Arthritis & Rheumatism, Volume 63,
November 2011 Abstract Supplement
Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Chicago, Illinois November 4-9, 2011.
Expression of Dendritic Cell-Specific Transmembrane Protein (DC-STAMP) and Osteoclast Precursor (OCP) Frequency in Psoriasis (PsC) Patients Who Develop Psoriatic Arthritis (PsA).
Chiu1, Yahui Grace, Shanmugarajah2, Sutharshini, Gladman2, Dafna D., Panepento1, Ben, Moorehead1, Sharon, Eder2, Lihi, Chandran2, Vinod
Approximately 20% of psoriasis (PsC) patients (pts) develop psoriatic arthritis (PsA) within 10 years after PsC onset. Identification of an arthritis biomarker in PsC would facilitate early intervention with the potential to delay and/or prevent the onset of psoriatic arthritis (PsA). Previously, we reported an increased frequency of circulating osteoclast precursors (OCP) in one third of PsC pts, and examined the potential of Dendritic Cell-Specific Transmembrane Protein (DC-STAMP), a transmembrane protein required for monocyte fusion during osteoclast (OC) formation, as an arthritis susceptibility biomarker in PsC. Four major DC-STAMP expression patterns were identified in human PBMC, in which OC counts increase from pattern I to pattern IV. Healthy controls usually belong to DC-STAMP pattern I, whereas PsA pts manifest DC-STAMP patterns II-IV. Herein we present the data on DC-STAMP and OCP on 10 PsC pts who developed PsA in the International Research Team (IRT) registry..
PsC and PsA pts were diagnosed by rheumatologists according to a standard criterion and enrolled in the IRT registry. Patients were evaluated annually or earlier if they developed joint pain. Diagnosis of new PsA onset was based on the Classified Criteria for Psoriatic Arthritis (CASPAR) criteria. The DC-STAMP pattern and OCP frequencies were examined in pts by flow cytometry and cell culture.
Between 2006 and 2011, 516 PsC pts were enrolled in the IRT registry and 22 pts developed PsA. The DC-STAMP and OCP frequency were analyzed on 43 PsC pts who did not develop PsA and 10 pts who developed PsA as shown in the table below. For 10 pts who developed PsA, 3 samples were collected before PsA onset and 7 samples were collected on or after PsA diagnosis. Among these 7 subjects, 3 pts were on methotrexate and 1 was on etanercept at the time of blood draw.
|OCP frequency||PsC||629 + 1036||839 + 1213||286 + 353||1039 + 1064|
|PsA||28 + 40||850 + 0||360 + 318||775 + 576|
70% of PsC pts who developed PsA had patterns III or IV compared to 37% of PsC patients who had not developed PsA. Consistent with our previous finding, DC-STAMP pattern IV was associated with the highest OCP frequencies.. Nail disease and increased PASI score were two risk factors associated with PsA onset.
These data suggest that DC-STAMP may be a susceptibility marker for arthritis in PsC patients. The lower levels of circulating OCP in some PsA compared to PsC pts may reflect increased migration of these cells into inflamed joints. Additional studies with these biomarkers on PsC pts at risk for arthritis in the IRT registry are in progress.
To cite this abstract, please use the following information:
Chiu, Yahui Grace, Shanmugarajah, Sutharshini, Gladman, Dafna D., Panepento, Ben, Moorehead, Sharon, Eder, Lihi, et al; Expression of Dendritic Cell-Specific Transmembrane Protein (DC-STAMP) and Osteoclast Precursor (OCP) Frequency in Psoriasis (PsC) Patients Who Develop Psoriatic Arthritis (PsA). [abstract]. Arthritis Rheum 2011;63 Suppl 10 :544