Clinical and imaging findings suggestive of histopathological immunoglobulin G4-related disease: a single-center retrospective study

Objective: To investigate the clinical and imaging features predicting the histopathological diagnosis of immunoglobulin G4 (IgG4)-related disease (IgG4RD) in patients with suspected IgG4RD on computed tomography (CT). Methods: We retrospectively reviewed the medical records of 178 patients with CT findings suspicious of IgG4RD from January 2015 to December 2017. Patients who underwent tissue biopsy were included to evaluate the association between patient characteristics and histopathological diagnosis of IgG4RD. The histopathological diagnosis was classified into IgG4RD and non-IgG4RD. Clinical, laboratory, and imaging features were compared between patients with IgG4RD and non-IgG4RD, and logistic regression analysis was performed to identify the predictors for histopathologically confirmed IgG4RD. Results: Of the 103 patients with histopathologically proven diseases, 46 and 57 patients were classified as IgG4RD and non-IgG4RD, respectively. The median age was 64 years; 65% of patients were male. There were significant differences in sex (P = 0.035), fever (P = 0.039), serum IgG4 level (P < 0.001), renal involvement (P = 0.036), lacrimal or salivary glands involvement (P = 0.050), swelling pattern on CT (P = 0.001), and positron emission tomography (PET)-CT findings (P < 0.001) between patients with IgG4RD and non-IgG4RD. Multivariate analysis revealed elevated IgG4 level > 135 mg/dL (odds ratio [OR] = 5.418, P < 0.001), kidney involvement (OR = 6.170, P = 0.044), and the swelling feature on CT (OR = 4.301, P = 0.012) to be independent factors for histopathological diagnosis of IgG4RD. Conclusion: This study suggests that elevated IgG4 level, renal involvement, and swelling pattern on CT are associated with histopathological diagnosis of IgG4RD. The clinical and imaging features might help to decide further evaluation in patients with clinically suspected IgG4RD.Key Points• Computed tomography (CT) is not sufficient to discriminate between IgG4-related disease (IgG4RD) and non-IgG4RD conditions.• Histopathological diagnosis of IgG4RD is associated with elevated IgG4 level, renal involvement, and swelling pattern on CT.• Positron emission tomography-CT may be a useful diagnostic tool in patients with clinically suspected IgG4RD.>