Article Text

FRI0590 Soluble interleukin-2 receptor levels reflect disease activity in IGG4-related disease and primary sjÖgren's syndrome
  1. M Akiyama,
  2. T Sasaki,
  3. Y Kaneko,
  4. H Yasuoka,
  5. K Suzuki,
  6. K Yamaoka,
  7. T Takeuchi
  1. Division of Rheumatology, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan


Background Soluble interleukin-2 receptor (sIL-2R) is known as an indicator for activation status of lymphocytes and could be a potential biomarker for disease activity of lymphoproliferative disorders and autoimmune diseases.

Objectives The aim of this study was to examine the association of sIL-2R with disease activity in patients with IgG4-related disease (IgG4-RD) and primary Sjögren's syndrome (pSS).

Methods Consecutive 45 patients with active, untreated IgG4-RD, 117 patients with pSS, and 10 patients with sicca syndrome (subjects with xerostomia with neither anti-SSA/SSB antibodies nor lymphocytic infiltration by lip biopsy) were enrolled. Disease activity of IgG4-RD and pSS was determined based on the IgG4-RD responder index (IgG4-RD RI) score and the EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI) score, respectively. The association of sIL-2R with disease activity was analyzed.

Results The levels of sIL-2R and serum IgG were significantly higher in both IgG4-RD (709U/mL, and 1988mg/dL) and pSS (464U/mL, and 1851mg/dL) compared to sicca syndrome (276U/mL, and 1255mg/dL). Serum levels of IgG4, IgE, and circulating eosinophil counts were significantly higher in IgG4-RD (552mg/dL, 732IU/mL, and 366/mm3) compared to pSS (37mg/dL, 216IU/mL, and 157/mm3) and sicca syndrome (45mg/dL, 132IU/mL, and 137/mm3). On the other hand, the levels of serum IgA and IgM were significantly higher in pSS (312mg/dL, and 112mg/dL) compared to IgG4-RD (182mg/dL and 81mg/dL) and sicca syndrome (228mg/dL and 78mg/dL). The levels of serum C-reactive protein, lactate dehydrogenase, CH50, CC chemokine ligand (CCL17)/thymus and activation-regulated chemokines (TARC) were not different among the three groups. In patients with IgG4-RD, the baseline IgG4-RD RI scores significantly correlated with the levels of sIL-2R (ρ=0.715, p<0.0001), serum IgG (ρ=0.672, p<0.0001) and IgG4 (ρ=0.632, p<0.0001), but not serum IgE levels (ρ=0.290, p=0.082) and circulating eosinophil counts (ρ=0.149, p=0.335). In patients with pSS, the ESSDAI scores significantly correlated with the levels of sIL-2R (ρ=0.615, p<0.0001) and serum IgG (ρ=0.627, p<0.0001), but not the levels of serum IgA (ρ=0.169, p=0.073) and IgM (ρ=0.133, p=0.157). Furthermore, the number of affected organs positively correlated with sIL-2R levels in both IgG4-RD (ρ=0.725, p<0.0001) and pSS (ρ=0.559, p<0.0001). Receiver operating characteristic curve analysis demonstrated that sIL-2R was the most distinguishable biomarker for the presence of extra-dacryosialadenitis lesions in patients with IgG4-RD, compared to serum IgG and IgG4, with a cut-off value of 424 U/mL (AUC=0.917, p<0.0001), and in patients with pSS with 513 U/mL (AUC=0.894, p<0.0001). The sIL-2R levels in patients with IgG4-RD decreased significantly after glucocorticoid treatment. Notably, the cases which could be followed up at disease relapse or exacerbation showed the re-elevation of sIL-2R levels.

Conclusions Soluble IL-2R level is a biomarker for disease activity, in particular for the extent of organ involvements and extra-dacryosialadenitis lesions in patients with IgG4-RD and pSS. Furthermore, sIL-2R level could be useful for longitudinal disease monitoring in patients with IgG4-RD.

Acknowledgements We sincerely thank all the physicians and others caring for the patients enrolled in this study.

Disclosure of Interest None declared

Statistics from

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.