Volume 10 Supplement 1

2011 Pediatric Rheumatology Symposium: Abstracts

Open Access

Plasma osteopontin as a marker for future organ damage in pediatric systemic lupus erythematosus

  • Ornella J Rullo2,
  • Jennifer MP Woo2,
  • Alice DC Hoftman2,
  • Miriam F Parsa1,
  • Gil Amarilyo2,
  • Deborah K McCurdy2 and
  • Betty P Tsao3
Pediatric Rheumatology201210(Suppl 1):A123

https://doi.org/10.1186/1546-0096-10-S1-A123

Published: 13 July 2012

Purpose

Osteopontin (OPN) is a secreted phosphoprotein functioning in monocyte and T cell adhesion and migration. Expression of OPN in alternatively-activated macrophages has been implicated in post-inflammatory fibrosis of lung and kidney. In our previously conducted cross-sectional study of 72 pediatric SLE patients (pSLE; age of onset <18 years), increased circulating plasma OPN (cOPN) was observed in pSLE compared with healthy controls, and was associated of with ACR/SLICC damage index (SDI) scores >1 (p = 0.0007 and 0.001, respectively), although there was no association with SLEDAI. We therefore propose that OPN is a marker for pSLE disease progression, and that increased cOPN levels may predict the development of organ damage.

Methods

17 pSLE patients have been followed for at least 6 months with cOPN measured by ELISA at baseline and at 6 month intervals. Serum Cr, urine protein/creatinine and GFR were recorded at baseline and every 6 months. SLEDAI was recorded at 3 month intervals, and at disease flare, and SDI at every 6 months. Cumulative disease activity (adjusted-mean SLEDAI, or AMS) was calculated by finding the area under the curve of serial SLEDAI measurements. Statistical analysis was performed using Student’s t test, Pearson’s correlation, and Fisher’s exact test.

Results

6 of the 17 longitudinal subjects accumulated damage as per an increase in SDI during the course of the study (3 in the renal portion, 1 peripheral vascular, 1 pulmonary hypertension, 1 avascular necrosis). 5 of the 6 patients who accumulated damage had high cOPN levels (cOPN in the top quartile) in at least 1 of the previous 2 visits prior to the increase on SDI. 80% of subjects with a high cOPN had an increase in SDI, whereas only 11% of subjects with a cOPN in the bottom three quartiles had an increase in SDI, indicating an increase in SDI was more likely in those patients with a preceding high cOPN (p = 0.01). Cumulative disease activity (AMS) was associated with an increase in SDI scores (p < 0.0001) in this cohort, and was correlated with cOPN levels (Spearman r = 0.46, p = 0.02).

Conclusion

cOPN is correlated with cumulative disease activity and may be a potential marker for future organ damage in pSLE. The rapid and/or early accrual of organ damage in patients with SLE has been associated with poorer outcomes, therefore a marker of risk for irreversible damage could be a critical component for guiding treatment decisions in pSLE.

Disclosure

Ornella J. Rullo: None; Jennifer M.P. Woo: None; Alice D.C. Hoftman: None; Miriam F. Parsa: None; Gil Amarilyo: None; Deborah K. McCurdy: None; Betty P. Tsao: None.

Authors’ Affiliations

(1)
UCLA
(2)
UCLA
(3)
UCLA School of Medicine

Copyright

© Rullo et al; licensee BioMed Central Ltd. 2012

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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