Tratamiento de las hepatitis virales crónicas B y C según la medicina basada en la evidencia
D. Ledro Cano, M. Gómez Parra, M. Jiménez Sáenz, D. Ledro Molina*, J. M. Herrerías Gutiérrez
Servicios de Aparato Digestivo y Medicina Interna A*. Área Hospitalaria Virgen Macarena. Sevilla
RESUMEN
En todo el mundo, la hepatitis viral es la principal causa de ictericia, enfermedad hepática crónica, cirrosis y hepatocarcinoma. Aunque se han realizado importantes avances en el tratamiento y en la prevención, no existe un tratamiento totalmente satisfactorio para cada una de estas dos enfermedades. ]]>
Ambas representan un porcentaje elevado de la etiología de las hepatitis virales y tienen una alta tendencia a la cronicidad y al desarrollo de cirrosis, conllevando gran consumo de recursos sanitarios. Por otra parte los tratamientos son prolongados y con fármacos de precio elevado. Por ello es necesario aplicar la medicina basada en la evidencia en este tipo particular de patología para alcanzar la mejor relación coste/beneficio.
En la presente revisión, analizamos los diferentes fármacos y regímenes de tratamiento empleados en las hepatitis crónicas virales B y C, así como las respuestas obtenidas.
PALABRAS CLAVE: Ensayos controlados aleatorizados. Hepatitis crónica C. Hepatitis crónica B. Tratamiento.
Evidence-based medicine treatment of chronic viral hepatitis B and C
ABSTRACT
Worldwide, viral hepatitis is the most common cause of jaundice, chronic liver disease, cirrhosis and hepatocellular carcinoma. Although mayor advances have been made in the field of treatment and prevention, there is not a totally satisfactory treatment for each of both diseases.
They account for a high percentage of the etiology of viral hepatitis and have a tendency towards chronicity and developing cirrhosis, resulting in a tremendous waste of medical resources. On the other hand, their treatments are long-term ones and the drugs, which are employed, are expensive. Thus, it is necessary to make an evidence-based medicine approach in this particular kind of illness to obtain the best benefit/cost ratio . In this current review, we analyzed the different drugs and therapeutic schedules, which are used in the chronic viral hepatitis B and C, and as well as their obtained response.
]]> KEY WORDS: Randomized controlled trials. Chronic hepatitis C. Chronic hepatitis B. Treatment.Trabajo aceptado: 20 de Diciembre de 1999
Correspondencia: Diego Ledro Cano. Virgen de Luján 45 4ºC - 41011 Sevilla
INTRODUCCIÓN
En todo el mundo, la hepatitis aguda viral es la primera causa de enfermedad hepática aguda y de ictericia. La hepatitis crónica viral es la principal causa de cirrosis hepática y de hepatocarcinoma.
Importantes avances se han producido en el campo de la prevención mediante vacunaciones y medidas de salud publica, sin embargo no existen tratamientos, totalmente satisfactorios para ningún tipo de hepatitis (1).
HEPATITIS CRÓNICA POR VIRUS B
La terapia de la hepatitis crónica por virus B es actualmente no satisfactoria. El único agente que ha demostrado tener un efecto beneficioso duradero es el alfa-interferón (2). La terapia con interferón conduce a una rápida disminución de los niveles séricos de DNA viral e induce una remisión duradera de la enfermedad en una proporción de los pacientes. Múltiples ensayos randomizados y controlados han demostrado que un régimen de 4 a 6 meses de alfa-interferón induce una pérdida del AgHBe y del DNA viral del suero y una remisión de larga duración entre el 25 y el 40% de los pacientes (3-7). Las indicaciones del tratamiento con interferón de la hepatitis crónica B son la elevación persistente de los niveles de las transaminasas, la presencia del AgHBs; AgHBe y del DNA viral en suero, hepatitis crónica, confirmada por histología y la enfermedad hepática compensada. El régimen recomendado es de 5 millones de unidades diarias o 10 millones de unidades, tres veces por semana, subcutánea. Este régimen permite una remisión a largo plazo en el 40% de los pacientes (8). Los pacientes con el mutante AgHBe negativo necesitan regímenes más largos en el tiempo porque de lo contrario, recidivan (9-11). El tratamiento con interleuquina-2 no ha sido efectivo en el tratamiento de la hepatitis crónica B (12). Análisis multivariados retrospectivos han demostrado la existencia de factores predictivos de buena respuesta al tratamiento de la hepatitis crónica B mediante interferón, tales como un alto nivel de transaminasas séricas (13), corta evolución de la enfermedad, enfermedad activa con fibrosis, niveles bajos de DNA viral, ausencia de inmunosupresión (8,14). El tratamiento con alfainterferón ocasiona múltiples efectos secundarios, la mayoría autolimitados y leves. Entre los graves se encuentran depresión, psicosis, septicemia, insuficiencia cardiaca congestiva, insuficiencia renal aguda y exacerbación de enfermedades autoinmunes (15). Las formas atípicas de la enfermedad, la enfermedad hepática avanzada, los enfermos transplantados y los enfermos con otras patologías importantes no son candidatos a la terapia con interferón, por lo que nuevas opciones terapéuticas son necesarias (16,17). En un estudio realizado con el inmunodulador biológico Timosina alfa 1 (Talfa), los resultados fueron alentadores (18). Existe una vacuna eficaz en el tratamiento de la infección crónica por el virus B de la hepatitis (19). En los pacientes pediatricos, también se ha demostrado el efecto beneficioso del interferón alfa (20,21). Un estudio randomizado y controlado en pacientes con hepatitis crónica B con antígeno HB e positivo, utilizando diversas dosis de lamivudina, mostró resultados beneficiosos (22). La lamivudina parece especialmente indicada en pacientes sometidos a inmunosupresión por transplante de órganos sólidos (23). Recientemente han surgido resistencias a la lamivudina, achacables a mutaciones genéticas (24).
HEPATITIS CRÓNICA POR VIRUS C
]]> El único agente de beneficio probado en esta enfermedad es el interferón alfa. Antes de descubrirse el virus C, ya se conocía el efecto beneficioso del interferón (25), que fue constatado con los estudios serológicos (26). Por otra parte la erradicación del virus a largo plazo, provocaba una respuesta sostenida (27). Por todo ello varios estudios aleatorizados y controlados de varios regímenes y formas de terapia con interferón alfa de esta enfermedad han sido realizados (28-30). La mayoría de estos estudios mostraron que un régimen prolongado de interferón provoca un descenso en los niveles séricos de transaminasas en la mayoría de los pacientes y normalización de ]]>BIBLIOGRAFÍA
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