Related Experiment Video
Updated: Aug 16, 2026
08:32
A Pre-Clinical Model of Synovitis Using Ex vivo Human Synovial Tissue with Preserved Function and Architecture
Published on: March 20, 2026
Interaction between synovial inflammatory tissue and bone marrow in rheumatoid arthritis
Esther Jimenez-Boj1, Kurt Redlich, Birgit Türk
1Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Austria.
Journal of Immunology (Baltimore, Md. : 1950)
|August 6, 2005
Summary
Rheumatoid arthritis (RA) causes inflammation to invade bone marrow, forming B cell aggregates. This invasion leads to new bone formation, indicating bone marrow is a key site in RA disease progression.
Area of Science:
- Immunology
- Rheumatology
- Bone Biology
Background:
- Rheumatoid arthritis (RA) is characterized by cartilage and bone destruction.
- The impact of RA on adjacent subcortical bone marrow remains unclear.
Purpose of the Study:
- To investigate subcortical bone marrow changes in joints affected by RA.
- To elucidate the role of bone marrow in the pathogenesis of RA.
Main Methods:
- Histological examination of joint tissues from RA patients.
- Immunohistochemical analysis to identify cell phenotypes and molecular markers.
Main Results:
- Synovial inflammatory tissue penetrates the cortical barrier, invading the bone marrow cavity.
- Formation of B cell-rich aggregates (CD20+, CD45RA+, CD79a+, CD27+) and plasma cells within the bone marrow.
- Expression of B cell chemoattractants (BCA-1, CCL-21) and survival molecules (BAFF).
- Accumulation of osteoblasts and osteoid deposition in endosteal bone adjacent to aggregates.
Conclusions:
- Bone marrow serves as an additional disease compartment in rheumatoid arthritis.
- Synovial inflammation breaching the cortical barrier drives B cell aggregation and new bone formation in the marrow.
Related Concept Videos
01:24T Cell Types and Functions
When T cells with CD4 markers are activated, they give rise to two types of effector cells: helper T cells and regulatory T cells. Meanwhile, T cells with CD8 markers differentiate into effector cytotoxic T cells. The differentiation of CD4 T cells into helper T cell subsets, such as Th1, Th2, and Th17 cells, is dependent on the antigen type, antigen-presenting cell, and regulatory cytokines.
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
01:20The JAK-STAT Signaling Pathway
Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as SH2...
01:23Rheumatic Heart Disease I: Introduction
Rheumatic heart disease or RHD is a chronic condition that results from rheumatic fever, causing permanent damage to the heart valves.Etiology and Risk FactorsIt primarily arises from rheumatic fever, an inflammatory disease that can develop after untreated or inadequately treated group A streptococcal (GAS) pharyngitis. Streptococcus spreads through direct contact with oral or respiratory secretions. While the bacteria are the causative agents, factors like malnutrition, overcrowding, poor...
01:07Development of the Limb Synovial Joints
Joints form during embryonic development in conjunction with the formation and growth of the associated bones. The embryonic tissue that gives rise to all bones, cartilage, and connective tissues of the body is called mesenchyme.
The mesenchymal stem cells differentiate into chondrocytes that form the hyaline cartilage, and later the cartilaginous model of the bone. This model further transforms into a bone. This process is known as endochondral ossification.
During development, the limbs...
The mesenchymal stem cells differentiate into chondrocytes that form the hyaline cartilage, and later the cartilaginous model of the bone. This model further transforms into a bone. This process is known as endochondral ossification.
During development, the limbs...
01:22Bone Marrow Sampling and Transplants
Bone marrow transplant is a potential cure for several diseases, including cancer and specific genetic disorders. Notably, this procedure is applicable for patients suffering from aplastic anemia, certain types of leukemia, severe combined immunodeficiency disease (SCID), Hodgkin's disease, non-Hodgkin's lymphoma, multiple myeloma, thalassemia, sickle-cell disease, and certain cancers.
The transplant begins with high doses of chemotherapy and radiation treatment, which aim to destroy the...
The transplant begins with high doses of chemotherapy and radiation treatment, which aim to destroy the...
01:22Rheumatic Heart Disease II: Clinical Manifestations and Diagnostic Studies
The key clinical manifestations of Rheumatic heart disease (RHD) include several distinct cardiac symptoms.Carditis, a hallmark of acute rheumatic fever, involves inflammation of the heart's endocardium, myocardium, and pericardium. Chronic RHD often results from recurrent episodes of carditis. Its symptoms include the following:Murmurs are caused by valvular damage, especially to the mitral and aortic valves. Mitral stenosis or regurgitation is common, with characteristic heart murmurs...