Apolipoprotein A-IV amyloidosis in a cotton-top tamarin (Saguinus oedipus).

Apolipoprotein A-IV (ApoAIV) amyloidosis is a rare type of systemic amyloidosis characterised by ApoAIV-derived amyloid deposits in the kidney and heart [1,2]. To date, ApoAIV amyloidosis has been reported only in humans and not in animals. In this study, we performed a mass spectrometry-based proteomic analysis on a case of systemic amyloidosis in cotton-top tamarin (Saguinus oedipus) and identified ApoAIV amyloidosis with unique pathological characteristics that differ from humans. A 17-year-old female cotton-top tamarin who died in the Japanese zoo was used for the research. She had a medical history of pulmonary edema, hypothermia, diarrhoea, and loss of energy. Histologically, amyloid deposits in kidneys were severe in the cortical interstitium and glomeruli, but mild in the medulla (Figure 1(a–c)). Severe amyloid deposition was also observed in lamina propria of the intestine (Figure 1(d-f)) and in the space of Disse in the liver (Supplementary Figure 1(m–o)). In the spleen (Figure 1(g-i)),