|| |
Psoriasis is a chronic inflammatory skin disease which involves various immune cells and cytokines, resulting in hyperproliferation of the epidermis. In psoriasis, there is interplay of epidermal keratinocytes, dermal vascular cells, and activated antigen-presenting cells, monocytes/macrophages, Th1 and Th17 cells. Interaction of activated T-cells with monocytes/macrophages occurs through the Th17/IL-23 axis, which is an important mechanism in chronic inflammation in psoriasis. Neutrophils are an important source of IL-17 in psoriasis, and the cross-talk between keratinocytes and neutrophils is an important mechanism in the pathogenesis of psoriasis. In this cross-talk, IL-17 produced and/or stored by neutrophils, mast cells, and T cells stimulate epidermal cells to produce neutrophil chemoattractant, leading to increased neutrophil counts in psoriatic plaques. Inhibition of this crosstalk is an important mechanism in treatment of psoriasis.
An association has been reported between the occurrence of a group of conditions such as psoriasis, diabetes mellitus, hypertension, hypercholesterolemia, and metabolic syndrome. Psoriasis is associated with systemic inflammation, and there seems to be a common pathway in the etiopathogenesis of psoriasis and metabolic syndrome.
Munro's microabscess in skin biopsy samples of chronic plaque psoriasis is pathognomonic. IL-17 in biopsy specimens of psoriasis shows positivity in the munro's microabscess in the epidermis in a few studies., However, there is paucity of such data on the demonstration of IL-17 positivity in the munro's microabscess in psoriatic plaques. In this study, immunohistochemical demonstration of IL-17 in various areas of epidermis and dermis in cases of chronic plaque psoriasis and its correlation with metabolic syndrome was studied. This may form the basis of newer treatment modalities in chronic plaque psoriasis.
The present study aimed at demonstration of interleukin-17 (IL-7) positivity in histopathological sections of psoriatic plaques and to correlate the association of IL-7 positivity with metabolic syndrome and cardiovascular changes.
| Materials and Methods|| |
The study was approved by the institutional Ethics committee (MSRMC/EC/2016). Forty seven consecutive patients attending the dermatology out patient department of M S Ramaiah medical college and hospitals who were clinically diagnosed to have chronic plaque psoriasis with body surface area (BSA) involvement of >10% and with a Psoriasis area and severity index score (PASI) of >12 were included in the study. After obtaining a written informed consent, demographic details of the patient, duration of the disease, number of lesions, clinical morphology of lesions, BSA and PASI score, and associated medical conditions were recorded on a predesigned patient pro forma. The inclusion criteria included patients with age >18 years, clinically diagnosed with chronic plaque psoriasis with >10% BSA involvement with a PASI score of >12 and who were not on any topical or systemic treatment for psoriasis in the past 4 weeks.
A skin biopsy sample of 5 mm from the lesion was taken and processed in the conventional manner for histopathological examination. H and E-stained slides were prepared and evaluated for histopathological features of psoriasis. In cases which showed the classical features of chronic plaque psoriasis with munro's microabscesses, from the same formalin-fixed paraffin-embedded tissue, a 3-micron thin section was taken on a poly-L-lysine-coated glass slide for immune histochemical staining with anti-IL-17 antibody. Immunohistochemistry (IHC) was performed using heat-induced antigen retrieval. The sections on poly-L-lysine-coated slides were treated with rabbit polyclonal antibody against IL-17 A (Elabscience, dilution 1:150) for 60 min. Secondary antibody with horseradish peroxidase and chromogen diaminobenzidine was used. The slides stained for IHC for IL-17 were screened for positivity (brown staining reaction). IL-17 positivity in the munro's microabscess, other areas of the epidermis and dermis were identified.
IL-17 intensity was graded with a score ranging from 0 to 3
- 0: no positivity
- 1: weak positivity
- 2: moderate positivity
- 3: intense positivity.
IL-17 proportion of the involved tissue was scored from 0 to 3
- 0: up to 10%
- 1: 11%–25%
- 2: 26%–50%
- 3: >50%).
The National Cholesterol Education Program (NCEP) adult treatment panel (ATP) III criteria was adapted for the diagnosis of metabolic syndrome in our patients. Accordingly, all our patients were screened for (a) obesity (waist circumference >40 inches in males, >35 inches in females), (b) hyperglycemia (fasting glucose ≥100 mg/dl with or without treatment), (c) dyslipidemia (triglycerides ≥150 mg/dl with or without treatment), (d) dyslipidemia (high-density lipoprotein [HDL] cholesterol <40 mg/dl in males or <50 mg/dl in females with or without treatment), (e) hypertension (>130 mmHg systolic or >85 mmHg diastolic with or without treatment). The presence of any 3 out of the 5 criteria was considered diagnostic of metabolic syndrome. A screening electrocardiogram (ECG) in all patients and echocardiogram (ECHO) if necessary was done as per the protocol.
