Granulomatous liver diseases

A granuloma is a discrete collection of activated macrophages and other inflammatory cells. Hepatic granulomas can be a manifestation of localized liver disease or be a part of a systemic process, usually infectious or autoimmune. A liver biopsy is required for the detection and evaluation of granulomatous liver diseases. The prevalence of granulomas on liver biopsy varies from 1% to 15%. They may be an incidental finding in an asymptomatic individual, or they may represent granulomatous hepatitis with potential to progress to liver failure, or in chronic disease, to cirrhosis. This review focuses on pathogenesis, histological features of granulomatous liver diseases, and most common etiologies, knowledge that is essential for timely diagnosis and intervention.

Rheumatologic Diseases and the Liver

A variety of rheumatologic disorders may affect the liver. There is a significant epidemiologic, genetic, and immunologic overlap between immune-mediated rheumatologic disorders and autoimmune liver diseases. There is an increased frequency of autoimmune liver diseases, such as primary biliary cholangitis, autoimmune hepatitis, primary sclerosing cholangitis, or overlap syndrome, in patients with systemic lupus erythematosus, rheumatoid arthritis, Sjögren syndrome, systemic sclerosis, vasculitis, and other immune-related diseases. Non-immune-mediated rheumatologic diseases such as gouty arthritis may also have hepatic manifestations. Furthermore, medications used to treat rheumatologic diseases occasionally cause liver dysfunction. Conversely, primary immune-mediated and non-immune-mediated liver disorders may present with rheumatologic manifestations.

Gastrointestinal and Hepatic Disease in Vasculitis

Vasculitis is an inflammatory condition that targets the blood vessels, which may occur in isolation or as a component of a systemic inflammatory condition. Although many of the vasculitides can directly affect the organs of the gastrointestinal system, some types exhibit a proclivity for certain gastrointestinal and hepatic organs. Often a patient presents with nonspecific symptoms, delaying the diagnosis and treatment of the underlying vasculitis. Vasculitis can also present with severe manifestations, such as upper gastrointestinal bleeds and bowel perforation. It is important to identify the signs and symptoms of vasculitis in gastrointestinal system and institute appropriate treatment.

Gastrointestinal aspects of vasculitides

Systemic vasculitides are caused by inflammation of blood vessels and can affect any organ and any part of the gastrointestinal tract, hepatic and biliary system, as well as the pancreas. These disorders can cause a wide array of gastrointestinal manifestations, from asymptomatic elevated transaminase levels and mild abdominal pain to potentially life-threatening bowel perforations and peritonitis. A diagnosis based solely on gastrointestinal symptoms is challenging as these manifestations are not specific. Conversely, diagnostic and therapeutic delays can be rapidly detrimental. In this article, we review the epidemiology, characteristics and management of the main gastrointestinal manifestations of systemic vasculitides, including polyarteritis nodosa and antineutrophil cytoplasm antibody-associated vasculitides, as well as isolated vasculitides limited to the gastrointestinal tract.

Gut and Liver in Vasculitic Disorders

BACKGROUND

Although the gastrointestinal (GI) tract including its related organs is not generally regarded as one of the primary organ systems of primary and secondary vasculitic disorders, there are numerous mechanisms of these diseases operative in or around the different structures and compartments of the GI tract.

KEY MESSAGES

A majority of the respective clinical symptoms and problems are linked to an alteration of (peri)vascular homeostasis. Alteration of perivascular matrix metabolism can also affect the functional integrity and motility of the GI tract. Apart from the specific GI phenomena of the individual diseases as outlined in detail in this review, the epidemiology of GI involvement follows in general the characteristics of the respective underlying systemic disease. In addition, gender and age do neither influence the occurrence nor the severity of the GI manifestations significantly. With respect to clinical symptoms, vasculitides may result in abdominal pain, bleeding, ileus, intestinal necrosis and hematochezia because of reduced blood flow and hyper-acute occlusion in the antiphospholipid syndrome. Small-bowel involvement in vasculitic entities can cause pseudoobstruction, obstruction, malabsorption and bacterial overgrowth. Laboratory parameters can point to specific diseases but are frequently nonspecific. Thus, if biopsy fails or in unclear endoscopic situations, a variety of imaging techniques including Doppler ultrasound, abdominal CT, MRI and angiography are used and required for identification and localization of the underlying disease. Therapeutic strategies in vasculitides usually include corticosteroids and immunosuppressants, for example, cyclophosphamide in granulomatosis with polyangiitis and in panarteriitis nodosa but also biologics such as rituximab in ANCA-associated vasculitides. Virostatic drugs including interferon-α and ribavirin can be used in hepatitis B- and C-triggered vasculitides such as panarteriitis nodosa and hepatitis C-associated cryoglobulinemia.

CONCLUSIONS

Immediate diagnostic and therapeutic steps of action need to be performed if vasculitis of the GI tract is suspected in order to avoid irreversible damage to organs and to improve the well-being and life of the affected patient.