Mean platelet volume is a marker of inflammation but not a marker of disease activity in children with juvenile SLE

Aim of the work: To study the mean platelet volume (MPV) in children with juvenile-onset SLE (Jo-SLE), and whether MPV can be used as a biologic marker for disease activity or flare. Patients and methods: Twenty-nine patients from the rheumatology outpatient clinic, Pediatric Cairo University Hospitals and age 36 and gender matched healthy controls were included in the study. The MPV was determined within 4 h of blood sampling in all study populations. Recent routine laboratory investigations for Jo-SLE patients were obtained. Disease activity was estimated using SLE disease activity index (SLEDAI). Results: 29 Jo-SLE patients had a mean age of 12.8 +/- 2.9 years and disease duration of 3.5 +/- 3 year. The most frequent clinical manifestations were photosensitivity, malar rash, followed by arthritis and serositis. The MPV in Jo-SLE patients was 8.2 +/- 2.1 femtoliters (fL) compared with 5.6 +/- 0.9 fL in healthy controls (p<0.001). There was no significant difference between MPV in 18 active patients (8.3 +/- 2.1 fL) compared to 11 patients with inactive disease (8.1 +/- 2.5 fL). Furthermore, there were no significant correlations between the MPV and SLEDAI score (r = -0.19, p= 0.33), or between MPV and other disease parameters routinely used to estimate disease activity or flare. Conclusion: Results of the present study confirm the association between MPV and inflammation, but do not support the use of MPV as an indicator for monitoring disease activity or flare in juvenile SLE. Further longitudinal studies with larger numbers of patients are warranted to unveil the possibility of using MPV as a biologic marker of disease activity. (C) 2015 The Authors. Production and hosting by Elsevier B.V. on behalf of Egyptian Society of Rheumatic Diseases.