Descriptive statistics comprising of mean (± standard deviation [SD]) for continuous variables and proportion for discontinuous variables was used. IBM SPSS version 16.0 SPSS Inc. Released 2009. PASW Statistics for Windows, Version 18.0. Chicago: SPSS Inc was used. Independent t-test was used to assess the statistical significance between the mean (± SD) PASI scores and Chi-square test of proportion for positivity rates. The level of significance was P < 0.05.
| Results|| |
A total of 47 patients consistent with histopathological diagnosis of chronic plaque psoriasis were enrolled in our study. The mean (± SD) age of patients was 43 years (± 12). A total of 15 (31.9%) female and 32 (68.1%) male patients were enrolled for the study. The duration of the disease was categorized as <1 year, 1–5 years and more than 5 years with 12 (25.53%), 19 (40.4%) and 16 (34%) patients in each group, respectively. The mean PASI score was 21.6 (SD = 10.74) [Table 1]. The mean PASI score among patients with metabolic syndrome was higher as compared to patients without metabolic syndrome. However, owing to small sample size, it has not reached statistical significance [Figure 1].
|Figure 1: Error plot depicting mean and standard deviation of psoriasis area and severity index score among patients with or without metabolic syndrome (1 and 2 as depicted in the graph)|
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The patients were evaluated for metabolic syndrome using NCEP ATP III criteria. The various parameters studied according to the criteria are highlighted in [Table 2]. Metabolic syndrome was seen in 31 (65.96%) patients. Among them, 24 (51.1%) patients had obesity, 15 (31.9%) had hyperglycemia, 14 (29.8%) had dyslipidemia (increased triglycerides), 27 (57.4%) patients had dyslipidemia (low HDL levels), and 15 (31.9%) patients had hypertension. There was statistically significant association with raised diastolic blood pressure (DBP) in patients with metabolic syndrome (P = 0.042). The total number of patients with IL-17 positivity (in munro's microabscess/other areas of the epidermis/the dermis) were 33 (70.2%) out of total 47 patients enrolled in the present study. Of these, 12 (25.5%) patients showed IL-17 positivity in the munro's microabscess, 20 (42.5%) patients in the epidermis, and 26 (55.3%) in the dermis. It was noted that several patients had positivity reported at more than one site.
|Table 2: Various parameters in the National Cholesterol Education Program Adult Treatment Panel III criteria in patients with metabolic syndrome|
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Among 33 cases which showed IL-17 positivity, 4 (8.5%) patients showed an intensity of 3+, 18 (38.3%) showed 2+, and 11 (23.4%) showed 1+ [Table 3]. Among these 33 cases, 6 (12.8%) had a proportion score of 3, followed by 16 (34.0%) with score 2, 11 (23.4%) with score 1 [Table 3].
The total number of patients with IL-17 positivity who also had metabolic syndrome was 21 (63.6%) [Table 4] and [Table 5]A. Of these, there were 9 males and 12 females. Among them, 9 (42.9%) cases showed IL-17 positivity in the munro's microabscess, 14 (66.7%) cases in the rest of the epidermis, and 18 (85.7%) cases in the dermis [Table 5]B. It was noted that many of the patients had positivity at more than one site.
|Table 5: Comparism of IL-17 positivity in total number of patients versus patients with metabolic syndrome, at epidermis, munro microabscess and dermis|
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The intensity of IL-17 staining in patients with metabolic syndrome [Table 6] was 3+ in 3 (75%), 2+ in 14 (77.8%), and 1+ in 4 (36.4%) patients. The proportion of IL-17 staining in patients with metabolic syndrome [Table 7] was 3+ in 5 (83.3%), 2+ in 12 (75%), and 1+ in 4 (36.4%) patients [Table 7].
There was no statistically significant difference observed between IL-17 positivity in the munro's microabscess, other areas of the epidermis, and the dermis among patients with metabolic syndrome. There was also no statistical significant correlation between IL-17 positivity (including intensity and proportion) and the duration of the disease. There were also no differences in association between male and female patients.
| Discussion|| |
Chronic plaque psoriasis patients have various pro-inflammatory cytokines which are found in the plaques and these are known to be associated with metabolic syndrome and cardiovascular abnormalities. There are various studies which show mixed association of chronic plaque psoriasis with metabolic syndrome and its association with increased severity of psoriasis. There is a paucity of studies from India on the prevalence of chronic plaque psoriasis associated with metabolic syndrome. In a study by Pereira et al. on 77 patients of chronic plaque psoriasis and Lakshmi et al. in 40 patients of chronic plaque psoriasis in South India, there was no significant association between chronic plaque psoriasis and metabolic syndrome. In a study by Gisondi et al., there was no correlation between metabolic syndrome and severity of psoriasis. However, there was an increased occurrence of metabolic syndrome in psoriasis patients. In a study by Sommer et al., they did not observe any difference in the prevalence of metabolic syndrome among patients with chronic plaque psoriasis with a duration less than or more than 15 years. In a recent study by Madanagobalane and Anandan using the NCEP ATP III criteria, they observed that metabolic syndrome was significantly more in psoriatic patients but there was no correlation with severity of psoriasis.
