Assessment of disease activity in patients with rheumatoid arthritis using optical spectral transmission measurements, a non-invasive imaging technique

Abstract

ObjectivesIn rheumatoid arthritis (RA), treat-to-target strategies require instruments for valid detection of joint inflammation. Therefore, imaging modalities are increasingly used in clinical practice. Optical spectral transmission (OST) measurements are non-invasive and fast and may therefore have benefits over existing imaging modalities. We tested whether OST could measure disease activity validly in patients with RA.MethodsIn 59 patients with RA and 10 patients with arthralgia, OST, joint counts, Disease Activity Score (DAS) 28 and ultrasonography (US) were performed. Additionally, MRI was performed in patients with DAS28<2.6. We developed and validated within the same cohort an algorithm for detection of joint inflammation by OST with US as reference.ResultsAt the joint level, OST and US performed similarly inproximal interphalangeal-joints (area under the receiver-operating curve (AUC) of 0.79, p<0.0001) andmetacarpophalangeal joints (AUC 0.78, p<0.0001). Performance was less similar in wrists (AUC 0.62, p=0.006). On the patient level, OST correlated moderately with clinical examination (DAS28 r=0.42, p=0.001), and US scores (r=0.64, p<0.0001). Furthermore, in patients with subclinical and low disease activity, there was a correlation between OST and MRI synovitis score (RAMRIS (Rheumatoid Arthritis MRI Scoring) synovitis), r=0.52, p=0.005.ConclusionsIn this pilot study, OST performed moderately in the detection of joint inflammation in patients with RA. Further studies are needed to determine the diagnostic performance in a new cohort of patients with RA.

Sensitivity and specificity of optical spectral transmission imaging in detecting joint inflammation in rheumatoid arthritis

“…This confirms that OI is capable of measuring disease activity in RA at the patient level, as demonstrated in a recent study by van Onna et al 10. It may, however, not be more accurate than clinical examination at the joint level, and only after further development, it may become a useful tool for fast, physician-independent, non-invasive assessment of joint inflammation in RA.…”

A need for new imaging modality to detect inflammation in rheumatoid arthritis and osteoarthritis?

“…OST was found to have only moderate agreement with clinical examination, ultrasound and MRI assessments, and performed better in the proximal interphalangeal (PIP) and metacarpophalangeal (MCP) joints than the wrists. Most importantly, their results suggested that OST was a more sensitive method to detect joint areas with inflammation than clinical examination 1. However, Krabbe et al 2 did not confirm the high sensitivity of OST to detect inflammation, questioning the usefulness of the method and the validity of the results.…”

“…Whereas FOI has been tested in a number of studies on inflammatory arthritic diseases,14–17 we have limited knowledge about the performance of the OST. Van Onna et al 1 explored the performance of OST using ultrasound and MRI as reference in patients with RA and arthralgia (controls). Patients with RA were divided into groups with increasing levels of disease activity scores (DAS28), and increasing disease activity scores were associated with higher OST values.…”

“…The sensitivity and specificity to detect inflammation by OST will vary depending on the pre-defined cut-off value for presence of inflammation. Van Onna et al 1 used the same study sample for development and validation of the algorithm to be used for calculation of the inflammatory score, which may have overestimated the sensitivity of the method. Using the same cut-off values in a separate cohort, Krabbe et al 2 did not show any benefit of OST in comparison to clinical examination.…”

Imaging of osteoarthritis (OA): What is new?

“…OST and FOI have performed moderately compared to clinical examination, MRI and ultrasound in the detection of joint inflammation in patients with RA [94][95][96]. Glimm et al…”