Which bacterial component is most associated with fever when released during dialysis?

• A. Endotoxin
• B. Exotoxin
• C. Capsule
• D. Peptidoglycan

Answer: (A)

Fever from dialysis-related reactions is most strongly linked to endotoxin, the lipopolysaccharide (LPS) component of Gram-negative bacteria. When endotoxin is released into the bloodstream or dialysate, it activates the innate immune system by binding to LPS receptors on macrophages (via LPS-binding protein and CD14/TLR4). This triggers a cascade that releases proinflammatory cytokines such as IL-1 and TNF-α, which then act on the hypothalamus to raise the set point through prostaglandin E2, producing fever. In the dialysis setting, contamination or bacterial lysis releasing endotoxin into dialysate or blood products is a classic cause of pyrogenic fever and systemic inflammatory response. Exotoxins can cause fever in other contexts, but endotoxin is the hallmark culprit in this situation. Capsule and peptidoglycan are not the primary drivers of this febrile reaction during dialysis.