Systemic amyloidosis derived from EFEMP1 in a captive Tsushima leopard cat

Area of Science:

• Veterinary Pathology
• Biochemistry
• Genetics

Background:

• Systemic amyloidosis is uncommon in animals, with amyloid A (AA) type being most prevalent.
• Rare systemic amyloidosis types necessitate further investigation for accurate diagnosis and treatment.

Observation:

• A 15-year-old Tsushima leopard cat presented with systemic amyloidosis.
• Amyloid deposits were identified in arterial walls and interstitial tissues across multiple organs, confirmed by Congo red staining.

Findings:

• Proteomic analysis identified epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1) as the causative protein.
• Immunohistochemistry confirmed EFEMP1 N-terminal region involvement in the amyloid deposits.
• This represents the first documented case of EFEMP1-derived amyloidosis in an animal.

Implications:

• The identified EFEMP1-derived amyloidosis in the cat exhibits unique characteristics compared to human cases, particularly in deposition sites and the affected protein region.
• This suggests divergent pathogenic mechanisms between feline and human EFEMP1-derived amyloidosis.
• Further research is warranted to elucidate the specific pathogenesis in different species.