Considerable decrease in antibodies against hepatitis B surface antigen following kidney transplantation.

Area of Science:

• Nephrology
• Immunology
• Virology

Background:

• Hepatitis B virus (HBV) immunization is crucial for kidney transplant (KT) candidates and recipients.
• A protective anti-HBV surface antigen antibody (anti-HBsAb) titer is generally considered ≥10 IU/L, but optimal thresholds post-KT and titer evolution are unclear.
• The natural course of anti-HBsAb titers following kidney transplantation has not been well-documented.

Purpose of the Study:

• To assess the rate of protective HBV immunity at the time of kidney transplantation (baseline).
• To describe the changes in anti-HBsAb titers during the first year after kidney transplantation.

Main Methods:

• Retrospective analysis of HBV serology data from 141 kidney transplant recipients.
• Serological markers (anti-HBsAb, anti-HBcAb) were measured at baseline, 15 days, 4 months, and 12 months post-KT.
• Patients did not receive vaccinations during the study; prior vaccination history was unknown.

Main Results:

• 80% of recipients had protective anti-HBsAb titers (≥10 IU/L) at baseline.
• By 12 months post-KT, 25% of patients lost protective anti-HBsAb titers (p<0.001).
• Initial titers ≥100 IU/L maintained protection significantly longer than titers of 10-100 IU/L (p<0.0001), with 93% retaining protection vs. 33% at 12 months.

Conclusions:

• A significant proportion of kidney transplant recipients experience loss of protective anti-HBV immunity within a year.
• Initial anti-HBsAb titers <100 IU/L are associated with a higher risk of losing protective immunity post-KT.
• Higher initial titers may indicate a need for closer monitoring or booster vaccinations in kidney transplant recipients.