Occult hepatitis B virus (HBV) infection (OBI) is a form of the disease which does not present with Hepatitis B surface antigens (HBsAg) in the serum of patients with HBV DNA being detectable in the serum and hepatocytes. OBI is an important risk factor for acquiring post transfusion hepatitis. This could lead to reactivation of the HBV, liver cirrhosis, and hepatocellular carcinoma. We aimed to examine the prevalence of OBI in frequent blood and blood product transfused Egyptian pediatric patients.
Materials and Methods: This case-control study was done in pediatric department, Minia University. Forty-five patients randomly selected from the blood transfusion unit in the central Minia blood bank were enrolled. Their age ranged from 3-18 years. Another 12 known hepatitis B positive age- and sex-matched patients were enrolled as controls. Routine AST, ALT, blood urea, serum creatinine, and hemoglobin levels were done, HBsAg, anti-hepatitis B surface antibodies (anti-HBsAb), anti-hepatitis B core antibodies (anti-HBcAb), and HBV DNA (by nested PCR) were examined for both patients and controls.
Results: Although anti-HBs serum levels were ≥10IU/L, HBV DNA was present in 27 (60%) of the 45 HBsAg negative patients. Thirteen (48%) of the OBI patients were anti-HBcAb positive. No significant differences were found between HbcAb positive and negative OBI groups regarding age, gender, frequency of blood transfusion, presence of hepatomegaly, presence of splenomegaly, serum ferritin, AST, ALT, blood urea, serum creatinine, and hemoglobin levels. On the other hand, Hepatitis C Virus Ab positivity was significantly higher among HbcAb positive patients (p=0.02).
Based on the results, the risk of acquiring OBI is high in patients receiving frequent blood transfusions despite obligatory HBV vaccination.