Hepatitis A is a common, contagious viral disease in low-income countries. Hepatitis A is transmitted primarily by faecal-oral spread from person to person. Passive immunoprophylaxis for hepatitis A using immunoglobulin preparations were essential for prevention before development of specific hepatitis A vaccine (active immunisation). This review concludes that immunoglobulins seem effective for preventing hepatitis A in both children and adults. However, the evidence, on which the conclusion is based, is not strong as the included trials appear to have risk of bias and their number is insufficient. Because there is a potential risk of blood-borne diseases from immunoglobulins preparations, such as human immunodeficiency virus, and because of the availability of hepatitis A vaccine, the use of immunoglobulins has become limited. However, their use is still required in some specific populations, such as persons with compromised immune function, children under one year of age, or persons who have not developed a full response to vaccine immunisation. Future clinical trials should address the benefit and harm of immunoglobulins in these populations.
Lire le résumé complet
Hepatitis A (infectious hepatitis) is a common epidemic disease. Immunoglobulins for passive immunisation are used as prevention.
Objectifs
To assess the beneficial and harmful effects of the pre- and post-exposure prophylaxis with immunoglobulins for preventing hepatitis A.
Stratégie de recherche documentaire
We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, The Chinese Biomedical Database, and Science Citation Index Expanded for trials until October 2008. In addition, we read through reference lists of the identified publications and handsearched three journals.
Critères de sélection
Randomised clinical trials on immunoglobulin prophylaxis for preventing hepatitis A, irrespective of blinding, publication status, or language.
Recueil et analyse des données
Data were extracted by two authors and verified by a third author. Results were presented as relative risks (RR) with 95% confidence intervals (CI). The primary outcome was occurrence of hepatitis A (infectious hepatitis).
Résultats principaux
We included 13 trials with 567,476 participants randomised to pre- or post-exposure prophylaxis. The trials had high risk of bias. The trials were heterogeneous in terms of study setting, participants, interventions, and outcome measures. Our meta-analysis with six randomised trials showed that immunoglobulins, when used for pre-exposure prophylaxis, significantly reduced the number of adult patients with hepatitis A at 6 to 12 months (1020/286503 versus 761/134529; RR 0.53; 95% CI 0.40 to 0.70; random-effects model) in comparison with no intervention or inactive control. Four trials showed a similar effect in children aged 3 to 17 at 6 to 12 months follow-up (917/210822 versus 677/78960; RR 0.45; 95% CI 0.34 to 0.59). Comparing different doses of immunoglobulins, higher dosage was generally more effective than lower dosage (1.5 ml better than 0.75 ml and 0.75 ml better than 0.1 ml) in preventing hepatitis A. No significant systemic adverse events were reported. One trial showed that immunoglobulin was more effective than placebo for post-exposure prophylaxis. It appeared that there was no significant difference between immunoglobulins and inactivated hepatitis A vaccine in seroconversion to hepatitis A vaccine antibodies at four weeks (RR 1.16; 95% CI 0.98 to 1.38), but immunoglobulins were significantly less effective than vaccine regarding antibody levels at 8, 12, or 24 weeks.
Conclusions des auteurs
Immunoglobulins seem to be effective for pre-exposure and post-exposure prophylaxis of hepatitis A. However, caution is warranted for the positive findings due to the limited number of trials, year of conductance, and risk of bias. Conductance of rigorous trials will be justifiable.
