Epstein-Barr virus

Definition

Epstein-Barr virus (EBV) is a member of the herpesvirus family and is one of the most common viruses in humans, primarily known for causing infectious mononucleosis. Its ability to establish latency and reactivate can disrupt normal immune tolerance, contributing to autoimmunity and various autoimmune disorders, as well as being associated with certain secondary immunodeficiencies.

5 Must Know Facts For Your Next Test

1. EBV infects B lymphocytes, leading to their proliferation and potential transformation into malignant cells, which is linked to some cancers such as Hodgkin's lymphoma.
2. Infectious mononucleosis, often referred to as 'mono', occurs when EBV is contracted, leading to symptoms that can last for weeks or months.
3. The virus's ability to establish latency means it can evade the immune response and re-emerge later, which may trigger autoimmune responses.
4. EBV is associated with several autoimmune diseases, including multiple sclerosis and systemic lupus erythematosus, suggesting a role in breaking down immune tolerance.
5. Individuals with certain genetic predispositions may be more susceptible to EBV-related complications, including autoimmune diseases and secondary immunodeficiencies.

Review Questions

• How does Epstein-Barr virus contribute to the breakdown of immune tolerance and lead to autoimmune responses?
  • Epstein-Barr virus can disrupt immune tolerance by infecting B lymphocytes, which are crucial for maintaining immune balance. When the virus establishes latency, it can evade detection by the immune system. This prolonged presence increases the likelihood of inappropriate activation of autoreactive T cells that may target the body’s own tissues, thereby contributing to various autoimmune disorders.
• Discuss the mechanisms through which Epstein-Barr virus is linked to common autoimmune disorders.
  • Epstein-Barr virus is linked to several autoimmune disorders through molecular mimicry and persistent inflammation. The viral antigens may resemble self-antigens, leading the immune system to mistakenly attack host tissues. Additionally, the chronic activation of B cells during EBV infection may result in a breakdown of self-tolerance and contribute to conditions like multiple sclerosis and rheumatoid arthritis.
• Evaluate the role of Epstein-Barr virus in secondary immunodeficiencies and its implications for patients.
  • Epstein-Barr virus plays a significant role in secondary immunodeficiencies by affecting the immune system's functionality. In immunocompromised individuals, such as those with HIV or undergoing chemotherapy, EBV can cause severe complications, including opportunistic infections and lymphoproliferative disorders. The virus’s ability to reactivate in these populations poses significant health risks, underscoring the importance of monitoring EBV status in patients with weakened immunity.

Related terms

Infectious Mononucleosis: A viral infection caused by Epstein-Barr virus, characterized by fever, sore throat, and swollen lymph nodes.

Autoimmunity:

A condition where the immune system mistakenly attacks the body's own tissues, which can be influenced by infections like EBV.

Latency: The ability of a virus like EBV to remain dormant in the host cells after the initial infection, potentially leading to reactivation and complications.