Hepatitis-B : Mode of Transmission, HBV, Pathogenesis, Treatment And MCQs for NEET, GPAT,

Hepatitis-B : Mode of Transmission, HBV, Pathogenesis, Treatment And MCQs for NEET, GPAT,

INTRODUCTION :-

1.] Hepatitis – B virus [HBV] the cause of ”serum hepatitis” is the most versatile of the hepatotropic viruses.

2.] It has an longer incubation period of about 30 – 180 days and is basically transmitted such as in recipient of blood and blood products.

3.] HBV can produce severe form of illness that includes :-

  • acute hepatitis B
  • chronic hepatitis
  • progression to cirrhosis
  • fulminate (severe and sudden in onset) hepatitis
  • asymptomatic carrier stage

4.] HBV plays role in the development of hepatocellular carcinoma (most common primary malignant tumor of the liver).

MODE OF TRANSMISSION :-

  • HBV is an hardy virus and can withstand extremes of temperature and the humidity.
  • HBV can spread primarily through blood and body fluids.
  • Virus may also spread through contact with body secretion, such as semen, saliva, sweat, tears, breast milk and pathologic effusions.
  • During the active acute chronic hepatitis, HBV is present in all physiologic and pathologic body fluids with the exception of stool.

HEPATITIS – B VIRUS [HBV] :-

1.] HBV shows three forms of viral particles of 2 sizes :-

  • Small (spheres and tubules/filaments)
  • Large (spheres)

2.] Small particles are numerous and exist in two forms – as 22 nm sphere, and as tubules 22 nm in diameter and 100 nm long.

3.] Large particles, 42 nm in diameter, are double – shelled spherical particles, also called dane particles.

4.] The genomic structure of HBV is quite compact and complex. The HBV DNA consist of 4 overlapping genes which encode for multiply proteins :-

  • S gene code for the surface envelope protein, hepatitis B surface antigen (HBsAg) this protein in the major  protein. Pre S -1 and Pre S – 2 region of genome are the upstream of S – gene and code for pre – S gene protein products that include receptor on the HBV surface and for hepatocyte membrane protein.
  • P gene is the largest and codes for the DNA polymerase.
  • C gene codes for two nucleotide protein HBeAg and a core protein termed as HBcAg.
  • X gene codes for HBxAg which is a small non – particulate protein. HBxAg has a role in transactivation of the transcription of both viral and cellular genes.

Expression of HBxAg and its antibodies associated with enhanced HBV DNA replication has been implicated in a hepatocellular carcinoma in patients of chronic hepatitis.

PATHOGENESIS :-

There are certain evidence which links immune pathogenesis with the hepatocellular damage :-

  • When HBV is not directly cytopathic (refers to structural change in host cell that are caused by viral invasion) that means a carrier state of hepatitis B without the hepatocellular damage exists.
  • It has been observed that individuals with defect or deficiency of the cellular immunity have more persistent, hepatitis B diseases.
  • In support of cell mediated mechanism in  hepatocellular damage by HBV comes from the observation that viral antigens are attacked by host cytoxin CD8+T lymphocytes.
  • The host response of CD8+T lymphocytes by elaboration of antiviral cytokines is variable in different individuals, that determines whether an HBV – infected person recovers, develops mild or severe disease, or progresses to chronic disease.

TREATMENT :-

A.] Oral Antiviral drugs for Hepatitis – B :

Tenofovir disoproxil (Viread)

Tenofovir alafenamide (Vemlidy)

Entecavir (Baraclude)

Telbivudine (Tyzeka or Sebivo)

Adefovir Dipivoxil (Hepsera)

Lamivudine (Epivir-HBV, Zeffix, or Heptodin)

B.] Immune modulators (Interferon) for Hepatitis – B :

Pegylated Interferon (Pegasys)

Interferon Alpha (Intron A)

MULTIPLE CHOICE QUESTIONS :-

1.] Which of the following hepatitis virus is not RNA virus ?

a. Hepatitis – A virus

b. Hepatitis – B virus

c. Hepatitis – E virus

d. Hepatitis – G virus

2.] Which of the following nucleic acid is present in hepatitis – B virus ?

a. dsDNA

b. ssRNA

c. ssDNA

d. dsRNA

3.] The most serious infection is ?

a. super infection of an HBsAg carrier by HDV

b. infection with HBV and HDV

c. coinfection of HBV and HDV

d. None of the above

4.] Which of the following specimen contains hepatitis B virus in an infected person ?

a. Blood

b. Semen

c. Saliva

d. All of the above

5.] Which of the following antigenic type of hepatitis B virus is present in the envelope ?

a. HbsAg

b. HBcAg

c. HBeAg

d. HBxAg

6.] The development of hepatocellular carcinoma is associated with ?

a. ground squirrel hepatitis virus

b. hepatitis B virus

c. woodchuck hepatitis virus

d. all of the above

7.] Which of the following antigenic type of hepatitis B virus is prevalent in India ?

a. Adw

b. Adr

c. Ayw

d. Ayr

8.] Which of the following virus can be transmitted by parental route ?

a. HBV

b. HCV

c. HDV

d. All of the above

9.] Incubation period of HBV virus ?

a. 30 – 180 days

b. 2 days

c. 1 week

d. 10 days

10.] The tubule of small viral particle has a diameter of about ?

a. 23 nm

b. 30 nm

c. 22 micro meter

d. 22 nm

SOLUTIONS :-

1.] (b) hepatitis – B virus

2.] (a) dsDNA

3.] (a) super infection of an HBsAg carrier by HDV

4.] (d)

5.] (a) HbsAg

6.] (d)

7.] (c) Ayw

8.] (d)

9.] (a) 30 – 180 days

10.] (d) 22 nm

For More Standard and Quality Question Bank you can Join Our Test Series Programme for GPAT, NIPER JEE, Pharmacist Recruitment Exam, Drug Inspector Recruitment Exams, PhD Entrance Exam for Pharmacy

Participate in Online FREE  GPAT  TEST: CLICK HERE

  Participate in Online FREE  Pharmacist  TEST: CLICK HERE 

Participate in Online FREE  Drug Inspector  TEST: CLICK HERE 

 

REFERENCES :-

1.] Textbook Of Pathology By Harsh Mohan; 7th edition; Page no. 591 – 592.

2.] Robbin’s Basic Pathology; 5th edition; Page no. 844 – 846.

 

 

 

 

 

Leave a Reply

Your email address will not be published. Required fields are marked *

14 + twenty =

×

Developed By Connect Globes