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sIL7R concentrations in the serum reflect disease activity in the lupus kidney.

Lauwerys BR, Husson SN, Maudoux AL, Badot V, Houssiau FA - Lupus Sci Med (2014)

Bottom Line: These patients had significantly higher serum double-stranded DNA (dsDNA) Ab and urinary protein to creatinine (UPC) ratio.Administration of immunosuppressive therapy resulted in a significant decrease in serum sIL7R concentrations.Serum sIL7R is a sensitive and specific marker of renal disease activity in SLE.

View Article: PubMed Central - PubMed

Affiliation: Pôle de pathologies rhumatismales , Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain , Brussels , Belgium ; Service de Rhumatologie , Cliniques Universitaires Saint-Luc , Brussels , Belgium.

ABSTRACT

Objectives: Evaluation of disease activity in systemic lupus erythematosus (SLE) nephritis is a challenge, and repeated renal biopsies are usually needed in order to confirm a suspicion of flare. In a previous cross-sectional study, we reported that serum soluble form of the interleukin-7 receptor (sIL7R) levels is strongly associated with nephritis in SLE patients. In the present study, we wanted to confirm the association between changes in serum sIL7R concentrations and renal disease activity in a large longitudinal cohort of SLE nephritis patients.

Methods: Sera were harvested longitudinally in 105 SLE nephritis patients. Serum sIL7R cut-off value for the detection of SLE nephritis activity was determined as the mean sIL7R concentration in non-nephritis SLE patients + 2 SDs using data collected in our previous study. Patients with glomerular filtration rate (GFR) <60 mL/min/1.73 m(2) (n=17) were excluded from the study due to persistently elevated serum sIL7R values.

Results: Serum sIL7R concentrations above the renal cut-off value were observed in 25 (out of 88) patients with a normal GFR. These patients had significantly higher serum double-stranded DNA (dsDNA) Ab and urinary protein to creatinine (UPC) ratio. Strikingly, 12 of them developed a renal British Isles Lupus Assessment Group index (BILAG) A within the next 3 months, while this was only the case in four out of the 63 other patients (p<0.0001). The test had 75.0% sensitivity and 81.9% specificity for the detection of a renal BILAG A. Combination of serum sIL7R with any of the classical tests (anti-dsDNA Ab titres, UPC ratio, serum C3) resulted in an increased specificity for the detection of a renal flare. Administration of immunosuppressive therapy resulted in a significant decrease in serum sIL7R concentrations.

Conclusions: Serum sIL7R is a sensitive and specific marker of renal disease activity in SLE. Elevated serum sIL7R values in SLE patients are associated with or predict the occurrence of an SLE nephritis flare.

No MeSH data available.


Related in: MedlinePlus

Biological indices of disease activity in a longitudinal cohort of SLE nephritis patients according to serum soluble form of the interleukin-7 receptor (sIL7R) concentrations. Anti-double-stranded DNA antibodies (A), urinary protein to creatine (UPC) ratio (B) and serum C3 (C) are plotted in patients with serum sIL7R concentrations above (sIL7R high, n=25) or below the renal cut-off (sIL7R low, n=63). p Values by Mann–Whitney U tests in (A) and (B), by Student's t test in (C).
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LUPUS2014000036F1: Biological indices of disease activity in a longitudinal cohort of SLE nephritis patients according to serum soluble form of the interleukin-7 receptor (sIL7R) concentrations. Anti-double-stranded DNA antibodies (A), urinary protein to creatine (UPC) ratio (B) and serum C3 (C) are plotted in patients with serum sIL7R concentrations above (sIL7R high, n=25) or below the renal cut-off (sIL7R low, n=63). p Values by Mann–Whitney U tests in (A) and (B), by Student's t test in (C).

Mentions: Out of 88 SLE nephritis patients with a normal kidney function, 25 had serum sIL7R measurements above the renal cut-off value during longitudinal follow-up. In these patients, mean±SEM sIL7R concentration was 1678±160 versus 508±40 pmol/mL in the other patients. Patients with sIL7R serum concentrations above the renal cut-off had significantly higher dsDNA antibody titres and UPC ratios at that time point compared with the other patients (figure 1A and B). Serum C3 concentrations were lower in patients with serum sIL7R values above the renal cut-off, but the difference did not reach statistical significance (figure 1C).


sIL7R concentrations in the serum reflect disease activity in the lupus kidney.

