Other examples of this include porcine Hp reflecting more closely the extent of lung damage in respiratory diseases than CRP (C-reactive protein) [25], pigMAP (pig major acute phase protein) that was reported not to react to infection with PRRSV (porcine respiratory and reproductive syndrome virus) in naturally infected pigs [18], and increased Hp being associated with lesions due to enzootic pneumonia caused by Mycoplasma hyosynoviae but not with lesions due to pleuritis (caused by Actinobacillus pleuropneumoniae) at slaughter [16]. Here, HP is linked to respiratory system disorder.