REVIEW article

Front. Allergy, 03 October 2025

Sec. Mechanisms in Allergy

Volume 6 - 2025 | https://doi.org/10.3389/falgy.2025.1673041

The roles of serum Th1, Th2, and Th17 cytokines in patients with chronic urticaria: a systematic review and meta-analysis

  • 1. Department of Dermatology, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua Medicine, Tsinghua University, Beijing, China

  • 2. Photomedicine Laboratory, Institute of Precision Medicine, Tsinghua University, Beijing, China

Abstract

Objectives:

To conduct a systematic review and meta-analysis to identify Th1-, Th2, and Th17 related serum biomarkers that reflect disease activity in chronic urticaria (CU), thereby enhancing the assessment of disease activity in both trials and clinical practice.

Methods:

Systematic searches of PubMed, EMBASE, and Web of Science were conducted through November 2024 to identify articles reporting the associations between CU and serum biomarkers. Serum Th1, Th2, and Th17 related biomarkers were identified in CU patients and correlated with disease severity and patient characteristics (ex. Age, sex, and comorbidities). The study quality was assessed using the National Heart, Lung, and Blood Institute Quality Assessment Tool for case-control studies. Meta-analysis was performed using the random-effects model with Hedges' g to pool standardized mean differences (SMDs). For meta-analysis, data were included for biomarkers reported in at least four studies with available means and standard deviations (SDs). Data reported as medians with ranges or interquartile ranges (IQRs) were evaluated for skewness. If the data were found to be significantly skewed, the means and SDs were not calculated. Conversely, if the data were not skewed, the means and SDs were estimated using validated methods.

Results:

A total of 6,013 studies were screened, of which 50 were included, reporting 22 serum Th1, Th2, and Th17 related cytokines. Meta-analyses revealed significant pooled standardized mean differences (SMDs) for serum TNF-α and IL-17.

Conclusions:

Serum TNF-α and IL-17 levels are significantly increased in patients with CU compared to healthy age- and sex-matched controls. These findings have the potential to influence clinical guidelines for the diagnostic workup of CU to include testing the serum levels of TNF-α and IL-17.

1 Introduction

Chronic urticaria (CU) is a common and debilitating mast cell-driven skin disease that persists for over 6 weeks, and is characterized by wheals, angioedema, or both (). The underlying pathophysiology of CU remains poorly understood. While a central role for mast cells has traditionally been proposed, growing evidence suggests that immune dysregulation mediated by T lymphocytes also plays a significant role ().

The activity of T lymphocytes largely depends on the differentiation of CD4+ T cells into distinct functional subsets, such as Th1, Th2, Th17, and T follicular helper (Tfh) cells, mediated by specific cytokine production (). A complex network of cytokines released by Th cells into the peripheral circulatory microenvironment are thought to influence the immune response in CU ().

Th1 cells produce cytokines such as IL-1β, IL-2, IL-12, IL-18, IFN-γ, and tumor necrosis factor (TNF), and are involved in cell-mediated pro-inflammatory responses (). Th2 cells secrete cytokines like IL-4, IL-5, IL-6, IL-9, IL-10, IL-13, IL-17E, IL-31, and IL-33, which can inhibit Th1 cytokine production (). Th2 cytokines are involved in antibody responses, particularly IgE production, and activate eosinophils and mast cells (, ). The imbalance between Th1 and Th2 has long been considered a potential mechanism in urticaria (, ). Th17 cells, which produce IL-17, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, and transforming growth factor (TGF)-β, are implicated in the pathogenesis of autoimmune and allergic diseases (, ).

In this study, we aimed to better characterize the helper T-cell immune phenotype in CU patients. The clinical roles of serum Th1, Th2, and Th17 cytokines in CU patients are discussed in this systematic review.

2 Methods

2.1 Literature search strategy

We systematically searched PubMed, EMBASE, and Web of Science from inception to November 2024. The protocol was registered in PROSPERO (CRD42024608505). Eligible studies quantified serum cytokines in chronic urticaria (CU). The search strategy combined Medical Subject Headings and free-text terms for CU (“Chronic Urticaria”, “Chronic Spontaneous Urticaria”, “Idiopathic Chronic Urticaria”, “Autoimmune Urticaria”, and “Chronic Autoimmune Urticaria”) with terms for biomarkers (“Biomarkers”, “Biologic Markers”, “Clinical Marker”, “Serum Markers”, “Cytokines”, “Chemokines”, and “Inflammation Mediators”).

