In vitro effect of different non-steroidal anti-inflammatory drugs on human polymorphonuclear leukocyte activity measured by luminol-dependent chemiluminescence of the whole blood

Objectives: To define the well-known variability in the effects of non-ster oidal anti-inflammatory drugs and to search for predictors of such variabil ity using an in vitro model. Methods: Polymorphonuclear leukocyte activity was measured by luminol-depen dent chemiluminescence of the whole blood using barium sulphate as a stimul ator. Blood was taken from 40 apparently healthy volunteers (22 males and 1 8 females; their age ranged from 20-50 years). Drugs (indomethacin 10ng/ml, aspirin 300 mug/ml, ibuprofen 25ug/ml or diclofenac 8ug/ml) were added int o the blond of each individual in vitro. The chemiluminescence was measured in a photon counting system. Results: There was a marked inter and intra individual variation in the che miluminescence response to the it nonsteroidal anti-inflammatory drugs, add ed in vitro. The variation exhibited a continuous pattern. No statistically significant correlation was found between the in vitro effect of one non-s teroidal anti-inflammatory drug and the other 3 drugs, nor between the effe ct of each drug and factors like age, sex, weight, bright, packed cell volu me, hemoglobin percentage and white blood cell count. Subjects with hemoglo bin-AS type (number = 9) responded mainly by enhancement to indomethacin an d diclofenac. When tl;e number of subjects rather than the average net effe ct was compared according to blood groups, those with blood group a showed chemiluminescence response?; towards enhancement with indomethacin and dicl ofenac and blood group O with aspirin. A consistent pattern of enhancement and inhibition was evident: enhancements and inhibitions by any 2 drugs inv olve a seemingly constant proportion of subjects. Conclusions Luminol-dependent chemiluminescence responses of polymorphonucl ear leukocyte activity could be a good in vitro model to study the variabil ity in response to non-steroidal anti-inflammatory drugs. Characteristics o f each individual are not able to predict the pattern of variability. Abnor mal hemoglobin and the type of blood group seem to be an interesting area f or research.