Growth factors and IL-17 in hereditary angioedema

Hereditary angioedema (HAE) is a rare autosomal dominant disorder, due to C1-inhibitor deficiency, which causes episodic swellings of subcutaneous tissues, bowel walls and upper airways which are disabling and potentially life-threatening. We evaluated n = 17 patients with confirmed HAE diagnosis in basal and crisis state and n = 19 healthy subjects. The samples were tested for IL-17, FGFb, G-CSF and GM-CSF, using Bio-plex kit. Data analysis was performed via nonparametric Spearman's correlations and two sets of linear mixed models. When comparing HAE subjects during basal and crisis states, we found out significantly (i.e., p value <0.05) higher values in crisis states rather than in basal states for the three growth factors and cytokine IL-17. When comparing healthy subjects versus HAE patients at basal state, we found out significantly higher values in HAE subjects only for GM-CSF, FGFb and IL-17, but not for G-CSF. In HAE patients, there is a connection between IL-17 and growth factors. The low-grade inflammation in absence of attacks is demonstrated by constant higher amount of IL-17, FGFb and GM-CSF with respect to healthy patients. This could indicate that in this disease there is a level of activation that maintains the system in a "tick-over state," that can be activate by several stimuli that are able to induce a increase in inflammatory mediators during the acute attack.