Table 1.
Characteristics of the population considering the presence of high levels of IL15.
Figure 1.
Distribution of rheumatoid factor (RF), anti-cyclic citrullinated peptide antibodies (ACPA) and/or high sIL-15 levels (sIL-15) in the population of patients with Early Arthritis.
Data are shown as Venn diagrams whose circle size has been adjusted to represent, albeit not exactly, the number of patients with each combination of markers. The raw number of patients is displayed larger than the percentages that appear in brackets. The total number of patients is 171, although since some patients exhibited combinations of markers, the sum of the number of patients under the name of the biomarkers exceeds this figure.
Figure 2.
Increased serum IL-15 levels are associated with more severe disease activity during the follow-up of patients with Early Arthritis.
A) Evolution of disease activity estimated by DAS28 during the follow-up period in a population of patients with Early Arthritis (EA), and in accordance with the presence of different biomarkers. Left panel: patients with high (grey boxes; n = 50) or low (white boxes; n = 121) sIL-15. Middle panel: patients with positive (grey boxes; n = 75) or negative (white boxes; n = 96) rheumatoid factor reactivity. Right panel: patients with positive (grey boxes; n = 68) or negative (white boxes; n = 103) anti-cyclic citrullinated peptides antibodies. B) Evolution of disease activity estimated by the DAS28 during the follow-up in patients with early Rheumatoid Arthritis (RA; n = 121) or Undifferentiated Arthritis (UA; n = 50) depending on the presence of high (grey boxes) or low (white boxes) IL-15 serum levels. Data are presented as the interquartile range (p75 upper edge of the box, p25 lower edge, p50 midline in the box), as well as the p95 (upper line from the box) and p5. Dots represent the outliers. X-axis shows follow-up visits. Visit 1: baseline; visit 2: six months; visit 3: twelve months; visit 4: twenty four months.
Table 2.
Variables related with the evolution of disease activity in patients with Early Arthritis.
Table 3.
Risk ratio of Rheumatoid Factor, Anti-cyclic citrullinated peptide antibodies and sIL-15 levels associated with a higher mean disease activity or need for intensive treatment during the follow-up.
Figure 3.
Intensity of treatment in a population of early arthritis patients.
A) Cumulative DMARD treatment during the follow-up period, estimated through the IDT variable (see Methods), in the different subpopulations clustered by the elevated IL-15 serum levels (IL-15 h), the presence of rheumatoid factor (RF+) and/or anti-citrullinated peptides antibodies (ACPA+). B) Distribution of the cumulative glucocorticoid dose adjusted to the number of days of follow-up in the different subpopulations clustered by the elevated sIL-15, RF and/or ACPA. Grey boxes represent those patients with high IL-15 alone or in combination with other biomarkers. In all panels the data are presented as the interquartile range (p75 upper edge of the box, p25 lower edge, p50 midline in the box), as well as the p95 (upper line from the box) and p5. Dots represent the outliers. Statistical significance was established through Kruskal-Wallis test.
Figure 4.
Patterns of DMARD use in a population of early arthritis patients.
Left column: Proportion of patients treated with no DMARD (None; n = 17), DMARDs in monotherapy (Mono; n = 75) or in combined therapy (CT; n = 79) in function of the presence (grey columns) or absence (white columns) of high serum IL-15 (A panel), anti-cyclic citrullinated peptide antibodies (ACPA; B panel) or rheumatoid factor (RF; C panel). Statistical significance was established through Fisher's test. Right column: Proportion of patients treated with methotrexate (MTX; n = 133), leflunomide (LEF; n = 57) or tumor necrosis factor blockers (aTNF; n = 10) in function of the presence (grey columns) or absence (white columns) of high serum IL-15 (D panel), anti-cyclic citrullinated peptide antibodies (ACPA; E panel) or rheumatoid factor (RF; F panel). Statistical significance was established through χ2 test, except in the case of aTNF use that was analysed through Fisher's test.