Reassessing the role of watchful waiting strategy for IgG4-related disease: a real-world study

BACKGROUND: To investigate the feasibility and potential efficacy of “watchful waiting” strategy in IgG4-related disease (IgG4-RD) patients being asymptomatic or having low disease activity. METHODS: IgG4-RD patients presented in our station between October 2018 to October 2022, who met the criteria for “watchful waiting” modified from the 2015 International Consensus Guidance Statement were included. Deidentified clinical laboratory data were retrospectively collected and statistically analyzed between patients undergone watchful waiting (“WAIT” group) and received routine medical treatments (“TREAT” group). Subgroup analyses in “WAIT” group were also performed to compare the features between patients with and without receiving surgical resection of involved organs. RESULTS: A total of 49 patients meeting the “watchful waiting” criteria were included and followed for a median of 48 [IQR 24.00, 48.00] months. The median IgG4-RD responder index (RI) of them was 2; 71.4% of them were ‘Head and Neck-Limited’ clinical phenotype, and 63.3% were single organ involved. While 25 of the 49 patients chose “watchful waiting” strategy, others received treatment of glucocorticoids and steroid-sparing agents. The WAIT group showed a significantly higher cumulative recurrence rate (42.4%, 95%CI: 0.18–0.60) than the TREAT group (8.3%, 95%CI: 0-0.19), during the follow-up periods. Further analyses into the WAIT group revealed all relapse events of them were observed in patients undergone surgical resection of involved organs, who scored significantly higher based on the 2019 ACR/EULAR classification criteria for IgG4-RD. CONCLUSIONS: “Watchful waiting” strategy may not be the optimal immediate choice for patients with mild symptoms, low disease activity, and limited organ involvement, even after the surgical resection of involved organs.