Liver and Gastrointestinal Involvement

Amyloidosis and Amyloidogenesis: One Name, Many Diseases

Amyloidosis is a heterogenous group of disorders, caused by the deposition of insoluble fibrils derived from misfolded proteins in the extracellular space of various organs. These proteins have an unstable structure that causes them to misfold, aggregate, and deposit as amyloid fibrils with the pathognomonic histologic property of green birefringence when viewed under cross-polarized light after staining with Congo red. Amyloid fibrils are insoluble and degradation-resistant; resistance to catabolism results in progressive tissue amyloid accumulation. The outcome of this process is organ disfunction independently from the type of deposited protein, however there can be organ that are specifically targeted from certain proteins.

Gastroduodenal Involvement in AL Amyloidosis: Case Report and Literature Review

Gastrointestinal amyloidosis is a rare condition commonly found in the setting of systemic AL amyloidosis. Amyloid can deposit throughout the gastrointestinal tract and the resulting symptoms vary depending on the site of deposition. Gastrointestinal (GI) manifestations can range from weight loss or abdominal pain, to more serious complications like gastrointestinal bleeding, malabsorption, dysmotility, and obstruction. This case describes a patient with known history of IgG lambda AL amyloidosis, presenting with epigastric pain and unintentional weight loss found to have gastroduodenal amyloidosis. The definitive diagnosis of GI amyloidosis requires endoscopic biopsy with Congo red staining and visualization under polarized light microscopy. There are currently no specific guidelines for the management of GI amyloidosis. Generally, the goal is to treat the underlying cause of the amyloidosis along with symptom management. Our patient is being treated with cyclophosphamide, bortezomib, and dexamethasone (CyBorD) and started on hemodialysis due to progression of renal disease.

Implications of Extra-cardiac Disease in Patient Selection for Heart Transplantation: Considerations in Cardiac Amyloidosis

Disease-modifying therapies in both light chain and transthyretin amyloidosis have improved patient functional status and survival. Conceivably, as heart failure may progress despite amyloid therapies, more patients may be considered for heart transplantation. In earlier eras, extra-cardiac amyloid deposits significantly reduced post-heart transplant patient survival and functional status compared to the non-amyloid population. In the modern era, transplant centres have reported improved outcomes in amyloidosis as patient selection has grown more stringent. Importantly, systematic candidate evaluation should assess the degree of extra-cardiac involvement, the effectiveness of disease-modifying therapies and downstream effects on patients' nutrition and frailty. This review outlines such an overall approach while also considering that organ-specific selection criteria may vary between individual transplant centres. A methodical approach to patient evaluation will promote better understanding of the prevalence and severity of extra-cardiac disease in amyloidosis patients referred for heart transplantation and of any disparities in decision outcomes in this population.

Supportive Care and Symptom Management for Patients With Immunoglobulin Light Chain (AL) Amyloidosis

Immunoglobulin light chain (AL) amyloidosis is a disorder of clonal plasma cells characterized by deposition of amyloid fibrils in a variety of tissues, leading to end-organ injury. Renal or cardiac involvement is most common, though any organ outside the central nervous system can develop amyloid deposition, and symptomatic presentations may consequently vary. The variability and subtlety of initial clinical presentations may contribute to delayed diagnoses, and organ involvement is often quite advanced and symptomatic by the time a diagnosis is established. Additionally, while organ function can improve with plasma-cell-directed therapy, such improvement lags behind hematologic response. Consequently, highly effective supportive care, including symptom management, is essential to improve quality of life and to maximize both tolerance of therapy and likelihood of survival. Considering the systemic nature of the disease, close collaboration between clinicians is essential for effective management.

Prevalence and determinants of iron deficiency in cardiac amyloidosis

Aims

Iron deficiency (ID) is common in patient with chronic heart failure (HF) and has been widely studied. In contrast, data concerning ID in cardiac amyloidosis (CA) are limited. Amyloidosis is a severe and fatal systemic disease, characterized by an accumulation of amyloid fibrils in various tissues/organs, including nerves, kidneys, gastrointestinal tract, and heart. Amyloid deposits in the heart eventually cause HF. The main subtypes of CA are light chain (AL), hereditary transthyretin (ATTRv), and wild‐type transthyretin (ATTRwt). We performed this study to determine the prevalence, clinical outcome (all‐cause mortality), and determinants of ID among the three main subtypes of CA.

Methods and results

Iron deficiency status were analysed in 816 CA patients enrolled at the French Referral Centre for Cardiac Amyloidosis: 271 (33%) had AL, 164 (20%) ATTRv, and 381 (47%) ATTRwt. ID affected 49% of CA patients, 45% with AL, 58% with ATTRv, and 48% with ATTRwt. We identified ATTR status (ATTRv P = 0.003, ATTRwt P = 0.037), diabetes (P = 0.003), aspirin treatment (P = 0.009), haemoglobin levels (P = 0.006), and altered global longitudinal strain (P = 0.02) as independent ID determinants. There is no difference in all‐cause mortality considering ID status.

Conclusions

Iron deficiency is common in patients with CA, irrespective of the subtype. Patients seem more likely to have ID if diagnosed with ATTR, if diabetic, and/or treated with aspirin. In CA, the benefit of intravenous iron therapy, for ID, on morbidity and mortality needs further study.