Immunoglobulin G4-Related Disease
Conditions
Brief summary
This is a monocentric, comparative, cross-sectional, case-control study seeking to identify abnormalities of the C5a-C5aR1 axis between a population of patients with active IgG4-associated disease (MAG4) and two control groups: healthy subjects without MAG4 and patients with MAG4 in remission.
Detailed description
IgG4-associated disease is a rare fibrosing and inflammatory disorder whose pathophysiology remains poorly understood. Activation of certain monocyte/macrophage populations (in particular M2-type macrophages) has been shown to be involved during the course of the disease. The mechanisms behind this monocyte/macrophage activation are not known. Expression of the C5aR receptor on the surface of these populations, and preliminary findings of elevated C5a in these patients, suggest a potential role for this C5a-C5aR axis. Demonstration of the involvement of this pathway would open a path to therapeutic perspetives (C5aR inhibitors) for these patients, who frequently suffer from cortico-dependence and relapses. The aim of this research is to use healthcare technologies to identify cellular and molecular therapeutic targets in the context of the IgG4-associated disease
Interventions
PROCEDUREBlood sampling
Blood sampling will be taken for further analysis
Sponsors
Assistance Publique Hopitaux De Marseille
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
for patients suffering from IG4-related disease and patients in remission : * age \> 18 * diagnosis of IgG4-associated disease according to ACR/EULAR 2019 classification criteria (4,5) with a score ≥20. * disease activity score (IgG4-RD Responder Index) ≥2 in at least one affected organ
Exclusion criteria
for patients suffering from IG4-related disease and patients in remission : * presence of a differential diagnosis (IgG4-RD mimicker) or exclusion criterion according to ACR/EULAR 2019 classification criteria (4,5). * systemic corticosteroid treatment ≥5 mg/day ongoing or \< 1 month ; Study C5-MAG4\_RCAPHM21\_0433 Protocol Version 1.1 of 16/01/2024 Page 15 of 41 * immunosuppressive therapy ongoing or \< 3 months ; * current biotherapy treatment or \< 6 months; * absence of signed informed consent; * absence of affiliation to a Social Security scheme. * patient participating in an ongoing therapeutic trial ; * any condition which, in the opinion of the investigator, could influence the results of the study. Inclusion criteria for healthy volunteers : \- age \> 18
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Serum C5a concentration | 24 months | The C5a concentration in the serum will be compared between of healthy volunteers and patients suffering from IG4-related disease |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| frequency of C5aR1+ monocytes among total monocytes | 24 months | The frequency of C5aR1+ monocytes among total monocytes will be compared between : * patients suffering from IG4-related disease and healthy volunteers * patients suffering from IG4-related disease and patients in remission |
| frequency of Tumor Growth Factor B+ (TGF-B+) monocytes among total monocytes | 24 months | frequency of Tumor Growth Factor B+ (TGF-B+) monocytes among total monocytesill be compared between : * patients suffering from IG4-related disease and healthy volunteers * patients suffering from IG4-related disease and patients in remission |
Outcome results
None listed