gms | German Medical Science

Introduction: Fluorescence-optical imaging (FOI) is an indocyanine green (ICG) tailored method to detect microvascular changes in the hands using ICG kinetics over 360 sec. Different methods for the assessment of FOI are available. The aim of this study is to evaluate to what extent these methods can be used to differentiate psoriasis (PsO) from psoriasis arthritis (PsA).

Methods: FOI data (PsA n=62, PsO n=168) from a multicentre trial in Germany were used for two different methods: FOI activity score (FOIAS) and individual characteristics of ICG kinetics. For FOIAS, the signal enhancement levels were scored from 0 to 3 (0=no enhancement, 3=strong enhancement) per joint and the summation picture was assessed. Kinetics were determined by joint-related signal enhancements as well as by ICG related flow-on and flow-off behaviour. FOI total score and time durations were compared between indications.

Results: By use of FOIAS, the maximum score (overall signals of all joints assessed by FOIAS) showed a significant difference (p=0.0075) between PsA (median 3 with IQR 1-20) and PsO patients (median 1.0 with IQR 0-5). Neither the time to global maximum of ICG (PsA median 82 (IQR 64-112) sec vs. PsO 78 (IQR 60-119) sec), nor the time to clearance of ICG (PsA median 272 (IQR 221-304.5) sec vs. PsO 254 (IQR (227.5-293) sec) showed significant difference between the two indications. The mean duration of the 3 phases of kinetic (1: flow-in, 2: stable, 3: clearance) was 52.4 sec, 180.2 sec and 119.8 sec for PsA and 57.6 sec, 186.0 sec and 130.5 sec for PsO. In general PIP (proximal interphalangeal) joints had the most signals in FOIAS. In PsA patients, most frequently affected joints were PIP 3, 4 and 5, on the right.

Conclusion: The use of the manual FOIAS is able to differentiate between PsA and PsO patients by comparing the sum of scores over all joints. The assessment of ICG kinetics is limited to discriminate between musculoskeletal and joint disease, differentiation of diseases can only be seen by trend. A combination of both methods might be useful to increase the potential of manual assessment of FOI signals.

Figure 1 [Fig. 1]

Disclosures: Luis Haan: non declared; Michaela Koehm Grant/research support from: BMS, Pfizer, Janssen, Consultant for: Pfizer, Celgene, Janssen, Speakers bureau: Pfizer, Celgene, Janssen; Ann Christina Foldenauer: non declared; Ulf Henkemeier Grant/research support from: BMS; Harald Burkhardt Grant/research support from: BMS, Pfizer, Janssen, Consultant for: AbbVie, BMS, Pfizer, Janssen, Roche, Chugai, Speakers bureau: AbbVie, BMS, Pfizer, Janssen, Roche, Chugai; Frank Behrens Grant/research support from: AbbVie, Pfizer, Roche, Chugai, Prophylix, Bioline, Novartis, Consultant for: AbbVie, Pfizer, Roche, Chugai, UCB, Bristol-Myers Squibb, Celgene, MSD, Novartis, Biotest, Janssen, Genzyme, Eli Lilly, Speakers bureau: Ad board: AbbVie, Pfizer, Roche, Chugai, UCB, Bristol-Myers Squibb, Celgene, Novartis, Biotest, Janssen, Genzyme, Eli Lilly