Arthritis & Rheumatism, Volume 63,
November 2011 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Chicago, Illinois November 4-9, 2011.


Ethnic Differences of Early Disease Severity in Pediatric Systemic Lupus Erythematosus At An Urban Tertiary Care Center.

Woo1,  Jennifer M.P., Liu2,  Peony, Parsa1,  Miriam F., Amarilyo1,  Gil, Hoftman2,  Alice DC, McCurdy2,  Deborah K., Rullo2,  Ornella J.

University of California, Los Angeles, Los Angeles, CA
Mattel Children's Hospital, University of California, Los Angeles, Los Angeles, CA

Background/Purpose:

Systemic lupus erythematosus (SLE) can be characterized by increased incidence and disease severity in individuals of non-European descent. However, there exists a paucity of information describing disease manifestation at presentation and during the early stages of the disease process in pediatric SLE patients of different racial and ethnic backgrounds. We hypothesize that non-Caucasian pediatric SLE patients (pSLE) have an earlier, more severe disease course compared to Caucasian patients.

Methods:

We retrospectively reviewed the medical records of 152 patients with pSLE (diagnosis < 18 years) treated at an urban tertiary-care center between 2000 and 2010. Demographic and socioeconomic data were collected for each subject. ACR SLE criteria and SLE Disease Activity Index (SLEDAI) were evaluated at diagnosis, and any renal biopsy results were recorded. All subjects were assessed for cumulative steroid use, use of additional immunosuppressive agents, and urine protein-creatinine ratios at 12 months. Comparison of these data between Hispanic- (HA), Asian- (A), African- (AA), and Caucasian- (CA) American pSLE for was conducted using computed means, 95% confidence intervals, Student's one-tailed t-test, and Fisher's exact test.

Results:

HA, AA, and A pSLE patients were diagnosed at a younger age than CA pSLE (p < 0.05; Table 1). Although the number of ACR criteria at diagnosis did not differ among the groups compared to CA, AA and HA were more likely to have arthritis at diagnosis than CA (44% and 37% vs 25%; p = 0.007 and 0.09, respectively). Furthermore, A and HA were more likely to present with proteinuria than CA (42% and 44% vs. 25%, p = 0.02 and 0.007, respectively) although prevalence of renal involvement by ACR criteria at SLE diagnosis only reached statistical significance in A vs CA (53% vs 38%; p = 0.047). Interestingly, increased rates of abnormal urine protein-creatinine ratios were observed at 12 months after SLE diagnosis in the HA and AA groups (64% and 40% vs. 25% in CA; p < 0.0001 and 0.03, respectively), but not in A (33%; p = 0.3 vs. CA). Over the first 12 months, significantly more HA, AA, and A required >150mg/kg of cumulative steroids compared to CA subjects (p <= 0.03 for all) with additional immunosuppressive agents required for HA, AA, and A (Table 1). Of note, non-CA groups were significantly more likely to have government-assisted insurance and HA and AA tended to live in areas of significantly lower median family income compared to CA (Table 1).

Table 1. Clinical and socio-economic characteristics of CA, HA, AA and A rSLE patients.

 CA (n = 21)HA (n = 68)p*AA (n = 27)p*A (n = 33)p*
Female:male18.357.11 22:5 27.6 
Age at diagnosis, years1412.10.02120.0412.20.04
Clinical       
  ACR SLE criteria, median (range)5 (4.8)4 (4.7)0.54 (4.8)0.84 (4–6)0.3
  SLEDAI at diagnosis, median (range)8 (0–21)10 (0–27)0.312 (3–18)0.412 (2–26)0.19
  Cumulative steroid use, %131460.03560.0004470.03
  Immunosuppression mean1160.041.80.04170.06
  Abnormal urine Pr/CR, %†2564<0.0001400.03330.3
Sociodemographic       
  Median household income, $‡‡59,43739,484<0.000149,7390.0157,0470.4
  Insurance status, %  <0.0001 <0.0001 0.01
   Uninsured52 4 0 
   Government962 39 23 
   Private8636 57 77 
CA-Caucasian; HA-Hispanic American; AA-African American, A-Asian American
*p-values taken in comparison to CA values and considered significant at p < 0.05
†% of patients requiring cumulative prednisone >150mg/kg in 1st year after diagnosis
†† Number of immunosuppressive agents required in addition to steroids and/or hydroxychloroquine in 1st year after diagnosis
‡ Urine PL/Cr >0.2 at 1 year after SLE diagnosis
‡‡ Based on 1999 US census figures for zip codes of patients at diagnosis

Conclusion:

Pediatric patients of non-Caucasian background were diagnosed with SLE at a younger age, seemed to differ from Caucasian-American groups in SLE presentation, and had a potentially more severe early disease course, including increased immunosuppressive requirements. Prospective studies will help to clarify differences between these groups and to determine impact of socioeconomic factors.

To cite this abstract, please use the following information:
Woo, Jennifer M.P., Liu, Peony, Parsa, Miriam F., Amarilyo, Gil, Hoftman, Alice DC, McCurdy, Deborah K., et al; Ethnic Differences of Early Disease Severity in Pediatric Systemic Lupus Erythematosus At An Urban Tertiary Care Center. [abstract]. Arthritis Rheum 2011;63 Suppl 10 :2033
DOI:

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