2.2 Eligibility criteria

We included original research articles that compared serum levels of Th1-, Th2, and Th17 related cytokines between CU patients and healthy controls and examined associations with disease presence, activity, or severity. We excluded case reports, animal studies, editorials, letters, and studies that exclusively measured biomarkers in tissue biopsies, lymphocyte subsets, or genetic polymorphisms.

2.3 Study selection and data extraction

The outcome was the identification and correlation of cytokine levels with CU. Two reviewers (JWX and CHS) independently screened titles, abstracts, and full texts using EndNote. Discrepancies were resolved by a third reviewer (YZ). Data were extracted and verified by JWX and CHS. The author lists and publication years were screened to exclude possible duplicate or overlapping studies. The extracted variables included study characteristics, patient demographics (age and sex), biomarker levels, and reported associations with disease activity or severity, along with p-values. If any data were incomplete or unclear, the corresponding authors of the selected studies were contacted for further detail.

2.4 Quality evaluation

Study quality was assessed using the National Heart, Lung, and Blood Institute (NHLBI) Quality Assessment Tools, which are applicable to cohort, cross-sectional, case-control, and case series studies. This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. JWX and CHS drafted the manuscript. All authors contributed to the development of the selection criteria and the data extraction protocols. All the authors have read and approved the final manuscript.

2.5 Statistical analysis

Meta-analyses were performed using the random-effects model with Hedges' g to account for small-sample bias and between-study heterogeneity. Pooled standardized mean differences (SMDs) were calculated for biomarkers reported in at least four studies with available means and standard deviations (SDs). Studies were excluded from the meta-analysis if: (1) biomarker levels were reported as undetectable; (2) SDs were not reported or calculable; (3) data were presented only as medians with ranges or interquartile ranges (IQRs) and were determined to be skewed upon inspection. Data skewness was evaluated for studies that reported medians with IQRs or ranges. If not significantly skewed, means and SDs were estimated using validated methods (). When applicable, 95% confidence intervals or ranges were used to back-calculate the SDs.

3 Results

A total of 6,013 studies were screened, of which 50 were included, reporting 22 serum Th1-, Th2, and Th17 related cytokines (Figure 1: PRISMA flow diagram). Meta-analyses revealed significant pooled SMDs for serum TNF-α and IL-17.

Figure 1

3.1 Th1 cytokines

IL-18 was the most frequently assessed Th1-related cytokine in nine studies. Of these, five studies reported elevated IL-18 levels in CU patients compared to controls, one study described a reduction, and three studies found no significant difference. A pooled analysis of seven studies involving 511 participants yielded a standardized mean difference (SMD) of 0.55 (95% CI, −0.11–1.22), indicating considerable variation among study results (Figure 2A). TNF-α levels were examined in 11 studies. Eight studies identified increased serum levels in CU patients, while the remaining three reported no association. Meta-analysis of four studies with 319 participants showed a significant difference, with a pooled SMD of 1.40 (95% CI, 0.59–2.21) (Figure 2B). IFN-γ levels were evaluated in five studies. Three of these studies observed higher levels in CU patients than in healthy controls, and two did not find a statistically significant difference. IL-12 was reported in three studies, all of which documented elevated levels in CU patients relative to the control groups. IL-2 levels were measured in three studies. One study identified increased IL-2 concentrations in CU patients, while two reported no such association (Table 1). IL-1β was included in one study, which observed higher serum levels in the CU group than in the controls (Table 1).