Lauwerys BR, Husson SN, Maudoux AL, Badot V, Houssiau FA - Lupus Sci Med (2014)

Biological indices of disease activity in a longitudinal cohort of SLE nephritis patients according to serum soluble form of the interleukin-7 receptor (sIL7R) concentrations. Anti-double-stranded DNA antibodies (A), urinary protein to creatine (UPC) ratio (B) and serum C3 (C) are plotted in patients with serum sIL7R concentrations above (sIL7R high, n=25) or below the renal cut-off (sIL7R low, n=63). p Values by Mann–Whitney U tests in (A) and (B), by Student's t test in (C).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4225729&req=5

LUPUS2014000036F1: Biological indices of disease activity in a longitudinal cohort of SLE nephritis patients according to serum soluble form of the interleukin-7 receptor (sIL7R) concentrations. Anti-double-stranded DNA antibodies (A), urinary protein to creatine (UPC) ratio (B) and serum C3 (C) are plotted in patients with serum sIL7R concentrations above (sIL7R high, n=25) or below the renal cut-off (sIL7R low, n=63). p Values by Mann–Whitney U tests in (A) and (B), by Student's t test in (C).
Mentions: Out of 88 SLE nephritis patients with a normal kidney function, 25 had serum sIL7R measurements above the renal cut-off value during longitudinal follow-up. In these patients, mean±SEM sIL7R concentration was 1678±160 versus 508±40 pmol/mL in the other patients. Patients with sIL7R serum concentrations above the renal cut-off had significantly higher dsDNA antibody titres and UPC ratios at that time point compared with the other patients (figure 1A and B). Serum C3 concentrations were lower in patients with serum sIL7R values above the renal cut-off, but the difference did not reach statistical significance (figure 1C).

Bottom Line: These patients had significantly higher serum double-stranded DNA (dsDNA) Ab and urinary protein to creatinine (UPC) ratio.Administration of immunosuppressive therapy resulted in a significant decrease in serum sIL7R concentrations.Serum sIL7R is a sensitive and specific marker of renal disease activity in SLE.

View Article: PubMed Central - PubMed

Affiliation: Pôle de pathologies rhumatismales , Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain , Brussels , Belgium ; Service de Rhumatologie , Cliniques Universitaires Saint-Luc , Brussels , Belgium.

ABSTRACT

Objectives: Evaluation of disease activity in systemic lupus erythematosus (SLE) nephritis is a challenge, and repeated renal biopsies are usually needed in order to confirm a suspicion of flare. In a previous cross-sectional study, we reported that serum soluble form of the interleukin-7 receptor (sIL7R) levels is strongly associated with nephritis in SLE patients. In the present study, we wanted to confirm the association between changes in serum sIL7R concentrations and renal disease activity in a large longitudinal cohort of SLE nephritis patients.

Methods: Sera were harvested longitudinally in 105 SLE nephritis patients. Serum sIL7R cut-off value for the detection of SLE nephritis activity was determined as the mean sIL7R concentration in non-nephritis SLE patients + 2 SDs using data collected in our previous study. Patients with glomerular filtration rate (GFR) <60 mL/min/1.73 m(2) (n=17) were excluded from the study due to persistently elevated serum sIL7R values.

Results: Serum sIL7R concentrations above the renal cut-off value were observed in 25 (out of 88) patients with a normal GFR. These patients had significantly higher serum double-stranded DNA (dsDNA) Ab and urinary protein to creatinine (UPC) ratio. Strikingly, 12 of them developed a renal British Isles Lupus Assessment Group index (BILAG) A within the next 3 months, while this was only the case in four out of the 63 other patients (p<0.0001). The test had 75.0% sensitivity and 81.9% specificity for the detection of a renal BILAG A. Combination of serum sIL7R with any of the classical tests (anti-dsDNA Ab titres, UPC ratio, serum C3) resulted in an increased specificity for the detection of a renal flare. Administration of immunosuppressive therapy resulted in a significant decrease in serum sIL7R concentrations.

Conclusions: Serum sIL7R is a sensitive and specific marker of renal disease activity in SLE. Elevated serum sIL7R values in SLE patients are associated with or predict the occurrence of an SLE nephritis flare.

No MeSH data available.


Related in: MedlinePlus