Hepatitis B virus - Revision history

Aidan at 15:21, 27 January 2026

2026-01-27T15:21:19Z

← Older revision		Revision as of 15:21, 27 January 2026
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	===Microbiology===		===Microbiology===

	*Reverse-transcription double-stranded DNA (RT-dsDNA) virus		*[[Baltimore classification::dsDNA-RT virus\|Reverse-transcription double-stranded DNA (RT-dsDNA) virus]]
	*Genome encodes seven proteins:		*Genome encodes seven proteins:
	**Surface proteins (large, middle, and small) which form the envelope or surface antigen (HBsAg)		**Surface proteins (large, middle, and small) which form the envelope or surface antigen (HBsAg)

Aidan at 18:03, 6 August 2024

2024-08-06T18:03:11Z

← Older revision		Revision as of 18:03, 6 August 2024
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	=Prevention=		=Prevention=

			=== Needlestick Injury ===

			* See [[Needlestick injuries and post-exposure prophylaxis]]

	===Prophylaxis in Immunosuppression===		===Prophylaxis in Immunosuppression===

Aidan: /* Serology */

2022-02-18T20:45:00Z

Serology

← Older revision		Revision as of 20:45, 18 February 2022
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	\|Past infection (resolved)		\|Past infection (resolved)
	Acute infection (window period)		Acute infection (window period)

	Low level chronic infection		Low level chronic infection

	False positive (susceptible)		False positive (susceptible)
	\| align="center" \|–		\| align="center" \|–

Aidan: /* Risk Stratification */

2021-12-06T11:08:38Z

Risk Stratification

← Older revision		Revision as of 11:08, 6 December 2021
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	* * May be at lower risk if HBsAb titres are > 100 IU/L		* * May be at lower risk if HBsAb titres are > 100 IU/L
			*High risk indicates >10% risk of reactivation, moderate indicates 1-10%, and low is <1%

	==== Prophylaxis ====		==== Prophylaxis ====

Aidan: /* Prophylaxis in Immunosuppression */

2021-12-06T11:06:46Z

Prophylaxis in Immunosuppression

@@ Line 411: / Line 411: @@
 **Death
 *Prophylaxis can prevent hepatitis B reactivation
-*Risk stratify based on type of immune suppression and serologic status
+*Current Canadian guidelines recommend risk stratifying based on type of immune suppression and serologic status[[CiteRef::coffin2018ma]]
 ===Vaccination===

Aidan: /* Prevention */

2021-08-23T13:04:33Z

Prevention

← Older revision		Revision as of 13:04, 23 August 2021
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	*First-line is ultrasound every 6 months		*First-line is ultrasound every 6 months
	*Second-line is AFP levels every 6 months		*Second-line is AFP levels every 6 months

		⚫	=Prevention=

	===Prophylaxis in Immunosuppression===		===Prophylaxis in Immunosuppression===
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	*'''Monitoring''' is indicated for low-risk patients		*'''Monitoring''' is indicated for low-risk patients
	**Monitor HBV-DNA and liver enzymes every 1 to 3 months until 6 months after end of chemotherapy		**Monitor HBV-DNA and liver enzymes every 1 to 3 months until 6 months after end of chemotherapy

⚫	==Prevention==

	===Vaccination===		===Vaccination===

Aidan: /* Vaccination */

2021-02-23T21:53:09Z

Vaccination

← Older revision		Revision as of 21:53, 23 February 2021
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	\|}		\|}

	=== Pathophysiology ===		===Pathophysiology===

	* Virion binds its receptor, NTCP, on the hepatocyte cell membrane		*Virion binds its receptor, NTCP, on the hepatocyte cell membrane
	* Nucleocapsid is released into cytosol and transported to the nucleus		*Nucleocapsid is released into cytosol and transported to the nucleus
	** Occasionally integrates into host genome around this stage		**Occasionally integrates into host genome around this stage
	* Relaxed circular DNA (rcDNA) is converted into covalently closed circular DNA (cccDNA)		*Relaxed circular DNA (rcDNA) is converted into covalently closed circular DNA (cccDNA)
	* cccDNA forms the template for synthesis of RNA, which is reverse-transcribed into negative-sense DNA and positive-sense DNA to give partially double-stranded rcDNA, which is packaged in the endoplasmic reticulum into a new infectious virion		*cccDNA forms the template for synthesis of RNA, which is reverse-transcribed into negative-sense DNA and positive-sense DNA to give partially double-stranded rcDNA, which is packaged in the endoplasmic reticulum into a new infectious virion

	===Epidemiology===		===Epidemiology===
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	**In Canada, there is a range of genotypes due to high rate of immigration, but genotypes B and C are the most common		**In Canada, there is a range of genotypes due to high rate of immigration, but genotypes B and C are the most common

	=== Risk Factors for Hepatitis B Infection ===		===Risk Factors for Hepatitis B Infection===

