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The following is a summary of “A protocol for targeted B-lymphocyte depletion for the treatment of IgG4-related disease,” published in the December 2024 issue of Rheumatology by Colquhoun et al. 

Researchers conducted a retrospective study to assess the clinical outcomes of patients with IgG4-related disease (IgG4-RD) treated with a defined B cell depletion protocol using rituximab. 

They included patients with an IgG4-RD diagnosis at Imperial College Healthcare NHS Trust between February 2017 and October 2022, with >9 months of follow-up data after the first rituximab dose. The rituximab protocol targeted B cell depletion to <10 cells/µL for a 2-year maintenance period. Electronic records were reviewed for patient demographics, serological and radiological variables, and treatment responses based on the IgG4-RD responder index (RI). 

The results showed that 45 patients received rituximab induction, with 2 excluded due to insufficient follow-up. All patients responded to therapy per the IgG4-RD RI. Of 43 patients, 58% (25/43) were on low-dose glucocorticoids (median 5 mg daily), and 16% (4/25) remained on prednisolone at 2 years. Disease flares occurred in 26% (11/43) of patients; 9/11 flares were linked to B cell repopulation, and 2/11 (18.1%) occurred without repopulation. All flares re-treated with rituximab (7/7, 100%) responded positively. 

Investigators concluded that rituximab effectively treated IgG4-RD, limiting glucocorticoid use. Flares were rare and responsive to further rituximab. 

Source: academic.oup.com/rheumatology/advance-article-abstract/doi/10.1093/rheumatology/keae675/7921425