IGHE and gastroesophageal reflux disease: Moreover, in both CSU and GERD patients the CSU and GERD overlap syndrome was significantly and independently associated with increased levels of Tot-IgE (≥ 100 IU/ml) (p = 0.002) or EBC (≥ 250 cells/mmc) (p = 0.035) without a significant interaction between these two biological parameters (Table 6).