Imaging features of immunoglobulin G4-related disease

Current and future advances in practice: IgG4-related disease

IgG4-related disease (IgG4-RD) is an increasingly recognized cause of fibroinflammatory lesions in patients of diverse racial and ethnic backgrounds and is associated with an increased risk of death. The aetiology of IgG4-RD is incompletely understood, but evidence to date suggests that B and T cells are important players in pathogenesis, both of which are key targets of ongoing drug development programmes. The diagnosis of IgG4-RD requires clinicopathological correlation because there is no highly specific or sensitive test. Glucocorticoids are highly effective, but their use is limited by toxicity, highlighting the need for studies investigating the efficacy of glucocorticoid-sparing agents. B cell-targeted therapies, particularly rituximab, have demonstrated benefit, but no randomized clinical trials have evaluated their efficacy. If untreated or under-treated, IgG4-RD can cause irreversible organ damage, hence close monitoring and consideration for long-term immunosuppression is warranted in certain cases.

American College of Rheumatology and the European League Against Rheumatism classification criteria for IgG4-related disease: an update for radiologists

IgG4-related disease (IgG4-RD) is an immune-mediated, multiorgan, chronic inflammatory disease. The three-step classification criteria proposed in 2019 by the American College of Rheumatology and the European League Against Rheumatism (ACR/EULAR) encompass a wide range of clinical, radiological, serological, and histopathological findings. The ACR/EULAR proposed a three-step classification process, i.e., entry step, exclusion step, and scoring system. Radiologists need to know that the radiological findings observed in the five domains of the lacrimal and salivary glands, chest, pancreas and biliary ducts, kidney, and retroperitoneum are independently weighted with different points in the scoring system. A total score < 20 points indicates that the patient should not be classified as having IgG4-RD; conversely, a total score ≥ 20 points indicates that the patient should be classified as having IgG4-RD. In this review, the 2019 ACR/EULAR classification criteria are discussed, focusing on the interpretation of each radiological item, with the aim of applying them to the diagnosis of IgG4-RD in clinical practice.

Sonographic findings of immunoglobulin G4-related sialadenitis and differences from Sjögren's syndrome

OBJECTIVE

To evaluate ultrasonic features of the major salivary glands in patients with immunoglobulin G₄-related sialadenitis (IgG₄-RS) and to explore the differences between IgG₄-RS and Sjögren's syndrome (SS).

METHOD

We conducted the study in 150 patients with IgG₄-RS and 100 patients with SS. Ultrasonographic variables of the static images of major salivary glands were analysed. An experienced radiologist scored the confidence rating regarding the presence of the characteristic imaging findings using a five-grade rating system. Ultrasonography scores between IgG₄-RS and SS were compared.

RESULTS

The major salivary glands were significantly larger in patients with IgG₄-RS than in the SS group. The main features of ultrasonography of the salivary glands in IgG₄-RS were various hypoechoic lesions and increased colour Doppler signalling. In contrast, the major salivary glands in SS exhibited hyperechoic lines and/or spots and obscuration of the gland configuration. The scores of the summarized sonographic characteristics also showed statistically significant differences between the IgG₄-RS and SS groups.

CONCLUSION

This study revealed different ultrasonic features of the major salivary glands in patients with IgG₄-RS and SS. The scored sonographic features were helpful in differentiating IgG₄-RS from SS. Consequently, we suggest that ultrasonography of major salivary glands could be a useful imaging procedure in the evaluation of patients suspected of having IgG₄-RS.

Gastrointestinal adverse events of immunotherapy

Cancer immunotherapy with immune-checkpoint inhibitors (ICIs) has emerged as an effective treatment for different types of cancer. ICIs are monoclonal antibodies that inhibit the signaling pathway that suppress antitumor T-cell activity. Patients benefit from increased overall and progression-free survival, but the enhancement of normal immunity can result in autoimmune manifestations, called immune-related adverse events (IRAEs), which may lead to a discontinuation of cancer therapy and to severe also life-threating events. IRAEs may affect any organs or system in the human body, being the gastrointestinal (GI) tract one of the most involved districts. Imaging plays an important role in recognizing GI IRAEs and radiologist should be familiar with the main spectrum of radiological appearance. Indeed, early detection of GI IRAEs is crucial for proper patient management and reduces morbidity and mortality. The purpose of this review is to present the most relevant imaging manifestation of GI IRAEs.

Imaging Features of Toxicities by Immune Checkpoint Inhibitors in Cancer Therapy

Purpose of review

With the increasing use of immune checkpoint inhibitors in cancer therapy radiographic profiling of frequent and serious immune-related adverse events (irAEs) becomes more relevant. This article reviews imaging features of irAEs induced by the anti-CTLA-4 and anti-PD-1 antibodies ipilimumab, nivolumab and pembrolizumab.

Recent findings

Important radiological manifestations are immune-related colitis, hepatitis, pancreatitis, hypophysitis, pneumonitis, arthritis and sarcoid-like lymphadenopathy. Typical imaging features are summarized and compared with other relevant differential diagnoses.

Summary

Early diagnosis and appropriate therapeutic decisions are required for a successful treatment of irAEs. In addition to staging and follow-up imaging, identification and monitoring of adverse events becomes an important radiologic aspect in oncologic care.

Autoimmune Pancreatitis

Autoimmune pancreatitis (AIP) is a rare and underdiagnosed fibrosclerosing inflammatory variant of chronic pancreatitis. Its true incidence and prevalence in the general population is still not confirmed despite advances in medicine. Differentiating it from pancreatic cancer is of paramount importance. In this imaging review, we highlight the imaging findings of this intriguing entity.