MIF and meningitis: In purulent meningitis of known bacterial aetiology, the following were all associated with high CSF MIF levels: positive Gram stain (10,905 [6,227 to 20,935] ng/l versus 2,821 [772 to 4,111] ng/l for negative Gram stain; P = 0.006), positive CSF culture (10,905 [5,161 to 20,935] ng/l versus 2,608 [733 to 5,750] ng/l for negative CSF culture; P = 0.008) and positive blood culture (11,270 [8,502 to 21,185] versus 4,315 [2,251 to 6,227] ng/l for negative blood culture; P = 0.006).