engleski

Synovial osteoprogenitor phenotype in patients with rheumatoid arthritis.

Introduction: Rheumatoid arthritis (RA) is a chronic, autoimmune joint inflammation, which results in disability due to irreversible joint destruction. Current treatments can slow the progression of the disease, but are still ineffective in a number of individuals and mainly target inflammation. Since there is increasing evidence on the ability of mesenchymal cells to promote regeneration and suppress inflammation, we focused on the phenotype of non-hematopoietic progenitor populations in synovial tissue of patients with arthritis. Materials and methods: We analyzed cellular composition of synovial tissue from 9 RA patients undergoing surgery, and 6 control patients undergoing arthroscopic treatment. Cells were released by collagenase digestion and analyzed by flow cytometry after labeling with two panels: 1. CD3-FITC, CD14-PE, 7- AAD, CD11b-PECy7, CD235a-APC, CD19-APCeF780, and 2. CD140a-PE, 7-AAD, CD105- PECy7, CD45/CD31/CD235a-APC, CD200-APCeF780. Results: Synovial infiltrate in RA had higher proportions of CD3+ and CD19+ cells, and similar variable proportions of CD11b+ and CD14+ in comparison to control samples. Amongst non- hematopoietic (CD45- CD31-CD235a-) cells, proportion of CD105+ cells was significantly increased in RA patients, whereas proportion of CD200+ cells was similar to controls. Amongst CD200+ cells, CD200+ CD105+ population was more abundant, while CD200+ CD105- cells were slightly less abundant in RA samples in comparison to healthy controls. Conclusions: There are significant differences in the composition of synovial non-hematopoietic compartment between RA patients and healthy synovia. According to experimental studies, CD200+ CD105- cells are considered as earliest osteoprogenitors, and also implicated in regulation of myeloid cell accumulation and activity. Loss of these cells might favor inflammation and arthritis progression.

osteoprogenitors ; arthritis ; phenotyping

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