Optical imaging of rheumatoid arthritis

1. A method for the diagnosis of an inflammatory disease of a joint comprising

(i) administering to a subject a diagnostically effective amount of

(a) an indocarbocyanine dye of formula (I)

wherein C stands for a radical (II) or (III)

wherein the position that is labelled with the star means the point of linkage with radical A and wherein A stands for a group (IV), (V), (VI), (VII), or (VIII)

wherein

R 1 and R 2 , independently of one another, stand for a C 1 -C 4 -sulfoalkyl chain or a saturated or unsaturated, branched or straight-chain C 1 -C 50 -alkyl chain, which optionally is substituted by 0 to 15 oxygen atoms and/or by 0 to 3 carbonyl groups and/or with 0 to 5 hydroxyl groups or optionally interrupted by 0 to 15 oxygen atoms and/or by 0 to 3 carbonyl groups and/or can be substituted with 0 to 5 hydroxyl groups;

R 3 stands for a straight-chain carbohydrate chain with up to 20 carbon residues, which is substituted with one or more —OH, —COOH, —SO 3 groups and/or optionally interrupted one or more times by —O—, —S—, —CO—, —CS—, —CONH, —NHCO—, NHCSNH—, —SO 2 —, —PO 4 31 —, -aryl- and/or —NH— group;

R 4 stands for the group —COOE 1 , —CONE 1 E 2 , —NHCOE 1 , —NHCONHE 1 , —NE 1 E 2 , —OE 1 , —OSO 3 E 1 , —SO 3 E 1 , —SO 2 NHE 1 or -E 1 , wherein

E 1 and E 2 , independently of one another, stand for a hydrogen atom, a C 1 -C 4 -sulfoalkyl chain, a saturated or unsaturated, branched or straight-chain C 1 -C 50 -alkyl chain, which optionally is interrupted by 0 to 15 oxygen atoms and/or by 0 to 3 carbonyl groups and/or is substituted with 0 to 5 hydroxyl groups;

R 5 stands for a hydrogen atom, or a fluorine, chlorine, bromine or iodine atom, methyl, ethyl, propyl or iso-propyl;

b means the number 2 or 3; and

X and Y, independently of one another, stand for O, S, ═C(CH 3 ) 2 or—(CH═CH)—,

or a salt or solvate of thereof or

(b) an indocarbocyanine dye which is Cy7, indocyanine green (ICG), an analog of ICG, or indotricarbocyanine (ITC),

wherein no targeting moiety is attached to the dye (a) or (b),

(ii) exposing the joint to be imaged to light of a wavelength between 700 nm and 900 nm and

(iii) measuring fluorescence at multiple time points within 500 seconds after administration of said dye,

wherein the distribution of said indocarbocyanine dye in the joint regions suspected of having inflammation is indicative of the presence of inflammatory joint disease.

2. A method according to claim 1 , wherein the inflammatory disease is arthritis.

3. A method according to claim 2 , wherein the arthritis is selected from the group consisting of rheumatoid arthritis, osteoarthritis, psoriatic arthritis, traumatic arthritis, bacterial arthritis, post-infectious arthritis, lyme disease (Borreliose), ankylosing spondyliitis and rubella arthritis.

4. A method according to claim 1 , wherein the indocarbocyanine dye is administered in an amount of 10 mg/kg body weight or less.

5. A method of diagnosing an inflammatory joint disease comprising:

(a) administering to a subject a diagnostically effective amount of an indocarbocyanine dye, by bolus injection

(b) exposing a region of the body of said subject to light of a wavelength between 700 nm and 900 nm

(c) measuring fluorescence in the region of the body at multiple time points which are less than 500 seconds after administration of said dye,

wherein the indocarbocyanine dye has the formula (I)

wherein C stands for a radical (II) or (III)

wherein the position that is labelled with the star means the point of linkage with radical A and wherein A stands for a group (IV), (V), (VI), (VII), or (VIII)

wherein

R 1 and R 2 , independently of one another, stand for a C 1 -C 4 -sulfoalkyl chain or a saturated or unsaturated, branched or straight-chain C 1 -C 50 -alkyl chain, which optionally is substituted by 0 to 15 oxygen atoms and/or by 0 to 3 carbonyl groups and/or with 0 to 5 hydroxyl groups or optionally interrupted by 0 to 15 oxygen atoms and/or by 0 to 3 carbonyl groups and/or can be substituted with 0 to 5 hydroxyl groups;

