NEW POSSIBILITIES FOR DYNAMIC ASSESSMENT OF SYSTEMIC INFLAMMATORY RESPONSE IN PATIENTS WITH RHEUMATOID ARTHRITIS

Abstract

Systemic inflammation in rheumatoid arthritis (RA) is associated with changes in both the number and composition of circulating inflammatory blood cells such as neutrophils and lymphocytes. Accurate monitoring of inflammation intensity and disease status in patients with RA is important in the inpatient setting. Purpose of the study: to determine inflammatory indices derived from the general blood count (CBC) in patients with active RA during inpatient treatment and to study the association of these indices with clinical and laboratory parameters of the disease. Inflammatory indices (NLR - neutrophil to lymphocyte ratio, MLR - monocyte to lymphocyte ratio, PLR - platelet to lymphocyte ratio, SII - systemic immune inflammation index, SIRI - systemic inflammatory response index) were determined based on the results of CBC performed using automated hematology analyzers in 43 patients with RA (55.8% men; aged 22 to 78 years; 88% with high disease activity) twice (at admission to hospitalization and at discharge). The average length of hospitalization was 14 [9;14] days. Common inflammatory markers (ESR and CRP) correlated with each other (rs=0.64); correlations of CRP with leukocyte count (rs=0.47), with PLR (rs=0.43) and age of patients (rs=0.34), as well as correlations of ESR with PLR (rs=0.37) and age of RA patients (rs=0.33) were found. The SII index correlated strongly with NLR (rs=0.85) and PLR (rs=0.86), moderately with MLR (rs=0.49), but not with SIRI (p>0.05). The SIRI index showed a degree correlation with DAS-28 (β= -0.072, p=0.008). Markers obtained from OAC were not associated with age or sex of the examined individuals (except SIRI, p=0.027), no intergroup differences in the studied hematologic markers were found when dividing RA patients by the content of antibodies to cyclic citrullinated peptide, presence of erosions and systemic manifestations (except PLR, p=0.048). Only CRP and systemic immune inflammation index (SII) showed a significant decrease (p=0.24 and p=0.43, respectively) during hospitalization of patients with RA. No advantage was found in using two-component indices (NLR, MLR, PLR) as useful tools both for assessing inflammatory status and in the management of patients with highly active RA. The SII index, combining the prognostic value of three parameters (platelets, neutrophils and lymphocytes), can be considered not only more powerful for predicting inflammation than single- or two-component hematologic markers, but also a valuable tool for monitoring inflammation and RA progression. Thus the SII index (along with CRP) may be in demand as a potential biomarker for determining the outcome of inpatient treatment of patients with highly active RA.