A patient infected with a tissue-invasive intestinal nematode has marked peripheral blood eosinophilia. Which preformed granule constituent of the eosinophil accounts for much of its ability to kill helminths?
- A Myeloperoxidase
- B Major basic protein ✓
- C Perforin and granzyme B
- D Defensins
Correct answer: B. Major basic protein
Explanation
Eosinophil secondary granules contain major basic protein, a highly cationic protein that is directly toxic to helminths; IgG- and IgE-coated parasites trigger eosinophil degranulation onto the worm surface. Perforin and granzymes belong to cytotoxic T lymphocytes and NK cells. Defensins are antimicrobial peptides of neutrophils and Paneth cells directed mainly against bacteria and fungi, and myeloperoxidase is a neutrophil azurophilic granule enzyme.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.