Distribution of vasoactive intestinal peptide( VIP)- and substance P (SP)- containing innervation in bronchi of patients with bronchial asthma

Airway-wall remodelling with changes in neuropeptide-containing innervation is known to characterise bronchial asthma but there are still contradictional data about changes in neuropeptide-containing innervation in bronchi of asthmatics.
The aim of study was to investigate VIP- and SP-containing innervation in 40 biopsies from asthmatics with mild and moderate disease by use of immunohistochemistry. 19 patients received glucocorticoids (GC) and 22 patients were GC-naive.
Results showed structural changes like partly detached epithelium and increased basal membrane. 8 patients possessed also regional metaplastic and 9 – mucoid epithelium. Hypertrophy of muscles was seen in most cases and hypertrophy of glands - in 7 cases. Eosinophil¢s infiltration was observed in most of cases, with no difference between allergic and non-allergic patients.
Patients with GC therapy show network of SP-immunoreactive nerves beneath the basal membrane, among smooth muscle and around bronchial glands in 15 cases and no SP innervation in 4 cases . Interestingly, GC naive patients had richer innervation in all mentioned locations.
VIP-containing nerve fibers were seen in all patients. However, there was a tendency for this peptide to dominate in GC treated patients. Often VIP- positive prominent nerve trunks were seen, particulary in non-allergic patients.
In conclusion, we suggest about rich VIP- and SP-containing innervation pattern in asthmatics under regular treatment with GC, that might be connected to the more developed stage of disease and/or under influence of other additional inductive factors.