Pepsin deteriorates prognosis of children with otitis media with effusion who undergo myringotomy or tympanostomy tube insertion.

Objective: To investigate the concentrations of pepsin and pepsinogen within the middle ear cavity and determine whether pepsin and pepsinogen affect the prognosis of children with otitis media with effusion (OME).

Methods: All middle-ear lavage fluid from patients with OME undergoing myringotomy (M subgroup) or tympanostomy tube insertion (T subgroup) was collected and pepsin and pepsinogen were detected using enzyme-linked immunosorbent assay. After close follow-up over 2 years, the effects of pepsin and pepsinogen on the prognosis of the patients with OME in the M and T subgroups were analyzed.

Results: The average pepsin and pepsinogen concentrations were significantly lower in the M subgroup (n=54; 24.38±16.10mg/mL and 286.49±91.95mg/mL, respectively) than in the T subgroup (n=55; 45.56±16.60mg/mL and 664.92±107.06mg/mL; t=2.484, P=0.018 and t=2.670, P=0.011, respectively). In the M subgroup, the average time to tympanic membrane healing and tympanic pressure restoration to normal was much longer in pepsin(+) patients (17.0±2.0 days and 26.0±2.5 days, respectively) than in pepsin(-) patients (14.0±1.1 days and 22.0±1.0 days; t=3.871, P=0.001 and t=5.734, P=0.000, respectively), and the hearing level of pepsin(+) patients with OME ascended to 13.08±1.19dB, which was much lower than that of pepsin(-) patients (18.29±1.27dB; t=11.001, P=0.000). In the T subgroup, the complication rate including otorrhea and myringosclerosis was much higher in patients with high pepsin concentrations than in those with low pepsin concentrations (P<0.05). Finally, in both subgroups, the recurrence rates of OME in pepsin(+) or patients with high pepsin concentrations (34.6% [9/26] and 28.6% [10/35]) were significantly higher than those in pepsin(-) or low pepsin concentrations (10.7% [3/28] and 5.0% [1/20]; χ(2)=4.456, P=0.035 and χ(2)=4.420, P=0.036). However, pepsinogen had no significant effect on OME prognosis or recurrence.

Conclusion: Pepsin but not pepsinogen could postpone tympanic membrane healing and pressure restoration in children with OME undergoing myringotomy and increase the incidence of recurrence and complications including otorrhea and myringosclerosis for those undergoing tympanostomy tube insertion. Therefore, pepsin could be considered a poor prognostic factor for OME, further emphasizing the important role of pepsin in OME pathogenesis.