Hepatitis B virus vaccine immune response and mortality in dialysis patients: a meta-analysis

Background We performed a systematic review and meta-analysis to examine factors associated with HBV immune response in dialysis patients, and the association between the immune response to the HBV vaccine and mortality. Methods Electronic databases were searched for studies of dialysis patients that compared the characteristics of HBV vaccine responders and non-responders. Mortality was also analyzed according to the vaccine immune response (defined by hepatitis B surface antibody titer > 10 mIU/mL). Random-effects model meta-analyses were performed to compute a weighted mean difference (WMD), a pooled odds ratio (OR), and a pooled risk ratio (RR) between groups. Results We identified 61 studies with a total of 6628 dialysis patients who completed the course of HBV vaccination, 4582 responders (69%) and 2046 non-responders (31%). By meta-analysis, relative to non-responders, HBV vaccine responders had a higher dialysis adequacy as measured by Kt/V (WMD 0.08, P < 0.001), a higher serum albumin (WMD 0.12 gm/dL, P < 0.001), a higher normalized protein catabolic rate (WMD 0.12 gm/kg/day, P = 0.001), a higher hemoglobin (WMD 0.15 gm/L, P = 0.03), and a higher parathyroid hormone level (WMD 44 pg/mL, P = 0.004). HBV vaccine responders were younger (WMD - 4.68 years, P < 0.001), had been on dialysis for longer (WMD 2.60 months, P < 0.001), were less likely to have diabetes mellitus (pooled OR 0.65, P < 0.001), and were less likely to carry the human leukocyte antigen (HLA) DR3 (pooled OR 0.38, P = 0.01). Compared to non-responders, HBV vaccine responders had lower risk for all-cause mortality (pooled RR 0.64, P < 0.001), and lower risk for cardiovascular-related mortality (pooled RR 0.74, P = 0.02). Conclusion In dialysis patients, the lack of immune response to the HBV vaccine is associated with older age, diabetes mellitus, HLA-DR3 status, shorter time on dialysis, lower nutritional status, lower hemoglobin, lower PTH level, and lower dialysis adequacy. Tackling some of these modifiable factors might improve the HBV vaccine immune response.