False positivity of the surface antigen of the Hepatitis B virus (HBsAg) after vaccination.

Letter to the editor.

Abstract

Introduction: The chronic hemodialysis population has a greater exposure and risk to the hepatitis B virus, which is why immunoprophylaxis using the double dose scheme (40mcg) on days 0-30-60-180, with application of this regimen for a second extra time in nonresponders, is common practice in this population.

Clinical case: This is a 67-year-old male patient of Afro-Ecuatorian ethnicity who started hemodialysis (HD) in August 2023 for chronic kidney disease (CKD) secondary to diabetic nephropathy. When starting HD, he had negative serology for hepatitis and negativity for HBsAg. For this reason, he received his first vaccination dose on November 29, 2023, and on December 15, he had HBsAg positivity with values of 4.14 S/CO (≥1 positive), with Ac-ANTI-HBSAG levels < 2 IU/L.

Management: Given the findings, it was decided to isolate the patient with control of liver function, which is normal, and a new test of HBsAg levels in 15 days, which were subsequently negative.

Conclusion: In this case, we want to remember the false politicization of HBsAg after vaccination in hemodialysis patients, a situation associated with the vaccine being composed of live attenuated viruses or recombinant particles of surface proteins.