RESUMO
In the non-specific immune system of human, neutrophils, lymphocytes, monocytes and platelets are important components that play a role in regulating and inducing tissue damage and can reflect the body′s level of immunity.These peripheral blood cells are functionally and quantitatively abnormal in the presence of serious infections or immune deficiencies, but these parameters are usually interpreted in isolation.Recent studies have found that comprehensive indicators derived from peripheral blood parameters, such as neutrophil to lymphocyte ratio, platelet to lymphocyte ratio, monocyte to lymphocyte ratio or lymphocyte to monocyte ratio have predictive value for the occurrence and prognosis of diseases.This article reviews the role of these indicators in common childhood diseases and provides a reference for the diagnosis and treatment of some diseases.