Romano C, et al. - Authors evaluated the possible impact of tocilizumab on complement proteins. Findings suggested that after 12 months of therapy, abnormally low C3 and C4 serum levels were seen in 68.75 and 56.25% of patients, respectively. all known acute phase reactants were reduced with tocilizumab including C3 and C4 levels. Experts suggested the inclusion of reduction in C3 and C4 serum levels among the anti-inflammatory effects exerted by tocilizumab. Therefore these ought to be considered as an expected outcome of the mechanism of action of this drug.