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NCT Number: NCT07448896

Alterations in Mast Cell and Macrophage Infiltration, as Well as Micro Vessel Density

Obesity is a global health problem that has reached epidemic proportions, affecting more than one billion people worldwide and significantly increasing the risk of multiple comorbidities, including type 2 diabetes, cardiovascular diseases, and cancer (World Health Organization, 2024). Increasing evidence suggests that chronic low-grade inflammation associated with obesity plays a critical role in the development of obesity-related malignancies, including gastric cancer. Adipose tissue dysfunction in obesity leads to the recruitment and activation of various immune cells, such as macrophages and mast cells, which contribute to a pro-inflammatory microenvironment through the release of cytokines, growth factors, and angiogenic mediators.

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Key information

Conditions

Obesity Body Weight Nutrition Disorders Nutritional and Metabolic Diseases Overnutrition Overweight Pathological Conditions, Signs and Symptoms Signs and Symptoms

Sex eligibility

All sexes

Study type

Observational

Primary location

The surgical department of Medical Research Institute Hospital, Alexandria University

Alexandria, Alexandria Governorate, 21531, Egypt

Location status: Recruiting

Location contact

Mohamed H Ashour, PhD

CONTACT

[email protected]

00201002600970

About this study

In the gastric mucosa, this inflammatory micro environment associated with obesity may promote epithelial proliferation, DNA damage, and neovascularization, establishing conditions favorable for early carcinogenic transformation. Mast cells presence at the periphery and infiltrating tumors, argues for their role in the modulation of tumor biology it has been implicated in tumor progression through their ability to release histamine, tryptase, and vascular endothelial growth factor (VEGF), thereby enhancing angiogenesis and stromal remodeling. Similarly, macrophages especially those exhibiting an M2-like phenotype can facilitate tissue remodeling and angiogenesis, further supporting tumor initiation. The number and phenotype of macrophages vary at different stages of tumor progression. The number of macrophages markedly increases during the early stages of tumor growth.

Despite the growing recognition of the link between obesity, inflammation, and cancer, few studies have explored the immunopathological changes occurring in the gastric mucosa of obese patients before overt malignancy. Bariatric surgery provides a unique opportunity to study these changes in human gastric tissue. Understanding alterations in mast cell and macrophage infiltration, as well as microvessel density, may throw light on the early events leading to gastric carcinogenesis in obesity.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adult patients undergoing bariatric surgery (laparoscopic sleeve gastrectomy).
  • BMI > 35 kg/m²
  • All participants underwent preoperative evaluation, including blood tests and assessment by a multidisciplinary team (nutritionist, psychiatrist, endocrinologist, radiologist, anesthesiologist, and surgeon).

Exclusion criteria

  • Patients with secondary causes of obesity, such as Cushing's syndrome or polycystic ovary syndrome (PCOS).
  • Patients with malignant gastric conditions or previous gastric surgery.
  • Patients with systemic inflammatory diseases, autoimmune disorders, or chronic infections that may influence immune cell infiltration.
  • Patients with incomplete clinical data or poor-quality tissue samples.
  • Patients taking anti-inflammatory, immunosuppressive, or corticosteroid therapy within the last 3 months before sampling.

Treatment and study plan

bariatric surgery laparoscopic sleeve gastrectomy

Procedure

Adipose tissue macrophages (ATMs), mast cells positive for tryptase (MCPT), and microvascular density (MVD) were assessed by immunohistochemistry.

Quantitative assessment was performed using a light microscope. For each GTO and NT tissue section, five highly immunostained areas ("hot spots") were identified at low magnification.

lean control patients undergoing endoscopic biopsy for benign or malignant gastric conditions.

Procedure

Adipose tissue macrophages (ATMs), mast cells positive for tryptase (MCPT), and microvascular density (MVD) were assessed by immunohistochemistry.

Quantitative assessment was performed using a light microscope. For each GTO and NT tissue section, five highly immunostained areas ("hot spots") were identified at low magnification.

Primary outcomes

  1. Immunohistochemistry

    Time frame: Baseline

    Compare the 2 groups:

    Adipose tissue macrophages (ATMs) was assessed by immunohistochemistry using a three-step biotin-avidin-peroxidase detection method. five-micrometer-thick serial sections were cut from formalin-fixed, paraffin-embedded gastric tissue of obese (GTO) and control normal tissue (NT) samples. Antigen retrieval was performed using a microwave oven (500 W for 10 minutes), followed by endogenous peroxidase blocking with a 3% hydrogen peroxide solution.

