بررسی فعالیت کاندیدیاکشی نوتروفیل ها در بیماران مبتلا به سوختگی با استفاده از نمک تترازولیوم

Background and purpose: Ïnfection remains the major problem of the burned patients. Factors such as disruption of the integrity of the skin, vast antibiotic treatment which causes loss of the normal flora of the body and impairment of phagocytotic system, contribute to the increased susceptibility to mycotic infections. Âmong the fungi, Çandida albicans which is an opportunistic microorganism and one of the normal flora of the body, causes the most dreaded septic complications in thermal injured patients. Neutrophils with their phagocytotic activities are effector cells especially essential for protection against fungal infections. Post burn impairment of PNL cells activity as a result of intrinsic defect or alternation in opsonic activity of serum has been reported. Materials and methods: Ïn this study the Çandidiacidal activity of neutrophils in 30 patients with second and third degree burns and 30 aged matched normal persons were compared using MTT assay for determination of fungal viability. Çandida specimens were prepared by serial passage of a standard species on sabouard dectrose agar (SDÂ). Yeast were grown overnight in yeast-nitrogen base broth (YNBÂ). Ïn using them for experiment the viability of all specimens were more than 90%. Neutrophils were obtained from whole blood by dextran sedimentation followed by ficoll separation. The neutophil of patient and normal controls were cultured and normal and patient serum was added as opsonins after an hour of incubation with candida samples. Neutrophils were lysed by addition of dexycholic acid and the viability of remaining yeasts were measured using MTT assay. Statistical analysis was done using student t-test and variance analysis. Results: Ôur results indicated an increase in neutrophil abundance in patient’s blood as compare to healthy individuals. But the candidiacidal activity of patient’s neutrophils was significantly decreased. The observed decrease of activity was not only related to intrinsic defect of cells, but also to serum changes. So that when adding patient’s serum to normal neutrophils the killing activity was also significantly reduced. Çonclusion: Çonsidering the above results if we can increase the neutrophil activity of burned patients using cell stimulator drugs or cytokines which is the scope of another study we can hope to reduce the infectious problems of thermaly injured patients. Specially the fungal infections