Fig. 4

Therapy assessment and quantitative analysis of [⁶⁴Cu]Cu-NOTA-CD4 in arthritic lesions 24 h p.i. a Timeline of the overall experiment starting at with immunization of collagen-induced arthritis (CIA) mice followed by booster injection three weeks later, treatment regimen, i.v. injection of [⁶⁴Cu]Cu-NOTA-CD4 and 24 h PET/CT imaging. Flow cytometric analysis of the carpal and tarsal joints was performed on the last day of the experiments. b Untreated CIA mice were scored according to degree of inflammation (swelling and erythema) in each paw on a scale from 0 to 4 (n = 23). Data are shown as mean CIA score per mouse starting on day 26 after immunization to injection of tracer (day 35). Each line represents the development of arthritis in one mouse. c Mean CIA score per mouse of dexamethasone (DXM) (1 mg/kg, i.p.)-treated CIA mice (n = 12). d Quantitative analysis of [⁶⁴Cu]Cu-NOTA-CD4 uptake 24 h p.i. in the carpal and tarsal joints of control (n = 11), DXM treated (n = 12) and untreated CIA mice (n = 23). Uptake is calculated as %ID/joint and %Max ID/g. Each point represents a joint. e Representative maximum intensity projections (coronal view) of control, DXM treated and untreated CIA mice. Images were acquired 24 h p.i. as maximum intensity projections (%ID/g). Liver (L), spleen (S), kidney (K) and white ring encircle a joint with high [⁶⁴Cu]Cu-NOTA-CD4 activity. f Joint/blood ratios of [⁶⁴Cu]Cu-NOTA-CD4 uptake in control, DXM treated and untreated CIA mice 24 h p.i. Data are presented as mean ± SEM. The significance level is indicated by asterisks (*). p < 0.05 (*), p < 0.01 (**), p < 0.001 (***) and p < 0.0001 (****)