Date: Monday, October 22, 2018
Session Type: ACR Poster Session B
Session Time: 9:00AM-11:00AM
Anti-citrullinated protein antibodies (ACPA) are detectable long before the manifestation of rheumatoid arthritis (RA). EULAR provided a clinical definition of individuals with arthralgia suspicious for progression to RA (clinically suspect arthralgia, CSA). The alteration of monocyte subpopulations in patients with established RA has been described. We aimed to evaluate possible predictive value of the monocyte and lymphocyte subpopulations in individuals in the preclinical phase of RA.
Thirty-four individuals with arthralgia (mean age 45.11±12.6 years; 91% females) and 80 age and gender matched healthy controls (HC) were included. Leukocytes from peripheral blood were analysed by flow cytometry. Lymphocyte subpopulations were defined as CD19+CD3-, CD3+CD4+, CD3+CD8+ and CD16/56+CD3- (NK) cells, monocytes were segregated into classical (CD14+CD16-), intermediate (CD14+CD16+/++) and non-classical (CD14-/dimCD16++) subsets. Data were analysed using t-test and Spearman’s correlation and are expressed as median and interquartile range (IQR).
Out of 34 patients with arthralgia, 27 were ACPA+ and 17 met CSA definition (10 of them were ACPA+), with symptoms duration 36 months (IQR: 77.5), CRP 2.27 mg/L (IQR 3.35), DAS28 2.13 (IQR 1.32). As per definition, there was no clinical synovitis at baseline. Five individuals developed RA within 3-9 months of follow up.
Patients with arthralgia had higher %CD3+ (p=0.002) and %CD3+CD8+ (p=0.034) T cells and lower %NK (p=0.003) and absolute count of NK cells (p=0.002) compared to HC. This was confirmed in a subgroup of ACPA+ patients. The count of tender joints correlated positively with %CD3 (p=0.009; r=0.491) and %CD3CD8 (p=0.034; r=0.410) T cells and negatively with %NK cells (p=0.019; r=0.045). Moreover, individuals who developed RA during follow up, had higher baseline %CD3+ cells (p=0.046) with the trend for lower %NK cells (p=0.065). No differences were seen between patients meeting CSA definition and non-CSA individuals.
Expansion of intermediate (p=0.012) and non-classical (p=0.007) monocytes with reduction of classical monocytes (p=0.001) were demonstrated in all patients with arthralgia compared to HC. Importantly, ACPA+ patients had higher non-classical (p=0.041) and lower classical monocytes (p=0.022) than ACPA- patients. Similarly, ACPA+ patients had higher intermediate (p=0.006) or non-classical (p=0.012) and lower classical (p=0.004) monocytes compared to HC, while no differences were seen between ACPA- patients and HC.
We demonstrate lower NK cells, expansion of intermediate and non-classical monocyte subpopulation in patients in the preclinical phase of RA, especially in ACPA+ individuals. Since this pattern has been described so far in patients with established RA, our data suggest their role even in early phases of RA development. These leukocyte subpopulations could be considered as prognostic biomarkers for further development of RA.
Acknowledgement: Projects AZV-17-32612A and MHCR 023728.
To cite this abstract in AMA style:Prajzlerová K, Kryštůfková O, Hánová P, Hulejová H, Gregová M, Pavelka K, Vencovsky J, Šenolt L, Filková M. Altered Count of NK Cells and Non-Classical Monocyte Subpopulation in the Pre-Clinical Phase of Rheumatoid Arthritis [abstract]. Arthritis Rheumatol. 2018; 70 (suppl 10). https://acrabstracts.org/abstract/altered-count-of-nk-cells-and-non-classical-monocyte-subpopulation-in-the-pre-clinical-phase-of-rheumatoid-arthritis/. Accessed April 8, 2020.
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