Table 1 Available imaging agents for rheumatoid or experimental arthritis

General tracers

¹⁸ F-fluoro-2-deoxy-D-glucose

Glucose metabolism, inflammation

Clinical use for detection of inflammation and cancer

[1, 35]

^99mTc-diphosphonates

Alterations in bone metabolism, osteoblastic activity

Clinical use for bone scanning

[33, 34]

¹¹C-choline

Cell membrane synthesis, inflammation

Clinical use for detection of prostate cancer

[36, 37]

Trial in 10 patients with inflammatory joint disease

⁶⁷Ga-citrate

Circulating blood plasma proteins and leukocytes, inflammation

Clinical use for detection of inflammation

[14]

^99mTc-polyclonal human immunoglobulin G

Increase in vascular permeability, hyperemia, inflammation

Multiple trials in patients with rheumatic disorders

[38, 39]

^99mTc-/¹¹¹In-labeled leukocytes

Influx of leukocytes into inflamed tissue

Clinical use for infectious and inflammatory disorders

[40]

Multiple trials in patients with RA

^99mTc-RP128

Leukocytes (binds to receptors on neutrophils and mononuclear phagocytes)

Trial with 10 patients with RA

[41]

Radiolabeled biologicals

^99mTc-anti-CD4 mAb

T cells

Case study in 1 patient with RA, trial in 6 patients with RA

[42–45]

^99mTc-anti-CD3 mAb

T cells

Trials in 7 patients with RA, 2 psoriatic arthritis patients, and 38 patients with RA

[46–48]

¹²³I-IL-1Ra

Inflammation

Trial in 4 patients with active RA

[49]

^99mTc-anti-TNF-α

Inflammation

Multiple trials with patients with RA

[2, 50–52]

Phase 3 study (NCT01590966)

^99mTc-/¹²⁴I-anti-CD20 mAb

B cells

Trials in 6 patients with RA and 20 patients with chronic inflammatory autoimmune disease

[53, 54]

Specific molecular markers

^99mTc-acetylated poly-(1,3)-D-galactoside

Mononuclear phagocyte trafficking (binds CD14 and CD11b)

Trials for tumoral, inflammatory and infectious diseases

[55]

Preclinical, rabbit antigen-induced arthritis

^99mTc-/¹¹¹In-octreotide

Endothelium activation and macrophage recruitment (binds to somatostatin receptor)

Clinical use for detection of tumors

[56]

Trial in 14 patients with RA

¹¹C-(R)-PK11195

Monocytes and macrophages (binds to peripheral benzodiazepine receptors)

Trials in 11 patients with RA, 6 patients with RA, and 29 patients with arthralgia

[57, 58]

¹¹¹In-E-selectin-binding peptide

Activated vascular endothelium

Preclinical, rat adjuvant arthritis

[59]

^99mTc-anti-E-selectin Fab/(Fab′)₂ fragment

Activated vascular endothelium

Trial in 26 patients with RA

[60]

NIR-anti-E-selectin Ab

Activated vascular endothelium

Preclinical, CIA, and TNF-α-induced paw edema

[61]

^99mTc-annexin V

Apoptosis (binds to phosphatidylserine)

Multiple trials in cancer patients

[62]

Preclinical, CIA

Cy5.5-anti-F4/80

Macrophages

Preclinical, AIA

[63]

^99mTc-anti-IL-6R

Inflammation

Preclinical, murine arthritis model

[64]

^99mTc-folic acid (EC20)

Activated macrophages, folate receptor

Phase 2 study in patients with autoimmune disease (NCT00588393)

[65–67]

NIR2-folate

Activated macrophages, folate receptor

Mouse arthritis models

[68]

¹⁸ F-PEG-folate

Activated macrophages, folate receptor

Preclinical, methylated bovine serum albumin-induced arthritis

[69]

⁶⁴Cu-/¹⁸ F-galacto-arginine-glycine-aspartic acid

Activated macrophages, osteoclasts, endothelial cells

Clinical use, tumor angiogenesis

[70]

Preclinical, osteopetrosis, and osteoporosis mouse models

NIR-matrix metalloproteinase-specific probe

Sites of matrix degradation and inflammation

Preclinical, CIA, rat OA

[71]

^99mTc-anti-macrophage mannose receptor

Subset of macrophages

Preclinical, CIA

[72]