Fibromyalgianess, Systemic Lupus Erythematosus

1
Fibromyalgianess, Systemic Lupus Erythematosus
the Evaluation of SLE ActivityR Katz1, M Petri2,
E Karlson3, G Alarcón4, E Chakravarty5, J
Goldman6, F Wolfe7, SLE in the Community Study
Group 1Rush Medical Center, Chicago 2John
Hopkins Univ, Baltimore 3Brigham and Womens
Hospital, Boston 4University of Alabama -
Birmingham 5Stanford Univ, Stanford 6Emory
Univ, Atlanta 7National Data Bank for Rheumatic
Diseases, Wichita
Purpose. To determine if fibromyalgia or
fibromyalgianess is increased in SLE compared
with non-SLE patients, whether fibromyalgianess
biases the systemic lupus erythematosus activity
questionnaire (SLAQ), and to determine if the
SLAQ is overly sensitive to fibromyalgia
symptoms. Method. We developed a 16-item SLE
symptom scale (SLESS) modeled on the SLAQ and
used that scale to investigate the relation
between SLE symptoms and fibromyalgianess in
23,321 rheumatic disease patients. Fibromyalgia
was diagnosed by survey fibromyalgia criteria and
fibromyalgianess was measured using the Symptom
Intensity Scale (SI). As comparison groups, we
combined patients with rheumatoid arthritis and
non-inflammatory rheumatic disorders into an
arthritis group and also utilized a
physician-diagnosed group of fibromyalgia
patients..
Percent of patients positive for SLE Symptom
Scale by Diagnostic Category
Original Abstract Performance of the SLAQ in SLE
and Non-SLE Subjects in a Longitudinal
Databank PURPOSE. The patient-reported systemic
lupus activity (SLE) questionnaire (SLAQ) is a
validated 24-item weighted lupus symptom index
based on the physician-reported systemic lupus
activity measure (SLAM). However, physicians and
patients report differently, and findings might
not be specific to SLE. Many of the SLAQ items
are not thought to be related to SLE disease
activity (fatigue, abdominal pain, headache,
cognitive problems, muscle pain, and Raynauds).
We examined the SLAQ properties and construct
validity by studying SLAQ variables in patients
without SLE. METHODS. We studied the SLAQ in 325
patients with SLE. To compare construct validity
of SLAQ items, we used binary symptom variables
similar to SLAQ items and constructed an SLE-like
symptom score (SSCORE) in patients with SLE
(N1,047), RA (N22,846), non-inflammatory
disorders (NONI) without fibromyalgia (FS)
(N3,716) and NONI with FS (N2,862). RESULTS.
The mean age of participants completing the SLAQ
was 51.3 years, and 92.5 were women. Current
therapies included hydroxychloroquine (62.5),
prednisone (51.1), immunomodulators excluding
MTX (27.7), and MTX (11.8). The mean (SD)
composite SLAQ score and the single item SLAQ
activity score was 10.9 (6.8) and 3.6 (2.7),
respectively. A mild, moderate and severe SLE
flare was reported by 37.7, 18.7 and 7.3
during the last 3 months. Alpha reliability of
SLAQ score items was 85.6. SLAQ score and SSCORE
were correlated at r0.747. Correlations of the
SSCORE in SLE and non-SLE were Joint score from
the RADAI (r0.585, 0.663), Regional Pain Scale
(r0.646, 0.615), Symptom Intensity Scale
(r0.624, 0.663), VAS pain scale (r0.549,
0.502), HAQ-II (0.550, 0.460), EuroQol (r0.533,
0.516), and SF-36 physical component score
(r0.583, 0.469). Analysis of individual items
showed substantially more SLE patients with
SLAQ/SSCORE items than arthritis patients (RA
NONI) (Table 1). However, the symptom differences
were inconsistent when compared with FS, with
higher percents noted in FS for fatigue,
headaches, stroke/numbness and cognitive
problems. The mean SSCOREs were SLE 7.6,
arthritis 4.5, and FS 7.3. These group scores
differed from each other significantly
(plt0.001). CONCLUSION. SLAQ variables are more
common in SLE than in other rheumatic disorders
and easily distinguish SLE from other conditions
except for FS.
Results. The mean (SD) age of the 599 SLE
participants completing the SLAQ was 50.4 (12.3)
years, and 95.3 were women. Current therapies
included hydroxychloroquine (64.1), prednisone
(49.4), MTX (12.3), rituximab (0.8),
mycophenolate (11.8), azathioprine (11.0),
cyclophosphamide (11.2) and leflunomide (1.9).
The composite SLAQ score and the single item
SLAQ activity score was 12.1 (7.6) and 3.8 (2.8),
respectively. A mild, moderate and severe SLE
flare was reported by 34.1, 22.0 and 9.1
during the preceding 3 months. Alpha reliability
of SLAQ score items was 82.5. The SLESS score was
7.5 (3.6) and its alpha reliability in the same
SLE group was 83.9. The SLAQ score and SLE SS
were correlated at r0.738 (Figure 1), and the
correlation was not improved by non-linear
analyses.