Figure 2

Table 1

Th1 CytokinesStudy (author-yr)Overall associationSample size of CU patientsSample size of controlsValue in CU patients (mean ± SD) pg/ml/P valueValue in controls (mean ± SD) pg/mlAge of CU patients (mean ± SD, yrs)Age of controls (mean ± SD, yrs)Country
IL-1βSantos et al. ()Increased2933NA(P < 0.001)NA42.5 (20–66)35.5 (23–57)Brazil
IL-2Piconi et al. ()No association1915NANA39.15 (23–61)38.7 (23–54)Italy
IL-2Chen et al. ()Increased15747.4 (414.2–1,205.7)/0.001424.7 (218.3–545.2)NA24.6 (22–29)China
IL-2Grieco et al. ()No association844.8/NANA57 ± 440 ± 8Italy
IL-12Petrola et al. ()Increased203017.7 pgr/ml, P < 0.050 pgr/ml33.0 (6 14.8)NAVenezuela
IL-12Ene et al. ()Increased424038.0 ± 14.1(p < 0.001)17.9 ± 4.731.3 ± 10.829.8 ± 10.2Romania
IL-12Santos et al. ()Increased2933NA(P < 0.01)NA42.5 (20–66)35.5 (23–57)Brazil
IL-18Gora et al. ()Decreased3240115.8 (102.5–129.5)/<0.001 (115.9424 ± 20.9529)133.25 (122.95–142.15) (132.7532 ± 14.7635)11.21 (8–14.42)11 (7–14)Poland
IL-18Rasool et al. ()No association622762.95 ± 36.09/0.2454.35 ± 18.4528 (7–65)NAIndia
IL-18Sharma et al. ()Increased5030501.41 ± 208.98, P < 0.05218.39 ± 39.8333.84 ± 6.81633.20 ± 7.014India
IL-18Moos et al. ()No association524733.68 (30.92–38.47), P = 0.8, (34.3981 ± 5.7564)32.72 (31.13–36.76) (33.5877 ± 4.3055)40.6 ± 12.4 (19–68)41.6 ± 12.1 (19–64)Poland
IL-18Varghese et al. ()Increased4545144.3 (118.4–197.3), P < .001104.3 (89.0–115.8)35.91 (9.30), P = 0.6635.04 (9.20)India
IL-18Kurt et al. ()Increased5520290.0 ± 178.2, P = 0.031202.2 ± 96.840.3 ± 12.337.7 ± 9.8Turkey
IL-18Bary et al. ()Increased3015214.9 ± 167.3 pg/ml, P = 0.035115.6 ± 121.1 pg/ml35.70 ± 13.87 (16–81)NAEgypt
IL-18Tedeschi et al. ()No association3417246.47 ± 18.40 pg⁄ml, NS213.88 ± 22.24 pg⁄ml45.9 ± 2.6 years43.9 ± 3.3Italy
IL-18Puxeddu et al. ()Increased7340NA (P = 0.0003)NA41 ± 16, (14–89)50 ± 5, (25–89)Italy
TNF-αChen et al. ()Increased60151.6 (0.8–99.1)/0.0040.0 (0.0–0.0)NA24.6 (22–29)China
TNF-αTekin et al. ()No association315659.57 (35.51–500.46)/NA64.83 (32.84–613.41)NANATurkey
TNF-αTrinh et al. ()Increased19189NANA40 (19–60)38 (26–54)Korea
TNF-αGrieco et al. ()No association849.11/NANA57 ± 440 ± 8Italy
TNF-αAtwa et al. ()Increased753017.93 ± 6.05, P = 0.0046.87 ± 3.7331.8 ± 10.329.7 ± 9.1Egypt
TNF-αBostan et al. ()Increased3618156.7 (33.08–392), P < 0.01, (196.3929 ± 277.114)1.8 (1.5–2.91) (2.0923 ± 1.1343)38.5 ± 11.938 (30–47)Turkey
TNF-αTedeschi et al. ()No association4012NANANANAItaly
TNF-αGrzanka et al. ()Increased582218.25 (17.04–19.62), P < 0.05, (18.3065 ± 1.9614)16.89 (16.45–18.40) (17.274 ± 1.5454)39 (21–45)NAPoland
TNF-αSharma et al. ()Increased5030455.54 ± 253.54, P < 0.058.498 ± 3.64433.84 ± 6.81633.20 ± 7.014India
TNF-αSantos et al. ()Increased2933NA(P < 0.01)NA42.5 (20–66)35.5 (23–57)Brazil
TNF-αPiconi et al. ()Increased1915NA(CIU vs. HCs, p< 0.0001)NA39.15 (23–61)38.7 (23–54)Italy
IFN-γChen et al. ()Increased6015368.9 (223.5–433.5)/0.004250.8 (19.6–404.8)NA24.6 (22–29)China
IFN-γCaproni et al. ()No association6820NA2.4 ± 2.243 (19–81)39 (21–74)Italy
IFN-γGrieco et al. ()Increased848.37/<0.05NA57 ± 440 ± 8Italy
IFN-γPiconi et al. ()No association1915NANA39.15 (23–61)38.7 (23–54)Italy
IFN-γAlasandagutti et al. ()Increased3010080.762 ± 62.056/<0.000124.79 ± 21.8434.1NAIndia

Th1 cytokines results.

Yr, year; Yrs, years; SD, standard deviation; CU, chronic urticaria.

