Gastrointestinal Issues Prominent Among Patients With Hereditary ATTRv Amyloidosis

A stark 82% of assessed patients with hereditary transthyretin (ATTRv) amyloidosis exhibited gastrointestinal (GI) symptoms, warranting the need for gastroenterologists in the multidisciplinary management of the disease, according to study findings published in the Journal of Gastrointestinal and Liver Diseases.

As the researchers highlight, hereditary ATTRv amyloidosis represents a diagnostic challenge to clinicians due to the great variability in clinical presentation and multiorgan involvement. Although patients typically present with polyneuropathy, frequent issues in cardiac, ocular, and GI impairment have additionally been reported, with rates varying by geographic region.

In endemic areas, indicating that GI manifestation is prominent, patients are more likely to present with early-onset hereditary ATTRv amyloidosis and deteriorate quickly. In contrast, those in nonendemic areas are more likely to present with late-onset disease, with a slower progression of polyneuropathy.

Seeking to examine the prevalence of GI involvement in patients with hereditary ATTRv amyloidosis within a nonendemic area, the researchers retrospectively analyzed a cohort of 39 patients with the disease (mean age at onset, 63.1 years; 29 males) from the Neurology Unit of Fondazione Policlinico Universitario A. Gemelli IRCCS in Rome, Italy. Each participant presented with a documented mutation in the gene encoding the transthyretin and were systematically examined for neurological, cardiological, and GI manifestations at every monitoring visit.

“The reported GI symptoms included the following items: early satiety, nausea, vomiting, diarrhea, constipation, alternating diarrhea/constipation, fecal incontinence, abdominal pain, abdominal bloating, and unintentional weight loss,” noted the researchers.

In the patient cohort, neuropathy was observed in 92.3% (N = 36) of patients, of which half (n = 18) were in stage I of the disease, one-third (n = 12) were in stage II, and 16.6% (n = 6) were in stage III.

Among the patient cohort, 32 (82%) experienced at least 1 GI symptom, which the researchers highlight is higher than the prevalence of hereditary ATTRv amyloidosis (59%) reported in the largest analysis based on data from the THAOS registry.

Unintentional weight loss was indicated as the most frequently reported symptom (46.2%), followed by diarrhea (35.9%), abdominal bloating (28.2%), alternating diarrhea/constipation (25.6%), early satiety (23.1%), and constipation (20.5%). GI symptoms of nausea, vomiting, fecal incontinence, and abdominal pain were not as frequently reported. Moreover, there was no significant difference in overall GI symptom prevalence based on gender (80.0% of women vs 82.8% of men).

Based on the mutation of the disease, GI symptoms were usually present in those with the Val30Met mutation (93.8%), and in 66.7% of patients with the Phe64Leu mutation (66.7%). Comparably, all cases with a non-Val30Met mutation disclosed most GI symptoms within 5 years of disease onset, while patients with a Val30Met mutation continued to develop GI manifestations during the disease course.

“Better knowledge of GI manifestations of hereditary ATTRv amyloidosis and of their pathogenesis can provide novel targets for a more effective supportive treatment of these symptoms,” concluded the study authors.

Reference

Luigetti M, Tortora A, Romano A, et al. Gastrointestinal manifestations in hereditary transthyretin amyloidosis: a single-centre experience. J Gastrointestin Liver Dis. 2020;29(3):339-343. doi:10.15403/jgld-2474