Table 2. Severity, SLE symptoms and
fibromyalgia-related scales
As the SLE SS and SLAQ scores were highly
correlated, we next undertook a series of
analyses to evaluate the relationship of SLE
symptoms and fibromyalgia in patients with SLE,
arthritis and fibromyalgia using the complete set
of NDB patients. The mean age and percent males
for the three diagnostic groups was as follows
SLE 50.3 (13.6) years, 6.2 fibromyalgia 56.8
(12.9) years, 4.7 male and arthritis 57.9
(10.3) years, 22.8 male. The percent of
patients reporting specific symptoms from the
SLESS is shown in Table 1. Preliminary to
evaluating the relationship between SLE and
fibromyalgia, we first examined the level of
symptoms in SLE and arthritis patients (Table 2).
Not surprisingly as the SLESS was designed to
evaluate SLE symptoms, the SLESS was considerably
higher in SLE patients compared with those with
arthritis, 7.2 (3.7) vs. 4.5 (3.1), p lt0.001. The
individual scale items and their odds ratios for
these diagnoses are shown in Figure 2. All
symptoms were more common in SLE, but Reynauds,
rash and fever were particularly increased.

Plt0.05 compared with arthritis. Plt0.05
compared with fibromyalgia.
By contrast, as shown in Table 2, SLE and
arthritis did not differ significantly in patient
global severity and fatigue SLE and fibromyalgia
did not differ for the SLESS, but both had
considerably higher scores compared with
arthritis. We also studied the ratio of the
fibromyalgia variables (headache, abdominal pain,
paresthesias/stroke, fatigue, cognitive problems
and muscle pain or weakness) to the SLE variables
(Raynauds, rash, fever, easy bruising and hair
loss), as determined in Figure 3, as a function
of fibromyalgianess, or fibromyalgia severity. As
shown in Figure 6, there was no evidence of a
disproportionate fibromyalgia symptom reporting
associated with increasing fibromyalgianess.
Self-reported SLE was associated with an
increased prevalence of fibromyalgia when
unconfirmed by physician compared to confirmed
SLE.
We next compared the relative association of
SLESS variables with the diagnosis of SLE and
fibromyalgia, as shown in Figure 3. This direct
comparison indicates that headache, abdominal
pain, stroke or paresthesias, fatigue, cognitive
problems and muscle pain/weakness are more common
in fibromyalgia than SLE. Figure 4, comparing
persons with fibromyalgia and arthritis, confirms
the importance of these variables in
fibromyalgia. In addition patients with
fibromyalgia are more likely to report oral
ulcers (OR 2.0 (95 CI 1.8 to 2.2)) and pleurisy
(OR 2.9 (95 CI 2.6 to 3.2) than patients with
arthritis. With respect to the SLESS, the bold
lines in Table 2 separate variables that are more
or less common in SLE compared with fibromyalgia.
Therefore, these analyses define sets of
variables found in the SLESS and the SLAQ that
are more or less associated with fibromyalgia in
patients with SLE. We next examined the
relationship between fibromyalgianess and SLE
using the latent variable fibromyalgianess as
assessed by the SI scale (Table 2). Compared with
arthritis, the SI was slightly increased (0.4
units) in SLE compared with arthritis, but
substantially increased in fibromyalgia (2.2
units) compared with arthritis. The relation of
fibromyalgianess to the 3 diagnostic groups can
also be seen in Figure 5. Using the suggested
cutoff for diagnosis of survey fibromyalgia of 8
for the regional pain scale and 6 for fatigue,
22.1 of SLE patients and 17.0 of arthritis
patients would satisfy those criteria. When only
data on women are analyzed, the respective
proportions are 22.0 and 18.3.
Conclusions The proportion of patients with SLE
(22.1) is only slightly increased compared with
patients with arthritis (17.0). Similarly, there
is not substantially more fibromyalgianess in SLE
than in non-SLE patients. SLE questionnaire
assessment is not biased by the extent of
fibromyalgianess. The prevalence of survey
fibromyalgia is greater in self-referred SLE
patients with diagnostic confirmation compared to
self referred patients with diagnostic
confirmation.
Notice This poster extends the data of the
original abstract by adding subjects and analyses