increased total serum immunoglobulin e in children developing mycoplasma pneumoniae-related extra-pulmonary diseases

Mycoplasma pneumoniae has been recognized to be involved in several extra-pulmonary diseases, but the underlying immunologic mechanisms are still largely unknown. recently, we observed a significant elevation of serum immunoglobulin e (ige) in a small group of these children. here, we assessed total serum ige levels in children affected with mycoplasma pneumoniae-related extra-pulmonary diseases. we prospectively collected the data of 162 children admitted to the hospital (because of respiratory infections or extra-pulmonary diseases) who were evaluated for mycoplasma pneumoniae serology and total serum ige levels, concomitantly. based upon clinical and serology aspects, 3 groups of children were identified: i) with non-mycoplasma respiratory disease; ii) with mycoplasma-related respiratory diseases; iii) with extra-pulmonary diseases related to concomitant/recent mycoplasma pneumoniae infection. interestingly, children with mycoplasma pneumoniae-related extra-pulmonary diseases showed a significant elevation of total serum ige. in particular, patients developing mycoplasma pneumoniae-related extra-pulmonary diseases (group iii) showed significantly higher level of ige than both previous groups (p<0.001 vs. group i; p<0.01 vs. group ii). in conclusion, hospitalized children diagnosed with mycoplasma pneumoniae-related extra-pulmonary diseases resulted to have significantly increased serum ige compared to children developing respiratory illnesses only.