Joint Pain #1 Dr. Buxton 5/9/06

Front 1

1. Learning Objectives

Back 1

What are the 3 ways by which microorganisms induce joint disease?
What virulence factors of bacteria might be involved in promoting joint disease?
Which viruses are associated with joint pain?
What is the pathogenesis of viral-associated joint pain?

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2. Four components of the Joint

Back 2

Bone
Cartilage
Synovial membrane
(Synoviocytes
Fibrous connective tissue
Highly vascular)
Synovial fluid

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3. Describe Synoviocytes
A cells
B cells

Back 3

A are macrophage like
B are fibroblast like

the membrance is 3-4 cells thick

Front 4

4. One path of bacterial infection in the body causing joint disease?

Back 4

Microbial infection somewhere in body
Induce immune response leading to aseptic inflammatory joint disease

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5. ***what are the 4 Bacteria Triggering Reactive Arthritis***

note: this is an aseptic reaction, no bacteria are in the joint at the moment, but the reaction is associated with a u infections

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Campylobacter jejuni
Chlamydia trachomatis (non enteric)
Yersinia enterocolitica
Yersinia
Know the characterisitcs for all of these enteric GNR
These are usually weight bearing joint like the knee

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6. What are the three Viral Causes of Joint Pain?

Back 6

Parvovirus B19
Rubella virus
Hepatitis B virus

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7. What is reactive arthritis?
RA

Back 7

One of the spondyloarthropathies
Associated with prior bacterial infection
Vary clinically from mild arthralgia to severe disabling polyarthritis
Most commonly affect weight-bearing joints

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8. What are Spondyloarthropathies?

Back 8

Refers to group of diseases with following similarities:
Inflammatory (poly)arthritis
May have infectious etiology
Seronegative for RF
Most patients express HLA-B27
Ankylosing spondylitis
Reactive arthritis (also called Reiter’s syndrome)
Psoriatic arthritis
Enteropathic arthritis

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9. Ankylosing Spond, enteropathic arthritis, RA, and psoriatic arthritis all have this in common?

Back 9

HLA-B27
this is the nomenclature designating MHC in humans

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10. Why is HLA-B27 unique to these diseases?

Back 10

The peptide-binding groove of HLA-B27 has unique aa at key sites that distinguish B27 from other HLA-B molecules
Suggestions for link with HLA-B27 include:
1. Presentation of “arthritogenic peptide”
2.Molecular mimicry between peptides derived from B27 and those of several bacteria

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11. How do bacteria cause RA? ( 2 ideas)

Treatment?

Back 11

Microbial infection somewhere in body
1. Antigens mimic self-antigens in joint
Inflammation
2. Antigens accumulate in the synovial membrane

NSAID

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12. 2 factors for Gram + inflammation
1 factor for Gram - inflamm

Back 12

Capsule and M protein (strep)

LPS - lipid A

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13. Describe Yersinia enterocolitica and Campylobacter jejuni

Back 13

Enterobacteriaceae PIGS especially
Gram-negative bacilli
BOTH Causes gastroenteritis
Both Associated with ingestion of fecal-contaminated food/water

Campylobacteraceae
Spiral-shaped gram-negative bacilli
Reservoir hosts: poultry, cattle, pigs

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14. Main reason for Viral-Induced Joint Inflammation?

Back 14

Due to immune complex deposition

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15. Human Parvovirus B-19 (5th disease)
What kind of virus is it?
What does it cause?
Main presentation?
Seroprevalance it adults?

Back 15

DNA virus -Only parvovirus causing infection of humans
Causes:
Rash Joint pain Anemia Fetal death

Erythema infectiosum
Rash, begins on face; “slapped cheek” appearance
Lacy, erythematous rash on trunk and extremities

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