Successful treatment of protein-losing enteropathy due to AA amyloidosis with octreotide in a patient with rheumatoid arthritis

Gastrointestinal (GI) Amyloidosis Presenting As Chronic Diarrhea: A Diagnostic Dilemma

This case report describes a 63-year-old male patient with a four-year history of chronic diarrhea. Extensive diagnostic investigations failed to reveal a cause. Subsequent upper and lower gastrointestinal (GI) endoscopic procedures revealed the presence of amyloidosis in the GI tract. The patient was referred for further evaluation, but unfortunately, he presented with hypotension and shock, and ultimately succumbed to systemic amyloidosis involving multiple organs. GI amyloidosis, although rare, should be considered in patients presenting with chronic diarrhea, unexplained weight loss, or GI bleeding. Early recognition and appropriate management are crucial for optimizing patient outcomes. Healthcare providers should maintain a high index of suspicion for GI amyloidosis to ensure timely intervention and improve patient care.

Gastrointestinal amyloidosis: A focused review

Amyloidosis, a heterogenous group of disorders, is characterized by the extracellular deposition of autologous, insoluble, fibrillar misfolded proteins. These extracellular proteins deposit in tissues aggregated in ß-pleated sheets arranged in an antiparallel fashion and cause distortion to the tissue architecture and function. In the current literature, about 60 heterogeneous amyloidogenic proteins have been identified, out of which 27 have been associated with human disease. Classified as a rare disease, amyloidosis is known to have a wide range of possible etiologies and clinical manifestations. The exact incidence and prevalence of the disease is currently unknown. In both systemic and localized amyloidosis, there is infiltration of the abnormal proteins in the layers of the gastrointestinal (GI) tract or the liver parenchyma. The gold standard test for establishing a diagnosis is tissue biopsy followed by Congo Red staining and apple-green birefringence of the Congo Red-stained deposits under polarized light. However, not all patients may have a positive tissue confirmation of the disease. In these cases additional workup and referral to a gastroenterologist may be warranted. Along with symptomatic management, the treatment for GI amyloidosis consists of observation or localized surgical excision in patients with localized disease, and treatment of the underlying pathology in cases of systemic amyloidosis. In this review of the literature, we describe the subtypes of amyloidosis, with a primary focus on the epidemiology, pathogenesis, clinical features, diagnosis and treatment strategies available for GI amyloidosis.

Gastrointestinal manifestations of amyloidosis

Amyloidosis is a group of diseases which are caused by the extracellular deposition of amyloid fibrils, which have a beta lamella structure and are positive for Congo red staining. The diagnosis of amyloidosis still relies on histology. Brick red coloration in Congo red staining of biopsy tissue and apple green double refraction under a polarizing microscope are diagnostic features of amyloidosis. Patients with systemic amyloidosis often exhibit gastrointestinal symptoms, which have complicated patterns of manifestations, including giant tongue, dysphagia, constipation, diarrhea, abdominal pain, bleeding, malabsorption, and different levels of gastrointestinal bleeding. Clinical symptoms of amyloidosis are atypical and easy to be misdiagnosed, which often causes delayed treatment. In this review, we will briefly introduce the clinical and endoscopic features of gastrointestinal manifestations of amyloidosis as well as its treatment.

Gastrointestinal and Hepatic Disease in Rheumatoid Arthritis

Gastrointestinal (GI) manifestations of rheumatoid arthritis (RA) are rare, but can be impactful for patients. Some GI processes are directly related to RA, whereas others may be sequelae of treatment or caused by concomitant autoimmune diseases. This article discusses the role of the GI tract in RA pathogenesis; the presentation, epidemiology, and diagnosis of RA-related GI manifestations; concomitant GI autoimmune diseases that may affect those with RA; and GI side effects of RA treatment. The importance of appropriately considering conditions unrelated to RA in the differential diagnosis when evaluating new GI symptoms in patients with RA is noted.

