The Predictive Value of Serum Cytokines for Distinguishing Celiac Disease from Non-Celiac Gluten Sensitivity and Healthy Subjects

Interleukin-15 gene polymorphism in children with celiac disease: a single-center experience

The purpose of this study is to evaluate the demographics, clinical presentation, laboratory findings, and gastrointestinal endoscopic findings in children with CD and assess their relationship with interleukin-15 (IL-15) single-nucleotide polymorphism (SNP) (rs2857261) and serum IL-15 levels. This case-control and prospective cohort study included 54 newly diagnosed pediatric CD patients attending the Gastroenterology Clinic at Alexandria University Children's Hospital and 44 age- and sex-matched healthy controls. Demographics, clinical data, laboratory tests, Marsh classification, and IL-15 SNP (rs2857261) genotypes were analyzed. Follow-up after 9 months on a gluten-free diet (GFD) was conducted. The mean age of patients and controls was 8.62 ± 4.4 and 8.07 ± 4.7 years, respectively, with no significant difference (p = 0.55). Male representation was 48.1% in patients and 47.7% in controls (p = 0.97). The most common presenting symptoms in CD patients were abdominal distension (61.11%) and failure to thrive (59.26%). Laboratory findings showed that mean anti-tissue transglutaminase immunoglobulin A was 103 ± 168 U/ml, and anti-endomysium immunoglobulin A was positive in 51.85% of patients. Histopathological assessment revealed Marsh 3C as the most common finding (37%), while 37% of patients were diagnosed without biopsy. IL-15 SNP (rs2857261) analysis showed a significantly higher prevalence of the A/A genotype in CD patients compared to controls (p < 0.0001). The A/G and G/G genotypes were protective against CD, with odds ratios of 0.088 and 0.079, respectively. No significant associations were observed between IL-15 genotypes and clinical, laboratory, or histological variables. After 6 to 9 months on a GFD, genotype did not significantly influence symptom resolution (p > 0.05).

CONCLUSIONS

Serum IL-15 levels are elevated in newly diagnosed pediatric CD patients. The IL-15 SNP (rs2857261) A/A genotype is associated with increased susceptibility to CD, while the A/G and G/G genotypes appear protective. These findings highlight IL-15 as a potential biomarker and therapeutic target in CD. Further large-scale studies are warranted to validate these findings and explore therapeutic applications.

WHAT IS KNOWN

• Celiac disease is an immune-mediated enteropathy linked to HLA-DQ2/DQ8 alleles, with IL-15 playing a key role in its pathogenesis. • Variability in IL-15 genetic polymorphisms has been suggested but remains underexplored in pediatric populations.

WHAT IS NEW

• This study identifies the IL-15 SNP (rs2857261) A/A genotype as a risk factor for CD, while A/G and G/G genotypes are protective. • Elevated serum IL-15 levels in newly diagnosed patients highlight its potential as a biomarker and therapeutic target.

Nutrition in Patients with Lactose Malabsorption, Celiac Disease, and Related Disorders

Lactose malabsorption (LM), celiac disease (CD), non-celiac gluten sensitivity (NCGS), and irritable bowel syndrome (IBS) are conditions associated with food triggers, improvement after withdrawal, treatment with dietary restriction, and subsequent nutritional detriments. LM occurs when there is incomplete hydrolysis of lactose due to lactase deficiency and frequently produces abdominal symptoms; therefore, it can cause lactose intolerance (LI). A lactose-restricted diet is frequently recommended, although it can potentially lead to nutrient deficiencies. Furthermore, lactose is an essential component of fermentable oligo-, di-, and monosaccharides and polyols (FODMAPs) and is subsequently associated with intolerance to these compounds, especially in IBS. LM commonly presents in CD. Nutritional deficits are common in CD and can continue even on a gluten-free diet (GFD). Conditions triggered by gluten are known as gluten-related disorders (GRDs), including CD, wheat allergy, and NCGS. IBS can also be associated with a gluten sensitivity. A GFD is the treatment for CD, GRDs, and gluten sensitive IBS, although compliance with this restricted diet can be difficult. Strict dietary therapies can have a negative effect on quality of life. This review aims to provide an overview of the difficult nutritional elements of these disorders, which are critical for medical providers to recognize when managing these patients.

