Immune Response Flashcards
how can fever be used as a diagnostic tool?
fever cycles differ between infections caused by different plasmodium spp.
- P. Falciparum, Vivax, Ovale - 48 hours - a peak of fever before lowering again
- P. malariae - 72 hrs
48 hour blood
stage cycle of
invasion,
growth
and asexual
division.
how does malaria induce fever
when schizonts burst, Hemozoin is released
They are taken up by macrophages and recognized by Toll-like receptors (TLRs), triggering an immune response.
Pro-inflammatory cytokines (e.g., IL-1β, TNF-α) are released and act on the hypothalamus in the brain, causing fever
What happens to parasite components like hemozoin and DNA when infected red blood cells rupture?
taken up by macrophages and recognized by Toll-like receptors (TLRs), triggering an immune response.
which TLRs detect malaria components?
TLR 4 - GPI in concert with TLR 2
TLR 2- Activated by sporozoites and glycosylphosphatidylinositols (GPIs) from the malaria parasite, TLR2 induces macrophages to release proinflammatory cytokines.
TLR 7 - recognizes a Plasmodium-derived RNA molecule
TLR9 is located in the endosome of immune cells (e.g., macrophages and dendritic cells) and detects DNA fragments bound to hemozoin.
Parasite DNA, particularly AT-rich sequences, is also recognized by TLR9.
This recognition triggers the release of pro-inflammatory cytokines like IL-1β and TNF-α.
whats hemozoin
what cytokine is largely responsible for fever
TNF tumor necrosis factor
whats acidosis
how is severe malaria defined, and what causes it?
Severe Malaria = a metabolic disease problem caused by sequestration of RBCs leading to acidosis of blood, impaired oxygenation of tissues and tissue hypoxia.
sequestration of infected erythrocytes in the brain and other vital organs in association with high parasite burden is the most important feature of severe malaria pathogenesis - Sahu 2021
