title: Hematological changes as prognostic indicators of survival: similarities between Gottingen minipigs, humans, and other large animal models.
abstract: BACKGROUND
  The animal efficacy rule addressing development of drugs for selected disease categories has pointed out the need to develop alternative large animal models. Based on this rule, the pathophysiology of the disease in the animal model must be well characterized and must reflect that in humans. So far, manifestations of the acute radiation syndrome (ARS) have been extensively studied only in two large animal models, the non-human primate (NHP) and the canine. We are evaluating the suitability of the minipig as an additional large animal model for development of radiation countermeasures. We have previously shown that the Gottingen minipig manifests hematopoietic ARS phases and symptoms similar to those observed in canines, NHPs, and humans.
  
  
  RESULTS
  We establish here the LD50/30 dose (radiation dose at which 50% of the animals succumb within 30 days), and show that at this dose the time of nadir and the duration of cytopenia resemble those observed for NHP and canines, and mimic closely the kinetics of blood cell depletion and recovery in human patients with reversible hematopoietic damage (H3 category, METREPOL approach). No signs of GI damage in terms of diarrhea or shortening of villi were observed at doses up to 1.9 Gy. Platelet counts at days 10 and 14, number of days to reach critical platelet values, duration of thrombocytopenia, neutrophil stress response at 3 hours and count at 14 days, and CRP-to-platelet ratio were correlated with survival. The ratios between neutrophils, lymphocytes and platelets were significantly correlated with exposure to irradiation at different time intervals.
  
  
  CONCLUSIONS
  As a non-rodent animal model, the minipig offers a useful alternative to NHP and canines, with attractive features including ARS resembling human ARS, cost, and regulatory acceptability. Use of the minipig may allow accelerated development of radiation countermeasures.
authors.affiliation: Radiation Countermeasures Program, Scientific Research Department, Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America. moroni@afrri.usuhs.mil
authors.forename: Maria
authors.initials: M
authors.lastname: Moroni
authors.forename: Eric
authors.initials: E
authors.lastname: Lombardini
authors.forename: Rudolph
authors.initials: R
authors.lastname: Salber
authors.forename: Mehdi
authors.initials: M
authors.lastname: Kazemzedeh
authors.forename: Vitaly
authors.initials: V
authors.lastname: Nagy
authors.forename: Cara
authors.initials: C
authors.lastname: Olsen
authors.forename: Mark H
authors.initials: MH
authors.lastname: Whitnall
mesh_terms: D054508:Acute Radiation Syndrome / Q000097:blood* / Q000175:diagnosis*; D000818:Animals; D001772:Blood Cell Count; D001792:Blood Platelets / Q000528:radiation effects; D002097:C-Reactive Protein / Q000096:biosynthesis; D004285:Dogs; D006801:Humans; D008214:Lymphocytes / Q000528:radiation effects; D008297:Male; D023421:Models, Animal; D009504:Neutrophils / Q000528:radiation effects; D011323:Primates / Q000502:physiology; D011379:Prognosis; D011874:Radiometry / Q000379:methods; D013552:Swine; D013556:Swine, Miniature / Q000502:physiology*
chemical_list: D002097:C-Reactive Protein