There is enough data to indicate that various components of metabolic syndrome are higher in patients with chronic plaque psoriasis. In our study, the association between raised DBP and metabolic syndrome was significant (P = 0.042). Langan et al. have noted the association of severity of psoriasis to the presence of obesity, hypertension, and elevated fasting blood sugar. In their study, psoriasis was associated with metabolic syndrome and the association was seemed to increase in a “dose-response” manner wherein patients with more than 10% BSA involvement had an increasing association with metabolic syndrome. However, in their study, severity was assessed using BSA of involvement which can be a poor marker of severity as compared to PASI score. In our study, there was no statistically significant difference between severity of psoriasis (PASI >12) and metabolic syndrome [Figure 1].
In our study, patients were evaluated for metabolic syndrome using NCEP ATP III criteria. Among the parameters evaluated, there was a significant association between raised DBP in patients with metabolic syndrome and psoriasis. There were only 3 cases with ECG abnormalities (Sinus bradycardia), of which 2 had an abnormal ECHO. The ECHO changes noted in our study were hypokinesia in one patient and old anterior wall myocardial infarction changes in the second patient. This is in contrast with findings seen in studies by Kothiwala et al. and Biyik et al. wherein there were abnormal ECHO findings in more than 20% of cases.
IL-17 has been demonstrated in psoriatic plaques by IHC.,, In a study by Rich et al., 100 subjects with moderate-to-severe psoriasis were screened and more than 60% of patients showed the pathognomonic neutrophilic microabscesses and IL-17 was demonstrated in them and there was reduction of IL-17 inducible neutrophil chemoattractant (CXCL1, CXCL8) following treatment with secukinumab. In our study, IL-17 was demonstrated in munro's microabscess as well as other areas of the epidermis and dermis. IL-17 positivity in epidermis (P = 0.253), munro's microabscess [Figure 2] and [Figure 3] (P = 0.587), and dermis [Figure 4] (P = 0.278) in patients with/without metabolic syndrome was not statistically significant. In our study, a relationship between IL-17 positivity in munro's microabscess was established, which was, however, not statistically significant as compared to the IL-17 positivity in other areas of epidermis and dermis, in patients with or without metabolic syndrome. There was no statistically significant difference between comparison with IL-17 positivity in epidermis versus munro's microabscess or munro's microabscess versus dermis and epidermis versus dermis.
|Figure 2: Immunohistochemical demonstration of Interleukin-17 positivity (brown staining) in Munromicroabscess (40X)|
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|Figure 3: Immunohistochemical staining(brown) of Interleukin -17 in Munromicroabscess (10X)|
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|Figure 4: Immunohistochemical staining (brown) of interleukin-17 in dermis (×10)|
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The intensity of 2+ (moderate positivity) and proportion of 3+ (>50%) was noted in munro's microabscess, epidermal, and dermal inflammatory cells, respectively, in patients with metabolic syndrome.
There was also no statistical difference between IHC positivity in patients with/without metabolic syndrome (P = 0.266). However, in our study, patients with metabolic syndrome had significantly high DBP as compared to those without metabolic syndrome and IL-17 positivity was seen in patients with metabolic syndrome of which few of them also had high DBP. Since raised DBP is a marker for insulin resistance and development of metabolic syndrome, patients with IL-17 positivity in skin biopsy samples of chronic plaque psoriasis involving more than 10% BSA or PASI >12 need to be monitored for the development of insulin resistance and metabolic syndrome.
Owing to the small sample size, it is difficult to establish statistically significant association between the IL-17 positivity and severity of metabolic syndrome. This study being cross-sectional in nature does not take into account the directionality of association and larger prospective studies need to be done to validate the association of psoriasis and metabolic syndrome. No controls included in our study are also one of the limitations.
| Conclusion|| |
Our study has shown a relationship between IL-17 positivity and metabolic syndrome, however, this being a cross-sectional study, establishing temporal association between the IL-17 positivity with severity of psoriasis, is not possible. Further studies need to be done with a larger sample size to confirm the significance and derive causal associations. Patients with chronic plaque psoriasis in whom IL-17 can be demonstrated in skin biopsy samples need to be monitored for metabolic syndrome and cardiovascular comorbidities.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
- Dr. Nandakumar B S, Associate Professor, Department of Community medicine
- Dr. Santhosh, Pathologist, Metropolis laboratory attached to Ramaiah Memorial hospital.
Financial support and sponsorship
Educational grant from Bangalore dermatological society of Rs. 50000/-.
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7]