Vitamin B12: a Biological Marker of Systemic Disease or Infection Flare-up in Patients Treated with Tocilizumab?

Last updated: October 21, 2024
Sponsor: University Hospital, Clermont-Ferrand
Overall Status: Active - Recruiting

Phase

N/A

Condition

N/A

Treatment

variation of serum level vitamine B12

Clinical Study ID

NCT06654154
RNI 2023 CLEMENT
2023-A01673-42
  • Ages > 18
  • All Genders

Study Summary

Tocilizumab is a monoclonal antibody that acts as an IL-6 receptor antagonist It is responsible for a reduction in the hepatic synthesis of inflammatory proteins, including CRP (C-reactive protein).

Thus, the diagnosis of a relapse of the autoimmune or auto inflammatory disease (AI/ID) or an infection is made difficult in patients treated with tocilizumab and there is to date no marker of inflammation validated in patients receiving tocilizumab.

Vitamin B12 is an essential element that participates to haematopoiesis, myelin integrity, neuronal function and DNA synthesis. Vitamin B12 is carried by haptocorrin and transcobalamin II (TCII). Vitamin B12 increases in many pathological situations, including infections and AI/ID due to the increase of its transport proteins elevation (mostly transcobalamin II).

The sponsor did not find any study in the literature studying the level of vitamin B12 or TCII in patients taking tocilizumab. The sponsor also did not find any physiopathological argument in favor of an inhibition of TCII synthesis by tocilizumab.

As such, TCII dosage could be of interest, but the dosage is not available in routine whereas vitamin B12 dosage is available in every laboratory and is four times cheaper.

Eligibility Criteria

Inclusion

Inclusion Criteria:

  • Age > 18 years old

  • Patient with:

  • A diagnosis of rheumatoid arthritis according to ACR EULAR 2010 classificationcriteria

  • Or a diagnosis of polymyalgia rheumatica according to ACR EULAR 2012classification criteria

  • Or a diagnosis of giant cell arteritis (with or without polymyalgia rheumaticaassociated) according to 2022 revised classification criteria

  • Or a diagnosis of systemic sclerosis according to ACR EULAR 2013 classificationcriteria

  • Or a diagnosis of Takayasu vasculitis according to ACR 2022 classificationcriteria

  • Or a diagnosis of Still disease according to Yamaguchi or Fautrelclassification criteria

  • Or a diagnosis of VEXAS with UBA1 somatic mutation

  • Or a diagnosis of unclassified autoimmune or auto-inflammatory disease treatedby tocilizumab

  • Receiving intravenous or subcutaneous tocilizumab (treatment can be introduce beforeinclusion or started at the inclusion)

  • Capable of giving informed consent

  • Covered by a social protection system

Exclusion

Exclusion Criteria:

  • Patient treated by oral or subcutaneous vitamin B12

  • Pregnant or breastfeeding women

  • Patient under guardianship or curatorship, deprived or liberty, placed underjudicial protection

  • Rejection to participate

Study Design

Total Participants: 56
Treatment Group(s): 1
Primary Treatment: variation of serum level vitamine B12
Phase:
Study Start date:
April 03, 2024
Estimated Completion Date:
March 31, 2029

Study Description

The main objective is to study the variation in serum vitamin B12 level in case of clinical suspicion of AID/I flare or infection in patients treated with tocilizumab compared to the B12 level of the patient in remission period. , and excluding infection, under tocilizumab

Also, serum vitamin B12 will be measured during a biological assessment carried out either in the event of a suspected outbreak of MAI/I or infection, or in the event of remission (during the follow-up assessment carried out systematically in a patient on tocilizumab).

This determination of serum vitamin B12 will be carried out during a blood test carried out at the request of the patient's doctor.

The study will involve taking an additional tube of venous blood but will not result in additional venipuncture.

There will be no specific visit related to the study.

Connect with a study center

  • CHU clermont-ferrand

    Clermont-Ferrand,
    France

    Active - Recruiting

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