199 - Indocyanine Green Enhanced Optical Imaging Using for Monitoring of Treatment Response

Sunday, November 6, 2011: 9:00 AM-6:00 PM
Hall F2 - Poster Hall (McCormick Place West)
Stephanie G. Werner1, Felicitas Spiecker2, Sabine Mettler2, Gudrun Lind-Albrecht2, Carsten Schwenke3 and Hans-Eckhard Langer2, 1RHIO (Rheumatology, Immunology, Osteology) Duesseldorf, Duesseldorf, Germany, 2Duesseldorf, Germany, 3SCOSSIS, statistical consulting, Berlin, Germany
Presentation Number: 199

Background/Purpose: Indocyanine green (ICG) enhanced fluorescence optical imaging (FOI) is a novel diagnostic technology for the assessment of inflammation in arthritis. In cross-sectional studies FOI had a good agreement with MRI and US findings (1),(2). The semiquantitative fluorescence optical imaging activity score (FOIAS) correlated with clinical (DAS 28) and MRI (RAMRI) scores of disease activity and a semiquantitative score of swelling and tenderness in the hands (locDAI). This is the first study to use FOI for the measurement of treatment response in DMARD naïve patients and in subjects with inadequate response to non-biologic DMARDs (DMARD-IR) and switch to biologica.

Method:  33 patients with rheumatoid (RA) and psoriatic (PsA) arthritis were examined before starting treatment with DMARD or biological (visit 1) and at follow-up (visit 2 after ≥3 months). Treatment response was assessed using DAS28, locDAI and FOIAS. For locDAI swelling and tenderness were assessed separately and semiquantitativly for 15 joints of both hands (0 = no, 1 = subtle, 2 = distinct swelling/tenderness, distal interphalangeal joints (DIP) 2-5, interphalangeal joints (IP), proximal interphalangeal joint (PIP) 2-5, metacarpophalangeal joint (MCP) 1-5 and wrist, range 0-60) and a sum score was calculated. The FOI (Xiralite, mivenion GmbH, 0.1 mg/kg/BW of ICG i.v. over 6 minutes) sequences were analyzed for the automatically generated composite image (PVM) and three defined phases of FOI (P1, P2, P3). FOI findings of increased signal intensities were valued as 0=no, 1=low, 2=moderate, and 3=strong increased signal intensities. For FOIAS sum scores over all joints (DIP 2-5, PIP 2-5, IP, MCP 1-5, wrist, both hands, range 0-90) for PVM, the phases P1-3 and all phases were calculated. Standardized response means (SRM) were calculated for measurement of treatment response and Wilcoxon signed rank test was used to assess statistical significant change.

Result: The mean DAS28 at visit 1 was 4.3 and 2.9 at visit 2. All scores (DAS28, locDAI, FOIAS) showed a reduction of disease activity from visit 1 to visit 2. The mean reduction was 34% for DAS28, 47% for locDAI and 22%-34% for FOIAS. The SRMs showed high treatment response (SRM >0.8) for DAS28 (SRM -1.26) and locDAI (SRM -0.95) and moderate response (>0.5-0.8) for FOIAS (SRM -0.57 to-0.76) (3). The change from baseline was stated as statistical significant for all scores except FOIAS P1 (p<0.05).

Conclusion: The study suggests that FOI is a suitable tool to assess treatment response in subjects with RA and PsA. Further studies are required to test FOI as a possible additional outcome measure in clinical trails and clinical practice.

(1) Werner S, Schott P, Bahner M et al. Comparison of Xiralite with Clinical Examination and MRI Ann Rheum Dis 2011;70(Suppl3):555 (2)Werner S, Ohrndorf S, Bahner M et al. Comparison of Xiralite with Clinical Examination and Ultrasonography Ann Rheum Dis 2011;70(Suppl3):361 (3) Husted JA, Cook RJ, Farewell VT, et al. Methods for assessing responsiveness: a critical review and recommendations. J Clin Epidemiol 2000;53:459–68.

Keywords: DMARDs, biologic response modifiers, imaging techniques, psoriatic arthritis and rheumatoid arthritis (RA)

Disclosure: S. G. Werner, None; F. Spiecker, None; S. Mettler, None; G. Lind-Albrecht, None; C. Schwenke, None; H. E. Langer, None.