Infection in Hospitalized Patients With Systemic Lupus Erythematosus: Proposal of an Algorithm for Diagnosis

Area of Science:

• Rheumatology
• Infectious Diseases
• Clinical Diagnostics

Background:

• Identifying infections in systemic lupus erythematosus (SLE) patients presents significant clinical challenges.
• Distinguishing infection from disease flares is crucial for appropriate management.

Purpose of the Study:

• To evaluate clinical markers, including C-reactive protein (CRP), neutrophil-lymphocyte ratio (NLR), and platelet-lymphocyte ratio (PLR), for diagnosing infection in SLE patients.
• To assess the diagnostic performance of these markers individually and in combination.

Main Methods:

• A retrospective review of 104 SLE patients hospitalized between 2014 and 2018.
• Patients were categorized into infection, infection with disease activity, and isolated disease activity groups.
• Clinical and laboratory variables were compared, and accuracy measures for CRP, NLR, and PLR were calculated.

Main Results:

• CRP, NLR, and PLR levels were significantly higher in the infected group compared to others (p < 0.05).
• Fever, tachypnea, and PLR were independently associated with infection.
• An algorithm combining these markers achieved 86.6% sensitivity and 81% specificity for infection diagnosis.

Conclusions:

• The combined use of clinical and laboratory markers, particularly CRP, NLR, and PLR, offers superior diagnostic accuracy for infection in SLE patients.
• The developed algorithm demonstrates significant potential for practical clinical application in managing SLE patients.
• This approach aids in differentiating infection from disease activity, leading to more timely and effective treatment.