The pattern of chronic hepatitis C ( CHC ) treatment can be started with pegylated interferon ( PEG-GAMMA GLUTAMYLTRANSFERASE IMPACT IN THERAPEUTIC RESPONSE OF CHRONIC HEPATITIS C : a systematic review of the literature

Background The standard treatment of chronic hepatitis C is the administration of pegylated interferon α2a or α2b in combination with ribavirin, but adverse effects can be observed, as well as the high cost of this therapy. Therefore, there is interest in understanding the predictors of sustained virologic response, as the gamma glutamyltransferase. Objective To evaluate the serum levels of gamma glutamyltransferase as a predictor of response to treatment with pegylated interferon α and ribavirin in chronic hepatitis C. Methods This is a systematic review of literature, conducted by consulting PUBMED, LILACS, MEDLINE, SCOPUS, Cochrane electronic databases, and active search of articles selected between January 2000 and April 2013. Results A total of 4,785 titles were iden tified. Out of those material, following inclusion and exclusion criteria, 273 abstracts were selected, by two independent researchers. After reading those texts, the reviewers consensually included ten studies for systematization and classification, according to the criteria of the Oxford Scale. 1B studies are predominant (prospective cohort study six studies). Rapid virologic response and early virological response were considered as estimates for the sustained virological response. The frequency of virologic response was identified in three studies and early virological response in two, with a total of 392 and 413 patients, respectively; sustained virologic response was reported in nine articles corresponding to 3,787 patients (76.5 %). Conclusion Gamma glutamyltransferase is a predictor of sustained virologic response in the treatment of chronic hepatitis C with pegylated interferon α2a or α2b associated with ribavirin. HEADINGS Gamma glutamyltransferase. Hepatitis C. Sustained virological response. Review. Declared conflict of interest of all authors: none Disclosure of funding: no funding received 1 Programa de Pós-Graduação em Medicina e Saúde, Faculdade de Medicina, Universidade Federal da Bahia, Salvador, BA; 2 Centro de Ciências Biológicas e da Saúde, Unidade Acadêmica de Ciências Médicas, Curso de Medicina, Universidade Federal de Campina Grande, PB; 3 Universidade Federal da Paraíba, João Pessoa, PB. Brasil. Correspondence: Maria de Lourdes Albuquerque de Queiroga. Rua General Newton Estilac Leal, 503. Alto Branco CEP: 58401-750 Campina Grande, PB, Brasil. E-mail: qalb@uol.com. br IFN) α2a or α2b associated with ribavirin (RBV) for genotype 1, 4-6 for 48 weeks, but for genotypes 2 and 3 for 24 weeks(9, 23). The treatment of CHC is costly, and may have side effects. In addition, some factors contribute to the limited rate of sustained virologic response (SVR) of 50 % to 60 % as occurs in genotypes 1 and 4. Thus, before starting the treatment of CHC it is important to assess the predictive of therapeutic response to define who should be treated and when this treatment will be over(8). There are several therapeutic response predictor factors in CHC, such as age at infection, gender, heDOI: 10.1590/S0004-28032015000300016 Queiroga MLA, Paraná R, Medeiros Filho JEM, Figueiredo GCA, Araújo AP, Leite HWS, Aquino IS, Melo Neto LHA. Gamma glutamyltransferase impact in therapeutic response of chronic hepatitis C: a systematic review of the literature 240 Arq Gastroenterol v. 52 no. 3 jul./set. 2015 patic fibrosis, genotype, viral load, virologic response, and gamma glutamyltransferase (GGT) levels(8). It is important to highlight other predictors of therapeutic response: serum vitamin D(14, 25); and CC (rs 12979860) Interleukin 28B genotype(1, 22, 27). The GGT enzyme catalyzes the degradation of extracellular glutathione (GSH) in the transfer of amino acids and peptides across cell membranes(15, 19), forming a “gamma-glutamyl cycle”(30). GGT is located in hepatocytes, kidney, biliary tract, intestines, heart, spleen, pancreas, and brain(22). However, it may be elevated in liver dysfunction, cholestasis, use of hepatotoxic drugs, as a marker of alcohol intake in pancreatitis, and association with coronary heart diseases risk(3, 19, 30). Despite many studies, there are no conclusive data on the prediction of therapeutic response of GGT. Therefore, there is interest in understanding the predictive factors of SVR and GGT. Therefore, the aim of this systematic review (SR)(5, 17, 18) was to evaluate the serum levels of GGT as a predictor of treatment response in CHC.