title: Inverse correlation of programmed death 1 (PD-1) expression in T cells to the spinal radiologic changes in Taiwanese patients with ankylosing spondylitis.
abstract: Programmed death 1 (PD-1) has been shown to be involved in the negative regulation of the immune response. However, the role of PD-1 in ankylosing spondylitis (AS) has not been studied. Therefore, we analyzed the expression of PD-1 in peripheral blood mononuclear cells (PBMC) from patients with AS. Twenty-three AS patients, 20 rheumatoid arthritis (RA) patients, and 25 normal healthy subjects were recruited. The percentage of the PBMC and PD-1 levels in these subjects were measured by flow cytometry. A higher percentage of CD4+ T cells was noted in AS patients than in healthy controls (37.53±1.65% vs. 31.55±0.92%, P<0.01), but a similar result was not observed with regard to CD3+ T lymphocytes, CD4+CD25 high+regulatory T cells, CD19+ B cells, and CD14+ and CD16+ monocytes/macrophages. PD-1 levels in PBMC were not significantly higher in AS patients than in RA patients or age- and gender-matched healthy controls and were also not correlated to the erythrocyte sedimentation rate, C-reactive protein, limitation of back flexion, and chest expansion in patients with AS. Of interest, the percentages of PD-1+CD3+ T cells and PD-1+CD4+ T cells were significantly lower in AS patients with higher modified Stokes Ankylosing Spondylitis Spinal Scores (mSASSS ≥30) than in those with lower mSASSS (<30; 0.07±0.04% vs. 0.42±0.14%, P<0.05; 0.06±0.03% vs. 0.40±0.14%, P<0.05, respectively). These results have suggested that the increased number of T helper cells lacking PD-1 may contribute to the spinal radiologic changes in AS patients.
authors.affiliation: Division of Allergy, Immunology and Rheumatology, Department of Medicine, Taipei Veterans General Hospital, 201 Section 2 Shipai Road, Taipei, Taiwan.
authors.forename: Ming-Han
authors.initials: MH
authors.lastname: Chen
authors.forename: Wei-Sheng
authors.initials: WS
authors.lastname: Chen
authors.forename: Hui-Ting
authors.initials: HT
authors.lastname: Lee
authors.forename: Chang-Youh
authors.initials: CY
authors.lastname: Tsai
authors.forename: Chung-Tei
authors.initials: CT
authors.lastname: Chou
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000175:diagnosis; D044466:Asian People; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism* / Q000473:pathology; D002452:Cell Count; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061026:Programmed Cell Death 1 Receptor / Q000097:blood*; D011859:Radiography; D013131:Spine / Q000000981:diagnostic imaging* / Q000473:pathology; D013167:Spondylitis, Ankylosing / Q000097:blood / Q000175:diagnosis*; D006377:T-Lymphocytes, Helper-Inducer / Q000378:metabolism* / Q000473:pathology; D013624:Taiwan; D055815:Young Adult
chemical_list: C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor