Recently, we have shown that the extent of systemic inflammation of innate immune cells can be visualized by measuring the expression of activation markers on blood PMNs [9]. The most sensitive marker turned out to be the responsiveness of active FcγRII (CD32) on PMN’s for the innate immune stimulus fMLP [9, 10]. The most commonly used marker is MAC-1 (CD11b), which peaks between 6 and 18 hours after insult (i.e. trauma or surgery)[11]. In contrast to PMN’s, changes in activation of the systemic monocyte compartment can be determined by analyzing the percentage of circulating Palbociclib HLA-DR positive monocytes [7]. Blood samples
were taken at two distinct time points: one hour prior to IMN and 18 hours after the intramedullary nail was introduced. To investigate the influence of IMN, patients were stratified by isolated femur fracture and femur fractures
in multitrauma. Patients were compared with healthy, age and gender matched controls as described previously (see Table 1)[9]. Table 1 Patient demographics. Median (+ range) Number of patients (n) 38 Male/Female (n) 22/16 RG-7388 supplier Age (years) 30 (16-80) Injury Severity Score 13 (9-43) – Femur fracture (n = 23) 10 (9-19) – Multitrauma (n = 15) 29 (16-43) APACHE II Score 5 (0-24) Time on ICU (days) 0 (0-60) Time on ventilation (days) 0 (0-55) Packed red blood cells before first blood sample (units) 0 (0-22) Fresh frozen plasma before first blood sample (units) 0 (0-20) Trauma mechanism (n) - MVA 29 - Fall of height 8 - Direct impact 1 Complications (n) - No SIRS symptoms 14 - SIRS 17 - ALI/ARDS 7 Materials For analysis of PMN receptor expression
by flowcytometry the following monoclonal antibodies were commercially purchased: FITC-labeled IgG1 negative control (clone DD7, Chemicon, Hampshire, United Kingdom), RPE-labeled IgG2a negative control (clone MRC OX-34, Cobimetinib mw Serotec, Dusseldorf, Germany) and RPE-labelled CD11b (clone 2LPM19c, DAKO, Glostrup, Denmark). An antibody, which recognizes an active FcyRII/CD32 (designated FcyRII*), is manufactured at the Department of Pulmonary Science at the University Medical Center Utrecht (MoPhab A27, UMCU, Utrecht, The Netherlands)[12, 13]. For analysis of monocyte HLA-DR expression by flowcytometry the following monoclonal antibody was commercially purchased: FITC-labeled HLA-DR (YE2/36-HLK, Serotec, Dusseldorf, Germany). Pmn and monocyte receptor expression The inflammatory status of a patient can be assessed by analyzing the expression of active FcyRII (FcyRII*) on PMNs in the peripheral blood [9]. A low expression of fMLP induced FcyRII* correlates with increased inflammation. This approach has been validated in a Selleck Pevonedistat previous study [9]. The expression of fMLP induced FcyRII* was compared with a more common activation marker MAC-1 (CD11b)[14].