BACKGROUND: The etiology of vitiligo has not been completely elucidated. Recently, 25-hydroxyvitamin D (25(OH)D) and IL-33 levels were found to be associated with the development of the vitiligo. The aim was to assess relationship between 25(OH)D, IL-33 levels, and clinical improvement after narrow-band UVB treatment in vitiligo.
METHODS: Patients with vitiligo who underwent at least 48 sessions of narrow-band UVB treatment were included in this study. Age, gender, smoking status, family history of vitiligo, type of vitiligo, body surface area affected by vitiligo, and vitiligo activity were recorded. 25(OH)D and IL-33 were measured and compared at baseline, second month, and fourth month.
RESULTS: Twenty patients with vitiligo and 20 healthy controls were included in this study. The mean baseline 25(OH)D level of vitiligo group was statistically significantly lower than the control group\'s (p < .05). The mean baseline IL-33 level was higher in vitiligo group with no statistically significantly difference (p > .05). The increase in 25(OH)D level and the decrease in vitiligo-affected body surface area were found to be statistically significant during treatment (p < .05). The mean IL-33 levels were found to be lower at the second and fourth month compared to baseline. However, there were no statistical significance (p > .05).
CONCLUSIONS: Low levels of 25(OH)D are thought to play a role in the etiopathogenesis of vitiligo. 25(OH)D increase due to phototherapy may have a role in repigmentation independently from the direct effect of narrow-band UVB.

Interleukins play a very important role in the pathophysiology of asthma. Interleukin-33 (IL-33) is a partially explored cytokine in asthma. It binds with a specific receptor called suppression of tumorigenicity 2 (ST2). The study aims to evaluate the serum levels of IL-33, sST2 and IgE in asthmatic patients and healthy controls and its further association with the forced expiratory volume in one second (FEV 1%) and absolute eosinophil count.
We enrolled 100 asthmatic patients and 57 healthy subjects for the study. We measured serum levels of IgE, IL-33, and sST2. Based on serum IgE levels, patients were divided into allergic and non-allergic groups. Statistical analysis was done by using Graph pad prism software 8.
We found significantly elevated levels of IL-33 and IgE in asthmatic patients as compared to healthy subjects. However, sST2 levels were significantly lower in asthmatic patients than in healthy subjects. FEV1% values were decreased in uncontrolled asthmatic patients. In addition, serum levels of IL-33 were significantly correlated with the IgE. Furthermore, we found a significant correlation between IL-33 and AEC in allergic asthmatic patients.
In this study, we reported elevated IL-33 and IgE levels and decreased sST2 levels in asthmatic patients compared to healthy controls. IL-33 and sST2 may act as inflammatory biomarkers for allergic diseases such as asthma.

Opium abuse is one of the social hazards in the Middle Eastern countries. Opium consumption attributes to various malignancies. However, the exact molecular mechanism of this correlation still remains unclear. Cancer and inflammation are closely correlated. Interleukin-33 (IL-33) and its receptors, transmembrane ST2 (ST2L) and soluble ST2 (sST2), have been significantly associated with tumorigenicity. The present study aimed to investigate whether IL-33 and sST2 levels serve as cancer biomarkers in opium users.
Serum samples were collected from 100 opium users and 100 healthy non-opium users in a nested case-control design. The subjects with over five years of history of opium abuse were enrolled. To assess the incidence of malignancies, the opium users were followed up from 2014 to 2019. Serum levels of IL-33 and sST2 were measured using an ELISA kit. For comparison of IL-33 and sST2 levels between the groups, two-tailed Student\'s t test and Mann-Whitney U test were utilized, accordingly. Logistic regression analysis was performed to evaluate the influence of confounders on the incidence of cancer.
During the five-year follow-up, eight opium users were diagnosed with cancer. Cancer was developed by 9.3 folds in the individuals abusing opium compared to that in the non-opium users (P=0.040, OR=9.3; 95%CI [1.1-79.4]). Serum levels of IL-33 were found to be significantly higher in the opium users than those in the healthy control group (P=0.001). The sST2 levels were significantly lower in the opium users (P=0.001). The opium users with cancer exhibited significantly higher levels of IL-33 and lower levels of sST2 than the cancer-free ones (P=0.001).
Decline in sST2 levels and rise in the level of IL-33 are valuable biomarkers in predicting cancers. Regarding the significant alterations in the levels of these biomarkers in the opium users, as well as those in the opium users diagnosed with cancer, IL-33 and sST2 may serve as potential biomarkers in the early prediction of cancer.

