BC Childrens Hospital, Vancouver, BC, Canada
Hosp for Sick Children, Toronto, ON, Canada
Hospital for Sick Children, Toronto, ON, Canada
IWK Health Centre, Halifax, NS, Canada
Montreal Children's Hospital, Montreal, QC, Canada
St Joseph Health Care London, London, ON, Canada
The Hospital for Sick Children, Toronto, ON, Canada
University of Manitoba, Winnipeg, MB, Canada
Purpose
To determine the influence of ethnicity and sociodemographic factors on disease presentation, manifestations, disease activity, and disease outcomes, using baseline data from the pediatric arm of the 1000 Canadian Faces of Lupus Study, a multicenter, prospective study of the Canadian Lupus population.
Methods
Childhood-onset SLE (<18th birthday) patients at four pediatric centers (Halifax, Montreal, Toronto and Vancouver). Collected data included sociodemographics, disease manifestations, current/past medications, laboratory measures and multiple disease measures. The Child Health Questionnaire (CHQ), measuring multiple domains of health status was administered. For analysis, patients were categorized by their primary self-selected ethnic category.
Results
Between November 2005 and February 2009, 213 cSLE patients were enrolled. The number of patients enrolled at each site mirrored the size of the clinical centre: Toronto 134 (63%), Vancouver 54 (25%), Montreal 17 (8%), and Halifax 8 (4%). There were 176 (83%) females, mean age at diagnosis was 12.5 ± 0.3 years, mean disease duration was 2.5 ± 2.7 years, and 175 patients (82%) were born in Canada. Demographic data were similar across the geographic sites, except for a longer disease duration in Vancouver (3.9 ± 3.6 years, p<.001). Primary self-reported race/ethnicity data was available for 191 patients: White (31%), Asian (30%), South Asian (15%), Black (10%), Latino/Hispanic (4%), Aboriginal (4%) and Arab/Middle Eastern (3%). Because of low numbers, the Latino/Hispanic and Arab/Middle Eastern groups were excluded from the analysis. Ethnic distribution across the centers differed (p<.001), reflecting known differences in the urban populations. The distribution of household income, and prescription drug plan coverage did not differ across ethnicities, however, fewer Asians (64%) had dental insurance coverage as compared to White (88%) and Aboriginal (100%) patients (p<.01). Missed school days did not differ by ethnicity, although 26% of the entire cohort reported missing on average 6 days per month. CHQ scores were lower in 7 of 10 domains in white patients vs. non-white ethnicities (p<.05 for each). Autoantibodies and SLE classification criteria present at any time that differed by ethnicity are listed in table
Classification criteria by ethnicity
Criterion %present
Total (n=191)
Aboriginal (n=9)
Asian (n=63)
South Asian (n=32)
Black (n=22)
White (n=65)
p-value
Malar rash
65
33
65
66
36
78
<0.05
Arthritis
62
78
46
72
59
71
<0.05
Serorsitis
18
44
16
16
41
11
<0.05
Renal
36
33
51
28
59
22
<0.01
Immunologic
81
100
87
97
82
65
<0.001
dsDNA
66
56
75
81
73
49
<0.01
Anti-Sm
32
56
43
22
41
20
<0.05
aPL (ACL or LAC)
47
33
49
53
55
42
NS
Medications were prescribed equally across ethnicities; most patients were taking prednisone (75%), hydroxychloroquine (84%), and 56% required additional immunosuppression (azathioprine, methotrexate, mycophenolate mofetil or cyclophosphamide). Disease measures were similar across ethnicities, overall SLEDAI was 3.1 ± 4.2, SLAM 3.4 ± 3.7; SDI median 0.3 (range 0-5), and physician global VAS was 15 ± 23 (range 0-99).
Conclusion
Canadian cSLE patients reflect our multi-ethnic population, with observed differences in disease manifestations, antibody profiles and health status by ethnicity.
Disclosure
Deborah M. Levy: None; Earl D. Silverman: None; Lori B. Tucker: None; Gaelle Chédeville: None; Adam Huber: None; Janet E. Pope: None; Christine A. Peschken: None; CaNIOS Investigators: None.