This study aims to identify the nail ultrasonography (NUSG) properties in patients with psoriatic arthritis (PsA) and healthy controls by a participant-based evaluation; to assess feasibility, reliability, and discriminative performances; to explore final scorings; and to determine associations between the NUSG scores and participant characteristics, including demographics and disease-related factors.
NUSG is a visualization method suitable for evaluating the subunits of the nail. The main purpose of this study is to identify NUSG properties in patients with PsA and healthy controls. The investigators recruited patients with PsA according to the CASPAR criteria and sex- and age-matched healthy controls into the study. NUSG parameters were examined by grayscale and power Doppler techniques for all of the fingernails and first toenails (12 nails); and five scorings including nail plate impairment score (NPIs), nail plate thickness score (NPTs), nail bed thickness score (NBTs), nail thickness score (NTs), and the Doppler activity score (DAs) were calculated. The investigators compared the PsA and control groups in terms of the NUSG scorings and also documented the discriminative performances (with receiver operating characteristic curve analysis) of the scorings. Then, the feasibility and reliability analysis of the NUSG scorings were performed. Finally, the association between the NUSG scores and participant characteristics, including sex, age, body weight, height, labor market participation, smoking, hemoglobin, disease duration, history of dactylitis, current enthesitis, radiographic sacroiliitis, C reactive protein, minimal disease activity, Disease Activity Index for Psoriatic Arthritis, Nail Psoriasis Severity Index, and Psoriasis Area Severity Index were explored.
Study Type
OBSERVATIONAL
Enrollment
90
The MyLab 60 (Esaote Biomedica Genoa, Italy) device and linear probe were used. Nails were examined in B-mode grayscale and power Doppler.
Marmara University
Istanbul, Turkey (Türkiye)
The nail plate impairment score
The sonographic normal nail plate term indicates a trilaminar band of the nail plate with two hyperechoic layers separated by a hypoechoic one. The "nail plate impairment score" means the number of nails with impaired trilaminar band (plate) among the 12 nails (all hand nails and toenails). The score ranges between 0-12, with 0 indicating no plate impairments (better) and 12 reflecting the maximal prevalence of impairment (worse).
Time frame: Baseline (T0)
The nail plate thickness score
The plate thickness of each nail was measured (in millimeters) by greyscale USG, then, the sum of 12 nails evaluated (all hand nails and toenails) was calculated as "nail plate thickness score" for a participant (in millimeters). Higher scores were expected to mean worse outcome.
Time frame: Baseline (T0)
The nail bed thickness score
The sonographic nail bed is the dark area below the nail plate to the cortical bone. The nail bed thickness of each nail was measured (in millimeters) by greyscale USG, then, the sum of 12 nails evaluated (all hand nails and toenails) was calculated as "nail bed thickness score" (in millimeters) for a participant. Higher scores were expected to mean worse outcome.
Time frame: Baseline (T0)
The nail thickness score
The total nail thickness (including the plate and bed) of each nail was measured (in millimeters) by greyscale USG, then, the sum of 12 nails evaluated (all hand nails and toenails) was calculated as "nail thickness score" (in millimeters) for a participant. Higher scores were expected to mean worse outcome.
Time frame: Baseline (T0)
The Doppler activity score
Doppler activity of the nail bed and matrix was measured by power Doppler USG. The power Doppler signal for each nail was graded from 0 to 3: 1 point for a signal in less than 25 percent of the nail bed area, 2 points for a signal 25 to 50 percent, 3 points for a confluent signal in more than 50 percent of the nail bed area, and 0 point for no signal. Then, the sum of 12 nails evaluated (all hand nails and toenails) was calculated as "Doppler activity score". The score ranges between 0-36, with 0 indicating no activity (better) and 36 reflecting the maximal activity (worse).
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Time frame: Baseline (T0)
Interobserver reliability of the NUSG scorings
Patients with PsA were evaluated twice in order to assess interobserver reliability. For this purpose, another investigator experienced in musculoskeletal USG performed the ultrasonographic evaluations with the same device but separately from the one who made the first assessment. Then, the consistency between the observers was calculated for each scoring by intraclass correlation coefficient (range 0-1).
Time frame: Baseline (T0)
Intraobserver reliability of the NUSG scorings
Patients with PsA were evaluated again in order to assess intraobserver reliability. For this purpose, the same rheumatologist experienced in musculoskeletal USG performed the ultrasonographic evaluations again, after 2 weeks. Then, the consistency between the observers was calculated for each scoring by intraclass correlation coefficient (range 0-1).
Time frame: Two weeks after the baseline (T1)