Pemphigus is a group of immune-mediated blistering diseases of skin and mucus membrane caused by destruction of the intercellular junction (desmosomes) by autoantibodies. Pemphigus vulgaris (PV) is considered the most common type of all pemphigus family. Various cytokines play a major role in pemphigus pathogenesis. Interleukin-33 (IL-33) role has been studied in various autoimmune diseases as; psoriasis and rheumatoid arthritis, yet it has not been studied in Egyptian patients with PV. The study aimed to evaluate the possible role of IL-33 in PV by assessing its level in the serum using ELISA and to detect its correlation with activity score using Pemphigus Disease Area Index (PDAI). Forty-four patients with PV and 36 age and sex-matched healthy controls were enrolled in the study. After full history taking and complete dermatological examination, the severity score was calculated using PDAI, then serum samples were taken from each patient and control subjects and subjected to quantitative measurement of serum IL-33 using ELISA. Serum level of IL-33 is significantly raised in PV patients compared to control subjects (P-value = .007). The level of IL-33 was found to be strongly correlated with the activity of the disease measured by PDAI. IL-33 might have a role in PV pathogenesis as shown by its rising level in PV patients. In addition, serum level of IL-33 is strongly correlated with the activity of PV. Thus, we suspect that IL-33 can be used as marker for monitoring PV severity and measuring treatment efficacy.

The importance of interleukin (IL)-33 in promoting effective antiviral immune responses is evident, yet the critical cellular sources of IL-33 in homeostasis and infection are largely unknown. In this issue of the European Journal of Immunology, Aparicio-Domingo et al. [Eur. J. Immunol. 2021. 51: 76-90] explore the main source of IL-33 expression in lymph nodes (LNs) and dissect its role in LN homeostasis and antiviral adaptive immune response. The authors reveal that fibroblastic reticular cells and lymphatic endothelial cells are both producing IL-33 in steady-state LNs. Remarkably, however, by using cell-type specific deletion approaches, the authors demonstrate that exclusively fibroblastic reticular cells, and not lymphatic endothelial cells, are the critical cellular source for promoting antiviral CD8+ T-cell responses upon infection. These findings provide an important insight into the role of specific LN stromal cell subsets as potent modulators of antiviral immunity.

Despite more effective management of heart failure over the past few decades, its burden as a chronic disease has grown and is expected to continue to rise, representing a major health problem for years to come. Having reliable tools for early diagnosis and risk stratification can help managing the condition more efficiently. In this context, the interest for biomarkers has increased considerably in the last years following the useful clinical role of B-type natriuretic peptides. These biomarkers have been extensively studied and have become established diagnostic and prognostic biomarkers in heart failure. Despite their usefulness, limitations still remain a problem in clinical practice and the search for new biomarkers has therefore continued. Amongst the most promising newer biomarkers, soluble ST2 deserves further consideration. The present review will focus on the role of this new biomarker in the context of heart failure.

Aims. Previous evidence has proved that interleukin-31 (IL-31) and interleukin-33 (IL-33) can be potential markers in some cancers\' formulation. We aimed to determine the potential role of IL-31 and IL-33 in prognosis of endometrial cancer patients. Methods. Serum samples were collected from 160 patients with endometrial cancer and 160 healthy controls. The ELISA kits (Raybio® Systems) specific for human IL-31 and human IL-33 were used. Serum levels of tumor markers (CEA, CA-125, and CA19-9) were measured by chemiluminescence immunoassay. A two-side P value < 0.05 was indicated to be significant. Results. Serum levels of IL-31 and IL-33 in patients were significantly elevated compared to those of healthy controls. The interleukin levels were also related to clinical characteristics, including tumor stages, depth of invasion, and existence of node metastases and distant metastases. The sensitivity and specificity of IL-31 and IL-33 were higher than the counterparts of tumor markers, both separately and in combination of IL-31, IL-33, and the clinical markers. Conclusions. This report is the first one mentioning the possible association between serum IL-31 and IL-33 and endometrial cancer. With their sensitivity and specificity, the interleukins may be useful biomarkers for endometrial cancer\'s prognosis.

