[Proteomics, a new tool for an accurate typing of amyloidosis]

Descriptive study of the clinical and myocardial status of a population with anatomopathological aortic valve amyloidosis

BACKGROUND

Aortic stenosis (AS) and transthyretin (ATTR) cardiac amyloidosis (CA) share the same clinical profiles and cardiac phenotype. Amyloid deposits have been frequently reported in aortic valves of patients with severe AS referred for surgical aortic valve replacement (SAVR). The aim of this study was to determine the clinical and myocardial status of patients with aortic valve amyloidosis after aortic valve surgery.

METHODS AND RESULTS

We performed a retrospective descriptive study of 46 patients who underwent SAVR for severe AS with amyloid deposits upon histological analysis. All patients were screened for cardiac involvement. Amyloid deposits typing was successful in 35 (76%) patients and 28 (80%) were ATTR. Two (4%) had positive bone scintigraphy and among the 5 myocardial biopsies performed during surgery, 80% were positive for ATTR deposits.

CONCLUSION

ATTR is the predominant type in the presence of amyloid deposits on the aortic valve after surgery for severe AS but is only rarely accompanied by cardiac uptake on bone scintigraphy. Early stages of myocardial involvement are frequent and myocardial biopsy is more sensitive for detection of mild amyloid deposits than bone scintigraphy.

Clinicopathological Features of Amyloid Neuropathy: A Four Decade Experience

BACKGROUND

Peripheral neuropathy is one of the manifestations of primary or familial amyloidosis. Published studies from India are limited.

MATERIALS AND METHODS

We reviewed the clinical and pathological features of amyloid neuropathy diagnosed at our Institute over the last 39 years.

RESULTS

Fifty-five cases of amyloid neuropathies were diagnosed between 1981 and 2019, constituting 0.28% of peripheral nerve biopsies (55/19,081). Age at presentation ranged from 24 to 81 years (mean-48 years) with male preponderance [M:F = 3.58:1]. Duration of symptoms at presentation varied from 3 months to 10 years (mean-2.31 years). Majority presented with small fiber neuropathy (85%). Pure sensory symptoms predominated in 23%, while 72% had sensorimotor neuropathy and 35.8% had autonomic involvement, with isolated autonomic failure in one patient. Amyloid neuropathy was clinically suspected in 22.6% of nonfamilial cases. Familial amyloid neuropathy was suspected in eight patients. Genetic testing detected ATTR and gelsolin mutation in one each of tested patients. Nerve biopsies revealed characteristic birefringent amyloid deposits stained mahogany brown by Congo red predominantly surrounding endoneurial microvessels (34.5%), also in perineurium and epineurium in 25.45% cases. Preferential loss of small diameter myelinated fibers was noted. Axonal degeneration or regeneration was conspicuously absent.

CONCLUSION

Amyloid neuropathy is uncommon (0.28% of nerve biopsies in our series). Nerve biopsy is essential for the diagnosis. We report our experience of amyloid neuropathy and underscore the importance of making an assiduous search for amyloid deposits in the appropriate setting. Awareness of this entity is important for early diagnosis in the light of emerging therapeutic advances.