531. Humoral response to the pandemic (A/H1N1 2009) vaccine in in patients with non-Hodgkin B-cell lymphoma following the administration of rituximab-CHOP
Session: Poster Abstract Session: Vaccine Use in Immunocompromised Hosts
Thursday, October 3, 2013
Room: The Moscone Center: Poster Hall C
Background:   

Rituximab, chimeric anti-human CD20, has been demonstrated to be an effective treatment for non-Hodgkin B-cell lymphoma (NHL) and its administration results in the profound depletion of normal B-cells for several months. However, pertinent data regarding the effects of rituximab on the immune response to active immunization with the influenza vaccine in NHL patients are scarce.

Methods:

To assess the humoral response to the flu pandemic vaccine (A/H1N1pdm09) in patients treated with rituximab combined with CHOP therapy for NHL, the anti-hemagglutinin (HA) titers in 16 NHL patients (age, 47-90; median, 70) receiving this therapy were prospectively compared with those observed in 33 control group subjects (age, 22-79; median, 58) (six patients with CHOP alone, 16 patients with rheumatoid arthritis treated with monoclonal antibodies [infliximab: 10, tocilizumab: 4, adalimumab: 1, etanercept: 1] and 11 healthy subjects) during the 2009/2010 season. The HI antibody titers were measured just before vaccination and 28 days later.

Results:  

The mean fold increase was significantly lower in the patients treated with R-CHOP than in the non R-CHOP subjects [2.3±3.8 vs 8.8±15.7, p=0.03]. In addition, the seroresponse was significantly lower in the patients treated with R-CHOP than in the control subjects [18.8% vs 48.5%, p=0.04]. In contrast, no significant differences were observed between the R-CHOP group and the CHOP alone group or between the RA group and the healthy subjects. The minimum number of days from the last administration of rituximab to the flu shot in the positive seroresponse subjects was 160. One patient in the R-CHOP group developed influenza, but later recovered without any serious complications. Vaccination against influenza was not associated with the significant worsening of any clinical or laboratory indices.

Conclusion:

 The vaccination of B-cell lymphoma patients against influenza is therefore considered to be safe. In this study, a significant impairment was observed in the humoral response in the NHL patients treated with R-CHOP therapy in comparison to that observed in the RA/healthy subjects; however, the respective impact of rituximab or CHOP on the immunogenicity of influenza was not apparant.

Tohru Takata, MD, PhD, Fukuoka Univ. Sch. of Med., Fukuoka, Japan

Disclosures:

T. Takata, None

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