The aim of our study was to investigate the association of five single nucleotide polymorphisms in interleukin-1 (IL-1) gene with susceptibility to systemic sclerosis (SSc) in a Chinese population. A total of 58 SSc patients and 113 healthy controls were enrolled. TaqMan allele discrimination assay was performed to detect the genotyping of IL-1A -889C/T (rs1800587), IL-1B -511C/T (rs16944), IL-18 -607C/A (rs1946518), IL-18 -137G/C (rs187238) and IL-33 rs7044343. The association between these SNPs and SSc risk was analyzed. Furthermore, a meta-analysis of relevant studies on the association of IL-1A -889C/T (rs1800587) and IL-1B -511C/T (rs16944) with the susceptibility to SSc was performed. Through the genotyping, significant associations for SSc were found for: IL-1A -889C/T genotype frequencies (P = 0.000), dominant model (P = 0.000), recessive model (P = 0.001) and allele T frequency (P = 0.000). Among SSc patients, dyspnea was significantly associated with IL-18 -607C/A genotype frequency and IL-33 rs7044343 allele frequency (P = 0.037, P = 0.042, respectively). In addition, elevated erythrocyte sedimentation rate was significantly associated with IL-18 -137G/C (rs187238) genotype and allele frequency (P = 0.019, P = 0.006, respectively). While meta-analysis showed there was no significant association between IL-1A -889C/T polymorphism and SSc, for IL-1B -511C/T (rs16944), significant associations were found in the comparison of allele C versus T (OR 1.267, 95 % CI 1.016-1.580) by combined different outcomes. Results showed that IL-1A -889C/T (rs1800587) was associated with SSc susceptibility in the Chinese population. However, this association was not supported by a meta-analysis of all relevant studies. Further investigations are required to verify our findings.

OBJECTIVE: Preeclampsia (PE) is a systemic inflammatory response syndrome involving varieties of cytokines, and previous studies have shown that IL-33 and its receptor IL-1RL1 play pivotal roles in the development of it. As a polygenetic hereditary disease, it is necessary to study the gene analysis for PE. Therefore, the present study was to determine whether IL-33 rs3939286 and IL-1RL1 rs13015714 associated with susceptibility to PE in Chinese Han women.
METHODS: 1,031 PE patients and 1,298 controls were enrolled and the genotyping for rs3939286 in IL-33 and rs13015714 in IL-1RL1 was performed by TaqMan allelic discrimination real-time PCR. Hardy-Weinberg equilibrium (HWE) was examined to ensure the group representativeness and Pearson\'s chi-square test was used to compare the differences in genetic distributions between the two groups.
RESULTS: No significant differences in genotypic and allelic frequencies of the two polymorphisms loci were observed between cases and controls. There were also no significant differences in genetic distributions between mild/severe and early/late-onset PE and control groups.
CONCLUSIONS: Although our data suggested that the polymorphisms of IL-33 rs3939286 and IL-1RL1 rs13015714 might not be critical risk factors for PE in Chinese Han women, the results need to be validated in different nations.

OBJECTIVE: The development of inflammation in asthma involves an intricate network of cytokines that recruit and activate numerous immune cells. This study was aimed to compare serum levels of IL-10, IL-17F, and IL-33 in asthmatic patients and non-asthmatic controls and correlate cytokine levels to asthma severity and various clinical, spirometric, and laboratory variables.
METHODS: Using ELISA, serum levels of IL-10, IL-17F, and IL-33 were evaluated in 44 asthmatics (14 mild persistent, 15 moderate persistent, and 15 severe persistent) and 44 controls.
RESULTS: This is one of the first reports showing a significant difference in serum levels of asthma-associated cytokines, anti-inflammatory IL-10, and pro-inflammatory IL-17F and IL-33, in the same subset of asthmatic patients. Our results showed diminished level of IL-10 and elevated levels of IL-17F and IL-33 in asthmatics than in controls (p < 0.001). Assessment of cytokine levels between subjects of different gender, age group, and BMI showed non-significant differences. Correlation analysis of cytokine levels to clinical variables showed that IL-17F is associated negatively to FVC % predicted (forced vital capacity) and FEV1% predicted (forced expiratory volume in one second) and positively to number of allergens sensitized and FEV1 reversibility. A strong negative correlation was found between IL-10 and IL-33 levels (p = 0.001).
CONCLUSIONS: Negative correlation between IL-10 and IL-33 levels may reflect a converse relationship between anti-inflammatory and pro-inflammatory cytokines in an individually balanced pattern. The association between IL-17F level and asthmatic phenotypes such as reduced FVC and FEV1, higher degree of sensitization, and post-bronchodilator reversibility needs further assessments.