Immunotyping lymph nodes in immune-mediated inflammatory diseases (IMIDs):
lymph node cellular and molecular biomarkers in IMIDs

Immune-mediated inflammatory diseases (IMIDs) refers to inflammatory arthritic
and systemic inflammatory diseases. Examples of these diseases are rheumatoid
arthritis (RA), spondyloarthritis (SpA), osteoarthritis (OA) and gout, systemic
lupus erythematosus (SLE), Sjogren*s Syndrome (SS), systemic sclerosis (SSc),
IgG4-mediated disease and various forms of vasculitis. The cellular and
molecular alterations of the immune system (the immunotype) driving these
diseases still remain largely unknown. Accordingly, it remains difficult to
correctly diagnose and classify these diseases at an early stage and to predict
the evolution of the disease in an individual patient. Moreover, despite the
development of a variety of novel and powerful drugs (including the so-called
biologicals), the patient*s response to treatment remains heterogeneous and
difficult to predict, and no curative therapies exist. Therefore, there is a
clear need for the identification and validation of cellular and molecular
biomarkers which reflect directly the immunotype of a given disease and can
provide useful clinical information for diagnosis, classification, prognosis
and treatment, as well as the development of new therapeutic strategies.
Biomarkers of the immunotype can be found and analyzed in different body
compartments, of which the peripheral blood and the intra-articular synovial
fluid or tissue are most easily accessible. However, previous studies in RA and
other IMIDs showed that adaptive immune responses take place before clinical
signs of arthritis or inflammation in other tissues are present. Investigating
other immune compartments of the body such as the lymph nodes could reveal
early driving pathogenic mechanisms, because the immune response in lymph nodes
generally precedes the influx of effector immune cells into the target tissue.
To study the early pathogenesis of inflammatory arthritic conditions, in 2008
our department initiated core-needle inguinal lymph node biopsy sampling. Since
then we performed more than 80 lymph node biopsy procedures. We showed that the
procedure is generally well tolerated and that, other than a small hematoma
which does not require therapy in most of the cases, no complications were
reported. In the current study, we aim to extend our analyses by investigating
and comparing the pathogenesis of different IMIDs by studying the immune
alterations taking place in lymph nodes during early and pre-clinical disease
in comparison to peripheral blood ánd immune alterations taking place in the
endorgan, e.g. the joint (knee or ankle) by taking synovial biopsies during a
mini-arthroscopy. This procedure has been performed frequently in our
department over the last 15 years and we have ample expertise. Recently, new
MRI techniques have become available that are able to quantify joint
inflammation more accurately (hitherto only tested in children). Therefore, we
want to perform an MRI of the joint that will be biopsied later. In this way we
will be able to asses and compare immune alterations in the lymph nodes
(secondary lymphoid organ), peripheral blood (systemic) and the joint (end
organ for the disease).

The primary goal of this study is to identify immunological alterations in
lymphoid tissue of patients with various forms of inflammatory arthritis and
systemic inflammatory diseases, and to correlate these alterations with
diagnosis, disease stage, prognosis, and treatment response. We aim to identify
and validate novel biomarkers that can be used for personalized medicine in
IMIDs.

The specific types of immunological alterations that we will study include: TCR
and BCR repertoire, phenotype and function of (auto-reactive) T and B cells,
cytokine production by innate immune cells and stromal cells, genetic,
epigenetic and transcriptional alterations of immune cells and stromal cells,
signalling events in immune cells and stromal cells, antigen presentation and
immunomodulation by stromal cells

All these parameters will be compared between lymph nodes, blood and joint
(synoviumbiopsies and MRI, optional) in different diseases, between different
patients within one disease, and between different phases of the disease to
determine their potential value as disease biomarker.
To interpret our findings, inclusion of autoantibody-negative healthy controls
and (autoantibody positive) patients at risk of developing IMIDs, as well as
first degree relatives of certain patient groups is crucial.

Patients with IMIDs will be recruited from the outpatient clinics of the
Amsterdam Rheumatology and immunology Center (AMC, VUmc and Reade) and referred
to the AMC for participation in this study. Any patient with arthritis or
inflammatory systemic disease from known (e.g. RA, SpA, OA, UA, crystal
arthropathies, SLE, SS, SSc, vasculitis) or unknown origin can be included in
the study. Demographic data and clinical data regarding classification of
diagnosis, medication use and disease activity will be collected. In total 600
patients will be included starting march 2018 with an inclusion period of 3
years. In addition, we will include patients who are at risk of developing
IMIDs, first degree relatives of patients with IMIDs 18-40 years old,
autoantibody-negative healthy controls, in order to better understand
pathogenetic processes leading to the development of clinically manifest RA,
SpA and other IMIDs. Lymph node and blood samples will be obtained in all
individuals. From patients with an IMIDs or an increased risk of developing an
IMID, mini-arthroscopy for synovial biopsies and/or MRI will be performed if
patients are willing (optional).

The risk of developing a hematoma after the biopsy is approximately 3%. This
will heal spontaneously. Mini-arthroscopy gives a small (<0,3%) risk on a
hematoma, bleeding or infection. MR imaging does not give any additional risk,
besides a possible allergic reaction to the contrast agent. The contrast agent
used is however the same as used in standard clinical practice.
The patient will visit our outpatient clinic several times. Total duration: 5
hours.
For the healthy controls the total study duration will be 1,5 hours.