Detection of systemic amyloidosis in the pig-tailed macaque (Macaca nemestrina)
Renee R Hukkanen1, H Denny Liggitt, David M Anderson
1Department of Comparative Medicine, University of Washington School of Medicine, Seattle, USA. rgamboa@u.washington.edu
Abstract:
Secondary amyloidosis is a progressive systemic disease for which there is no reliable diagnostic assay, preventive measure, or treatment. In an attempt to elucidate an antemortem diagnosis, 30 female pig-tailed macaques (Macaca nemestrina) at the Washington National Primate Research Center were surveyed for amyloidosis. Amyloid was demonstrated histologically in 47% (14 of 30) of the animals. The distribution and severity of amyloid deposition was variable. Affected animals had a mean age (+/-1 standard deviation) of 13.2 +/- 4.9 y, which was significantly greater than the mean age of unaffected animals (9.3 +/- 4.1) y. Twelve tests were evaluated for detection of amyloidosis; the diagnostic value of each was determined through comparison of histologically positive and histologically negative animals. Diagnostic tests evaluated were endoscopic examination and biopsy of the stomach and colon, abdominal ultrasonography, hepatic radiology, serum amyloid A (SAA), endothelin 1, alpha-fetal protein, aspartate aminotransferase (AST), alanine aminotransferase, gamma-glutamyltransferase (GGT), alkaline phosphatase, cholesterol, blood urea nitrogen, total bilirubin, C-reactive proteins, and erythrocyte sedimentation rate. Amyloidotic animals demonstrated a distinctive serologic profile: elevated SAA, GGT, and AST in combination with decreased total protein and albumin. Radiology demonstrated hepatomegaly in animals with hepatic amyloid deposition. In the absence of known infection or trauma, an amyloidotic serologic profile and radiologic hepatomegaly are consistent with systemic amyloidosis in M. nemestrina.
Insights
Secondary amyloidosis diagnosis in macaques is challenging. This study identified a distinct serologic profile (elevated SAA, GGT, AST) and radiologic findings (hepatomegaly) for antemortem diagnosis in Macaca nemestrina.
Area of Science:
- Veterinary Pathology
- Primate Medicine
- Diagnostic Imaging
Background:
- Secondary amyloidosis is a progressive systemic disease lacking reliable diagnostic, preventive, or treatment options.
- Antemortem diagnosis of amyloidosis in non-human primates is crucial for research and welfare.
- Macaca nemestrina (pig-tailed macaques) are susceptible to systemic diseases, making them a relevant model.
Purpose of the Study:
- To investigate the prevalence of amyloidosis in pig-tailed macaques.
- To evaluate diagnostic tests for antemortem detection of amyloidosis.
- To identify a diagnostic profile for systemic amyloidosis in Macaca nemestrina.
Main Methods:
- Histological examination of 30 female pig-tailed macaques to determine amyloidosis prevalence.
- Evaluation of twelve diagnostic tests including endoscopic biopsy, ultrasonography, radiology, and various serum biomarkers.
- Comparison of test results between histologically confirmed amyloidotic and non-amyloidotic animals.
Main Results:
- Amyloidosis was histologically confirmed in 47% of the macaques, with higher prevalence in older animals (mean age 13.2 years).
- A distinctive serologic profile for amyloidotic macaques included elevated serum amyloid A (SAA), gamma-glutamyltransferase (GGT), and aspartate aminotransferase (AST), with decreased total protein and albumin.
- Radiology revealed hepatomegaly in animals with hepatic amyloid deposition.
Conclusions:
- A combination of specific serologic markers (SAA, GGT, AST) and radiologic findings (hepatomegaly) can aid in the antemortem diagnosis of systemic amyloidosis in Macaca nemestrina.
- Older pig-tailed macaques are at higher risk for developing amyloidosis.
- Further research is warranted to develop targeted treatments and preventive strategies for secondary amyloidosis in non-human primates.
