ACHE and paroxysmal nocturnal hemoglobinuria: Markedly reduced erythrocyte AChE activity was demonstrated in cases of paroxysmal nocturnal haemoglobinuria (PNH) (Auditore & Hartmann, 2004).Previous studies showed a correlation between AChE inhibition in blood and inhibition in target tissues (Kale et al., 1999, Igisu et al., 1994).