Effect of 25-Hydroxyvitamin D Status on Serological Response to Influenza Vaccine in Prostate Cancer Patients

BACKGROUND. Epidemiologic data suggest that there is an association between vitamin D deficiency and influenza infection. We conducted a prospective influenza vaccination study to determine the influence of vitamin D status on serological response to influenza vaccine in prostate cancer (CaP) patients. METHODS. During the 2006-2007 influenza season, CaP patients treated at Roswell Park Cancer Institute were offered vaccination with the trivalent influenza vaccine (Fluzone (R), 2006 2007) and sera collected for hemagglutination inhibition (HI) assay titers before and 3 months after vaccination. Response to vaccination was defined as >= 1:40 titer ratio or a fourfold increase in titer at 3 months, against any of the three strains. Serum 25-hydroxyvitamin D (25-D-3) levels were measured using DiaSorin I-125 radioimmunoassay kits. RESULTS. Thirty-five patients with CaP participated in the study. Median baseline 25-D-3 level was 44.88 ng/ml (range: 9.16-71.98 ng/ml) Serological response against any of the three strains was noted in 80%. There was a significant effect of baseline 25-D3 level when tested as a continuous variable in relation to serological response (P = 0.0446). All patients in the upper quartile of 25-D3 level responded by mounting a serological response (P = 0.0344). None of the other baseline variables (age, race, chemotherapy status, or white cell count) had an effect on serological response. CONCLUSIONS. In this study in CaP patients, a replete vitamin D status was associated with more frequent serological response to influenza vaccine. Prostate 71: 368-372, 2011. (C) 2010 Wiley-Liss, Inc.