Predictive potential of the disease activity index and C-reactive protein for infection in systemic lupus erythematosus patients

Aim of the workThe aim of the present work was to determine the prevalence of infections in a cohort of Egyptian Systemic lupus erythematosus (SLE) patients and to describe their sites and relation to clinical characteristics, laboratory features and disease activity.Patients and methodsMedical records of 250 Egyptian SLE patients attending the Rheumatology department, Cairo University hospitals were reviewed retrospectively for the clinical and laboratory features, SLE disease activity index (SLEDAI) and treatment received.ResultsInfection was found in 119 (47.6%) patients, with bacterial infection being the commonest in 99 (83%) followed by fungal infection in 30 (25%) and viral infection in 22 (18.5%). The commonest site of infection was the skin (37%) followed by the urinary tract (31%) and chest (19%). In SLE patients with infection there was a significant increase in the frequency of malar rash (p = 0.001), photosensitivity (p = 0.01), oral ulcers (p < 0.001), alopecia (p = 0.017) and Raynauds (p = 0.017) compared to those without infection. Pulmonary and neuropsychiatric manifestations were also significantly increased in those with infection (p = 0.001 and p < 0.001). A significantly higher number of patients with infection were receiving pulse steroids (p = 0.016), cyclophosphamide (p = 0.011) and a higher oral prednisolone dose (p = 0.03). The SLEDAI was significantly higher (26.02 ± 8.23) in those with infection compared to those without (15.57 ± 6.43) (p < 0.001). C-reactive protein (CRP) was significantly higher in those with infection (p < 0.001). On performing a logistic regression analysis, only SLEDAI (p < 0.001) and CRP (p < 0.001) were significant predictors of infection.ConclusionDisease activity and CRP are important predictors for infection in SLE patients.