Non-Celiac Gluten Sensitivity: An Update

Non-celiac gluten sensitivity (NCGS) is a clinical entity characterized by the absence of celiac disease and wheat allergy in patients that trigger reproducible symptomatic responses to gluten-containing foods consumption. Due to the lack of sensitive and reproducible biomarkers for NCGS diagnosis, placebo-controlled gluten challenges must be carried out for its diagnosis. The gluten challenges can be either double- or single-blind, for research or clinical practice purposes, respectively. For improving our understanding about the magnitude and relevance of NCGS in different populations, epidemiological studies based on self-report have been carried out. However, the gluten challenge-based prevalence of NCGS remains to be estimated. Since NCGS was recently recognized as a clinical entity, more studies are needed to delve into NCGS pathogenesis, for instance, the molecular interactions between the suspected cereal grain components that trigger NCGS, such as fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs) and amylase and trypsin inhibitors, and the immune system remains to be elucidated. Although still under debate, NCGS patients can be susceptible to only one or more than one of the NCGS triggers. The treatment of NCGS involves the dietary restriction of the suspected triggers of the disease, but there is controversial data about the effectiveness of different dietary interventions such as the gluten-free diet and low-FODMAP diet. Certainly, our understanding of NCGS is improving quickly due to the constant availability of new scientific information on this topic. Thus, the aim of the present narrative review is to present an up-to-date overview on NCGS from epidemiology to current therapy.

Non-Celiac Gluten/Wheat Sensitivity: Clinical Characteristics and Microbiota and Mycobiota Composition by Response to the Gluten Challenge Test

The aims of this observational “proof-of-concept” study were to analyze the clinical/psychological characteristics and gut microbiota/mycobiota composition of individuals with suspected non-celiac gluten/wheat sensitivity (NCGS/WS) according to responses to the double-blind-placebo-controlled (DBPC) crossover gluten challenge test. Fifty individuals with suspected NCGS/WS were subjected to the DBPC challenge test; anthropometric measurements, psychometric questionnaires, and fecal samples were collected. Twenty-seven (54%) participants were gluten responsive (NCGS), and 23 were placebo responsive, with an order effect. NCGS individuals displayed a significantly lower risk of eating disorders and a higher mental health score when compared to placebo-responsive participants, confirmed by multiple logistic regression analyses (OR = 0.87; 95% CI 0.76–0.98, p = 0.021, and OR = 1.30; 95% CI 1.06–1.59, p = 0.009, respectively). Principal coordinate analyses based on microbiota composition showed a separation by the DBPC response (p = 0.039). For Bacteroides (p = 0.05) and Parabacteroides (p = 0.007), the frequency of amplicon sequence variants was lower, and that for Blautia (p = 0.009) and Streptococcus (p = 0.004) was higher in NCGS individuals at multiple regression analyses. No difference in the mycobiota composition was detected between the groups. In conclusion, almost half of the individuals with suspected gluten sensitivity reported symptoms with placebo; they showed lower mental health scores, increased risk for eating disorders, and a different gut microbiota composition.

More fuel to the fire: some patients with non-celiac self-reported wheat sensitivity exhibit adaptive immunological responses in duodenal mucosa

BACKGROUND

In contrast to the well-characterized Celiac Disease (CD), the clinical scenarios encompassed by the non-celiac self-reported wheat sensitivity (NCSRWS) might be related to different antigens that trigger distinct immune-inflammatory reactions. Although an increased number of intestinal intraepithelial lymphocytes is observed at the inception of both diseases, the subsequent immunopathogenic pathways seem to be different. We aimed to describe the cytokine profile observed in the duodenal mucosa of patients with NCSRWS.

METHODS

In a blind, cross-sectional study, we included duodenal biopsies from 15 consecutive untreated patients with active CD, 9 individuals with NCSRWS and 10 subjects with dyspepsia without CD and food intolerances. Immunohistochemistry and flow-cytometry were used to determine the presence of pro-inflammatory cytokine expressing monocytes and monocyte-derived dendritic cells involved in innate immune activation, cytokine-driven polarization and maintenance of Th1 and Th17/Th 22, and anti-inflammatory/profibrogenic cytokines.

RESULTS

The percentage of cells expressing all tested cytokines in the lamina propria and the epithelium was higher in CD patients than in the control group. Cytokines that induce and maintain Th1 and Th17 polarization were higher in CD than in NCSRWS and controls, also were higher in NCSRWS compared to controls. Similar differences were detected in the expression of IL-4 and TGF-1, while IL-10-expressing cells were lower in NCSRWS patients than in controls and CD subjects.

CONCLUSIONS

NCSRWS patients exhibit components of both, innate and adaptive immune mechanisms but to a lesser extent compared to CD.