title: Serum YKL-40 in psoriasis with and without arthritis; correlation with disease activity and high-resolution power Doppler ultrasonographic joint findings.
abstract: BACKGROUND
  YKL-40 may be involved in angiogenesis in psoriasis and psoriatic arthritis (PsA). High-resolution power Doppler ultrasound (PDUS) can detect angiogenesis of synovium in PsA.
  
  
  OBJECTIVE
  To assess serum YKL-40 in psoriasis patients with or without PsA, and to correlate its levels with disease activity and high-resolution PDUS findings.
  
  
  METHODS
  In this case-control study, 48 patients with psoriasis (26 of them also had PsA) and 30 controls were assessed by high-resolution PDUS, and assayed for serum levels of YKL-40 by ELISA. Patients were clinically assessed using Composite Psoriatic Disease Activity Index (CPDAI). Total joint score (TJS) was used to assess joint involvement in PsA.
  
  
  RESULTS
  A statistically significant elevation was found in YKL-40 levels in psoriatics with or without PsA compared with controls (P < 0.001), as well as in PsA (group II) compared to patients without arthritis (group I) (P = 0.002). CPDAI, synovial thickness score and colour Doppler ultrasound (CDUS) score were highly significantly higher in group II vs. group I (P < 0.001). In all patients, CPDAI, synovial thickness and CDUS score were positively correlated to each other, and each of them was positively correlated to serum YKL-40 levels (P < 0.05). In either group I or II, serum YKL-40 levels correlated positively with CPDAI (P < 0.05). In group II, TJS, synovial thickness and CDUS score were positively correlated to each other (P < 0.05).
  
  
  CONCLUSIONS
  Serum YKL-40 can be used as a new biological marker for angiogenesis and disease activity in psoriasis with or without PsA. High-resolution PDUS is a non-invasive tool for the evaluation of angiogenesis in PsA patients as well as for the detection of early synovial changes in psoriasis patients without arthritis.
authors.affiliation: Department of Physical Medicine, Rheumatology, and Rehabilitation, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
authors.forename: S F
authors.initials: SF
authors.lastname: Ahmed
authors.forename: E A S
authors.initials: EA
authors.lastname: Attia
authors.forename: A A
authors.initials: AA
authors.lastname: Saad
authors.forename: M
authors.initials: M
authors.lastname: Sharara
authors.forename: H
authors.initials: H
authors.lastname: Fawzy
authors.forename: E M A
authors.initials: EM
authors.lastname: El Nahrery
mesh_terms: D054392:Adipokines / Q000097:blood*; D000293:Adolescent; D000328:Adult; D015535:Arthritis, Psoriatic / Q000097:blood; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D000071451:Chitinase-3-Like Protein 1; D005260:Female; D005384:Finger Joint / Q000000981:diagnostic imaging; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging; D037102:Lectins / Q000097:blood*; D008297:Male; D008662:Metacarpophalangeal Joint / Q000000981:diagnostic imaging; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000097:blood* / Q000000981:diagnostic imaging*; D011565:Psoriasis / Q000097:blood*; D012720:Severity of Illness Index; D013583:Synovial Membrane / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology; D014033:Toe Joint / Q000000981:diagnostic imaging; D018615:Ultrasonography, Doppler, Color / Q000379:methods*; D014955:Wrist Joint / Q000000981:diagnostic imaging; D055815:Young Adult
chemical_list: D054392:Adipokines; D015415:Biomarkers; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D037102:Lectins