1. pregnancy and breastfeeding 2. history of g6pdh deficiency 3. preadmission anticoagulation 4. severe renal insufficiency (glomerular filtration rate \<30 ml/min/1.73m2) 5. medical records of cirrhosis 6. active chronic hepatitis 7. severe hepatic disease defined by got or gpt levels three times above the normal upper limit 8. patients with history of allergic reaction or significant sensitivity to methylene blue 9. treatment with immunosuppressive agents 10. use of other investigational drugs in the moment of inclusion

1. pregnancy and breastfeeding 2. history of g6pdh deficiency 3. preadmission anticoagulation 4. severe renal insufficiency (glomerular filtration rate \<30 ml/min/1.73m2) 5. medical records of cirrhosis 6. active chronic hepatitis 7. severe hepatic disease defined by got or gpt levels three times above the normal upper limit 8. patients with history of allergic reaction or significant sensitivity to methylene blue 9. treatment with immunosuppressive agents 10. use of other investigational drugs in the moment of inclusion

pregnancy and breastfeeding history of g6pdh deficiency preadmission anticoagulation severe renal insufficiency (glomerular filtration rate <30 ml/min/1.73m2) medical records of cirrhosis active chronic hepatitis severe hepatic disease defined by got or gpt levels three times above the normal upper limit patients with history of allergic reaction or significant sensitivity to methylene blue treatment with immunosuppressive agents use of other investigational drugs in the moment of inclusion

pregnancy and breastfeeding history of g6pdh deficiency preadmission anticoagulation severe renal insufficiency (glomerular filtration rate <30 ml/min/1.73m2) medical records of cirrhosis active chronic hepatitis severe hepatic disease defined by got or gpt levels three times above the normal upper limit patients with history of allergic reaction or significant sensitivity to methylene blue treatment with immunosuppressive agents use of other investigational drugs in the moment of inclusion

1. pregnancy and breastfeeding 2. history of g6pdh deficiency 3. preadmission anticoagulation 4. severe renal insufficiency (glomerular filtration rate <30 ml/min/1.73m2) 5. medical records of cirrhosis 6. active chronic hepatitis 7. severe hepatic disease defined by got or gpt levels three times above the normal upper limit 8. patients with history of allergic reaction or significant sensitivity to methylene blue 9. treatment with immunosuppressive agents 10. use of other investigational drugs in the moment of inclusion

1. pregnancy and breastfeeding 2. history of g6pdh deficiency 3. preadmission anticoagulation 4. severe renal insufficiency (glomerular filtration rate <30 ml/min/1.73m2) 5. medical records of cirrhosis 6. active chronic hepatitis 7. severe hepatic disease defined by got or gpt levels three times above the normal upper limit 8. patients with history of allergic reaction or significant sensitivity to methylene blue 9. treatment with immunosuppressive agents 10. use of other investigational drugs in the moment of inclusion