	* Chronic carrier within the family		*Chronic carrier within the family
	* Injection drug use		*Injection drug use
	* High-risk sexual activity		*High-risk sexual activity
	* Body piercing and tattooing		*Body piercing and tattooing
	* History of blood transfusion		*History of blood transfusion
	* Chronic carrier status within Canada: immigrants, Indigenous people, and stree-connected people		*Chronic carrier status within Canada: immigrants, Indigenous people, and stree-connected people

	===Risk Factors for Hepatocellular Carcinoma===		===Risk Factors for Hepatocellular Carcinoma===
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	===Vaccination===		===Vaccination===

			*See [[Hepatitis B vaccine]]
	*Post-vaccine serology
	**A cutoff of 10 IU/mL defines protective antibody titres
	**About 5% are primary non-responders and never had positive titres; they are not immune
	**However, their titres may have waned over time but they maintain the ability to mount an antibody response once exposed
	**Often need to revaccinate

	==Further Reading==		==Further Reading==

Aidan at 17:46, 13 October 2020

2020-10-13T17:46:23Z

← Older revision		Revision as of 17:46, 13 October 2020
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	*Reverse-transcription double-stranded DNA (RT-dsDNA) virus		*Reverse-transcription double-stranded DNA (RT-dsDNA) virus
			*Genome encodes seven proteins:
			**Surface proteins (large, middle, and small) which form the envelope or surface antigen (HBsAg)
			**Nucleocapsid core or C protein (HBcAg)
			**Secretory envelope antigen (HBeAg)
			**Viral reverse transcriptase or polymerase
			**X protein
	*Genotypes A through J vary in geographic distribution and clinical severity[[CiteRef::sunbul2014he]]		*Genotypes A through J vary in geographic distribution and clinical severity[[CiteRef::sunbul2014he]]

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	\| colspan="2" \|No data		\| colspan="2" \|No data
	\|}		\|}

			=== Pathophysiology ===

			* Virion binds its receptor, NTCP, on the hepatocyte cell membrane
			* Nucleocapsid is released into cytosol and transported to the nucleus
			** Occasionally integrates into host genome around this stage
			* Relaxed circular DNA (rcDNA) is converted into covalently closed circular DNA (cccDNA)
			* cccDNA forms the template for synthesis of RNA, which is reverse-transcribed into negative-sense DNA and positive-sense DNA to give partially double-stranded rcDNA, which is packaged in the endoplasmic reticulum into a new infectious virion

	===Epidemiology===		===Epidemiology===

			*Approximately 260 million chronic carriers worldwide, and 900,000 deaths annually from [[cirrhosis]] and [[Hepatocellular carcinoma\|HCC]]
⚫	*Genotypes ~~very~~ by ~~location~~
			**Prevalence of chronic carriers is estimated at 2% of the Canadian population
⚫	*In Canada, there is a range of genotypes due to high rate of immigration, but genotypes B and C are the most common
			*Bloodborne and sexually-transmitted, transmitted primarily by intravenous drug use drug use and sexual contact
		⚫	*Genotypes vary by region and country
		⚫	**In Canada, there is a range of genotypes due to high rate of immigration, but genotypes B and C are the most common

			=== Risk Factors for Hepatitis B Infection ===

			* Chronic carrier within the family
			* Injection drug use
			* High-risk sexual activity
			* Body piercing and tattooing
			* History of blood transfusion
			* Chronic carrier status within Canada: immigrants, Indigenous people, and stree-connected people

	===Risk Factors for Hepatocellular Carcinoma===		===Risk Factors for Hepatocellular Carcinoma===
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	*Male sex		*Male sex
	*Immunocompromise		*Immunocompromise
	*Family ~~historyof~~ [[HCC]]		*Family history of [[HCC]]
	*Presence of [[cirrhosis]], conferring 2-3% risk per year		*Presence of [[cirrhosis]], conferring 2-3% risk per year
	*HBV DNA >2000 IU/mL		*HBV DNA >2000 IU/mL
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	====Indications for Treatment====		====Indications for Treatment====

