Is initial C-reactive protein level associated with corticosteroid use in lupus erythematosus patients during a bacterial infection episode?

- CRP level is not suppressed by corticosteroid or immunosuppressant in SLE patients.
- CRP level reflects bacterial infection under SLE background.
- CRP level is a good indicator for bacterial infection in SLE patients.

ObjectiveC-reactive protein (CRP), a marker for inflammation, indicates bacterial infection in systemic lupus erythematosus (SLE) when markedly elevated. Our study investigated the association of regular corticosteroid or immunosuppressant use with initial CRP level in febrile SLE patients with bacterial infection.MethodsThis retrospective cohort study included adult SLE patients (18 years of age or older) who presented with fever at the emergency department from January 2008 to December 2012. Data were retrieved from our institutional database.ResultsCRP levels in the total 193 patient database were significantly increased in the bacterial infection group compared to the no infection and non-bacterial infection groups. Seventy-eight (86.7%) of the 90 patients in the bacterial infection group took regular corticosteroids (mean equivalent dose of prednisolone 0.33 ± 0.26 mg/kg/day) and 55 (61.1%) used immunosuppressants. Mean CRP level in the bacterial infection group was 97.8 mg/L. CRP level was lower in patients using corticosteroids, but the difference between users and nonusers of corticosteroids was not statistically significant (p = 0.367). The difference in CRP level between immunosuppressant and non-immunosuppressant users was also not significant (p = 0.599). The Spearman test found no correlation between corticosteroid dosage and CRP level (p = 0.911).ConclusionInitial CRP level was not significantly associated with regular corticosteroid or immunosuppressant use in SLEs patients during a bacterial infection episode, and CRP level was not dose-dependently related to daily corticosteroid use. An elevated CRP level might be an appropriate marker for bacterial infection at the emergency department for febrile SLE patients.