Towards prevention of chronic auto-immune disease: dominant B-cell receptor clones predict the onset of rheumatoid arthritis

Rheumatoid arthritis (RA) is a prototypic autoimmune disease affecting
approximately 1% of the general population [1]. Inflammation of joint tissue is
the hallmark of disease, but the pathogenesis remains to be elucidated.
Currently, there is no cure for this disease. Drugs need to be taken on a
chronic basis to alleviate pain and prevent joint damage [1]. Interestingly, it
might be feasible to prevent RA from occurring.

The rationale lies in the observation that the onset of RA is preceded by a
phase of systemic auto-immunity (preclinical phase) [2]. During this phase
specific autoantibodies are present in the blood, but there are no signs of
inflammation in the joints yet. Individuals with such autoantibodies have a
20-30% to develop RA [3]. This phase truly forms a window of opportunity to
intervene with disease development. If we succeed in understanding what causes
these at-risk individuals to develop RA, we might be able to prevent the
disease.

In this context, we recently identified a population of B-cell receptor (BCR)
clones that is only present in the blood of autoantibody-positive individuals
who will proceed to full-blown RA (see preliminary work). Once RA becomes
manifest, these clones migrate to the inflamed joint tissue. We hypothesize
that these BCR clones are pathogenic and consequently form an attractive target
for preventive therapies. The challenge lies in proving that these otherwise
poorly characterized cells are pathogenic. To target these clones
(demonstrating their pathogenicity) we aim to develop intervention strategies
in this project to do so while further characterizing these BCR clones.

As such this project helps to understand if specific BCR-clones contribute to
the initiation of RA and focuses on prevention of RA, which is an unmet need in
the field. The results will also be of relevance for other diseases in which
auto-reactive BCR clones are thought to play a role such as vasculitis,
Sjögren*s disease, celiac disease and type 1 diabetes.

Importantly, this research is a follow up on the earlier by METC approved
studies conducted in the AMC regarding this subject (MEC 05/107 #05.17.0858
*Pre-synoviomics advanced genomics initiative in pre-clinical arthritis* and
MEC 09/048 #09.17.1872 *Prevention of clinically manifest rheumatoid arthritis
by B cell directed therapy in the earliest phase of the disease (PRAIRI)*). The
promising results of these studies have been an important incentive to resume
research in this field. Of note, in contrast to the aforementioned studies,
this is a less invasive study (without repeated biopsies.

1. Scott DL, Wolfe F, Huizinga TW. Rheumatoid arthritis. Lancet.
2010;376(9746):1094-108. Epub 2010/09/28. doi: 10.1016/S0140-6736(10)60826-4.
PubMed PMID: 20870100.
2. van Schaardenburg D, Dijkmans BA. Clinical approaches to early inflammatory
arthritis. Nature reviews Rheumatology. 2009;5(11):627-33. Epub 2009/09/30.
doi: 10.1038/nrrheum.2009.203. PubMed PMID: 19786990.
3. Bos WH, Wolbink GJ, Boers M, Tijhuis GJ, de Vries N, van der Horst-Bruinsma
IE, et al. Arthritis development in patients with arthralgia is strongly
associated with anti-citrullinated protein antibody status: a prospective
cohort study. Annals of the rheumatic diseases. 2010;69(3):490-4. Epub
2009/04/14. doi: 10.1136/ard.2008.105759. PubMed PMID: 19363023.

Overall aim:
Understand the function of BCR clones in the initiation of RA

Specific objectives:
• Find discriminating surface markers for dominant clones;
• Perform single cell transcriptome sequencing to find distinguishing activated
inflammatory genes/pathways;
• Determine specificity of dominant clones against known and unknown
auto-antigens;
• Evaluate whether clones are pro-inflammatory

The results of this study will helpsto understand if specific BCR-clones
contribute to the initiation of RA and focuses on prevention of RA, which is an
unmet need in the field. The results will also be of relevance for other
diseases in which auto-reactive BCR clones are thought to play a role such as
vasculitis, Sjögren*s disease, celiac disease and type 1 diabetes.

This is a prospective study in approximately 75 participants with increased
risk of developing RA (arthralgia and high IgMRF and/or anti-CCP) who will
accept to participate by signing a written Informed Consent prior to study
sampling. The collection of samples of blood and synovial tissue will be used
for in vitro cellular assay(s). The total duration of the study is 6 years,
consisting of a 36 months inclusion period and up to 36 months for patient
participation.

Inclusion visit: This visit takes up to 1 hour. We will get to know the
participants and inform them about the study. If they agree to participate,
then they will sign the informed consent prior to any study related action. We
will take the demographic data, medical history, medication use and perform a
global physical and joint examination resulting in a DAS-28 score for each
participant. 2,5ml blood for PAXgene, 4 ml for EDTA, 4ml of IgMRF and anti-CCP
and 8,5ml for ESR and CRP will be drawn to conclude this visit. The total blood
drawn in this visit is 19ml. This blood can then be used to identify the
participants with dominant B cell receptor clones in the blood. Participants
without dominant BCR clones will form the control group for those with dominant
BCR clones.

Visits 1-6: There will be 6 fixed study visits every half year and 1 variable
study visit, spread out over 3 years. The visits will take up to 30 minutes
each. During these visits we take the medication use, the current complaints,
if infections have arisen and perform joint examination. In visit 6 or when
arthritis develops, inflammatory parameters (ESR, CRP 8,5ml) will be
determined, in addition to 2,5ml PAXgene and 70ml heparin for PBMC isolation
that we will draw in each of these visits. This blood can be used for FACS,
cell sorting and sequencing experiments.

The study ends for participants in case they develop arthritis or if they
complete the trial period. In participants that develop arthritis, we draw
blood once more as in visit 6. Furthermore, in these patients, a
mini-arthroscopy will be planned to obtain tissue samples. Afterwards, the
patients will directly be enrolled in regular clinical care and will be
treated. Beneficial to the participants is that they will remain under clinical
supervision every 6 months, will have immediate access to care when they
develop arthritis and will be treated very soon after disease manifestation.

This is a study without any interventions, except for blood withdrawal and
synovial tissue biopsies during mini-arthroscopy in patients who develop
arthritis. We do not expect any serious adverse events (SAE) from venepuncture.
There are very small chances of bleeding after the mini-arthroscopy. If a SAE
occurs, this will immediately be reported to the METC.

The participants will be invited several times to come to the hospital during
the research period.

Inclusion visit: One visit of approximately 60 minutes. We do not expect any
difficulties regarding the joint examination and blood withdrawal.

Other visits: Participants will visit every 6 months for a total period of 36
months. These visits take up to 30 minutes each. We do not expect any
difficulties regarding the joint examination and blood withdrawal. When an
arthritis develops during the research period, we can react quickly. The
patients will undergo a mini-arthroscopy to gather synovial biopsy. Clinically
this technique is performed frequently and is safe. The risk of a serious
adverse events is low (1%). Furthermore, the mini-arthroscopy might aleviate
pain.