OBJECTIVES: Suppressor of cytokine signaling 3, myxovirus resistance protein and osteopontin gene polymorphisms may influence the therapeutic response in patients with chronic hepatitis C, and an association with IL28 might increase the power to predict sustained virologic response. Our aims were to evaluate the association between myxovirus resistance protein, osteopontin and suppressor of cytokine signaling 3 gene polymorphisms in combination with IL28B and to assess the therapy response in hepatitis C patients treated with pegylated-interferon plus ribavirin. METHOD: Myxovirus resistance protein, osteopontin, suppressor of cytokine signaling 3 and IL28B polymorphisms were analyzed by PCR-restriction fragment length polymorphism, direct sequencing and real-time PCR. Ancestry was determined using genetic markers. RESULTS: We analyzed 181 individuals, including 52 who were sustained virologic responders. The protective genotype frequencies among the sustained virologic response group were as follows: the G/G suppressor of cytokine signaling 3 (rs4969170) (62.2%); T/T osteopontin (rs2853744) (60%); T/T osteopontin (rs11730582) (64.3%); and the G/T myxovirus resistance protein (rs2071430) genotype (54%). The patients who had ≥3 of the protective genotypes from the myxovirus resistance protein, the suppressor of cytokine signaling 3 and osteopontin had a greater than 90% probability of achieving a sustained response (p<0.0001). The C/C IL28B genotype was present in 58.8% of the subjects in this group. The sustained virological response rates increased to 85.7% and 91.7% by analyzing C/C IL28B with the T/T osteopontin genotype at rs11730582 and the G/G suppressor of cytokine signaling 3 genotype, respectively. Genetic ancestry analysis revealed an admixed population. CONCLUSION: Hepatitis C genotype 1 patients who were responders to interferon-based therapy had a high frequency of multiple protective polymorphisms in the myxovirus resistance protein, osteopontin and suppressor of cytokine signaling 3 genes. The combined analysis of the suppressor of cytokine signaling 3 and IL28B genotypes more effectively predicted sustained virologic response than IL28B analysis alone.

RACIONAL: Estudos em cinética viral na hepatite C demonstraram que há uma queda dos níveis séricos de interferon 48 h após a sua administração, quando a carga viral do vírus C volta a se elevar. Antes da disponibilidade do interferon peguilado, diversos ensaios clínicos investigaram a terapia de indução com interferon standard OBJETIVOS: Avaliar a segurança e eficácia do esquema de indução diário com interferon alfa associado à ribavirina. PACIENTES E MÉTODOS: Noventa e três pacientes com hepatite crônica C foram incluídos. Através de randomização, foram alocados em um de dois braços terapêuticos: 44 indivíduos no grupo A: IFN 3MU três vezes por semana + ribavirina 1,0-1,2 g diariamente por 48 semanas e 49 indivíduos no grupo B: IFN 3MU diariamente por 12 semanas, seguindo-se por IFN 3MU três vezes por semana até completar 48 semanas + ribavirina 1,0-1,2 g diariamente por 48 semanas. A genotipagem do vírus C foi realizada em 85 indivíduos. Considerou-se resposta virológica sustentada a persistência do HCV-RNA negativo 6 meses após o término da terapia RESULTADOS: Oitenta e três pacientes completaram o tratamento. Houve cinco abandonos (um do grupo A e quatro do grupo B) e em cinco pacientes a terapia foi retirada devido a efeitos adversos (dois do grupo A e três do grupo B). Não houve diferença estatisticamente significante entre os grupos quanto à interrupção do tratamento. A freqüência de cirrose foi 29%, semelhante entre os grupos. Na análise "intention to treat" a resposta virológica sustentada foi 39,8%. Não houve diferença estatística na taxa de resposta virológica sustentada entre ambas as estratégias terapêuticas (36,4% grupo A vs 42,9% grupo B). Nos 83 pacientes que finalizaram o estudo, a resposta virológica sustentada foi 44,6%. Entre os pacientes com genótipo 1, a resposta virológica sustentada foi 42% (40,9% grupo A vs 42,9% grupo B) e entre os pacientes com genótipo 2/3, a resposta virológica sustentada foi 55,6% (50% grupo A vs 63,6% grupo B) CONCLUSÕES: A taxa de resposta virológica sustentada foi 39,8% para a terapia combinada (análise "intention to treat"). Não houve diferença entre as taxas de RVS do grupo de indução comparado ao regime padrão. Efeitos adversos, mesmo mais freqüentes no grupo de indução, não interferiram nas estratégias terapêuticas.

BACKGROUD: Studies on hepatitis C virus kinetics showed that serum levels of interferon fall 48 h after drug administration, when viral load is increasing again. Previously to the availability of pegylated interferon, daily induction therapy with standard interferon was under evaluation. AIMS: To evaluate the safety and efficacy of interferon alpha daily induction regimen in combination with ribavirin. PATIENTS AND METHODS: A randomized trial including 93 patients with chronic hepatitis C was carried out. On satisfying all eligibility criteria, patients were randomly allocated to two different treatment groups: 44 individuals in treatment arm A: IFN 3 MU thrice weekly + ribavirin 1.0-1.2 g daily for 48 weeks (IFN TIW) and 49 individuals in treatment arm B: IFN 3 MU daily + ribavirin 1.0-1.2 g daily for 12 weeks followed by IFN 3 MU thrice weekly + ribavirin 1.0-1.2 g daily, until completion of 48 weeks of therapy (IFN QD). HCV genotyping was obtained in 85 subjects. A negative HCV-RNA 6 months after cessation of therapy was considered a sustained virological response RESULTS: Eighty three patients completed treatment, five dropped out (one from IFN TIW and four from IFN QD) and in five patients therapy was discontinued due to medical request (two from IFN TIW and three from IFN QD). There was no statistically significant difference between groups with respect to therapy interruption. The frequency of cirrhosis was 29%, similar in both groups. In the "intention to treat" analysis the overall sustained virological response was 39.8%. There was no significant difference in sustained virological response rate between both treatment strategies (36.4% IFN TIW vs 42.9% IFN QD). In the 83 patients who finished the trial, sustained virological response was 44.6%. Among subjects with HCV genotype-1, the sustained virological response was 42% (40.9% IFN TIW vs 42.9% IFN QD) and among patients with HCV genotype 2 or 3, the sustained virological response was 55.6% (50% IFN TIW vs 63.6% IFN QD) CONCLUSIONS: Combination therapy had an overall sustained virological response rate of 39.8% ("intention to treat analysis"). There was no difference with respect to sustained virological response rates between patients who used daily induction schedule compared to standard regimen. Adverse events, even more frequent in the daily induction group, did not interfere with the treatment strategies.