Table 1.

Studies with neutrophil to lymphocyte ratio as a dependent variable in nonhuman primates.

Citation	Species	Age	Sex	Findings
[17]	Macaca fascicularis	3–4 years	5 males	Increased NLR (as well as cortisol) following 15 h of air and truck transport from China to Korea. Returned to baseline 1 week after arrival.
[18]	Macaca mulatta	3–4 years	10 females	Increased NLR (as well as cortisol) following chair-restraint training. Returned to baseline after 3 weeks.
[19]	Macaca mulatta	mean age = 1.9 years	27 males	Higher NLR following relocation to a new housing area. Higher NLR in monkeys with a short-version serotonin allele (higher emotionality monkeys) compared to a long-version allele (normal emotionality monkeys).
[14]	Pan troglodytes	3–31 years	19 males, 20 females = 30	Higher NLR with higher BMI and older age.
[11]	Pan troglodytes	2–58 years	185 males, 225 females = 410	Longitudinal data: no change within individuals over a 10-year timespan.
				Cross-sectional data: NLR highest in middle-aged individuals. Higher NLR in males and mother-reared individuals.
				Mortality data: individuals with higher NLRs died at younger ages.
[15]	Macaca mulatta	88–134 days	2071 males, 2506 females = 4557	Lower NLRs in indoor-reared, SPF, and male individuals.
				Lower NLR was associated with higher stress values, emotionality, later risk for airway hyperresponsiveness, and diarrhea.
[12]	Papio anubis	0–19 years	159 males, 228 females = 387	Higher NLR in females, mother-reared individuals, and young adult individuals.
				NLR was higher during pregnancy and following transport to a new facility.
				Transport stress NLR was heritable, while routine NLR was not heritable.
Current study	Papio anubis	0–21 years	284 females, 233 males = 517	Longitudinal data: no significant change within individuals in NLR over a 5-year timespan. However, females, juveniles, and young adults show an increase in NLR over time.
				Cross-sectional data: significant positive correlation between sedation order and NLR. Baboons with higher sedation rates per month exhibited lower NLRs.