RT Journal Article SR Electronic T1 Th2 cytokine profile in appendicular lavage fluid is compatible with allergy as an etiology for acute appendicitis JF bioRxiv FD Cold Spring Harbor Laboratory SP 569947 DO 10.1101/569947 A1 Nuno Carvalho A1 André Barros A1 Hélder O. Coelho A1 Catarina F. Moita A1 Ana Neves-Costa A1 Dora Pedroso A1 Filipe C. Borges A1 Luís F. Moita A1 Paulo M. Costa YR 2019 UL http://biorxiv.org/content/early/2019/09/30/569947.abstract AB Acute appendicitis is the most frequent surgical abdominal emergency, but its etiology remains poorly understood. Histological examination of the appendix, following its removal due to acute appendicitis, consistently shows features in common with bronchial asthma, suggesting an allergic reaction as a candidate etiologic factor. Here we propose the concept of appendicular lavage and used it to study the levels of the Th2 cytokines IL-4, IL-5 and IL-9 in patients with a clinical diagnosis of acute appendicitis. The study group included 20 patients with a histological diagnosis of phlegmonous appendicitis, 13 patients with gangrenous appendicitis, and a control group of 8 patients with clinical diagnosis of appendicitis but with normal histology. Cytokines levels were higher in acute appendicitis. The difference was more pronounced when comparing phlegmonous appendicitis with non-pathological appendix (p=0.01) for IL-4 (48,3 vs 21,3 pg/mL), IL-5 (29,2 vs 8,0 pg/mL) and IL-9 (34,1 vs 16,6 pg/mL). This Th2 cytokine profile is compatible with the hypothesis of allergy as an etiologic factor for acute appendicitis and may have important implications for the diagnosis, prevention and treatment of this condition.