Systemic lupus erythematosus and rheumatoid arthritis

 
 
 
 
 
 
 
 
 
 
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STUDY POPULATIONS AND METHODOLOGY 
10. Study populations 
Three patient materials were included: the SLE case-control material, the case-
control material of individuals before onset of any symptoms of RA, and the 
early RA case-control material. The Ethics Committee at the University 
Hospital, Umeå, approved these studies and written informed consent was 
obtained from all patients. 
 
The SLE
case-control material (Papers I-III) 
The material comprised 279 patients, consecutively included, during the year 
2000, from the four northernmost counties of Sweden. All patients fulfilled the 
ACR criteria for SLE 
52; 53
[mean number ± standard deviation (SD) of 5.6 ± 
1.4]. Demographic data is presented in Table 5. Five rheumatologists were 
involved in the assessment of the patients to determine their diagnosis, disease 
activity using the SLEDAI 
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[mean score ± SD of 3.4 ± 4.4], and organ damage 
according to the SLICC/ACR damage Index 
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[mean score ± SD of 2.4 ± 2.5]. 
Included in the SLEDAI are descriptors with: a score of 8 (seizures, psychosis, 
organic brain syndrome, visual disturbance, cranial nerve disorder, lupus 
headache, cerebrovascular accident, and vasculitis); with a SLEDAI score of 4 
(arthritis, myositis, urinary casts, haematuria, proteinuria, and pyuria); with a 
SLEDAI score of 2 (new rash, alopecia, mucosal ulcers, pleurisy, pericarditis, 
low complement, and increased DNA binding); and with a SLEDAI score of 1 
(fever, thrombocytopenia, and leukopenia).
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The SLICC/ACR damage index is 
scored based on damage of the following organ systems: ocular, 
neuropsychiatric, renal, pulmonary, cardiovascular, peripheral vascular, 
gastrointestinal, musculoskeletal, and skin.
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Of the 279 patients diagnosed with 
SLE, 260 agreed to participate in the studies and donated blood for DNA 
extraction. The controls (n=670) were population-based and geographically 
matched with the patients
. 
In paper III, the SLE patients and controls from northern Sweden were co-
analysed with SLE patients and controls from mid- and southern Sweden 
resulting in materials of 571 unrelated patients diagnosed with SLE and 1042 
controls. The case-control materials from mid-Sweden (Stockholm-region) and 
southern Sweden (Lund) were matched with controls from the same 
geographical area. 
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