Biomarkers of infectious pneumonia in naturally infected calves

OBJECTIVETo investigate the clinical value of selected biomarkers for evaluation of systemic inflammatory response and pulmonary inflammation and damage pattern in calves with different pneumonia forms. ANIMALS16 calves with fibrinous pneumonia (FP group; infected with Mannheimia haemolytica or Pasteurella multocida), 12 calves with caseonecrotic pneumonia (CNP group; infected with Mycoplasma bovis), and 10 healthy calves (C group) based on results of bronchoalveolar lavage fluid (BALF) examination. PROCEDURESBlood and BALF samples were collected. Annexin-A2 (Anx-A2), endothelin-1 (ET-1), calgranulin B (S100A9), transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α), interleukin-17A (IL-17A), haptoglobin (Hp), lipopolysaccharide-binding protein (LBP), and albumin (Alb) concentrations and lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) activities were measured and compared across groups. RESULTSSerum concentrations of Anx-A2, S100A9, TGF-β1, TNF-α, IL-17A, Hp, and LBP and activities of LDH and ALP were higher and Alb concentrations were lower for the pneumonia groups versus C group. BALF concentration ratios of S100A9:Alb, LBP:Alb, LDH:Alb, and ALP:Alb were higher for the pneumonia groups versus C group (P < .05). BALF concentration ratios of Anx-A2:Alb, TGF-β1:Alb, and IL-17A:Alb were higher for the FP group versus other groups (P < .05). CLINICAL RELEVANCEResults indicated that serum Anx-A2, S100A9, TGF-β1, TNF-α, IL-17A, Hp, LBP, and Alb concentrations were useful in determining the systemic inflammatory response and that BALF concentration ratios of S100A9:Alb, TGF-β1:Alb, LBP:Alb, and ALP:Alb were useful biomarkers in determining pulmonary inflammation and damage. Measurements of BALF concentration ratios of Anx-A2:Alb, TGF-β1:Alb, and IL-17A:Alb could be beneficial to defining fibrinous characterization of pulmonary inflammation.