3.2 Th2 cytokines

Among the Th2 cytokines, IL-6 was the most frequently studied, as reported in 18 articles. Fifteen studies observed elevated IL-6 levels in CU patients compared to healthy controls, while three studies reported no association. A meta-analysis based on four studies involving 329 participants indicated a pooled SMD of 1.94 (95% CI, −0.11–3.99), suggesting a trend toward elevation without reaching statistical significance (Figure 2C). IL-4 levels were investigated in eight studies. Two studies documented increased IL-4 levels in CU patients, two reported reduced levels, and four found no significant association (Table 2). IL-5 expression was examined in two studies. One study recorded higher levels in CU patients than in controls, and another found no difference (Table 2). IL-10 was reported in nine studies. Among these, five studies observed increased levels in CU patients, one study noted a decrease, and three reported no association (Table 2). IL-13 levels were evaluated in four studies. Three studies reported elevated IL-13 levels in CU patients, and one study showed no statistically significant difference (Table 2). IL-31 was included in seven studies. Four studies identified higher IL-31 levels in CU cases than in controls, one study reported reduced levels, and two studies found no association (Table 2). IL-33 has also been reported in seven studies. Two studies observed increased IL-33 levels in CU patients, two reported lower levels, and three studies did not identify a significant difference (Table 2). A meta-analysis of four studies with 317 participants revealed a pooled SMD of 0.30 (95% CI, −2.67–3.27) (Figure 2D). IL-9 levels were measured in two studies, both of which found no significant differences between CU patients and controls (Table 2). IL-24 was investigated in one study that reported higher levels in the CU group than in the control group (Table 2).

