Simple chemiluminescence assays for free radicals in venous blood and serum samples: Results in atopic, psoriasis, MCS and cancer patients

Objective: To investigate the generation of reactive oxygen species (ROS) i n serum and venous blood as well as the serum antioxidative activity (AOA) in patients and healthy controls by means of a simplified chemiluminescence (CL) methodology. Study Participants: 48 Atopic eczema, 23 psoriasis, 15 multiple chemical se nsitivity (MCS) end 35 cancer patients together with 22 healthy volunteers. Methods: ROS generation/photon emission in blood and serum samples under ba sal conditions and after light exposure as well as the AOA of the serum sam ples was investigated at room temperature (22 degrees C) in all 143 fasted subjects. The 3-step methodology resumes in adding a constant amount of blo od or serum to a constant amount of CL substrate (or to an ROS-generating m ixture for the AOA test), followed by a short preincubation and registratio n of the photon counts over a 600-second time interval. Results: In the basal and light exposure tests significantly higher photon counts (> 14,000 counts/600 s) were registered in venous blood in all patie nt groups when compared to healthy controls (p<0.001), suggesting increased amounts of activated leukocytes and tight-sensitizing compounds, respectiv ely. By contrast, most patient sera showed in all three CL tests a strongly inhibited light emission (p < 0.005), suggesting an adaptive antioxidative response to oxidant stress factors. Conclusions: Atopic, psoriasis, NICS and cancer patients are exhibiting sig nificantly changed blood and serum CL patterns when compared to healthy con trols. The described assays are simple, well reproducible and enable a fast assessment of ROS generation and AOA in biological samples at low operatio nal costs.