2.6.4. PATH LAB - Bone Pathology I (Part 3 of 3) Flashcards
Discuss the blood supply, lymphatics and nerve supply of hyaline cartilage and the general function of it. What type of collagen is it made up of?
-Hyaline cartilage is a connective tissue ideally suited to serve as an elastic shock absorber and wear-resistant surface. It lacks a blood supply and does not have lymphatic drainage or innervation. It is 10% type II collagen.
Describe Osteoarthritis
Osteoarthritis, also called degenerative joint disease, is characterized by degeneration of cartilage that results in structural and functional failure of synovial joints. It is the most common type of joint disease.
Where do osteoarthritis lesions come from?
The lesions of OA stem from degeneration of the articular cartilage and its disordered repair.
In the earlym orphology of osteoarthritis, what occurs?
In the early stages, chondrocytes proliferate, forming clusters.
Collagen type II fibers are cleaved, yielding fissures and clefts at the articular surface.
In osteoarthritis, after chondrocytes proliferate and
Collagen type II fibers are cleaved yielding fissures and clefts at the articular surface, what happens to the chondrocytes and eventually the joint?
Eventually, chondrocytes die and full-thickness portions of the cartilage fall off.
The dislodged pieces fall into the joint, forming loose bodies (“joint mice”).
Friction with the opposing surface smooths and burnishes the exposed bone, giving it the appearance of polished ivory (bone eburnation).
What shape of ostephytes do we see with osteoarthritis?
Mushroom-shaped osteophytes develop at the margins of the articular surface and are capped by fibrocartilage and hyaline cartilage that gradually ossify.
Symptoms of osteoarthritis
Symptoms include deep, aching pains that get worse with use, morning stiffness, crepitus, and limitation of range of movement
What are the structural abnormalities seen with osteoarthritis?
Heberden nodes are common in women
With time, joint deformity can occur, but unlike in rheumatoid arthritis, fusion does not take place
What is Rheumatoid Arthritis
RA is a chronic inflammatory disorder of autoimmune origin that may affect many tissues and organs but principally attacks the joints, producing a nonsuppurative proliferative and inflammatory synovitis
The most important cytokines that can be isolated from the inflamed joints in Rheumatoid Arthritis are
IFN-γ
IL-17
TNF and IL-1
RANKL
*Note that your go to supported cytokine implicated with RA is TNF
The synovium of RA contains germinal centers with secondary follicles and abundant _____ cells which produce what?
The synovium of RA contains germinal centers with secondary follicles and abundant plasma cells which produce antibodies, some of which are against self-antigens.
What type of arthritis, symmetrical or asymmetrical, is RA and what does it affect primarily?
Typically manifests as a symmetric arthritis principally affecting the small joints in the hands and feet
Hallmark histologically of RA
Hallmark = Synovitis leading to formation of a pannus - mass of edematous synovium, inflammatory cells, granulation tissue, and fibroblasts that grows over the cartilage and causes its erosion
Over time, what happens with a joint afflicted with RA?
Over time, the cartilage is destroyed and the pannus bridges the apposing bones to form a fibrous ankylosis, which eventually ossifies and fuses the bones (bony ankylosis).
What are the most common cutaneous lesions associated with RA?
Rheumatoid subcutaneous nodules are the most common cutaneous lesions.
Describe the clinical course of RA
Symptoms usually begin in the hands and feet, followed by wrists, ankles, elbows and knees. It is uncommon for the spine to be involved.
Often progresses to destruction of the articular cartilage and ankylosis of the joints
How is pain related to activity with Rheumatoid Arthritis?
Pain improves with activity
What lab results support RA?
Combination of rheumatoid factor and anti-CCP antibody
Also, IgM autoantibody against Fc portion of IgG (rheumatoid factor)
What is Juvenile Idiopathic Arthritis (JIA)?
JIA is a heterogeneous group of disorders of unknown cause that present with arthritis before age 16 and persist for at least 6 weeks
When comparing JIA to RA, in JIA: Oligoarthritis is more or less common?
Oligoarthritis is more common
When comparing JIA to RA, in JIA: Systemic disease is more or less frequent?
Systemic disease is more frequent
When comparing JIA to RA, in JIA: Large joints are affected more often or are small joints?
Large joints are affected more often than small joints
When comparing JIA to RA, in JIA: Rheumatoid nodules and rheumatoid factor are usually absent or present?
Rheumatoid nodules and rheumatoid factor are usually absent
In JIA, what antibody is usually present?
ANA (antinuclear antibody) is common
Like in adult RA, damage by JIA appears to be caused by what cells?
Like in adult RA, damage appears to be caused by Th1 and Th17 cells
What mediators are associated with JIA?
IL-1, IL-17, TNF, and IFN-γ
What are Seronegative Spondyloarthropathies?
Heterogenous group of disorders that are unified by pathologic changes in the ligamentous attachments rather than synovium. SI joints are often involved.
What surface antigen are Seronegative Spondyloarthropathies related to?
HLA-B27
What rheumatoid factor is linked to Seronegative Spondyloarthropathies?
Absence of Rheumatoid factor
What is Ankylosing spondylitis also called and what is it
Ankylosing Spondylitis (aka rheumatoid spondylitis or Marie-Strumpell disease) is a spondyloarthopathy that causes destruction of articular cartilage and bony ankylosis, especially of the sacroiliac and apophyseal joints (between tuberosities and processes)
What surface antigen is positive in Ankylosing spondylitis?
HLA-B27
What is Reactive Arthritis also known as and what is it?
Reactive Arthritis (Reiter syndrome)
Defined by a triad of arthritis, non-gonococcal urethritis or cervicitis, and conjunctivitis.
(Can’t See, Can’t Pee, Can’t Climb a Tree)