Leukotriene B4 (LTB4) is a potent chemotactic agent derived from arachidonic acid via the 5-lipoxygenase pathway. Its principal chemotactic target is:

• A Eosinophils (via CysLT1 receptor)
• B Mast cells (via GPR99)
• C Dendritic cells (via CXCR3)
• D Neutrophils (via BLT1 receptor) ✓

Explanation

LTB4 is the most potent neutrophil chemotactic lipid mediator, signaling through BLT1 (high-affinity) and BLT2 (low-affinity) receptors on neutrophils, driving directional migration and priming for degranulation. Cysteinyl leukotrienes (LTC4, LTD4, LTE4) signal via CysLT1 on smooth muscle and eosinophils, mediating bronchoconstriction and eosinophil recruitment in asthma. Mast cell activation signals through FcεRI crosslinking rather than GPR99. CXCR3 is a chemokine receptor on activated T cells and NK cells, not specifically targeted by LTB4.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.