1418 AJVR, Vol 73, No. 9, September 2012 I t is well-known that perinatal infections and PAS are the major causes of morbidity among equine neo- nates. An in-depth understanding of the pathophysiol- ogy of these diseases could help generate new diagnos- tic and prognostic tools that would have a major impact on equine medicine. Cytokines are endogenous inflammatory mediators and integral components of the adaptive and innate im- mune responses. They may be classified as proinflam- matory (eg, IFN-γ, TNF, IL-1, IL-2, IL-6, and IL-8) or anti-inflammatory (eg, IL-4, IL-5, IL-10, IL-11, IL-13, and TGF-β). The balance between pro- and anti-inflam- matory cytokines is critical to allow the reestablishment of homeostasis after an inflammatory insult. Proinflam- Expression of interleukin-1β, interleukin-8, and interferon-γ in blood samples obtained from healthy and sick neonatal foals Carolina Castagnetti, DVM, PhD; Jole Mariella, DVM, PhD; Alessandro Pirrone, DVM, PhD; Stefano Cinotti, DVM; Gaetano Mari, DVM; Angelo Peli, DVM, PhD Objective—To evaluate and compare the gene expression of interleukin(IL)-1β, IL-8, and interferon-γ during the first 72 hours after birth in healthy foals and during the first 72 hours after hospitalization in sick neonatal foals and investigate correlations of clinicopathologic variables with cytokine expressions in healthy and sick neonatal foals. Animals—33 foals < 7 days old (10 healthy foals, 7 foals with sepsis, 6 foals with peripar- tum asphyxia syndrome, and 12 foals with other diseases [2 with failure of passive transfer of immunity only were not further evaluated]). Procedures—A blood sample (15 mL) was collected from each foal immediately after birth or hospital admission (0 hours) and at 24 and 72 hours later. Clinicopathologic variables were evaluated, and cytokine gene expression in WBCs was measured with an absolute quantitative real-time reverse transcriptase PCR assay. Results—At all time points, gene expression of interferon-γ was low in all groups. No time- dependent changes in cytokine expressions were detected in healthy or sick foals. Foals with sepsis had significantly higher IL-1β gene expression than did healthy foals, foals with peripartum asphyxia syndrome, or foals with other diseases. At 0 hours, IL-1β expression was correlated with plasma fibrinogen concentration in healthy foals and with the neutro- phil-to-lymphocyte ratio in foals with sepsis; IL-8 expression was correlated with monocyte count in foals with sepsis and with arterial pH, plasma fibrinogen concentration, and plasma lactate concentration in foals with peripartum asphyxia syndrome. Conclusions and Clinical Relevance—Data have suggested that evaluation of IL-1β expression in sick neonatal foals could help identify those with sepsis. (Am J Vet Res 2012;73:1418–1427) matory cytokines mainly have host-protective actions, but accentuation of their normal protective functions may lead to damaging effects on the integrity of the host organism. Ultimately, the deleterious events re- sulting from the derangement of the normal function of the cytokine network may lead to shock, multiorgan failure, and death. 1,2 In adult horses, as in other species, TNF-α is in- volved in early stages of inflammation and is respon- sible for the induction of IL-1. 3 A marked increase in Received November 15, 2010. Accepted July 22, 2011. From the Department of Veterinary Medical Sciences, Faculty of Vet- erinary Medicine, University of Bologna, 40064 Ozzano Emilia, Bo- logna, Italy. Supported by funds of the University of Bologna. Presented in abstract form at the 54th American Association of Equine Practitioners Annual Convention, San Diego, December 2008. Address correspondence to Professor Castagnetti (carolina. castagnetti@unibo.it). ABBREVIATIONS cDNA Complementary DNA FPT Failure of passive transfer of immunity IFN Interferon IL Interleukin MAP Mean arterial blood pressure N:L Neutrophil-to-lymphocyte PAS Peripartum asphyxia syndrome PBMC Peripheral blood mononuclear cell TGF Transforming growth factor TNF Tumor necrosis factor Unauthenticated | Downloaded 10/21/22 03:39 AM UTC