Escalation in mucus cystatin 2, pappalysin‐A, and periostin levels over time predict need for recurrent surgery in chronic rhinosinusitis with nasal polyps

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is treated using oral/topical steroids and surgery. Despite maximal medical therapy, some patients remain recalcitrant. Mucus cystatin 2, pappalysin-A, and periostin can predict the presence of CRSwNP and correlate with disease severity. This study was designed to determine whether prospective sampling of these mucus proteins could predict medical failure and the need for revision surgery. METHODS: This investigation was an institutional review board-approved, prospective study of 66 patients with CRSwNP. All patients underwent surgery, administration of topical/oral steroids, and outpatient mucus sampling at 10 time-points over 2 years. Five proteins, including cystatin 2 (CST2), pappalysin-A (PAPP-A), and periostin (PST), were analyzed and correlated with subjective parameters (including scores on the 22-item Sino-Nasal Outcomes Test [SNOT-22]). Variables were then analyzed and compared between those requiring revision surgery within 2 years (n = 5) and those with stable disease (n = 61). RESULTS: All patients demonstrated a significant decline in CST2, PAPP-A, and periostin after their initial surgery. The recalcitrant group demonstrated escalations in all proteins despite steroids, with levels higher than those of the stable group at 1 year (CST2: 258.1 ± 205.2 pg/mL vs 235.3 ± 275.7 pg/mL, p = 0.86; PAPP-A: 170.3 ± 150.4 pg/mL vs 74.6 ± 106.7 pg/mL, p < 0.05; periostin: 188.8 ± 192.4 ng/mL vs 54.5 ± 47.6 ng/mL, p < 0.001). Escalation in all proteins correlated significantly with worsening SNOT-22 score at each time-point (domain 1: 8.2 ± 1.3 vs 5.5 ± 1.1; p < 0.05). CONCLUSION: Early recurrences and medical recalcitrance in CRSwNP may be predicted noninvasively through the serial, prospective sampling of mucus CST2, PAPP-A, and periostin levels. These biosignatures may help to predict disease course and guide individualized therapy.