Effects on lung compliance, lung volume, and single-breath transfer factor for carbon monoxide in sheep with lentivirus-induced lymphoid interstitial pneumonia

Abstract

SUMMARY Static lung compliance, static lung volumes, and transfer factor for carbon monoxide were measured in 12 anesthetized adult Texel ewes seropositive for maedi-visna virus (MVV) and in 11 breed-, sex-, and age-matched seronegative controls. Median static lung compliance in MVV-infected sheep (1.24 L⋅kPa−1; range, 0.27 to 2.20 L⋅kPa−1) was not significantly different from that in controls (1.58 L⋅kPa−1 range, 0.82 to 2.08 L⋅kPa−1). Median body weight of MVV-infected sheep (56 kg; range, 40 to 75 kg) was significantly (P < 0.05) less than that of controls (65 kg; range, 53 to 87 kg). Median effective alveolar lung volume in MVV-infected sheep (3.36 L; range, 1.44 to 4.52 L) was significantly (P < 0.01) less than that in controls (4.12 L; range, 3.75 to 4.90 L). Median effective end expiratory lung volume in MVV-infected sheep (1.20 L; range, 0.56 to 1.99 L) was significantly (P < 0.001) less than that of controls (1.98 L; range: 1.76 to 2.78 L). Median lung volumes expressed per unit of body weight did not differ significantly between the groups. Median single-breath transfer factor for carbon monoxide in MVV-infected sheep (7.89 mmol⋅min−1⋅kPa−1; range, 3.45 to 12.74 mmol⋅min−1⋅kPa−1) was significantly (P < 0.001) less than that in controls (14.10 mmol⋅min−1⋅kPa−1; range, 10.02 to 18.30 mmol⋅min−1⋅kPa−1). Median transfer factor expressed per liter of alveolar volume in MVV-infected sheep (2.44 mmol⋅min−1⋅kPa−1⋅L−1; range, 1.28 to 3.72 mmol⋅min−1⋅kPa−1⋅L−1) was significantly (P < 0.05) less than that in controls (3.22 mmol⋅min−1⋅kPa−1⋅L−l; range, 2.47 to 3.74 mmol⋅min−1⋅kPa−1⋅L−1). These findings indicate that static lung volumes and transfer factor for carbon monoxide are significantly decreased in adult sheep naturally infected with MVV.