BackgroundC-reactive protein (CRP) is a marker of inflammation and infection. The main proinflammatory cytokine that leads to CRP gene expression is IL-6[1]. Different DMARDS may influence CRP levels due to their specific mechanisms of action and alter its usage as an important indicator of acute infection/inflammationObjectivesThe study aimed to compare CRP level between patients who were treated with Tocilizumab (TCZ), an il-6 receptor blocker, and other advanced anti-inflammatory treatments (AAIT), as well as with other admitted and non-admitted populations.MethodsA cross-sectional study of all patients (≥18 years) hospitalized at tertiary medical center between 12/2009 and 02/2020 and treated before hospitalization with (AAIT). Data on background DMARDS treatment was collected and then categorized to one of the two following groups: tocilizumab treatment and other treatments. In further investigation, the other treatments groups were divided into 3 subgroups: anti-TNF subgroup which included Infliximab (IFX), Adalimumab (ADA), etanercept (ETN), Golimumab, and Certolizumab, JAK-inhibitor subgroup which included Tofacitinib and Baricitinib, and another subgroup which included Rituximab, Abatacept and Anakinra Only the first hospitalization of each patient was included. Women admitted to obstetrics department were excluded. Demographic data, first blood tests results, and comorbidities were collected.ResultsThe study included 563 patients treated with AAIT (2.5% received TCZ). Patients treated with TCZ were older (median 75 vs. 50 years, p<0.001), had higher Charlson score (median 5 vs. 1, p<0.001) and more infectious diseases at admission (50% vs. 23.4%, p=0.05). Patients treated with TCZ had lower CRP levels (median 0.5 vs. 25mg/l, p<0.001) and more common normal values (64.3% vs. 20.8%, p<0.001) compared to patients treated with other AAIT.CRP level in patients treated TCZ (median 0.5mg/l) was lower than that of 58,548 patients admitted to the hospital between 2010-2020 (median 12.55mg/l, p<0.001) and not statistically different from 140 non-admitted randomly selected individuals without acute disease (1.33 mg/l, p=0.294).ConclusionWhen compared to other anti-inflammatory drugs, tocilizumab is associated with lower CRP levels in individuals admitted to an acute care hospital. This finding must be considered by treating physician to avoid misinterpretation of CRP results.References[1]Zhang D, Sun M, Samols D, Kushner I. STAT3 participates in transcriptional activation of the C-reactive protein gene by interleukin-6. J Biol Chem. 1996;271(16):9503-9509. https://doi.org/10.1074/jbc.271.16.9503Disclosure of InterestsNone declared
