Amyloidosis of the gastrointestinal tract and the liver: clinical context, diagnosis and management

Abstract

Amyloidosis is a group of disorders that can manifest in virtually any organ system in the body and is thought to be secondary to misfolding of extracellular proteins with subsequent deposition in tissues. The precursor protein that is produced in excess defines the specific amyloid type. This requires histopathological confirmation using Congo red dye with its characteristic demonstration of green birefringence under cross-polarized light. Gastrointestinal (GI) manifestations are common and the degree of organ involvement dictates the symptoms that a patient will experience. The small intestine usually has the most amyloid deposition within the GI tract. Patients generally have nonspecific findings such as abdominal pain, nausea, diarrhea, and dysphagia that can often delay the proper diagnosis. Liver involvement is seen in a majority of patients, although symptoms typically are not appreciated unless there is significant hepatic amyloid deposition. Pancreatic involvement is usually from local amyloid deposition that can lead to type 2 diabetes mellitus. In addition, patients may undergo either endoscopic or radiological evaluation; however, these findings are usually nonspecific. Management of GI amyloidosis primarily aims to treat the underlying amyloid type with supportive measures to alleviate specific GI symptoms. Liver transplant is found to have positive outcomes, especially in patients with specific variants of hereditary amyloidosis.

Gastrointestinal Amyloidosis: Review of the Literature

“…Any site can be affected, but the small bowel is most commonly affected [28]. Endoscopic appearance may be highly variable and there have been disputing reports of the correlation between the type of amyloidosis and endoscopic findings.…”

Isolated Ileal Stricture Secondary to Antigen-Negative GI Histoplasmosis in a Patient on Immunosuppressive Therapy

“…GI histoplasmosis should be considered in both immunocompromised and immunocompetent hosts who have persistent fever, hepatosplenomegaly, GI complaints, and weight loss 1,3,15. Serum and urine antigen detection tests are not 100% sensitive, and further workup should be performed if clinical suspicion remains high, considering the mortality of untreated disseminated histoplasmosis can be as high as 80%.…”

Immunohistochemical Typing of Gastrointestinal Amyloid Deposits Using an Expanded Panel of Antibodies Directed Against Al-Kappa Amyloidosis

“…Воз-можно поражение почек, сердца, печени, нерв-ной системы, желудочно-кишечного тракта. Од-ной из распространенных форм является гастро-интестинальный амилоидоз, который может клинически проявляться болями в животе, тош-нотой, запорами, диареей, снижением веса [3][4][5]. Около 60 лет назад биопсия прямой кишки была введена в диагностический алгоритм для выявле-ния амилоидоза [6].…”