Text Box: ROLE OF CYTOKINES IN THE PATHOGENESIS OF PERSISTENT DIARRHEA Osman Gilane A *, El-Hodhod MA * and El-Badawi N A **. From the Pediatric * and Clinical Pathology** Departments, Faculty of Medicine Ain Shams University，Cairo, Egypt Backgrounds: Diarrhea is the focus of extensive public health program efforts in developing countries. Since introduction of the oral rehydration therapy, the morbidity and mortality from acute diarrhea was diminished. However the magnitude of persistent diarrhea and its risk was increased. The exact mechanisms that enhance persistence of acute diarrhea is not clearly established and a list of predisposing factors is available Subjects and methods: A prospective study was conducted on 100 patients with acute diarrhea. They were subjected to thorough history taking, clinical examination and laboratory investigations including, serum elcetrolytes, arterial blood gases, stool analysis and culture as well as serum levels of TNFµ and IL2. They were managed with oral rehydration therapy with or without antibiotics according to the causative agents. After 2 weeks they have been divided into two groups; those who recovered and those who had persistent diarrhea. Serum levels of TNFµ and IL2 were re-evaluated in all cases. A group of 20 healthy cohort infants and children were chosen as a control group. Results：At the onset of acute diarrhea serum levels of TNFµ and IL2 were slightly higher among patients who recovered (86. 2 ± 53.2 pg/ml and 12.5 ± 5.47 IU/ml respectively) compared to controls (58.3 ± 20.47 pg/ml and 8.32 ± 2.19 IU/ml respectively). Patients with persistent diarrhea showed significantly higher results (427.8 ± 245.07 pg/ml and 22.3 ± 12.81 IU/ml respectively) than the other 2 groups. After 2 weeks patients who recovered have results (62.2 ± 24.7 pg/ml and 9.3 ± 3.2 IU/ml respectively) similar to controls. However values from patients with persistent diarrhea showed further elevation of these cytokines (680.5 ± 345.6 pg/ml and 30.5 ± 12.5 IU/ml respectively). The two most important factors that were related to the high values of cytokines in our patients were the social class and use of antibiotics whether in the same attack or before. Conclusion：Excess outpouring of cytokines in acute diarrhea is greatly related to the persistance of diarrhea after an acute attack. Low socio-economic status and abuse of antibiotics are the most important aggravating factors. 1988