Procalcitonin Level in Systemic Lupus Erythematosus Patients and its Correlation with Disease Activity and Infection

Abstract Background Systemic lupus erythematosus (SLE) is a systemic autoimmune disease, characterized by a chronic autoimmune response to multiple autoantigens and involving multiple organs. With the development of medical technologies, the diagnosis and treatment of SLE have been significantly improved. So far, SLE treatment mainly relies on glucocorticoids and immuno- suppressive drugs. Thus, the SLE disease itself and the immunosuppressive therapy increase the risk of infection, multiple organ dysfunction syndrome, and multiple organ failure syndrome. Moreover, infection is considered as a common complication of SLE and one of the leading causes of death. Aim of the Work To evaluate the role of available biomarkers mainly procalcitonin (PCT) and C- reactive protein (CRP) to differentiate flare from infection in a febrile patient with SLE. Patients and Methods Patients age ranged between 18-50 years old from outpatient clinic and the inpatients of department of Rheumatology at Ain Shams University Hospital. Informed consent was taken from all subjects. Approvement by ethical committee of Ain Shams University was taken and included. All the patients were surely diagnosed with SLE and fulfilled the clinical criteria. Patients with other autoimmune diseases were excluded. Full history has been taken and thorough clinical examination was done including general and musculoskeletal system. Results Eighty patients (88.9%) of this study were females while 10 patients (11.1%) of them were males. Comparison between the study participants as regard clinical manifestations revealed that the most frequent SLE manifestations were 58.9% have arthritis, 51.1% have skin rash, 37.8% mucosal ulcers and 36.9% have nephritis. As regard laboratory data When we compared between active group and remission group as regard procalcitonin we found a statistically significant higher levels in active group of SLE patients. In the present study, there was a highly statistically significant difference between SLE patients with and without infection as regard procalcitonin. By comparing active SLE patients with and without infection, there was a statistically significant higher levels in infected group as regard N/L ratio and P/L ratio. Conclusion Although the serum PCL and CRP levels, and neutrophils to lymphocytes ratio rise with SLE disease activity, their levels are significantly higher when associated with infection, indicating that high levels of these inflammatory markers could be used in differentiation between infection and disease activity in SLE patients.