We used linear regression analysis to assess associations between ZPP and iron markers ( including anaemia ) , factors known or suspected to be associated with iron status , inflammation markers ( plasma concentrations of C-reactive protein and 1-acid glycoprotein ) , infections ( Plasmodium infection , HIV infection ) , and other disorders ( ( + ) - thalassaemia , plasma concentrations of total bilirubin , and lactate dehydrogenase ) .