Lesson of the month 1: Septic arthritis with normal acute phase reactants and white cell count in a patient receiving tocilizumab

Abstract

Septic arthritis represents 8-27% of cases of monoarthritis presenting to the emergency department. Tocilizumab is an interleukin-6 blocking monoclonal antibody with the mechanistic potential to interfere with the body's normal inflammatory response to an infectious insult. We present a case of septic arthritis with a normal white cell count, C-reactive protein, erythrocyte sedimentation rate and fibrinogen in a patient treated with tocilizumab.

Pneumatosis Intestinalis and Intestinal Perforation in a Patient Receiving Tocilizumab

“…This finding may be due to masking of the systemic inflammatory response by tocilizumab or due to a benign underlying etiology. 16 We propose that in this case, tocilizumab predisposed to the development of PI. Subsequently, rupture of an intramural gas-filled pseudocyst led to pneumoperitoneum in the absence of frank intestinal perforation.…”

The Effect of Tocilizumab on Inflammatory Markers in Patients Hospitalized with Serious Infections. Case Series and Review of Literature

“…Our literature search in PubMed using “tocilizumab” with special attention to cases of infectious diseases during TCZ therapy and reported CRP levels at the time of diagnosis yielded a total of 28 case reports on this specific issue ( Table 2 ) [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ]. In 15 out of 28 reported cases, CRP was normal or only slightly elevated.…”