Features of IgG4-related sclerosing mesenteritis: A Chinese cohort study and literature review

Abstract Objectives This study aimed to summarize the features of IgG4-related sclerosing mesenteritis (IgG4-SM) based on both our large prospective IgG4-related disease (IgG4-RD) cohort and literature-reported IgG4-SM cases. Methods We applied a mixed-methods approach, integrating data from 29 patients with IgG4-SM and 87 matched IgG4-RD patients without mesenteritis, all enrolled in a prospective cohort of IgG4-RD from Peking Union Medical College Hospital (PUMCH) since 2011. Additionally, we included 32 IgG4-SM cases reported in public databases since 2011. Demographic, clinical, laboratory, imaging and treatment data were systematically compared. Results Compared with IgG4-RD without mesenteritis, IgG4-SM predominantly affected elderly males and accompanied with more organ involvement ( P = 0.019) and elevated responder index (RI) scores and Physician Global Assessment (PGA) scores ( P = 0.005 and P = 0.018, respectively). Compared to the literature-reported cases, IgG4-SM patients in our cohort exhibited a lower prevalence of abdominal pain ( P < 0.001) but a higher frequency of submandibular gland ( P < 0.001) and lacrimal gland enlargement ( P < 0.001). Imaging features included a spectrum of mesenteric abnormalities, ranging from misty opacities to soft-tissue masses on computed tomography (CT), with significantly increased 18 F-fluorodeoxyglucose ( 18 F-FDG) uptake on positron emission tomography-computed tomography (PET-CT). Despite divergent treatments (glucocorticoids/immunosuppressants in our cohort vs . surgical resection in reported cases, P < 0.001), long-term relapse rates were comparable ( P = 0.17). Conclusions IgG4-SM is a significant but under-recognized manifestation of IgG4-RD, characterized by a predilection for elderly males, multi-organ involvement, higher disease activity and distinct imaging features. Systemic radiological evaluation, including PET-CT could assist diagnosis and treatment monitoring. Glucocorticoid-based therapy achieved outcomes comparable to surgery, challenging the necessity of invasive interventions. This study expands the clinical spectrum of IgG4-SM and advocates for personalized, non-surgical management strategies in most cases.