Usefulness of the hemogram as a measure of clinical and serological activity in systemic lupus erythematosus

Background and objectives: Systemic Lupus Erythematosus (SLE) follow-up is based on clinical, and analytical parameters. We aimed to determine the differences between the Neutrophil-to-lymphocyte ratio (NLR), Platelet-to-lymphocyte ratio (PLR) and Red blood cell distribution width (RDW) between SLE patients and healthy controls and to assess their association with anemia status, classical inflammatory biomarkers and cytokines, disease activity, SLE related factors and treatment received for SLE. Methods: Seventy-seven patients with SLE according to 2012 SLICC criteria and 80 healthy controls were included. Patients with SLE were classified in SLE with anemia (SLE-a) and SLE without anemia (SLE-na). Statistical analysis between SLE patients and controls and the association of serological and clinical activity markers with proposed hematological indices among SLE patients were performed. Results: RDW, NLR and PLR, were significantly higher in SLE patients than in healthy control group (p < 0.001), in SLE-a patients as compared to SLE-na (p < 0.0001) and were significantly associated with hypocomplementemia (p < 0.05). PLR was higher in active patients measured by SLEDAI-2K score and with longer disease duration (p < 0.05). RDW was associated with serological activity of the patients (p < 0.05) and was correlated with SLEDAI-2K and SLICC/ACR scores, hsCRP, D-dimer, fibrinogen, IL-6 and TNF as well as with corticosteroids intake (p = 0.05). A logistic regression analysis confirmed that after adjustment by age and hemoglobin values, RDW presented linear correlation with IL-6 levels (Beta-coefficient = 0.369, p = 0.003). Conclusion: NLR, PLR and RDW values suggest SLE serological and clinical activity. Given their availability, these markers not only could be useful tools to identify and monitor active SLE patients but whose application should be considered in inflammatory pathologies orchestrated by IL-6 and TNF