Hepatitis C virus infection diagnosis using metabonomics M. M. G. Godoy, 1 E. P. A. Lopes, 1 R. O. Silva, 2 F. Hallwass, 2 L. C. A. Koury, 1 I. M. Moura, 1 S. M. C. Gonc ¸alves 2 and A. M. Simas 2 1 Departamento de Medicina Clı ´nica, Hospital das Clı ´nicas, Centro de Cie ˆncias da Sau ´de, Universidade Federal de Pernambuco, Recife, PE, Brazil; and 2 Departamento de Quı ´mica Fundamental, Centro de Cie ˆncias Exatas e da Natureza, Universidade Federal de Pernambuco, Recife, PE, Brazil Received August 2009; accepted for publication October 2009 SUMMARY. Metabonomics based on nuclear magnetic reso- nance (NMR) can reveal the profile of endogenous metabo- lites of low molecular weight in biofluids related to disease. The profile is identified a Ômetabolic fingerprintÕ like from the pathological process, why this metabonomics has been used as a diagnostic method. The aim of the present study was to apply metabonomics to identify patients infected with the hepatitis C virus (HCV) through an analysis of 1 H NMR spectra of urine samples associated with multivariate sta- tistical methods. A pilot study was carried out for the diag- nostic test evaluation, involving two groups: (i) 34 patients positive for anti-HCV and HCV-RNA and negative for anti-HBc (disease group); and (ii) 32 individuals positive for anti-HBc and negative for HBsAg and anti-HCV. The urine samples were analyzed through 1 H NMR, applying principal component analysis and discriminant analysis for classifi- cation. The metabonomics model was capable of identifying 32 of the 34 patients in the disease group as positive and 31 of the 32 individuals in the control group as negative, demonstrating 94% sensitivity and specificity of 97% as well as positive and negative predictive values of 97% and 94%, respectively, and 95% accuracy (P < 0.001). In conclusion, the metabonomics model based on 1 H NMR spectra of urine samples in this preliminary study discriminated patients with HCV infection with high sensitivity and specificity, thereby demonstrating this model to be a potential tool for use in medical practice in the near future. Keywords: 1 H NMR, HCV, hepatitis C, metabonomics, spectroscopy. INTRODUCTION Hepatitis C virus (HCV) infection is a public health problem in both developed as well as developing countries [1]. Recent data indicate that HCV accounts for 70% of cases of chronic hepatitis and 30% of liver transplants performed in the developed countries [2,3]. In the majority of situations, it is difficult to establish the natural history of HCV infection because of its silent onset and its course with few symptoms. After contamination, some patients progress toward a cure of the virus, but most often, the infection evolves toward chronicity, with persis- tence of the antibody (anti-HCV) and viremia (HCV-RNA) [4–8]. Routinely used tests for both the screening and diagnostic confirmation of HCV infection are divided into two groups: enzyme immunoassay (EIA) for the detection of anti-HCV and molecular tests for the identification of HCV-RNA. The study of anti-HCV with third-generation EIA offers high sensitivity and specificity, achieving a correct diagnosis in approximately 97% of cases. The detection of HCV-RNA, which reflects the infection in course, is routinely performed using polymerase chain reaction (PCR) [9–12]. In practice, both the study of anti-HCV and HCV-RNA are carried out with blood samples, which requires the puncturing of a peripheral vein. Furthermore, the more prolonged time for PCR, the higher the potential risk of contamination and the high cost of the procedure limit its application in daily practice [13]. Thus, a simpler, faster, more inexpensive test would be important for identifying and screening patients infected with HCV. In recent years, there has been increasing interest in metabonomics technology, which offers the capability of associating changes in the profile of metabolites in a given organic biofluid with environmental, pathological or toxi- cological aggression [14–17]. Nuclear magnetic resonance Abbreviations: ALT, alanine aminotransferase; AST, aspartate aminotransferase; DA, discriminant analysis; EIA, enzyme immunoassay; GGT, gamma-glutamyl transferase; HCV, hepatitis C virus; MNV, maximal normality value; NMR, nuclear magnetic resonance; PCA, principal components analysis; PCR, polymerase chain reaction; PLS, partial least squares; SIMCA, simple classification analysis. Correspondence: Michele Maria Gonc ¸alves de Godoy, Hospital das Clı ´nicas, Bloco A, Departamento de Medicina Clı ´nica, Av. Prof. Moraes Rego, s/n, Recife, PE, 50670-901, Brazil. E-mail: michelegodoy@oi.com.br Journal of Viral Hepatitis, 2010, 17, 854–858 doi:10.1111/j.1365-2893.2009.01252.x Ó 2010 Blackwell Publishing Ltd