IL1B and gastroenteritis: Similarly, urinary IL-1β proved to be a helpful marker in another study comparing patients with acute pyelonephritis (n = 41), lower UTI (n = 34), and febrile controls (n = 20, patients with upper respiratory infection, lower respiratory infection, otitis media, and gastroenteritis).29 There was a significant difference in IL-1β levels at presentation in all three groups; acute pyelonephritis (172 ± 263.3 pg/ml, mean ± SD), lower UTI (20.4 ± 41.2 pg/ml) and febrile controls (4.6 ± 14 pg/ml).