A team from the SingHealth Duke-NUS AMC has made research discoveries that will help in the diagnosis and treatment of juvenile idiopathic arthritis (JIA), the most common form of arthritis among those below 16 years of age.
Civil war rages in the body when
arthritis strikes. Its main defender –
the immune system – turns traitor.
Instead of protecting the body as
it is supposed to, it attacks the tissue,
explained Professor Salvatore
Albani, who is director of the SingHealth Translational Immunology
and Inflammation Centre.
This causes a wide variety of
symptoms ranging from inflamed
joints to fatigue.
Selecting the most appropriate
therapy has often come down to
guesswork, and trial and error, as
symptoms look similar even though
patients respond differently.
Now, Prof Albani and his team
from the SingHealth Duke-NUS Academic
Medical Centre have uncovered
a specific type of immune
cells that could be used to predict if
a patient will respond to treatment.
This group of regulatory T (Treg)
cells – a subset of white blood cells
that helps regulate the immune system
– promotes joint inflammation
when there are too many of them.
The team found that juvenile idiopathic
arthritis (JIA) patients who
have this type of Treg cells do not respond
to Anti-TNF – the most common
type of biologics, or complex
medicines made from living organisms,
used to treat human arthritis.
Said Prof Albani: “Clinicians could
use this novel group of cells as a
marker to diagnose JIA in patients,
as well as predict or monitor patients’
responsiveness to therapy.”
So patients without the specific
Treg cells, a subset of synovial Treg
cells that are inflammation-associated,
could be put on Anti-TNF,
while other medicines would be
used for those who have such cells.
What is also promising is that
these cells can be detected in blood,
which means a simple blood test
could in future easily distinguish
those who will respond to treatment
from those who will not.
Prof Albani said the technology
used in the discovery could be used
to identify biomarkers that can predict
the outcomes of other biologics.
In addition, the team found that
one’s clinical “fate” is determined
by epigenetics – the way each
body uses its genes – rather than
by genetic make-up.
“You must remember that the immune
system is meant to defend us,
so when you suppress it, you get a
lot of side effects. You need to understand
why the civil war started,”
noted Prof Albani.
The findings – which could be applied
to adult rheumatoid arthritis,
a condition that affects one in 100
adults worldwide – were published
in the Annals of Rheumatic
Diseases and Proceedings of the
National Academy of Sciences of
the United States.
Further studies are being conducted
by the researchers to validate
JIA is the most common form of
the condition among those below
16, and affects an estimated 45 to
50 out of 100,000 individuals here.
Juvenile arthritis has no cure, and
young patients can only ease the
pain or prevent joint deterioration
through medication or therapy.
There are three lines of treatment:
drugs, disease-modifying anti-
rheumatic drugs and biologics.
Associate Professor Thaschawee
Arkachaisri, who heads the Rheumatology
and Immunology Service at
KK Women’s and Children’s Hospital,
said 50-70 per cent of patients
need third-line treatment, which
costs $1,000 to $2,500 a month.
Because of the cost and variety
of the biologics available, said Prof
Arkachaisri, a co-author of the research
paper, it is crucial to pick
one that will elicit a response, so
the patient can go into remission
as soon as possible.
“We are dealing with kids who
have 70 more years to go. You
don’t want them to have a disability
that impairs them for the rest
of their lives,” he said.