Fig. 3From: Subcutaneous administration, higher age and lower renal function are associated with erythrocyte methotrexate accumulation in Crohn’s disease: a cross-sectional studyMean erythrocyte MTX-PGtotal concentration with standard deviation of our study population and other published IBD populations. MTX-PG concentrations expressed in nmol/8 × 1012 red blood cells as nmol/L, because the articles used packed or washed erythrocytes with a Red Blood Cell International System of Units Reference Range of 8 × 1012 red blood cells per litre.17–19Back to article page