Occult Hepatitis B in Jember Donors: Genotype Characterization
- Okay, here's a breakdown of the mutations discussed in the provided text, categorized by the gene they affect (HBsAg or Pol/RT) and their associated implications. I'll also include...
- These mutations affect the Hepatitis B surface antigen, impacting immune recognition and possibly diagnostic tests.
- * sK122R: Found in samples (frequency not specified, but noted as important).
Okay, here’s a breakdown of the mutations discussed in the provided text, categorized by the gene they affect (HBsAg or Pol/RT) and their associated implications. I’ll also include the frequency of detection within the samples studied.
I. HBsAg (Surface Antigen) Mutations
These mutations affect the Hepatitis B surface antigen, impacting immune recognition and possibly diagnostic tests.
* sK122R: Found in samples (frequency not specified, but noted as important). Associated with immune escape and diagnostic failure. It’s a serotype-determining amino acid.
* Y161F: Found in 3 samples. linked to Occult HBV Infection (OBI) and immune evasion.
* Y206C: Found in 1 sample. Linked to reduced viral replication, lower HBsAg levels, and less ALT activity (suggesting a milder infection).
II. Pol/RT (Polymerase/Reverse Transcriptase) Mutations
These mutations affect the polymerase gene, frequently enough leading to drug resistance.
* N124H & N134D: Present in 100% of OBI samples. Significance currently unclear.
* S135Y: Detected in 56% of samples. Common in treatment-naïve patients with chronic hepatitis B (especially genotype D).Implicated in lamivudine treatment failure.
* L217R: Found in 44% of samples. associated with adefovir resistance, notably in HBV subgenotype A2.
* I187V: found in 3 OBI samples. Rare, associated with entecavir resistance.
* N123H: Found in 1 OBI sample. Rare, associated with entecavir resistance.
* V207M: Found in 1 sample. Ofen found with other mutations that contribute to lamivudine resistance.
Key Takeaways:
* Immune Escape: Several mutations (sK122R, Y161F) are directly linked to the virus evading the host’s immune system.
* OBI Association: Mutations like Y161F, N124H & N134D, I187V and N123H are specifically mentioned in the context of Occult HBV Infection.
* Drug Resistance: Mutations in the Pol/RT domain (S135Y, L217R, I187V, N123H, V207M) are strongly associated with resistance to antiviral drugs like lamivudine, adefovir, and entecavir.
* Severity: The Y206C mutation suggests a potentially less aggressive infection course.
Let me know if you’d like me to elaborate on any specific mutation or aspect of this data!