Rheumatoid Arthritis
Last Updated: December 14, 2020
access_time14 min
Learning Objectives (5)
After completing this brick, you will be able to:
● Define rheumatoid arthritis (RA) and summarize the main clinical
findings.
● 1
● Describe the epidemiological factors and pathogenesis of RA.
● 2
● Describe the articular and extra-articular clinical manifestations of
RA.
● 3
● Define the diagnostic tests for RA.
● 4
● Outline the treatment of RA.
● 5
CASE CONNECTION
BN is a 42-year-old woman seeing you for a preoperative assessment
prior to elective hysterectomy under general anesthesia for
symptomatic uterine fibroids. BN has a history of rheumatoid arthritis
and is taking methotrexate. Her RA is currently well controlled,
although she left her job as a machine operator 2 years ago because of
the physical impairment of her multiple joint deformities. On exam,
,she has the classic joint findings of RA in the hands and rheumatoid
nodules at the elbows.
What further testing will you do before her surgery? Consider your
answers as you read, and we’ll revisit at the end of the brick.
What Is Rheumatoid Arthritis?
Rheumatoid arthritis (RA) is a chronic autoimmune disease that
causes symmetric, inflammatory joint destruction and deformation of
the joints (Figure 1). The most affected joints are the fingers, wrists,
and feet. Not surprisingly, the debilitating inflammation and
deformation of those joints impairs the patient’s quality of life. The
hallmark symptom of RA is morning stiffness, but it can have other
systemic effects as well.
,Figure 1
CREDIT: Courtesy of James Heilman, MD
Who Gets Rheumatoid Arthritis and
What Causes It?
RA is the most common inflammatory arthritis and affects
approximately 1% of the population. Women are affected two to three
, times more often than men. It can occur in patients of any age but is
most common in patients aged 50-75 years.
Like most of the rheumatologic diseases, RA is an autoimmune
disorder in which the patient’s immune system attacks its own body.
We don’t yet fully understand the mechanisms underlying the
pathogenesis of RA. However, we do know that it results from a
complex interplay between genes and environment that leads to the
breakdown of immune tolerance.
Genetic Risk Factors
Susceptibility to RA is defined by a pattern of inherited genes such as
the human leukocyte antigen (HLA) major histocompatibility (MHC)
genes. HLA-DR4 serotype is associated with the development of RA.
However, many other minor genes are also involved, and genes are
not solely responsible, as we’ll see next.
Environmental Components
Specific environmental exposures that have been found to be risk
factors for RA include smoking, low amounts of vitamin D, silica
exposure, and possibly poor dental hygiene.
Last Updated: December 14, 2020
access_time14 min
Learning Objectives (5)
After completing this brick, you will be able to:
● Define rheumatoid arthritis (RA) and summarize the main clinical
findings.
● 1
● Describe the epidemiological factors and pathogenesis of RA.
● 2
● Describe the articular and extra-articular clinical manifestations of
RA.
● 3
● Define the diagnostic tests for RA.
● 4
● Outline the treatment of RA.
● 5
CASE CONNECTION
BN is a 42-year-old woman seeing you for a preoperative assessment
prior to elective hysterectomy under general anesthesia for
symptomatic uterine fibroids. BN has a history of rheumatoid arthritis
and is taking methotrexate. Her RA is currently well controlled,
although she left her job as a machine operator 2 years ago because of
the physical impairment of her multiple joint deformities. On exam,
,she has the classic joint findings of RA in the hands and rheumatoid
nodules at the elbows.
What further testing will you do before her surgery? Consider your
answers as you read, and we’ll revisit at the end of the brick.
What Is Rheumatoid Arthritis?
Rheumatoid arthritis (RA) is a chronic autoimmune disease that
causes symmetric, inflammatory joint destruction and deformation of
the joints (Figure 1). The most affected joints are the fingers, wrists,
and feet. Not surprisingly, the debilitating inflammation and
deformation of those joints impairs the patient’s quality of life. The
hallmark symptom of RA is morning stiffness, but it can have other
systemic effects as well.
,Figure 1
CREDIT: Courtesy of James Heilman, MD
Who Gets Rheumatoid Arthritis and
What Causes It?
RA is the most common inflammatory arthritis and affects
approximately 1% of the population. Women are affected two to three
, times more often than men. It can occur in patients of any age but is
most common in patients aged 50-75 years.
Like most of the rheumatologic diseases, RA is an autoimmune
disorder in which the patient’s immune system attacks its own body.
We don’t yet fully understand the mechanisms underlying the
pathogenesis of RA. However, we do know that it results from a
complex interplay between genes and environment that leads to the
breakdown of immune tolerance.
Genetic Risk Factors
Susceptibility to RA is defined by a pattern of inherited genes such as
the human leukocyte antigen (HLA) major histocompatibility (MHC)
genes. HLA-DR4 serotype is associated with the development of RA.
However, many other minor genes are also involved, and genes are
not solely responsible, as we’ll see next.
Environmental Components
Specific environmental exposures that have been found to be risk
factors for RA include smoking, low amounts of vitamin D, silica
exposure, and possibly poor dental hygiene.
