ESTABLISHMENT OF REFERENCE INTERVAL FOR SYMMETRIC DIMETHYLARGININE IN HAMADRYAS BABOONS (PAPIO HAMADRYAS)

Symmetric dimethylarginine (SDMA) has expedited the diagnosis of kidney disease in small animal practice and has become the gold standard for diagnosis and screening. SDMA could be a useful screening tool for kidney dysfunction in nonhuman primates under human care, allowing for earlier intervention if indicated. These results could also help stage kidney disease in nonhuman primates when coupled with other diagnostics, to assist with quality-of-life decision-making. This study evaluated 55 serum samples from two different zoologic institutions to establish an SDMA reference interval for healthy hamadryas baboons (Papio hamdryas), by using the published American Society for Veterinary Clinical Pathology reference interval guidelines. Samples from each animal were submitted to IDEXX Laboratories, Inc. and analyzed via a high-throughput immunoassay called the IDEXX SDMA test. Once analyzed, one value was omitted as an outlier. For clinically healthy baboons, the SDMA reference interval ranges from 4 to 11 µg/dl. The average value for the entire population is 7.7 µg/dl, with a SD of 1.9 µg/dl, a 90% lower confidence interval of 3-5 µg/dl, and a 90% upper confidence interval of 11-12 µg/dl. There is no significant difference between males and females. The hamadryas baboon reference interval indicated that values exceeding 11 µg/dl should be considered possibly elevated and warrant further investigation of kidney function in that animal. Furthermore, determination of species-specific reference interval is critical for correct interpretation of SDMA data.