The Association of Fibromyalgia Symptoms with SLE Outcome and Diagnosis Robert S' Katz1, Frederick W

1
The Association of Fibromyalgia Symptoms with SLE
Outcome and Diagnosis  Robert S. Katz1,
Frederick Wolfe2, Kaleb Michaud2, Carisa M.
Cooney3 1Rush University Medical Center,
Chicago, IL 2National Data Bank for Rheumatic
Diseases, Wichita, KS 3Oklahoma Medical
Research Foundation, Oklahoma City, OK
Abstract PURPOSE. To describe the association
between fibromyalgia symptoms and systemic lupus
erythematosus (SLE) diagnosis and
outcome. METHODS. We studied 421 patients with
SLE diagnosed by rheumatologists and compared
them to 10,492 patients with other rheumatic
disorders. Fibromyalgia was identified using
survey fibromyalgia criteria (VAS fatigue score
gt 6 and a Regional Pain Score (RPS) gt 8) and
further analyzed as a continuous variable as the
Symptom Intensification scale (SIS) (fatigue
(RPS/2))/2. We used the 4 quartiles of the SI
Scale to classify patients according to the
degree of fibromyalgia symptoms. All patients in
Quartile 4 and 33 of patients in Quartiles 3
satisfy fibromyalgia criteria. Quality of life
(QOL) was determined using the EQ-5D
utility. RESULTS. Using multivariate regression,
we determined that photosensitivity Raynauds,
rash, oral ulcers, purpura, pleurisy, low WBC,
low platelet count, vasculitis, renal disease,
age sex, ethnicity, hydroxychloroquine and
prednisone best separated SLE and non-SLE
patients (area under ROC .91) and the 8
symptoms from a review of systems (ROS) described
above had a ROC curve of 0.79 alone.
Additionally, the 8 ROS variable were summed to
make a Lupus ROS scale (0-8). Among SLE patients,
31 satisfied FM criteria, 18 had vasculitis and
35 had renal disease (Table 1). We examined the
relation between lupus symptoms and degree of
fibromyalgia in Figure 1 where it can be seen
that SLE symptoms increased stepwise in each
quartile of the SI scale. Similarly, Table 1
showed strong and statistically significant
associations between the SLE symptom scale, VAS
pain, Social Security disability, QOL and direct
medical costs by contrast, there were weak or no
associations with vasculitis, renal disease and
SLE treatment. CONCLUSIONS. Fibromyalgia
(characteristics) exists as a continuum among SLE
patients rather than as a dichotomous condition,
and there is no clear separation of fibromyalgia
status at any level of the SI scale. Fibromyalgia
symptom intensity reflects the total burden of
SLE illness, as manifested by pain intensity, QOL
and medical costs. This association is similar to
what is seen in all other rheumatic disorders and
suggests that fibromyalgia diagnosis and symptoms
are a response to illness severity
Figure 1. The Symptom Intensity Scale A Measure
of Fibromyalgianess


Table 1. Quartiles of Fibromyalgia Symptom
Intensity and SLE Outcomes

• 31 of patients with SLE and 19 of patients
  without SLE satisfied survey fibromyalgia criteria

• Fibromyalgia (characteristics) exists as a
  continuum among SLE patients rather than as a
  dichotomous condition
• There is no clear separation of fibromyalgia
  status at any level of the SI scale.
• Fibromyalgia symptom intensity reflects the total
  burden of SLE illness, as manifested by pain
  intensity, QOL and medical costs. This
  association is similar to what is seen in all
  other rheumatic disorders and suggests that
  fibromyalgia diagnosis and symptoms are a
  response to illness severity

References F. Wolfe and J. J. Rasker. The
symptom intensity (SI) scale, fibromyalgia, and
the meaning of fibromyalgia-like symptoms. J
Rheumatol. November 2006. R. S. Katz, F. Wolfe,
and K. Michaud. Fibromyalgia diagnosis A
comparison of clinical, survey, and American
College of Rheumatology criteria. Arthritis
Rheum. 54 (1)169-176, 2006.