R 3 stands for a straight-chain carbohydrate chain with up to 20 carbon residues, which is substituted with one or more —OH, —COOH, —SO 3 groups and/or optionally interrupted one or more times by —O—, —S—, —CO—, —CS—, —CONH, —NHCO—, NHCSNH—, —SO 2 —, —PO 4 − —, -aryl- and/or —NH— group;

R 4 stands for the group —COOE 1 , —CONE 1 E 2 , —NHCOE 1 , —NHCONHE 1 , —NE 1 E 2 , —OE 1 , —OSO 3 E 1 , —SO 3 E 1 , —SO 2 NHE 1 or -E 1 , wherein

E 1 and E 2 , independently of one another, stand for a hydrogen atom, a C 1 -C 4 -sulfoalkyl chain, a saturated or unsaturated, branched or straight-chain C 1 -C 50 -alkyl chain, which optionally is interrupted by 0 to 15 oxygen atoms and/or by 0 to 3 carbonyl groups and/or is substituted with 0 to 5 hydroxyl groups;

R 5 stands for a hydrogen atom, or a fluorine, chlorine, bromine or iodine atom, methyl, ethyl, propyl or iso-propyl;

b means the number 2 or 3; and

X and Y, independently of one another, stand for O, S, ═C(CH 3 ) 2 or —(CH═CH)—, or

wherein the indocarbocyanine dye is Cy7, indocyanine green (ICG), an analog of ICG, or indotricarbocyanine (ITC)

as well as a salt or solvate thereof,

wherein no targeting moiety is attached to the dye.

6. A method according to claim 5 , wherein the inflammatory joint disease is arthritis.

7. A method according to claim 6 , wherein the arthritis is rheumatoid arthritis, osteoarthritis, psoriatic arthritis, traumatic arthritis, bacterial arthritis, post-infectious arthritis, lyme disease (Borreliose), ankylosing spondyliitis or rubella arthritis.

8. A method according to claim 5 , wherein the indocarbocyanine dye is administered in an amount of 10 mg/kg body weight or less.

9. A method according to claim 5 , wherein the indocarbocyanine dye is injected into the joint region to be diagnosed or into a blood vessel or the lymphatic system, which provides blood or lymph to the joint region of the body to be diagnosed.

10. A method according to claim 9 , wherein the blood vessel is the vein of the arm.

11. A method according to claim 5 , wherein the light in step (b) is applied continuously, amplitude modulated or pulsed.

12. A method according to claim 5 , wherein the fluorescence is measured at multiple time points at least for 20 s, 30 s, 40 s, 50 s, 60 s, or 120 s after administration of the indocarbocyanine.

13. A method according to claim 5 , wherein the fluorescence in the joint region is detected at each time point as one image and/or by scanning the joint region of the body.

14. A method according to claim 5 , wherein the fluorescence is detected in intervals of 5 s or less.

15. A method according to claim 5 , wherein a fluorescent standard is provided on or in the vicinity of the imaged joint region to normalize the measured fluorescence.

16. A method according to claim 5 , wherein a computer program is used to determine a time resolved pattern of circulation, preferably a pattern of blood circulation within the joint region of the body.

17. A method according to claim 16 , wherein the pattern of blood circulation in a patient suspected of having a joint inflammatory disease is compared to the pattern of blood circulation in a healthy patient and wherein alterations of the pattern of blood circulation are indicative of a joint inflammatory disease.

18. A method according to claim 5 , wherein the joint region of the body is the hand, foot, knee, elbow or shoulder.

19. A method according to claim 18 , wherein an increase of fluorescence at the joints is indicative of an inflammatory disease.

20. A method according to claim 5 , wherein the indocarbocyanine wavelength of excitation maximum differs from the wavelength of the fluorescence maximum by at least 10 nm.

21. A method according to claim 4 , wherein the indocarbocyanine dye is administered in an amount of 1 mg/kg body weight or less.

22. A method according to claim 4 , wherein the indocarbocyanine dye is administered in an amount of 0.1 mg/kg body weight or less.

23. A method according to claim 1 , wherein an increase of fluorescence is detected within less than 300 seconds after administration of the indocarbocyanine dye.

24. A method according to claim 5 , wherein an increase of fluorescence is detected within less than 300 seconds after administration of the indocarbocyanine dye.