Is the fluorescence optical imaging (FOI) able to discriminate between rheumatoid arthritis patients with and without need of rituximab retherapy? A cohort study

ObjectiveTo evaluate the ability of fluorescence optical imaging (FOI) Xiralite in the discrimination between rheumatoid arthritis (RA) patients with and without need of rituximab (RTX) retherapy—in comparison to clinical, laboratory and musculoskeletal ultrasound parameters.Patients and methodsPatients with established RA were prospectively followed over 1 year by Disease Activity Score 28, patient’s global disease activity (visual analogue scale 0–100 mm), C reactive protein and erythrocyte sedimentation rate, ultrasound seven joint (US7) score and FOI in phases 1–3 and automatically generated PrimaVista mode (PVM) at baseline (before RTX) and after 3, 6 and 12 months. The need for RTX retherapy was decided by the treating rheumatologist—blinded to imaging data.Results31 patients (female 77.4%, mean age 60.1±11.4, mean disease duration 14.9±7.1 years) were included. Fourteen (45.2%) patients received RTX retherapy within 12 months. In the group with RTX retherapy, FOI in PVM mode was the only parameter that presented significant increase over time (β: 0.40, 95% CI: 0.08 to 0.71, p=0.013)—compared with the group without retherapy. In the prediction model via ROC analysis, FOI in PVM reached the highest values of all imaging, clinical and laboratory parameters which was associated with retherapy over 1 year with an area under the curve (AUC) of 0.78 (OR: 0.84, 95% CI: 0.72 to 0.98, p=0.031). US7 GS synovitis score revealed similar association with an AUC of 0.73 (p=0.049).ConclusionUS7 GS synovitis score and FOI in PVM are able to discriminate between patients with and without need for RTX retherapy better than clinical and laboratory parameters.

Fluorescence optical imaging: ready for prime time?

The novel technique of fluorescence optical imaging (FOI, Xiralite), which is approved in the European Union and the USA for clinical use, has been the object of studies since 2009. Indocyanine green-based FOI can demonstrate an impaired microcirculation caused by inflammation in both hands in one examination. Several studies have investigated FOI for detection of joint inflammation by comparing FOI to magnetic resonance imaging (MRI) and/or musculoskeletal ultrasound (MSUS). The results have shown a generally good agreement (>80%) between FOI and clinical examination, MRI and MSUS by power Doppler in inflammatory joint diseases. Moreover, characteristic enhancements in skin and nails are seen in PsA, which potentially can be useful in the diagnostic process of early undifferentiated arthritis. Furthermore, FOI has been investigated for the visualisation of a disturbed microcirculation in the hands and fingers of patients with systemic sclerosis (SSc), highlighting the potential of monitoring vascular changes in SSc and other vasculopathies. The available data indicate that it is time to consider FOI as a useful part of the imaging repertoire in rheumatology clinical practice, particularly where MSUS and MRI are not easily available.

POS1401 ASSESSMENT OF INTERREADER RELIABILITY IN SCORING PATIENTS WITH HAND OSTEOARTHRITIS AND PSORIATIC ARTHRITIS BY FLUORESCENCE OPTICAL IMAGING

Background:Fluorescence Optical Imaging (FOI) utilises the fluorophore indocyanine green (ICG) to reflect enhanced microcirculation in hand and finger joints due to inflammation.Objectives:We wanted to assess the interreader reliability of FOI enhancement in patients with hand osteoarthritis (OA) and psoriatic arthritis (PsA). Furthermore, predefined typical morphologic patterns were included to determine the ability of FOI to discriminate between both diagnoses.Methods:An atlas with example images of grade 0-3 in different joint groups and typical morphologic patterns (‘streaky signals’[1], ‘green/blue nail sign’[2], ‘Werner sign’[3,4], and ‘Bishop’s crozier sign’) of PsA and hand OA was created. Two readers scored all joints in both hands (30 in total) of 20 cases with hand OA and PsA. The cases were randomly mixed and both readers were blinded to diagnosis. Each joint was rated on a semiquantitative scale from 0 to 3 in five different images (PrimaVista Mode (PVM), phase 1, 2 (first and middle image), and 3) during the FOI sequence according to the scoring method FOIAS (fluorescence optical imaging activity score)[1,3]. Interreader reliability on scoring joint enhancement was calculated using linear weighted Cohen’s kappa (κ). Agreement on diagnosis (hand OA vs. PsA) and different morphologic patterns was assessed by calculating (regular) Cohen’s kappa.Results:Overall agreement on scoring joint enhancement (all phases) was substantial (κ = 0.75), with greatest consensus in phase 2 first (κ = 0.75) and lowest agreement in phase 1 (κ = 0.46). Reliability varied in different joint groups (wrist, MCP, (P)IP, DIP), with almost perfect overall agreement on PIP joint affection (κ = 0.81), substantial agreement on wrist (κ = 0.69) and DIP joint affection (κ = 0.63), and moderate agreement on MCP joint affection (κ = 0.49) across all phases. Consensus on morphologic patterns showed overall fair agreement (κ = 0.37) with a similar kappa value on the ability to discriminate between both diagnoses (κ = 0.3).Conclusion:Joint enhancement in FOI can be reliably assessed using a predefined scoring method. The ability of FOI to differentiate between hand OA and PsA seems to be limited. Clearer definition and more training might be needed to better agree on morphologic patterns in FOI.References:[1] Glimm AM, Werner SG, Burmester GR, et al. Ann Rheum Dis. 2016 Mar;75(3):566-570[2] Wiemann O, Werner SG, Langer HE, et al. J Dtsch Dermatol Ges. 2019 Feb;17(2):138-148[3] Werner SG, Langer HE, Ohrndorf S, et al. Ann Rheum Dis. 2012 Apr;71(4):504-510[4] Zeidler H 2019. Fluoreszenzoptische Bildgebung. In: Zeidler H, Michel BA. Differenzialdiagnose rheumatischer Erkrankungen 5. Aufl. Springer, Heidelberg, S. 88-89Disclosure of Interests:Benedict Drude: None declared, Øystein Maugesten: None declared, Stephanie Gabriele Werner: None declared, Gerd Rüdiger Burmester: None declared, Jörn Berger Employee of: Xiralite GmbH, Ida K. Haugen: None declared, Sarah Ohrndorf: None declared