Gastrointestinal Amyloidosis: Review of the Literature

Gastrointestinal amyloidosis (GIA), a protein deposition disorder, represents a complex common pathway that encompasses multiple etiologies and presentations. It represents a significant diagnostic and treatment challenge. The disease results from the deposition of insoluble extracellular protein fragments that have been rendered resistant to digestion. GIA can be acquired or genetic, and most commonly results from chronic inflammatory disorders (AA amyloidosis), hematologic malignancy (AL amyloidosis), and end-stage renal disease (Beta-2 amyloidosis). The deposition of these abnormal proteins interferes with gastrointestinal tract (GI) organ structure and function, most notably in the liver and small bowel. Presentation from GI involvement includes cirrhotic sequelae, abdominal pain, malabsorption, and GI bleeding. Diagnosis hinges on pathologic examination of affected tissue, with classic green birefringence under polarized light. Abdominal fat pad and rectal mucosal biopsy have been described as sites of higher sensitivity for diagnosis. Serum amyloid P scintigraphy is near 90% sensitive for diagnosis of AA amyloidosis. Patients should be considered for further evaluation to rule out additional organ involvement, notably cardiac and renal. Treatment hinges on an adequate suppression of the predisposing inflammatory disorder, or malignancy, followed by supportive therapy. Prognosis varies depending on the etiology of the disease, with the AL subtype showing worse outcomes, as well as those with hepatic involvement. 

Marginal Zone Lymphoma Complicated by Protein Losing Enteropathy

Protein losing enteropathy (PLE) refers to excessive intestinal protein loss, resulting in hypoalbuminemia. Underlying pathologies include conditions leading to either reduced intestinal barrier or lymphatic congestion. We describe the case of a patient with long-lasting diffuse abdominal problems and PLE. Repetitive endoscopies were normal with only minimal lymphangiectasia in biopsies. Further evaluations revealed an indolent marginal zone lymphoma with minor bone marrow infiltration. Monotherapy with rituximab decreased bone marrow infiltration of the lymphoma but did not relieve PLE. Additional treatments with steroids, octreotide, a diet devoid of long-chain fatty-acids, and parenteral nutrition did not prevent further clinical deterioration with marked weight loss (23 kg), further reduction in albumin concentrations (nadir 8 g/L), and a pronounced drop in performance status. Finally, immunochemotherapy with rituximab and bendamustine resulted in hematological remission and remarkable clinical improvement. 18 months after therapy the patient remains free of gastrointestinal complaints and has regained his body weight with normal albumin levels. We demonstrate a case of PLE secondary to indolent marginal zone lymphoma. No intestinal pathologies were detected, contrasting a severe and almost lethal clinical course. Immunochemotherapy relieved lymphoma and PLE, suggesting that a high suspicion of lymphoma is warranted in otherwise unexplained cases of PLE.

Small bowel amyloidosis

Amyloidosis often involves the gastrointestinal tract. The small intestine is the most commonly involved gastrointestinal site. Gastrointestinal manifestations of amyloidosis involvement of the small intestine include diarrhea, gastrointestinal bleeding, and obstruction. High index of suspicion leading to early diagnosis is important in tailoring appropriate therapeutic management of these patients.

Role of Janus kinase 3 in mucosal differentiation and predisposition to colitis

Janus kinase 3 (Jak3) is a nonreceptor tyrosine kinase expressed in both hematopoietic and nonhematopoietic cells. Previously, we characterized the functions of Jak3 in cytoskeletal remodeling, epithelial wound healing, and mucosal homeostasis. However, the role of Jak3 in mucosal differentiation and inflammatory bowel disease was not known. In this report, we characterize the role of Jak3 in mucosal differentiation, basal colonic inflammation, and predisposition toward colitis. Using the Jak3 knock-out (KO) mouse model, we show that Jak3 is expressed in colonic mucosa of mice, and the loss of mucosal expression of Jak3 resulted in reduced expression of differentiation markers for the cells of both enterocytic and secretory lineages. Jak3 KO mice showed reduced expression of colonic villin, carbonic anhydrase, secretory mucin muc2, and increased basal colonic inflammation reflected by increased levels of pro-inflammatory cytokines IL-6 and IL-17A in colon along with increased colonic myeloperoxidase activity. The inflammations in KO mice were associated with shortening of colon length, reduced cecum length, decreased crypt heights, and increased severity toward dextran sulfate sodium-induced colitis. In differentiated human colonic epithelial cells, Jak3 redistributed to basolateral surfaces and interacted with adherens junction (AJ) protein β-catenin. Jak3 expression in these cells was essential for AJ localization of β-catenin and maintenance of epithelial barrier functions. Collectively, these results demonstrate the essential role of Jak3 in the colon where it facilitated mucosal differentiation by promoting the expression of differentiation markers and enhanced colonic barrier functions through AJ localization of β-catenin.