	*The goal of treatment is to decrease the risk of cirrhosis and ~~hepaticellular~~ carcinoma, so is generally reserved for those at higher risk of these sequelae		*The goal of treatment is to decrease the risk of cirrhosis and hepatocellular carcinoma, so is generally reserved for those at higher risk of these sequelae
	**The risk is generally higher with higher HBV-DNA and HBsAg titres, and possibly higher ALT		**The risk is generally higher with higher HBV-DNA and HBsAg titres, and possibly higher ALT
	*The decision to treat requires consideration of patient age, viral load, HBeAg, and evidence of significant liver disease (i.e. persistent ALT elevation, fibrosis or inflammation on biopsy, or non-invasive assessment of hepatic fibrosis)		*The decision to treat requires consideration of patient age, viral load, HBeAg, and evidence of significant liver disease (i.e. persistent ALT elevation, fibrosis or inflammation on biopsy, or non-invasive assessment of hepatic fibrosis)
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	***HBsAg negative or HBcAb positive, plus [[prednisone]] <10 mg/day for ≥4 weeks		***HBsAg negative or HBcAb positive, plus [[prednisone]] <10 mg/day for ≥4 weeks
	*'''Prophylaxis''' is indicated for high- and moderate-risk patients		*'''Prophylaxis''' is indicated for high- and moderate-risk patients
	** [[Lamivudine]], [[tenofovir]], or [[entecavir]]		**[[Lamivudine]], [[tenofovir]], or [[entecavir]]
	** Continue until 6 months after end of chemotherapy, or until 12 months after anti-CD20 immunotherapy like [[rituximab]]		**Continue until 6 months after end of chemotherapy, or until 12 months after anti-CD20 immunotherapy like [[rituximab]]
	*'''Monitoring''' is indicated for low-risk patients		*'''Monitoring''' is indicated for low-risk patients
	**Monitor HBV-DNA and liver enzymes every 1 to 3 months until 6 months after end of chemotherapy		**Monitor HBV-DNA and liver enzymes every 1 to 3 months until 6 months after end of chemotherapy

	== Prevention ==		==Prevention==

	=== Vaccination ===		===Vaccination===

	* Post-vaccine serology		*Post-vaccine serology
	** A cutoff of 10 IU/mL defines protective antibody titres		**A cutoff of 10 IU/mL defines protective antibody titres
	** About 5% are primary non-responders and never had positive titres; they are not immune		**About 5% are primary non-responders and never had positive titres; they are not immune
	** However, their titres may have waned over time but they maintain the ability to mount an antibody response once exposed		**However, their titres may have waned over time but they maintain the ability to mount an antibody response once exposed
	** Often need to revaccinate		**Often need to revaccinate

	==Further Reading==		==Further Reading==

Aidan: /* Prophylaxis in Immunosuppression */

2020-09-02T13:53:52Z

Prophylaxis in Immunosuppression

← Older revision		Revision as of 13:53, 2 September 2020
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	===Prophylaxis in Immunosuppression===		===Prophylaxis in Immunosuppression===

			*Immunosuppression in patients with latent hepatitis B infection can lead to reactivation, which can cause:
		⚫	**Asymptomatic hepatitis B viremia and elevated ALT
		⚫	**Hepatic failure
		⚫	**Death
			*Prophylaxis can prevent hepatitis B reactivation
	*Risk stratify based on type of immune suppression and serologic status		*Risk stratify based on type of immune suppression and serologic status
	**'''High-risk''' (>10%):		**'''High-risk''' (>10%):
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	***HBsAg positive, or HBsAg negative but HBcAb positive, plus traditional immunosuppressants ([[azathioprine]], [[6-MP]], [[methotrexate]])		***HBsAg positive, or HBsAg negative but HBcAb positive, plus traditional immunosuppressants ([[azathioprine]], [[6-MP]], [[methotrexate]])
	***HBsAg negative or HBcAb positive, plus [[prednisone]] <10 mg/day for ≥4 weeks		***HBsAg negative or HBcAb positive, plus [[prednisone]] <10 mg/day for ≥4 weeks
	*Concern especially with chronic [[steroids]] and [[rituximab]]
	*Can have the following effects
⚫	**Asymptomatic ~~HBV~~ ~~DNA~~ and ALT
⚫	**Hepatic failure
⚫	**Death
	*If ≥7.5mg/d should be screened
	**HBsAg +/- HBcAb if they're adding a second agent ([[rituximab]], [[TNF-alpha inhibitors]], or other)
	**Refer to Hepatology or Infectious Diseases
	*'''Prophylaxis''' is indicated for high- and moderate-risk patients		*'''Prophylaxis''' is indicated for high- and moderate-risk patients
	** [[Lamivudine]], [[tenofovir]], or [[entecavir]]		** [[Lamivudine]], [[tenofovir]], or [[entecavir]]

Aidan: /* Prophylaxis in Immunosuppression */

2020-09-02T13:52:15Z

Prophylaxis in Immunosuppression

← Older revision		Revision as of 13:52, 2 September 2020
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	** [[Lamivudine]], [[tenofovir]], or [[entecavir]]		** [[Lamivudine]], [[tenofovir]], or [[entecavir]]
	** Continue until 6 months after end of chemotherapy, or until 12 months after anti-CD20 immunotherapy like [[rituximab]]		** Continue until 6 months after end of chemotherapy, or until 12 months after anti-CD20 immunotherapy like [[rituximab]]
	*'''Monitoring'' is indicated for low-risk patients		*'''Monitoring''' is indicated for low-risk patients
	**Monitor HBV-DNA and liver enzymes every 1 to 3 months until 6 months after end of chemotherapy		**Monitor HBV-DNA and liver enzymes every 1 to 3 months until 6 months after end of chemotherapy