A Novel Fluorescence Optical Imaging Scoring System for Hand Synovitis in Rheumatoid Arthritis – validity and agreement with ultrasound

Objectives To develop and validate a new semiquantitative Fluorescence Optical Imaging (FOI) scoring system – the FOI Enhancement-Generated rheumatoid arthritis (RA) Score (FOIE-GRAS) for synovitis assessment in the hand. Methods The development of FOIE-GRAS was based on consensus of 4 experts in musculoskeletal imaging. Forty-six RA patients, eligible for treatment intensification and with ≥1 clinically swollen joint in the hands and 11 healthy controls were included. FOI, ultrasound and clinical assessment of both hands were obtained at baseline and for RA patients after 3- and 6-months’ follow-up. Twenty RA patients had an FOI rescan after 4 hours. Synovitis was scored using FOIE-GRAS and the OMERACT ultrasound synovitis scoring system. All FOI images were scored by 2 readers. Inter-scan, inter-and intra-reader reliability were determined. Furthermore, FOIE-GRAS agreement with ultrasound and responsiveness was assessed. Results FOIE-GRAS synovitis was defined as early enhancement and scores based on the degree of coverage of the specific joint region after 3 seconds (0–3). Inter-scan, intra- and inter-reader intraclass correlations coefficients (ICC) were good-excellent for all baseline scores (0.76-0.98) and moderate-to-good for change (0.65-76). The FOIE-GRAS had moderate agreement with ultrasound (ICC 0.30-0.54) for total score, a good standardized response mean (>0.80), and moderate correlation with clinical joint assessment and DAS28-CRP. The median (IQR) reading time per FOI examination was 133 (109;161) seconds. Scores were significantly lower in controls 1(0;4) than RA patients 11(6;19). Conclusion The FOIE-GRAS offers a feasible and reliable assessment of synovitis in RA, with a moderate correlation with ultrasound and DAS28CRP, and good responsiveness.

Correction to: Validity and diagnostic performance of fluorescence optical imaging measuring synovitis in hand osteoarthritis: baseline results from the Nor-Hand cohort

An amendment to this paper has been published and can be accessed via the original article.

Associations between fluorescence optical imaging and magnetic resonance imaging and symptoms in hand osteoarthritis

Objectives To investigate whether Fluorescence Optical Imaging (FOI) enhancement and MRI-defined synovitis are associated with pain and physical function in hand OA patients. Methods Bilateral FOI scans and MRI of the dominant hand were available for 221 patients. Finger joints were examined for tenderness on palpation. Pain in individual finger joints during the last 24 h and last 6 weeks and hand pain intensity by the Australian/Canadian hand index and Numeric Rating Scale were self-reported. On joint level, we applied logistic regression with generalized estimating equations to examine whether FOI enhancement and MRI-defined synovitis were associated with pain in the same joint. On subject level, we applied linear regression to assess whether FOI and MRI sum scores were associated with pain intensity and physical function. Results Metacarpophalangeal and thumb base joints were excluded from analyses due to little/no FOI enhancement. Finger joints with FOI enhancement on the composite image had higher odds (95% CI) of pain during the last 6 weeks [grade 1: 1.4 (1.2–1.6); grade 2–3: 2.1 (1.7–2.6)]. Similar results were found for joint pain during the last 24 h and joint tenderness in fingers. Numerically stronger associations were found between MRI-defined synovitis and finger joint pain/tenderness. FOI and MRI sum scores demonstrated no/weak associations with hand pain and physical function. Conclusion FOI enhancement and MRI-defined synovitis were associated with pain in the same finger joint. None of the imaging modalities demonstrated consistent associations with pain, stiffness and physical function on subject level.

Photoluminescence and magnetism integrated multifunctional black phosphorus probes through controllable P=O bonds orbital hybridization

Biological probes with integrating photoluminescence and magnetism characteristic play a critical role in modern clinical diagnosis and surgical protocols combining fluorescence optical imaging (FOI) with magnetic resonance imaging (MRI) technology....