Table 2

Th2 CytokinesStudy (author-yr)Overall associationSample size of CU patientsSample size of controlsValue in CU patients(mean ± SD) pg/ml/P valueValue in controls(mean ± SD) pg/mlAge of CU patients(mean ± SD, yrs)Age of controls(mean ± SD, yrs)Country
IL-4Degirmenci et al. ()Decreased4020NA/0.04NA38.2 ± 10.436.5 ± 5.45Turkey
IL-4Chen et al. ()No association60153.1 (1.5–7.6)/0.0212.2 (0.5–3.9)NA24.6 (22–29)China
IL-4Hoşgören-Tekin et al. ()Decreased3156101.1 (57.8–418.6)/0.001138.85 (70.5–508.4)NANATurkey
IL-4Ferrer et al. ()Increased60251.03/0.0280.244.39 ± 2.9140 ± 6.49USA
IL-4Caproni et al. ()No association6820NA0.01 ± 0.0643 (19–81)39 (21–74)Italy
IL-4Grieco et al. ()No association840.04/NANA57 ± 440 ± 8Italy
IL-4Mohamed et al. ()Increased251018,300 ± 14,700/0.0085,100 ± 4,100NANAEgypt
IL-4Zheng et al. ()No association2828NA/>0.05NA35.6 ± 6.135.8 ± 7.9China
IL-5Chen et al. ()Increased60158.5 (5.6–18.6)/0.0185.6 (2.6–9.5)NA24.6 (22–29)China
IL-5Hoşgören-Tekin et al. ()No association315661.65 (34.1–471.4)/NA73.1 (30.9–660.3)NANATurkey
IL-6Chen et al. ()Increased6015167.0 (126.6–261.2)/0.004107.8 (29.4–171.6)NA24.6 (22–29)China
IL-6Trinh et al. ()Increased19189NANA40 (19–60)38 (26–54)Korea
IL-6´Gora et al. ()Increased324013.91 (11.32–15.71)/<0.001(13.6,287 ± 3.4068)7.42 (6.21–8.45)(7.3561 ± 1.7224)11.21 (8–14.42)11 (7–14)Poland
IL-6Ucmak et al. ()Increased503346.57/<0.00120.3435 (18–55)36 (20–60)Turkey
IL-6Amin et al. ()Increased4040NA/<0.001NANANAEgypt
IL-6Grieco et al. ()Increased846.2/<0.05NA57 ± 440 ± 8Italy
IL-6Kasperska-Zajac et al. ()Increased58223.32/<0.00010.6938 (24–52)NAPoland
IL-6Grzanka et al. ()Increased58223.95 (1.98–9.2)/<0.00011.0 (0.43–1.58)39 (21–45)NAPoland
IL-6Valerieva et al. ()Increased45NA1.91 ± 0.50/<0.0010.03 ± 0.02NANABulgaria
IL-6Kasperska-Zajac et al. ()Increased820NA/0.0026NA37 (28–43)NAPoland
IL-6Kasperska-Zajac et al. ()Increased18201 (0.12–2.22)/0.033(1.1227 ± 1.6894)0.39 (0.05–0.97)(0.4763 ± 0.734)30.5 (19–37)NAPoland
IL-6Kasperska-Zajac et al. ()Increased58301.85/<0.0011.140NAPoland
IL-6Rajappa et al. ()Increased4545NA/<0.0001NANANAIndia
IL-6Alasandagutti et al. ()Increased3010039.37 ± 11.06/<0.00017.175 ± 4.8134.1NAIndia
IL-6Rasool et al. ()No association62270.82 ± 4.6/0.440.12 ± 1.728 (7–65)NAIndia
IL-6Grzanka et al. ()No association171611.64 (10.34–11.93)/<0.00014.95 (4.05–5.7)42 (29–45)NAPoland
IL-6Bostan et al. ()No association36181.37 (0.90–3.93)1.0 (0.7–1.6)38.5 ± 11.938 (30–47)Turkey
IL-6Santos et al. ()Increased2933NA(P< 0.001)NA42.5 (20–66)35.5 (23–57)Brazil
IL-9Bhatia et al. ()No association95421,607 ± 1,182.5/0.0821,838.70 ± 929.8933.77 ± 8.07NAIndia
IL-9Zheng et al. ()No association2828NA/>0.05NA35.6 ± 6.135.8 ± 7.9China
IL-10Degirmenci et al. ()Decreased4020NA/0.04NA38.2 ± 10.436.5 ± 5.45Turkey
IL-10Chen et al. ()No association60153.1 (2.4–5.8)/NA3.0 (1.2–5.2)NA24.6 (22–29)China
IL-10Hoşgören-Tekin et al. ()No association3156113.57 (73.24–738.31)/NA119.52 (77.82–782.9)NANATurkey
IL-10Trinh et al. ()Increased19189NANA40 (19–60)38 (26–54)Korea
IL-10Grieco et al. ()No association8411.01/NANA57 ± 440 ± 8Italy
IL-10Valerieva et al. ()Increased45NA5.91 ± 0.48/<0.0010.86 ± 0.51NANABulgaria
IL-10Moos et al. ()Increased52474.25 (2.57–5.49),P = 0.043.36 (1.59–4.25)40.6 ± 12.4 (19- 68)41.6 ± 12.1 (19- 64)Poland
IL-10Santos et al. ()Increased2933NA(P < 0.001)NA42.5 (20–66)35.5 (23–57)Brazil
IL-10Piconi et al. ()Increased1915NA(CIU vs.HCs,p = 0.002)NA39.15 (23–61)38.7 (23–54)Italy
IL-13Chen et al. ()Increased601519.6 (13.6–31.2)/0.00815.0 (8.1–19.7)NA24.6 (22–29)China
IL-13Hoşgören-Tekin et al. ()No association31569.3 (5.80–58.47)/NA9.61 (5.22–55.82)NANATurkey
IL-13Bae et al. ()Increased8443508.5 ± 51.2/0.001200.7 ± 13.338.2 ± 12.730.4 ± 9.3Korea
IL-13Caproni et al. ()Increased6820NA2.4 ± 2.243 (19–81)39 (21–74)Italy
IL-24Laurence de Montjoye et al. ()Increased6923NA, P < 0.05NANANABelgium
IL-31Lin et al. ()Increased512027.79 ± 3.02 ng/L, P < 0.00118.78 ± 1.71 ng/L28 ± 13, p = 0.28532 ± 14China
IL-31Bostan et al. ()No association3618743.2 (121.3–3,447)213.1 (9–633.6)38.5 ± 11.938 (30–47)Turkey
IL-31Boyvadoglu et al. ()Decreased302065.30 (46.39–89.14),p = 0.001(67.0575 ± 33.2775)169.57 (115.8–237.27)(174.5813 ± 96.9144)39.83 ± 11.67, P = 0.00831.85 ± 6.77Turkey
IL-31Băruta et al. ()Increased5038NA, p < 0.0001NA50.14 ± 16.1044.32 ± 9.23Romania
IL-31Raap et al. ()Increased4626NA, P < 0.001NANA43.8 ± 16.5Germany
IL-31Chaowattanapanit et al. ()Increased6531(252.4 ± 115.5, P < 0.00136.3 ± 10.7 pg/ml43 ± 1544 ± 18Thailand
IL-31Hoşgören-Tekin et al. ()No association315643.69 (18.23–298.67)/NA47.33 (24.99–436.21)NANATurkey
IL-33Băruta et al. ()Increased5033220.67 ± 201.17, P < 0.000121.70 ± 22.6850.14 ± 16.1044.32 ± 9.23Romania
IL-33Puxeddu et al. ()No association7340575.3 ± 105.6, NS1,189 ± 271.541 ± 16, (14–89)50 ± 5,(25–89)Italy
IL-33Kulumbegov et al. ()No association302029.74 ± 5.02, P = 0.09333.2 ± 7.4337.6 ± 17.5744.45 ± 14.83Israel
IL-33Lin et al. ()Increased512045.53 ± 4.32 ng/L, P < 0.00130.09 ± 2.69 ng/L28 ± 13, p = 0.28532 ± 14China
IL-33Hoşgören-Tekin et al. ()Decreased3156154.89 (85.82–1,142.36)/0.038200.53 (108.78–1,381.42)NANATurkey
IL-33Valerieva et al. ()Decreased45NA0.89 ± 0.41/0.0055.04 ± 1.02NANABulgaria
IL-33Zheng et al. ()No association2828NA/>0.05NA35.6 ± 6.135.8 ± 7.9China

