[Prognostic values of serum concentration and urinary excretion of interleukin-1 receptor antagonist and tumor necrosis factor receptors type I and II in patients with IGA nephropathy].

Interleukin-1 receptor antagonist (IL-1ra) and tumor necrosis factor soluble receptors (sTNFR) type I and II reducing the activity of IL-1 and TNFalpha may inhibit inflammatory reactions. The aim of the study was to assess whether serum and urine IL-1ra and sTNFR measurements may be useful as the early predicting factors in patients with IgA nephropathy. Twenty seven patients (16 males, 11 females), mean age 41.6 +/- 22.3 years with biopsy-proven IgA nephropathy and nephrotic-range proteinuria were included in this study. Serum concentrations (sIL-1ra, ssTNFR I and II) and urinary excretions (uIL-1ra, usTNFR I and II) of IL-1ra, sTNFR I and II had been measured before the treatment was instituted. After 12 months of therapy with steroids and cyclophosphamide, the patients were divided into two subgroups i.e. R - responders, and NR - nonresponders according to the treatment results. The control groups comprised 8 healthy people. IL-1ra serum concentration and urinary excretion were lower in the patients than in the controls (202 vs 330 ng/ml and 970 vs 1607 ng/mg creatinine respectively; p < 0.05 both). Serum concentrations and urinary excretion rates of sTNFR 1 (5.1 vs 1.7 ng/ml and 4.1 vs 1.1 ng/mg creatinine respectively) and sTNFR II (14.4 vs. 5.0 ng/ml and 8.3 vs. 4.4 ng/mg creatinine respectively) were higher (p < 0.05 each) in the patients than in the controls. The subdivision of patients and their classification according to achieved treatment results showed no statistically significant differences between initial interstitium volume neither concentration of serum total protein, serum creatinine or proteinuria and glomerular filtration rate in R and NR subgroups. Initial IL-1ra serum concentration, its urinary excretion and sTNFR type I and II urinary excretion rates were significantly higher in R than NR (sIL-1ra - 297 vs 167 ng/ml, p < 0.05; uIL-1ra 1360 vs 87 ng/mg Cr, p < 0.01; and ssTNFR I 5.2 vs 2.2 ng/mg Cr, p < 0.05; ssTNF RII14 vs 6 ng/mg Cr, p < 0.05). However, serum concentration and urinary excretion of sTNF R type I and II were significantly higher in R and NR subgroups than in controls (p < 0.05 both), sIL-1ra and uIL-1ra were significantly lower in R and NR than in healthy subjects. The results of evaluations of serum concentration and urinary excretion of IL-1ra showed similar values to control group results only in responders. No statistically significant differences between sIL-1ra or/and uIL-1ra in both R and control groups were found. Increased serum concentration and urinary excretion of IL-1ra correlates with better prognosis for remission of proteinuria and lower risk of deterioration of kidney function. Those assessments may be helpful as a part of initial screening in patients with IgA nephritis and heavy proteinuria. In contrast the evaluation of both serum and urinary TNF RI and II seems to have no predictive value.