Results from the longitudinal NOR-GOUT study show that ultrasound
can help visualise decreases of
uric acid deposits that occur during a treat-to-target approach with
depositions decreased over the
course of the 1-year study for all
three ultrasound signs considered,
researcher Dr. Hilde B. Hammer reported at the Congress.
“Gout is a really painful disease
when there are flares,” said Dr.
Hammer, a senior consultant in
the rheumatology department at
Diakonhjemmet Hospital in Oslo.
Ultrasound has been shown to be
a sensitive method to detect uric
monosodium urate (MSU) deposition, and its use is included in the
classification criteria for gout.
“MSU depositions are found in
many different regions with some
predilection sites,” Dr. Hammer
noted. This led the OMERACT (Out-
come Measures in Rheumatology)
Ultrasound Group to develop three
key definitions for MSU lesions:
the “double contour sign” (DC),
which occurs when urate crystals
form on the surface of cartilage;
“tophus,” in which there is a larger,
hypoechoic aggregation of crystals
that is usually well delineated; and
“aggregates,” which are small, hy-
“There are, up until now, only a
few smaller studies that have ex-
plored the decrease of depositions
during uric acid–lowering treat-
ment,” Dr. Hammer observed.
NOR-GOUT was a prospective,
observational study of 161
with urate crystal–proven gout
who needed treatment with
urate-lowering therapy. Patients
were included if they had a recent
gout flare and had serum urate
levels of more than 360 micro-
mol/L and had no contraindication
to urate-lowering therapy.
“We used a treat-to-target ap-
proach with the medication,” Dr.
Hammer explained. The aim was
to get uric acid levels to 360 micro-
mol/L or lower or to less than 300
micromol/L if clinical tophi were
present. “The medication was op-
timised by monthly follow-up by
a study nurse until the treatment
target was met,” she added.
Patients underwent an extensive
ultrasound assessment at study
entry and again after 3, 6, and 12
months of urate-lowering therapy.
This included bilateral assessment
of all relevant joints and the pres-
ence of crystals semiquantitatively
scored from 0 to 3, the latter sig-
nifying many deposits. The sum of
scores for the three key OMERACT
definitions were calculated each
time the patients were assessed,
with a total score for all three also
Mean serum urate levels dropped
from a baseline of 487 to 312 mi-
cromol/L at 12 months (P less than
.001), Dr. Hammer reported. The
percentage of patients achieving
a urate target of less than 360 mi-
cromol/L increased from 71% at 3
months to 81% at 6 months and to
84% at 12 months, she said.
Ultrasound scores decreased
with decreasing urate levels at 3,
6, and 12 months, with the highest
numeric difference from baseline
seen at 12 months for DC ( 3. 1, 2. 3,
and 1. 2; all P less than .001 vs.
baseline of 4. 2). The respective val-
ues for tophi were 6. 3, 5. 4, and 4. 2
versus a baseline of 6. 5; for aggre-
gates, the values were 8. 8, 7. 9, and
6. 7 versus a baseline of 9. 1.
Standardised Response Mean
values from baseline to 3, 6, and
12 months showed that DC was
the most sensitive for change, with
a respective 0.73, 1.02, and 1. 26 in
ultrasound scores. Values for tophi
were 0.06, 0.57, and 0.91 and 0.20,
0.51 and 0.66 for aggregates.
“Not all patients had reached 12
months of follow-up when we made
these calculations,” Dr. Hammer
said, noting the limitations of the
study. Nevertheless, these interim
findings suggest that ultrasound
is a valuable tool that can help see
how patients fare on a treat-to-tar-
get approach, she concluded.
Dr. Hammer had no conflicts of
interest to disclose.
Ultrasound aids treat-to-target approach for
BY SARA FREEMAN
Podagra: The Gout
By James Gillray (1799)