[Autoimmune pancreatitis: An update]

[Guideline-based diagnosis of pancreatitis]

BACKGROUND

There is currently no S3 guideline that contains statements on the diagnosis and treatment of acute, chronic and autoimmune pancreatitis in a single guideline.

OBJECTIVES

This article presents the most relevant recommendations relating to radiological imaging from the new "S3 guideline for pancreatitis".

MATERIALS AND METHODS

The guideline was developed by the DGVS (German Society for Digestive and Metabolic Diseases). After an online-based Delphi survey, the statements were discussed by an interdisciplinary expert team at a 3-day consensus conference and then agreed upon. The level of evidence scheme (version 2) of the Oxford Centre for Evidence-based Medicine was used.

RESULTS

The new German "S3 guideline pancreatitis" comprises for the first time all entities of pancreatitis, acute, chronic and autoimmune pancreatitis and contains a large number of innovations with regard to diagnostic imaging and therapy. In addition to the evidence-based recommendations for diagnosis and therapy, a German-language glossary of the revised Atlanta classification on acute pancreatitis was adopted by consensus of the interdisciplinary guideline expert team. Furthermore, protocol recommendations for the performance of computed tomography (CT) are provided for the first time. In this article we introduce the key recommendations and innovations in the field of diagnostic radiologic imaging for acute, chronic and autoimmune pancreatitis.

CONCLUSIONS

In the future, every radiologist should have deep knowledge of the recommended time intervals for radiological imaging in acute pancreatitis and know the German terms for the description of acute pancreatitis; furthermore they should be able to classify the morphologies to the appropriate stages.

[Inflammatory and infectious abdominal peritoneal and mesenterial processes]

BACKGROUND

Mesenterial and peritoneal inflammation represents a major clinical challenge regarding differential diagnosis. In this review article, a systematic overview of the most common causes such as autoimmune reaction, infarction with consecutive necrosis and infection caused by protozoa or bacteria is provided.

RESULTS

The common clinical features of all inflammatory peritoneal and mesenterial diseases are the nonspecific abdominal symptoms. Even in radiological imaging an overlap of imaging features such as lymphadenopathy and nodular mesenteric structures is typical. Frequently the radiologist can narrow the differential diagnosis based on clinical information and anamnesis resulting in an optimized clinical outcome.

CONCLUSION

Having a huge spectrum of etiologies for inflammatory peritoneal and mesenterial conditions the radiologist has to consider autoimmune diseases (IgG4-associated disease), acute infarction with necrosis and bacterial or protozoan infection.

[IgG4-associated diseases : State of the art]

CLINICAL ISSUE

IgG4-related diseases are rare but the incidence is continuously increasing. The pathophysiology is only incompletely understood. Multiorgan involvement correlates with high relapse rates, high serum IgG4 levels and an aggressive disease course, which is why diagnostics and therapy must be carried out rapidly and efficiently according to international guidelines despite all the difficulties.

STANDARD TREATMENT

Currently the therapeutic standard is initial therapy (induction therapy) with glucocorticosteroids over a longer period of time and if necessary followed by low-dose maintenance therapy. Steroids are also the first choice therapy for management of relapses. Refractory disease courses are a rare but relevant problem.

TREATMENT INNOVATIONS

The B‑cell depleting antibody rituximab has shown excellent results in terms of remission induction and also maintenance therapy. The good effectiveness profile is likely to change the current treatment regimen for IgG4-related diseases in the future.

DIAGNOSTIC WORK-UP

The current diagnostic algorithms applicable for several organ systems are based on four major pillars: (i) patient history and physical examination, (ii) serological diagnostics, (iii) organ swelling in the appropriately selected imaging procedure and (iv) the histological picture as gold standard.

PERFORMANCE

The currently used algorithms allow a diagnosis to be made in most cases.

ACHIEVEMENTS

IgG4-related diseases are a relevant differential diagnosis, particularly of malignant diseases. It is often a diagnosis by exclusion. An interdisciplinary approach is essential for rapid diagnostics and induction of therapy.

PRACTICAL RECOMMENDATIONS

In Europe IgG4 serum levels are just one of several diagnostic criteria. Imaging studies should be chosen according to the organ and disease manifestations.

[Hepatopancreaticobiliary diseases in IgG4-associated autoimmune diseases]

BACKGROUND

IgG4-related diseases are rare systemic multiorgan diseases and can thus affect any organ system. The incidence of diagnosis has significantly increased due to increasing awareness.

OBJECTIVE

In the abdomen the hepatopancreaticobiliary system provides an essential organ system for the expression of IgG4-associated autoimmune diseases. The focus here is autoimmune pancreatitis type 1 but IgG4-associated sclerosing cholangitis and IgG4-associated hepatopathy, which can also occur in combination are less well-known.

METHODS

Various mostly Asiatic, histologically-based diagnostic systems, such as HISORt or international consensus diagnostic criteria (ICDC) are available for the diagnostics of hepatopancreaticobiliary IgG4-related autoimmune diseases, in which imaging techniques playing an increasingly important role.

RESULTS

In addition to generalized organ swelling further morphological and also functional imaging criteria have become increasingly well-known for autoimmune pancreatitis, such as late enhancement or the imaging response to steroid therapy. Magnetic resonance cholangiopancreatography (MRCP) and endoscopic retrograde cholangiopancreatography (ERP) can provide valuable information for the diagnostics of IgG4-related diseases in the hepatopancreaticobiliary system.

CONCLUSION

IgG4-related autoimmune diseases of the hepatopancreaticobiliary system are a rare group of diseases in which increasing knowledge of the radiological appearance also leads to an increasingly frequency of diagnosis. IgG4-related diseases must be distinguished from non-necrotizing pancreatitis and pancreatic cancer, which is often difficult but has significant therapeutic consequences for the patients.