Question

Kaposi sarcoma is caused by which of the following?

• A. Human Herpesvirus 6 (HHV-6)
• B. Human Herpesvirus 8 (HHV-8)
• C. Epstein-Barr Virus (EBV)
• D. Human Papillomavirus (HPV)

Hint:

Recall which herpesvirus is specifically associated with the most common AIDS-defining malignancy presenting as purplish skin lesions.

Answer 1

The Correct Option is B

Kaposi sarcoma (KS) is the most common AIDS-defining malignancy, presenting as purplish-red vascular lesions on skin, mucous membranes, and viscera.

The causative agent is $\text{Human Herpesvirus 8 (HHV-8)}$, also called Kaposi Sarcoma-associated Herpesvirus (KSHV). It belongs to the gamma-herpesvirus subfamily (same subfamily as EBV).

HHV-8 encodes viral oncoproteins that:
- Inhibit apoptosis (vFLIP, vBcl-2)
- Drive cell cycle progression (viral cyclin D)
- Stimulate angiogenesis (viral IL-6, viral VEGF homologue)

Four clinical variants of KS exist:
1. Classic KS (elderly Mediterranean men)
2. Endemic KS (sub-Saharan Africa)
3. Iatrogenic KS (organ transplant recipients on immunosuppression)
4. Epidemic/AIDS-associated KS (most aggressive)

Other herpesvirus associations to remember: EBV (HHV-4) -- Burkitt lymphoma; HHV-6 -- roseola; HPV -- cervical cancer.

\[\boxed{\text{HHV-8 (KSHV)}}\]