Israel Medical Association Journal

Background: Up to 60% of inflammatory bowel disease (IBD) patients treated with infliximab develop antibodies to infliximab (ATI), which are associated with low drug levels and loss of response (LOR). Hence, mapping out predictors of immunogenicity toward infliximab is essential for tailoring patient-specific therapy. Jewish Sephardi ethnicity, in addition to monotherapy, has been previously identified as a potential risk factor for ATI formation and infliximab failure.

Objectives: To explore the association between Jewish sub-group ethnicity among patients with IBD and the risk of infliximab immunogenicity and therapy failure. To confirm findings of a previous cohort that addressed the same question.

Methods: This retrospective cohort study included all infliximab-treated patients of Jewish ethnicity with regular prospective measurements of infliximab trough levels and ATI. Drug and ATI levels were prospectively measured, clinical data was retrieved from medical charts.

Results: The study comprised 109 Jewish patients (54 Ashkenazi, 55 Sephardi) treated with infliximab. There was no statistically significant difference in proportion of ATI between Sephardi and Ashkenazi patients with IBD (32% Ashkenazi and 33% Sephardi patients developed ATI, odds ratio [OR] 0.944, P = 0.9). Of all variables explored, monotherapy and older age were the only factors associated with ATI formation (OR 0.336, 95% confidence interval 0.145–0.778, P = 0.01, median 34 vs. 28, interquartile range 28–48, 23–35 years, P = 0.02, respectively).

Conclusions: Contrary to previous findings, Sephardi Jewish ethnicity was not identified as a risk factor for ATI formation compared with Ashkenazi Jewish ethnicity. Other risk factors remained unchanged.

Background: Guidelines recommend hepatitis B virus (HBV) vaccination of all adults positive for human immunodeficiency virus (HIV). Immune responses to single-antigen HBV vaccine among HIV-positive patients are low when compared with HIV-negative adults. Sci-B-Vac™ is a recombinant third-generation HBV that may be advantageous in this population.

Objectives: To examine the immune responses to Sci-B-Vac among HIV-positive adults.

Methods: We conducted a prospective cohort study involving HIV-positive adults who had negative HBV serology (HBSAg, HBSAb, HBcoreAb). Sci-B-Vac at 10 µg/dose was administered intramuscularly upon recruitment and after 1 and 6 months. HBSAb levels were checked 1 month after each dose; a level > 10 mlU/ml was considered protective. Data regarding age, gender, CD4 level, and viral load were collected.

Results: The study group comprised 31 patients. Average CD4 count was 503 ± 281 cells/ml, and average viral load was 44 copies/ml. Median interquartile range (IQR) HBVAb titers after the first, second and third immunizations were 0 (0, 3.5), 30 (6, 126) and 253 (81, 408) mlU/ml. Significant titer elevations were found between the second and third immunizations (P = 0.0003). The rate of patients considered protected was 16% after the first, 65% after the second (P < 0.0001), and 84% after the third dose (P = 0.045). No adverse events were reported. More patients under the age of 40 years responded to the first immunization (28% vs. 0%, P = 0.038). CD4 level had no influence on immunization rates.

Conclusions: Sci-B-Vac might achieve better immunization rates among HIV-positive adults compared to the single-antigen vaccine and thus deserves further evaluation in a randomized, double-blind study in this population.

Background: Previous data showed that new recombi­nant hepatitis B virus vaccine, which contains the S-protein component of the HBV surface together with the Pre-S₁ and Pre-S₂, is considerably more immunogenic than a second-generation recombinant I-IBV vaccine.

Objectives:To compare the immunogenicity and safety of a novel recombinant HBV vaccine S1, Pre-S₁ and Pre-S₂ protein components of the hepatitis B surface antigen - Bio­TM

Hep^TM 10 לg dose, to a licensed vaccine containing only the S-protein component - Engerix-B, 20 לg dose.

Methods: A prospective randomized study included 524 adults - 260 in the Bio-Hep group and 264 in the Engerix-B group. Both vaccines were administered in a three-dose regimen given at 0, 1 and 6 months, and adverse events were recorded on a diary card 5 days after each vaccination. lmmunogenicity was tested by measuring anti-hepatitis B surface antibody.

Results: One month after the third injection, 98% of the BioHep^TM subjects were found to be seroprotected vs. 85.1% of the Engerix-B group. In addition, the geometric mean titers were 2,203 mlU/ml and 326 mlU/ml in the Bio-Hep-B and Engerix-B groups respectively. An immunogenic advantage of Bio-Hep-B was suggested by the rapid onset of antibody response - 66.5% were seroconverted one month after the first injection as compared to 19.3% in the Engerix-B group. No unexpected adverse events were observed, and the recorded events were mild in both groups.

Conclusions: BioHepTM, a novel recombinant HBV vaccine containing 5, Pre-S₁ and Pre-S₂ protein components. at a lower dose, is safe and more immunogenic than the conventional HBV vaccine that contains only S protein.