AbstractAsthma is one of the most common chronic conditions affecting both children and adults. It is considered a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role. This chronic inflammation causes an associated increase in airway hyper-responsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness and cough. This work was carried out on 90 subjects (60 of them asthmatic patients and 30 healthy as control). Patients were diagnosed, treated and followed up in chest unit in Pediatric Department, Zagazig university.Two groups were included in this study:Group (1): 60 asthmatic patients in acute attack (5-15 years in age)Group (2): 30 healthy children as controlAll studied groups were subjected to:• Complete history taking, full clinical examination and laboratory investigations included.• Complete blood picture, chest –x ray, serum T.N.F-α by ELISA & serum IgE by ELISAIn our study, no statistical significant difference between studied groups as regard of sex.As regard to our study their was no statistical significant difference between studied group as regard to the age which range from 5-15 years which reveal characteristics of studied group as regard to age.In our study, their was statistical significant higher level of HB {60 cases (27 non-allergic&33 allergic), 30 control} with mean range from {(10.47±1.39), (10.54±1.53) & (12.48±1.05)} respectively, Neutrophils {60 cases (27 non-allergic&33 allergic), 30 control} with mean range from {(35.44±5.35), (58.54±6.10) & (25.43±5.62)} respectively, Eosinophils{60 cases (27 non-allergic&33 allergic), 30 control} with mean range from {(5.66±2.20), (15.06±3.54) & (2.66±2.84)} respectively & Platelets {60 cases (27 non-allergic&33 allergic), 30 control} with mean range from {(457±141.11), (469.48±118.90) & (391.76±103.48)} respectively in the asthmatic patients compared to the control groups & shows no statistical significant difference between studied groups as regard other criteria as R.B.Cs, W.B.Cs &Lymphocyte and no statistical significant difference between monocyte and asthma.In our study, mite was statistical significant from other allergens as hay, wool, tobacco and cotton among allergic asthmatic patient {Mite (66,7%) then Hay(12.1%),Wool(9%), Tobacco(6.1%) and Cotton (6.1%)} (P=0.000 significant).In our study, the mean of IgE in asthmatic allergic patients was the highest followed by non allergic then the control groups and the differences was statistically significant.In our study,the mean value of IgE was highly statistical significant increase in severe asthma compared to moderate & mild types of asthma & the mean value of IgE was highly statistical significant increase in moderate asthma compared to mild asthma (P=0.000 significant).In our study, the mean of T.N.F-α in asthmatic allergic patients were the highest followed by non allergic then the control groups and the differences was statistically significant.In our study, the mean value of T.N.F-α was highly statistical significant increase in severe asthma compared to moderate & mild types of asthma & the mean value of T.N.F-α was highly statistical significant increase in moderate asthma compared to mild asthma.In our study, non- statistical significantly between severity of asthma and allergy.In our study, ROC curve analysis ,which differentiate between T.N.F-α and IgE of the allergic asthmatic group, shows that the best cut off point for T.N.F-α was 42 pg/ml while for IgE was 247.5U/ml. T.N.F-α had a sensitivity of 97%, specifity of 96.3%, positive predictive value of 97% and negative predictive value of 96.3%. IgE had a sensitivity of 93.9%, specifity of 92.6%, positive predictive value of 93.6% and negative predictive value of 92.6% In conclusion, this work aims to evaluate the diagnostic and prognostic role of T.N.F-α & total IgE in diagnosis and management of asthma. Our data show that T.N.F-α & total IgE affect the severity of asthma and its prognosis.