Mast Cell Activation Test in Allergic Disease

Completed

Conditions: Asthma
Mastocytosis
Chronic Idiopathic Urticaria
Eczema
Anaphylaxis
Food Allergy
Mast Cell Activation Syndrome

Registration Number: NCT03406325

Lead Sponsor: Hong Kong Sanatorium & Hospital

Brief Summary: Activation of mast cells in the immune system is known to cause allergic reactions sometimes with severe systemic symptoms. The investigators have recently developed a blood-based mast cell activation diagnostic test in which levels of functional activation in-vitro in primary cultured mast cells generated from the peripheral blood of single individuals can be assessed. It is the hypothesis that the test can be used to predict the potential state of in-vivo mast cell activation in any individual based on the functional activation profiles exhibited by their cultured mast cells. The investigators now wish to translate their in-vitro findings in a pilot study to disease groups where mast cell activation is expected to be high. These include highly allergic individuals; those with chronic idiopathic urticaria; those with mastocytosis; and those with the mast cell activation syndrome. Furthermore, they will use the functional genomics approach to identify gene expression biomarkers that are correlated with such diseases. The results will be compared with data that have been collected from a cohort of healthy control blood donors.

Detailed Description: The objective of this study is to assess whether patients with severe allergic diseases exhibit high levels of mast cell activation as determined by the mast cell activation diagnostic test the investigators have developed. They anticipate that patients with history of severe allergic reactions will show up as high responders in the blood-based mast cell activation diagnostic test. Moreover, using microarray analysis as the approach for gene expression studies, they anticipate further that genomics biomarkers that are correlated with the high functional activation of the in-vitro mast cells derived from these patients can be readily identified.

About 100 ml of peripheral venous blood from individual patients will be drawn into heparinized syringes and collected in a blood-collecting bag/tube containing silica. The bag/tube will be promptly processed for the generation of primary human mast cell cultures using the protocol that has previously been developed \[Inflammation Research 66: 25 (2017). After culturing for 9 weeks, the resulting human mast cells will be analyzed for both their functional activity in terms of histamine release in response to the activation of high-affinity Immunoglobulin E (IgE) receptors in these cells and their gene expression profiles using microarray analysis. The in-vitro functional and genomics data will be correlated with specific diagnoses and measurements of blood prostaglandin D2 (PGD2), PGD2 metabolites, tryptase and histamine levels in blood. For mediator assays, plasma from each subject will be collected after the cluster of differentiation 34 positive (CD34+) isolation step and the samples will be aliquoted and frozen at -80 degrees centigrade for subsequent analysis.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 19

Inclusion Criteria

Any patients with the above diagnoses -

Exclusion Criteria

Children < 18 years old; those who are unwilling or unable to donate blood; pregnant mothers.

Study & Design

Study Type: OBSERVATIONAL

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Mast Cell Activation Test Results for Validation Group	Mast cells studied after 9 weeks in culture	Mast Cell Activation Test results of high/low level of house dust mite sensitivity by using normal donor cultured mast cells for validation.
Evaluation of Patient's Serum for Autoreactivity on Normal Average Responder Mast Cell Activation	Mast cells studied after 9 weeks in culture	Patient's serum was incubated with mast cells derived from normal donors for detection of mast cell activation as evidenced by histamine release.
Percentage Histamine Release by Normal Average Responder Mast Cells + Patient's Serum to Assess Autoreactivity	Mast cells studied after 9 weeks in culture	percentage of total histamine release by normal average responder mast cells that had been activated with patient's serum
Percentage Histamine Release by Patient's Mast Cells + Immunoglobulin E (IgE)/Anti-IgE	Mast cells studied after 9 weeks in culture	percentage of total histamine release by patient's mast cells that had been activated with anti-IgE
Percentage of Histamine Release by Patient's Mast Cells + Patient's Serum + Allergen	Mast cells studied after 9 weeks in culture	Percentage of total histamine release when patient's mast cells were activated with patient's own serum and Der p2. Each patient's results are reported individually.
Cell Yield Per 100ml Blood	Mast cells studied after 9 weeks in culture	Cell yield of patient's mast cell culture after 9 weeks in culture as an index of cell growth and differentiation.