Identification of serum proteomic biomarkers for early porcine reproductive and respiratory syndrome (PRRS) infection

Background: porcine reproductive and respiratory syndrome (prrs) is one of the most significant swine diseases worldwide. despite its relevance,serum biomarkers associated with early-onset viral infection,when clinical signs are not detectable and the disease is characterized by a weak anti-viral response and persistent infection,have not yet been identified. surface-enhanced laser desorption ionization time of flight mass spectrometry (seldi-tof ms) is a reproducible,accurate,and simple method for the identification of biomarker proteins related to disease in serum. this work describes the seldi-tof ms analyses of sera of 60 prrsv-positive and 60 prrsv-negative,as measured by pcr,asymptomatic large white piglets at weaning. sera with comparable and low content of hemoglobin (< 4.52 μg/ml) were fractionated in 6 different fractions by anion-exchange chromatography and protein profiles in the mass range 1-200 kda were obtained with the cm10,imac30,and h50 surfaces.results: a total of 200 significant peaks (p < 0.05) were identified in the initial discovery phase of the study and 47 of them were confirmed in the validation phase. the majority of peaks (42) were up-regulated in prrsv-positive piglets,while 5 were down-regulated. a panel of 14 discriminatory peaks identified in fraction 1 (ph = 9),on the surface cm10,and acquired at low focus mass provided a serum protein profile diagnostic pattern that enabled to discriminate between prrsv-positive and -negative piglets with a sensitivity and specificity of 77% and 73%,respectively.conclusions: seldi-tof ms profiling of sera from prrsv-positive and prrsv-negative asymptomatic piglets provided a proteomic signature with large scale diagnostic potential for early identification of prrsv infection in weaning piglets. furthermore,seldi-tof protein markers represent a refined phenotype of prrsv infection that might be useful for whole genome association studies. © 2012 genini et al.; licensee biomed central ltd.