Th2 cytokines.

Yr, year; Yrs, years; SD, standard deviation; CU, chronic urticaria.

3.3 Th17 cytokines

A meta-analysis of five studies involving 416 participants demonstrated a significant elevation in serum IL-17 levels among patients with chronic urticaria, with a pooled SMD of 1.43 (95% CI, 0.11–2.75) (Figure 2E). IL-17 was evaluated across nine studies; five of them identified increased levels in CU cases compared to controls, while the remaining four studies reported no statistically significant association (Table 3). Two studies investigated IL-17A concentration. Among them, one study documented elevated serum IL-17A levels in CU patients relative to controls, and another study found no significant difference between groups (Table 3). IL-17F was measured in one study, which indicated no notable difference in serum levels between CU and control cohorts (Table 3). IL-21 was reported in one study that observed higher levels in CU patients than in healthy controls (Table 3). IL-22 was included in one publication, with results showing no measurable differences between groups (Table 3). Five studies assessed the IL-23 levels. Of these, three studies observed elevated IL-23 concentrations in CU patients and two studies did not detect a meaningful difference when compared with controls (Table 3). IL-25 was included in one study that reported increased serum levels in the CU group compared to the control group (Table 3).

Table 3

Th17 CytokinesStudy (author-yr)Overall associationSample size of CU patientsSample size of controlsValue in CU patients(mean ± SD) pg/ml/P valueValue in controls(mean ± SD) pg/mlAge of CU patients(mean ± SD, yrs)Age of controls(mean ± SD, yrs)Country
IL-17Chen et al. ()No association60151.3 (0.4–2.7)/NA(1.4766 ± 1.747)0.6 (0.0–2.1)(0.9267 ± 1.7176)NA24.6 (22–29)China
IL-17Özçeker et al. ()No association50353.98 ± 3.88/3.1 (2.6–4.6), p = 0.0634.85 ± 2.96/3.9 (3.0–6.3)NANATurkey
IL-17Moghadam K et al. ()Increased6030NA209.47(sd:106.55)NANAIran
IL-17Bostan et al. ()No association361847.7 (8.2–268.8)100 (15.8–639)38.5 ± 11.938 (30–47)Turkey
IL-17Lin et al. ()Increased5120256.71 ± 25.07 ng/L, P < 0.001181.79 ± 16.6228 ± 13, p = 0.28532 ± 14China
IL-17Atwa et al. ()Increased753035.51 ± 31.14 pg/ml, P < 0.0014.60 ± 1.3831.8 ± 10.329.7 ± 9.1Egypt
IL-17Grzanka et al. ()Increased522121.97 (20.92–24.98/18.85–62.73) pg/ml, p < 0.00119.88 (18.85–20.92/17.82–59.16) pg/ml38 (24–50)NAPoland
IL-17Sharma et al. ()Increased50301.84 ± 0.81, P < 0.050.03 ± 0.0233.84 ± 6.81633.20 ± 7.014India
IL-17Hoşgören-Tekin et al. ()No association315645.92 (29.37–339.67)/NA45.36 (16.69–291.21)NANATurkey
IL-17AGora et al. ()Increased324041.4 (38.55–48.25)/<0.00127.13 (20.37–36.45)11.21 (8–14.42)11 (7–14)Poland
IL-17AZheng et al. ()No association2828NA/>0.05NA35.6 ± 6.135.8 ± 7.9China
IL-17FChen et al. ()No association601517.9 (0.0–55.1)/NA106.8 (0.5–229.7)NA24.6 (22–29)China
IL-21Chen et al. ()Increased60151,063.5 (581.9–1,825.2)/0.012562.8 (481.1–1,083.1)NA24.6 (22–29)China
IL-22Chen et al. ()No association6015861.6 (503.0–2,085.5)/NA589.8 (252.4–1,009.5)NA24.6 (22–29)China
IL-23Degirmenci et al. ()Decreased4020NA/0.01NA38.2 ± 10.436.5 ± 5.45Turkey
IL-23Chen et al. ()Increased6015306.3 (206.4–641.2)/0.038212.1 (47.3–372.0)NA24.6 (22–29)China
IL-23Atwa et al. ()Increased753038.95 ± 27.82, P < 0.0019.87 ± 4.6231.8 ± 10.329.7 ± 9.1Egypt
IL-23Sharma et al. ()Increased503025.57 ± 10.79, P < 0.050.15 ± 0.14
IL-23Gora et al. ()Decreased3240361.5 (289.0–364.9)/<0.001603.0 (527.5–674.0)11.21 (8–14.42)11 (7–14)Poland
IL-25Băruta et al. ()Increased5033140.27 ± 100.16, P = 0.0823105.03 ± 89.2150.14 ± 16.1044.32 ± 9.23Romania

