Evaluation of Systemic Injury in Calves with Rotavirus-Induced Diarrhea Using Sensitive Biomarkers and Immunopathology

Studies in human medicine have demonstrated that rotavirus infection can also affect extraintestinal sites due to its systemic effects. However, in veterinary medicine, the injury caused by rotavirus diarrhea is limited to the intestines, and its effects on various systemic structures remain poorly understood. In this observational case-control study, we aimed to determine the effects of HSP-27, Caspase-3, IL-2, γ-H2AX, HMGB-1, SP-D, and GDH (or GLDH) on the pathogenesis of rotavirus infection by using biomarkers for diagnostic purposes in lung and liver injury in neonate diarrheic calves naturally infected with rotavirus, both alive and post-mortem. Fifty-two Simmental calves (1-28 days old) of both sexes, 40 infected with rotavirus and 12 healthy, were studied. Twenty-eight out of 40 survived, while the remainder underwent necropsy for histopathological and immunopathological (HSP-27, Caspase-3, IL-2, γ-H2AX) examination of the lungs and livers. Lung and liver-specific serum E-selectin, glutamate dehydrogenase, surfactant protein-D, and high mobility group box-1 were analyzed by a bovine-specific ELISA kit (Shanghai Coon Koon Biotech Co., Ltd., China). Histopathological and immunohistochemical analyses confirmed lung and liver injury in naturally infected calves. HMGB-1, SP-D, and GDH concentrations were significantly higher in naturally infected calves than in the control group (<i>p</i> < 0.001, <i>p</i> < 0.001, and <i>p</i> < 0.05, respectively), showing an excellent diagnostic predictive capacity for lung and liver injury. Also, IL-2, HSP-27, CASP-3, and γ-H2AX were significantly expressed in the lungs (<i>p</i> < 0.001, <i>p</i> < 0.001, <i>p</i> < 0.001, and <i>p</i> < 0.05, respectively) and liver (<i>p</i> < 0.001, <i>p</i> < 0.001, <i>p</i> < 0.01, and <i>p</i> < 0.01, respectively). All these observations led us to hypothesize that oxidative stress, apoptosis, and DNA damage may underlie the pathogenesis of this condition. Nevertheless, further studies on large populations of rotavirus-infected calves are needed to confirm the data reported in the current study.