| 1. |
- Ihse, Elisabet, et al.
(author)
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Amyloid fibrils containing fragmented ATTR may be the standard fibril composition in ATTR amyloidosis
- 2013
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In: Amyloid. - : Informa UK Limited. - 1350-6129 .- 1744-2818. ; 20:3, s. 142-150
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Journal article (peer-reviewed)abstract
- The clinical phenotype of familial ATTR amyloidosis depends to some extent on the particular mutation, but differences exist also within mutations. We have previously described that two types of amyloid fibril compositions exist among Swedish ATTRV30M amyloidosis patients, one consisting of a mixture of intact and fragmented ATTR (type A) and one consisting of mainly intact ATTR (type B). The fibril types are correlated to phenotypic differences. Patients with ATTR fragments have a late onset and develop cardiomyopathy, while patients without fragments have an early onset and less myocardial involvement. The present study aimed to determine whether this correlation between fibril type and phenotype is valid for familial ATTR amyloidosis in general. Cardiac or adipose tissues from 63 patients carrying 29 different TTR non-V30M mutations as well as 13 Japanese ATTRV30M patients were examined. Fibril type was determined by western blotting and compared to the patients' age of onset and degree of cardiomyopathy. All ATTR non-V30M patients had a fibril composition with ATTR fragments, except two ATTRY114C patients. No clear conclusions could be drawn about a phenotype to fibril type correlation among ATTR non-V30M patients. In contrast, Japanese ATTRV30M patients showed a similar correlation as previously described for Swedish ATTRV30M patients. This study shows that a fibril composition with fragmented ATTR is very common in ATTR amyloidosis, and suggests that fibrils composed of only full-length ATTR is an exception found only in a subset of patients.
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| 2. |
- Ihse, Elisabet, 1977-, et al.
(author)
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Amyloid fibrils with fragmented ATTR may be the rule in non-Val30Met ATTR amyloidosis
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Other publication (other academic/artistic)abstract
- The clinical phenotype of familial ATTR amyloidosis depends to some extent on the particular mutation, but differences exist also within mutations. We have previously described that two types of amyloid fibril compositions exist among Swedish ATTRV30M amyloidosis patients, one consisting of a mixture of intact and fragmented ATTR (type A) and one composed of only intact ATTR (type B). Patients with type A fibrils have a late age of onset and signs of cardiomyopathy, while patients with type B fibrils have an early onset and much less myocardial involvement. The present study aimed to determine if the correlation between fibril type and clinical phenotype is true for familial amyloidosis in general. Cardiac and/or adipose tissue from 48 patients carrying 21 different non-TTRV30M mutations were examined, as well as 7 non-Swedish ATTRV30M patients. Fibril type was determined with western blotting and compared to the patients´ age of onset and degree of cardiomyopathy. Non-Swedish V30M patients showed the same correlation as described for Swedish V30M patients, with fibrils of only full-length ATTR (type B) linked to less myocardial involvement. In contrast, all patients with non-V30M mutations had a fibril composition with ATTR fragments (type A). Some of these patients had onset of disease at young age. The vast majority had increased thickness of left cardiac ventricle, but a few individuals had values within normal limits. This study shows that a fibril composition with fragmented ATTR is very common in ATTR amyloidosis. It also suggests that fibrils composed of only full-length ATTR is an exception, perhaps only found among young ATTRV30M amyloidosis patients.
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