Th 17 cytokines.

Yr, year; Yrs, years; SD, standard deviation; CU, chronic urticaria.

3.4 Quality assessment

Assessment of study quality using the NHLBI Quality Assessment Tool for Case-Control Studies indicated that 44 of the 50 included studies (88%) were rated as high quality with a low risk of bias, while the remaining 6 studies (12%) were considered to have a moderate risk of bias (Table 4).

Table 4

NumberQuality Assessment: Case. Control studies (https://www.nhlbi.nih.gov/health-topics/study-quality-assessment-tools)Abstract (fair)
Author year123456789101112Overall quality rating - good, fair, and poor
1Degirmenc ()yyNRyYyyNANAyyNAGood
2Chen ()yyNRyyyyNANAyyNAGood
3Hoşgören-Tekin ()yyNRyyyyNANAyyNAGood
4Bae ()yyNRyyyyNANAyyNAGood
5Ferrer ()yyNRyyyyNANAyyNAGood
6Caproni ()yyNRyyyyNANAyyNAGood
7Trinh ()yyNRyyyyNANAyyNAGood
8Góra ()yyNRyyyyNANAyyNAGood
9Ucmak ()yyNRyyyyNANAyyNAGood
10Najjar ()yyNRynyyNANAyyNAFair
11Grieco ()yyNRyyyyNANAyyNAGood
12Kasperska-Zajac ()yyNRyyyyNANAyyNAGood
13Grzanka ()yyNRyyyyNANAyyNAGood
14Valerieva ()yyNRynyyNANAyyNAFair
15Kasperska-Zajac ()yyNRyyyyNANAyyNAGood
16Kasperska-Zajac ()yyNRyyyyNANAyyNAGood
17Kasperska-Zajac ()yyNRyyyyNANAyyNAGood
18Rajappa ()yyNRyyyyNANAyyNAGood
19Alasandagutti ()yyNRyyyyNANAyyNAGood
20Rasool ()yyNRyyyyNANAyyNAGood
21GRZANKA ()yyNRyyyyNANAyyNAGood
22Bhatia ()ynNRyynyNANAyyNAGood
23ZHENG ()yyNRyyyyNANAyyNAGood
24Mohamed ()yyNRynyyNANAyyNAFair
25Piconi ()yyNRyyyyNANAyyNAGood
26Moos ()yyNRyyyyNANAyyNAGood
27Ene ()yyNRyyyyNANAyyNAGood
28Petrola ()yyNRynyyNANAyyNAFair
29Özçeker ()yyNRyyyyNANAyyNAGood
30Moghadam ()yyNRyyyyNANAyyNAGood
31Santos ()yyNRyyyyNANAyyNAGood
32Lin ()yyNRyyyyNANAyyNAGood
33Atwa ()yyNRyyyyNANAyyNAGood
34Grzanka ()yyNRyyyyNANAyyNAGood
35Sharma ()yyNRyyyyNANAyyNAGood
36Varghese ()yyNRyyyyNANAyyNAGood
37Kurt ()yyNRyyyyNANAyyNAGood
38Abdel-Bary ()yyNRyyyyNANAyyNAGood
39Tedeschi ()yyNRyyyyNANAyyNAGood
40Puxeddu ()yyNRyyyyNANAyyNAGood
41Montjoye ()yyNRynyyNANAyyNAFair
42Boyvadoglu ()yyNRyyyyNANAyyNAGood
43Băruta ()yyNRyyyyNANAyyNAGood
44Raap ()yyNRyyyyNANAyyNAGood
45Chaowattanapanit ()yyNRyyyyNANAyyNAGood
46Kulumbegov ()yyNRyyyyNANAyyNAGood
47Dobrican-Băruta ()yyNRyyyyNANAyyNAGood
48Bostan ()yyNRyyyyNANAyyNAGood
49Tedeschi ()yyNRyyyyNANAyyNAGood
50Grzanka ()yyNRynyyNANAyyNAFair

Quality assessment.

