POS0976 HAND FUNCTION IS ALREADY REDUCED BEFORE RA-DEVELOPMENT AND REFLECTS SUBCLINICAL TENOSYNOVITIS

Abstract

Background Clinically suspect arthralgia (CSA) is characterized by arthralgia of small joints and considered a risk stage for development of rheumatoid arthritis (RA). However, it remains unknown if the function of the hands is already affected and what mechanisms underlie impaired hand function in CSA. Objectives We aimed to study to what extent the function of the hands is affected in CSA-patients, whether that would reflect underlying subclinical inflammation, and if it can be of value in clinical practice. Methods We studied various measures of hand function in two CSA-populations. CSA-patients in the TREAT-EARLIER-trial (n=236) were evaluated at baseline for: grip strength on a dynamometer, patient-reported difficulties in the grip-domain of the HAQ-questionnaire and incomplete fist-closure at physical examination. Contrast-enhanced MRI of the hands measured synovitis/tenosynovitis/osteitis (summed as subclinical inflammation). Findings were validated in an independent CSA-cohort (n=600) where hand-function was measured as: grip strength evaluated by squeezing the examiner’s fingers, grip-domain of the HAQ-questionnaire, and fist-closure. Results Grip strength (on a dynamometer) was reduced in 75% compared to reference-values in healthy-controls (1), 60% reported grip-difficulties and 13% had incomplete fist-closure. Reduced grip strength was associated with subclinical inflammation (-0.38 kg per point inflammation, 95%CI -0.68;-0.08). Studying separate MRI-features, grip strength reduction was independently associated with tenosynovitis, decreasing with -2.63kg (-2.26; -0.33) per point tenosynovitis (range of observed tenosynovitis scores: 0-20). Similar relations with tenosynovitis were seen for patient-reported grip-difficulties (OR 1.12 per point, 1.07;1.42) and incomplete fist-closure (OR 1.36 per point, 1.03;1.79). In the validation-cohort, 36% had decreased examiner-assessed GS, 51% reported grip-difficulties, and 14% incomplete fist-closure: all were associated with tenosynovitis. Decreased dynamometer-measured grip strength was most sensitive for detecting tenosynovitis (75%), while incomplete fist-closure was most specific (88-90%). Conclusion Hand function is already often affected before RA-development, reflecting subclinical inflammation. In practice, testing hand-function in CSA-patients could conveniently objectify functional limitations and reveal subclinical tenosynovitis. Reference [1]Günther CM, Bürger A, Rickert M, Crispin A, Schulz CU. Grip strength in healthy caucasian adults: reference values. The Journal of hand surgery. 2008;33(4):558-65. Acknowledgements We thank G. Kracht (medical photographer) for preparing Figure 1. Disclosure of Interests None Declared.

Authors 9

1. Doortje I Krijbolder Aachen

   Leiden University Medical Center

   Affiliation as printed

   Leiden University Medical Center (LUMC), Rheumatology, Leiden, Netherlands

2. Sarah J H Khidir Aachen

   Leiden University Medical Center

   Affiliation as printed

   Leiden University Medical Center (LUMC), Rheumatology, Leiden, Netherlands

3. X. Matthijssen Aachen

   Leiden University Medical Center

   Affiliation as printed

   Leiden University Medical Center (LUMC), Rheumatology, Leiden, Netherlands

4. Robin Ten Brinck Aachen

   Leiden University Medical Center

   Affiliation as printed

   Leiden University Medical Center (LUMC), Rheumatology, Leiden, Netherlands

5. Jill van Aken

   Spaarne Gasthuis

   Affiliation as printed

   Spaarne Gasthuis, Rheumatology, Haarlem, Netherlands

6. Irene Speyer

   Stichting Haaglanden Medisch Centrum

   Affiliation as printed

   Haaglanden Medical Center, Rheumatology, Den Haag, Netherlands

7. Florus J van der Giesen Aachen

   Leiden University Medical Center

   Affiliation as printed

   Leiden University Medical Center (LUMC), Rheumatology, Leiden, Netherlands

8. Elise van Mulligen Aachen

   University of Leeds · Leeds Teaching Hospitals NHS Trust · Leiden University Medical Center

   Affiliation as printed

   Leiden University Medical Center (LUMC), Rheumatology, Leiden, Netherlands

   Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds and NIHR Leeds Biomedical Research Centre, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom;

9. A. Van der Helm – van Mil Aachen

   Leiden University Medical Center

   Affiliation as printed

   Leiden University Medical Center (LUMC), Rheumatology, Leiden, Netherlands