    Slides were incubated with the following primary antibodies for 1 hour at room temperature:

    • Anti-tryptase (clone AA1; Dako, Glostrup, Denmark; 1:100) for mast cell identification,
    • Anti-CD68 (clone KP1; Dako, Glostrup, Denmark; 1:100) for ATM detection,
    • Anti-CD31 (clone QB-END 10; Bio-Optica, Milan, Italy; 1:50) as a pan-endothelial marker to assess MVD.

  2. Immunohistochemistry

    Time frame: Baseline

    Compare the 2 groups:

    Mast cells positive for tryptase (MCPT) was assessed by immunohistochemistry using a three-step biotin-avidin-peroxidase detection method. five-micrometer-thick serial sections were cut from formalin-fixed, paraffin-embedded gastric tissue of obese (GTO) and control normal tissue (NT) samples. Antigen retrieval was performed using a microwave oven (500 W for 10 minutes), followed by endogenous peroxidase blocking with a 3% hydrogen peroxide solution.

    Slides were incubated with the following primary antibodies for 1 hour at room temperature:

    • Anti-tryptase (clone AA1; Dako, Glostrup, Denmark; 1:100) for mast cell identification,
    • Anti-CD68 (clone KP1; Dako, Glostrup, Denmark; 1:100) for ATM detection,
    • Anti-CD31 (clone QB-END 10; Bio-Optica, Milan, Italy; 1:50) as a pan-endothelial marker to assess MVD.

  3. Immunohistochemistry

    Time frame: Baseline

    Compare the 2 groups:

    Microvascular density (MVD) was assessed by immunohistochemistry using a three-step biotin-avidin-peroxidase detection method. five-micrometer-thick serial sections were cut from formalin-fixed, paraffin-embedded gastric tissue of obese (GTO) and control normal tissue (NT) samples. Antigen retrieval was performed using a microwave oven (500 W for 10 minutes), followed by endogenous peroxidase blocking with a 3% hydrogen peroxide solution.

    Slides were incubated with the following primary antibodies for 1 hour at room temperature:

    • Anti-tryptase (clone AA1; Dako, Glostrup, Denmark; 1:100) for mast cell identification,
    • Anti-CD68 (clone KP1; Dako, Glostrup, Denmark; 1:100) for ATM detection,
    • Anti-CD31 (clone QB-END 10; Bio-Optica, Milan, Italy; 1:50) as a pan-endothelial marker to assess MVD.

  4. Morphometric Analysis

    Time frame: Baseline

    Compare the 2 groups:

    Quantitative assessment was performed using a light microscope. For GTO tissue section, five highly immunostained areas ("hot spots") were identified at low magnification. ATMs, MCPT, and MVD were then quantified at ×40 magnification. The mean value across five hot spots per marker was used for each sample.

    To evaluate mast cell degranulation, the presence of tryptase-positive granules in the extracellular matrix was examined. Degranulating mast cells were identified by the diffusion of immunoreactive granules outside the cell boundaries, indicating active release of tryptase. This extracellular localization of tryptase provided morphological evidence of mast cell activation and was considered a marker of tissue inflammation and remodeling.

  5. Morphometric analysis

    Time frame: Baseline

    Compare the 2 groups:

    Quantitative assessment was performed using a light microscope. For NT tissue section, five highly immunostained areas ("hot spots") were identified at low magnification. ATMs, MCPT, and MVD were then quantified at ×40 magnification. The mean value across five hot spots per marker was used for each sample.

    To evaluate mast cell degranulation, the presence of tryptase-positive granules in the extracellular matrix was examined. Degranulating mast cells were identified by the diffusion of immunoreactive granules outside the cell boundaries, indicating active release of tryptase. This extracellular localization of tryptase provided morphological evidence of mast cell activation and was considered a marker of tissue inflammation and remodeling.

Study contacts

Contact information is provided by the study sponsor or research team.

Mohamed H Ashour, PhD

CONTACT

[email protected]

00201002600970

Sponsors and collaborators

Lead sponsor

General Committee of Teaching Hospitals and Institutes, Egypt

Other Gov

Registry information

Official study title

Understanding Alterations in Mast Cell and Macrophage Infiltration, as Well as Micro Vessel Density, May Throw Light on the Early Events Leading to Gastric Carcinogenesis in Obesity

Important dates

Study start
2026
Primary completion
2026
Study completion
2026
First posted
Mar 4, 2026
Registry last updated
Apr 29, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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