4 Discussion

To our knowledge, this systematic review represents the first registered evaluation of serum Th1, Th2, and Th17 cytokines in patients with CU. Our meta-analysis revealed statistically significant pooled SMDs values for serum TNF-α and IL-17 levels. These findings may influence the clinical practice for CU patients, as measurements of serum TNF-α and IL-17 levels are accessible to some clinicians.

Tumor necrosis factor alpha (TNF-α) plays a critical role in inflammation, immune regulation, and apoptosis (). It is released by human skin mast cells and other inflammatory cells present at urticarial lesion sites (), making it a candidate mediator in urticaria pathogenesis (). Our meta-analysis revealed a significant association between CU and elevated serum TNF-α levels, with a pooled SMD of 1.40 (95% CI of 0.59–2.21). This significant link confirms the autoimmune and inflammatory nature of CU, and supports the inclusion of TNF-α in the clinical assessment of CU.

IL-17, produced by T helper (Th) type 17 cells, binds to IL-17 receptors on epithelial, endothelial, and fibroblastic stromal cells (). IL-17 is associated with many autoimmune disorders, such as psoriasis, multiple sclerosis, inflammatory bowel disease, rheumatoid arthritis, and asthma (). Serum IL-17 levels were significantly elevated in CU patients compared to controls and correlated with urticaria severity (, , ) Our meta-analysis confirmed this, showing a significant pooled SMD of 1.43 (95% CI of 0.11–2.75). These findings support IL-17 as a valuable biomarker for CU clinical assessment.

A limitation of this systematic review and meta-analysis is the heterogeneity in assay methods. Variability in laboratory methods across studies (e.g., ELISA, multiplex assays) may lead to variations in cytokine measurements. Furthermore, data from some studies could not be pooled because of non-normal data distribution. In addition, owing to the limited number of related studies, we did not differentiate between chronic induced urticaria and chronic spontaneous urticaria in this review despite their distinct pathogenic mechanisms. The lack of subgroup analysis might restrict the clinical applicability of our findings.

Despite these limitations, the results of this review and meta-analysis provide high-quality evidence-based insights into the associations between serum Th1, Th2, and Th17 cytokines and CU. In conclusion, Th1 and Th17-derivated cytokines play crucial roles in the pathogenesis of CU. CU is thus characterized as a chronic inflammatory state mediated by diverse cytokines and autoimmune mechanisms. These findings may help inform clinical guidelines for CU diagnosis by incorporating serum TNF-α and IL-17 levels. However, the clinical cut-off values, sensitivity, specificity, and practical implementation of these biomarkers have not yet been explored. Therefore, well designed and large-scale studies are needed to determine the optimal cutoff levels of TNF-α and IL-17.

Statements

Author contributions

JX: Conceptualization, Formal analysis, Investigation, Methodology, Writing – original draft, Writing – review & editing. CS: Data curation, Methodology, Writing – original draft. MS: Formal analysis, Software, Writing – original draft. BL: Formal analysis, Software, Validation, Writing – original draft. YZ: Funding acquisition, Resources, Writing – review & editing.

Funding

The author(s) declare that financial support was received for the research and/or publication of this article. This work was supported by the Beijing Hospitals Authority’s Ascent Plan, Code: DFL20240901.

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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The authors declare that no Gen AI was used in the creation of this manuscript.

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Supplementary material

The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/falgy.2025.1673041/full#supplementary-material

References

Summary

Keywords

chronic urticaria, serum biomarkers, TNF-α, IL-17, T lymphocytes

Citation

Xue J, Sun C, Shi M, Li B and Zhao Y (2025) The roles of serum Th1, Th2, and Th17 cytokines in patients with chronic urticaria: a systematic review and meta-analysis. Front. Allergy 6:1673041. doi: 10.3389/falgy.2025.1673041

Received

25 July 2025

Accepted

16 September 2025

Published

03 October 2025

Volume

6 - 2025

Edited by

Indrashis Podder, College of Medicine & Sagore Dutta Hospital, India

Reviewed by

Atsushi Fukunaga, Osaka Medical and Pharmaceutical University, Japan

Hongtian Wang, Capital Medical University, China

Updates

Copyright

*Correspondence: Yi Zhao

† These authors have contributed equally to this work

Disclaimer

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

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