A 2-year-old presents with 5 days of fever followed by appearance of a maculopapular rash on the face that spreads centrifugally. Koplik's spots were noted on day 2. The immune evasion strategy that allows measles virus to cause profound immunosuppression for up to 2–3 years post-infection is:
- A Destruction of CD4+ T helper cells via viral gp120 analogue
- B Suppression of interferon-alpha production by non-structural protein NS1
- C Deletion of memory B and T cells (immune amnesia) via infection of lymphocytes ✓
- D Complement evasion by expression of CD46 as receptor leading to complement depletion
Explanation
Measles causes 'immune amnesia' by infecting and depleting memory lymphocytes (both B and T cells), leading to loss of pre-existing immunity to other pathogens for 2–3 years after acute infection. This explains the increased susceptibility to infections like pneumonia and diarrhea in the post-measles period. This has been demonstrated by studying antibody repertoire depletion using VirScan assay. NS1 is an influenza protein; CD46 is the measles receptor but its binding leads to complement evasion as a secondary effect, not the primary cause of prolonged immunosuppression. HIV uses gp120 to infect CD4+ cells.
Reference: Ghai Essential Pediatrics, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.