title: Impact of menstruation on select hematology and clinical chemistry variables in cynomolgus macaques.
abstract: BACKGROUND
  In preclinical studies with cynomolgus macaques, it is common to have one or more females presenting with menses. Published literature indicates that the blood lost during menses causes decreases in red blood cell mass variables (RBC, HGB, and HCT), which would be a confounding factor in the interpretation of drug-related effects on clinical pathology data, but no scientific data have been published to support this claim.
  
  
  OBJECTIVE
  This investigation was conducted to determine if the amount of blood lost during menses in cynomolgus macaques has an effect on routine hematology and serum chemistry variables.
  
  
  METHODS
  Ten female cynomolgus macaques (Macaca fascicularis), 5 to 6.5 years old, were observed daily during approximately 3 months (97 days) for the presence of menses. Hematology and serum chemistry variables were evaluated twice weekly.
  
  
  RESULTS
  The results indicated that menstruation affects the erythrogram including RBC, HGB, HCT, MCHC, MCV, reticulocyte count, RDW, the leukogram including neutrophil, lymphocyte, and monocyte counts, and chemistry variables, including GGT activity, and the concentrations of total proteins, albumin, globulins, and calcium. The magnitude of the effect of menstruation on susceptible variables is dependent on the duration of the menstrual phase. Macaques with menstrual phases lasting ≥ 7 days are more likely to develop changes in variables related to chronic blood loss.
  
  
  CONCLUSIONS
  In preclinical toxicology studies with cynomolgus macaques, interpretation of changes in several commonly evaluated hematology and serum chemistry variables requires adequate clinical observation and documentation concerning presence and duration of menses. There is a concern that macaques with long menstrual cycles can develop iron deficiency anemia due to chronic menstrual blood loss.
authors.affiliation: Department of Pathology, Drug Safety Evaluation, Research & Development, Bristol-Myers Squibb Company, New Brunswick, NJ, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Perigard
authors.affiliation: Department of Pathology, Drug Safety Evaluation, Research & Development, Bristol-Myers Squibb Company, New Brunswick, NJ, USA.
authors.forename: M Cecilia M
authors.initials: MC
authors.lastname: Parrula
authors.affiliation: Department of Pathology, Drug Safety Evaluation, Research & Development, Bristol-Myers Squibb Company, New Brunswick, NJ, USA.
authors.forename: Matthew H
authors.initials: MH
authors.lastname: Larkin
authors.affiliation: Global Biometric Sciences, Nonclinical Biostatistics, Research & Development, Bristol-Myers Squibb Company, Princeton, NJ, USA.
authors.forename: Carol R
authors.initials: CR
authors.lastname: Gleason
mesh_terms: D000818:Animals; D002623:Chemistry Techniques, Analytical / Q000662:veterinary*; D005260:Female; D006403:Hematologic Tests / Q000662:veterinary*; D008252:Macaca fascicularis; D008598:Menstruation; D012016:Reference Values; D015203:Reproducibility of Results
keywords: Bleeding; nonhuman primates; preclinical; red blood cell mass; total protein