The following is a summary of “Clinical Characteristics and Classification Criteria Performance in a Single-Center Cohort of 114 Patients With Immunoglobulin G4–Related Disease,” published in the January 2023 issue of Rheumatology by Spandorfer, et al.

IgG4-RD, also known as immunoglobulin G4-related disease, is a diverse fibroinflammatory disorder. The 2019 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) Categorization Criteria for IgG4-RD were released to offer uniform classification criteria in clinical research. For a study, researchers sought to describe the characteristics of IgG4-RD patients’ demographics, clinical symptoms, and therapeutic approaches, as well as to evaluate how well the Classification Criteria performed in a diverse cohort with a high proportion of Black patients.

All patients sent to a specialist IgG4-RD clinic had their medical records reviewed in this instance. They gathered and evaluated data on demographics, serology, histology, illness symptoms, and treatments. The performance in the definitive diagnosis, probable diagnosis, and mimicker groups was compared using an ACR/EULAR Classification Criteria score for IgG4-RD.

About 198 patients in total were assessed. 85 (or 43%) were imitators. The remaining 114 were divided into 56 likely cases and 58 definite cases by the treating doctors, respectively. Among the 28 organ presentations of IgG4-RD, pancreatitis was the most prevalent presentation (37%). Around 84% of patients with a confirmed clinical diagnosis of IgG4-RD and a mean score of 29 matched the criteria for IgG4-RD classification. With an average score of 8, and only 9% of the likely instances reached the level. None of the mimics complied with the classification requirements.

The study demonstrated the wide range of IgG4-RD and supported the use of the ACR/EULAR Classification Criteria for IgG4-RD, which included a significant percentage of patients who were Black.