Background: Hepatitis B virus (HBV) and Hepatitis C virus (HCV) represents two of the major health problem worldwide. Only few studies investigate by MALDI-TOF MS the presence of specific peptides/proteins that can be considered predictive indicators for HBV infection. In this study, we used MALDI-TOF MS to examine serum samples aiming at searching peptides/proteins that can be used as serological biomarkers to detect HBV and HCV. Materials/methods: Fifty-six serum samples, received for diagnostic purposes with suspected HBV and/or HCV infection, previously analyzed with the diagnostic assays currently used in our laboratory and resulted positive or negative for HBsAg or HCVcoreAg, were examined by MALDI-TOF MS. Results: In the first step, 3 different protein extraction approaches were evaluated to obtain valid, reliable and reproducible results. The protocol adopted involved ultracentrifugation of serum samples with water. The analysis performed at low molecular weight showed the presence of unique peaks for each class of sera (HBV-positive, HCV-positive or both negative), while the analysis carried out at high molecular weight showed the absence of significantly discriminating peaks. In particular, the detection of HBV-positive sera is associated with 8 discriminating peaks; similarly, detection of HCV-positive sera is associated with 8 discriminating peaks. Noteworthy the trend of the intensity of 3 peaks (3224, 6632, 7478 Da) showed a significantincrease or decrease depending on the virus responsible for the infection. However, it was not possible to identify the protein/ peptide matching to the markers found. The second step involved the creation of statistical models able to differentiate the three different categories of serum analyzed on the basis of these peaks. In particular, using this model it was correctly classified all 56 sera. Conclusions: Our results demonstrated, on a limited number of sera with high concentration of specific antigen, the presence of peaks differentiating classes of positive sera, for both HCV, for the first time to our knowledge, and HBV, as already reported by other Authors. This could be a starting point to add MALDI-TOF MS as a tool for the diagnosis of such infections, being independent of antigen mutations that could affect the conventional assays.
MALDI-TOF MS as new tool for the identification of serological biomarkers for diagnosis of hepatitis B and C viruses infections / Calderaro, A.; Buttrini, M.; Montecchini, S.; Ferraglia, F.; Pinardi, F.; Montagna, P.; Arcangeletti, M. C.; De Conto, F.; Chezzi, C. - (2020). (Intervento presentato al convegno XXX European Congress of Clinical Microbiology and Infectious Diseases (ECCMID)).
MALDI-TOF MS as new tool for the identification of serological biomarkers for diagnosis of hepatitis B and C viruses infections
Calderaro A.;Buttrini M.;Montecchini S.;Ferraglia F.;Pinardi F.;Arcangeletti M. C.;De Conto F.;Chezzi C
2020-01-01
Abstract
Background: Hepatitis B virus (HBV) and Hepatitis C virus (HCV) represents two of the major health problem worldwide. Only few studies investigate by MALDI-TOF MS the presence of specific peptides/proteins that can be considered predictive indicators for HBV infection. In this study, we used MALDI-TOF MS to examine serum samples aiming at searching peptides/proteins that can be used as serological biomarkers to detect HBV and HCV. Materials/methods: Fifty-six serum samples, received for diagnostic purposes with suspected HBV and/or HCV infection, previously analyzed with the diagnostic assays currently used in our laboratory and resulted positive or negative for HBsAg or HCVcoreAg, were examined by MALDI-TOF MS. Results: In the first step, 3 different protein extraction approaches were evaluated to obtain valid, reliable and reproducible results. The protocol adopted involved ultracentrifugation of serum samples with water. The analysis performed at low molecular weight showed the presence of unique peaks for each class of sera (HBV-positive, HCV-positive or both negative), while the analysis carried out at high molecular weight showed the absence of significantly discriminating peaks. In particular, the detection of HBV-positive sera is associated with 8 discriminating peaks; similarly, detection of HCV-positive sera is associated with 8 discriminating peaks. Noteworthy the trend of the intensity of 3 peaks (3224, 6632, 7478 Da) showed a significantincrease or decrease depending on the virus responsible for the infection. However, it was not possible to identify the protein/ peptide matching to the markers found. The second step involved the creation of statistical models able to differentiate the three different categories of serum analyzed on the basis of these peaks. In particular, using this model it was correctly classified all 56 sera. Conclusions: Our results demonstrated, on a limited number of sera with high concentration of specific antigen, the presence of peaks differentiating classes of positive sera, for both HCV, for the first time to our knowledge, and HBV, as already reported by other Authors. This could be a starting point to add MALDI-TOF MS as a tool for the diagnosis of such infections, being independent of antigen mutations that could affect the conventional assays.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
