Figure 3

Extravasation of fibrinogen reflecting vasogenic oedema. Left column: Different fibrinogen staining patterns in the brain parenchyma: diffuse (A), glial- (C) or neuronal-associated (E). Combinations of these patterns could be observed on the same section. Right column: The frequency of the different fibrinogen staining patterns were evaluated using the semi-quantitative scoring system: no staining (0), < 1% cells or vessels staining/grade 1, 1 - 10% cells or vessels staining/grade 2, > 10% cells or vessels staining/grade 3 in addition to measurement of total fibrinogen load (see Figures 4 & 5). The diffuse pattern of staining may reflect a more recent leak compared to cellular uptake of fibrinogen that may indicate an older lesion or cell injury. There was no significant difference in the frequency of fibrinogen extravasation between CM and non-CM cases (B, D, F) but there were differences between different brain regions. Greater numbers of vessels showed diffuse fibrinogen leakage in the brainstem compared with the cortex of severe malaria cases (B). Neuronal uptake of fibrinogen was more frequently observed in the brainstem compared with diencephalon or cortex (F).