T-lymphocyte activation in steroid-sensitive nephrotic syndrome in childhood

We undertook a sequential study in 29 children with steroid-sensitive nephrotic syndrome (SSNS) off treatment to seek evidence for T-cell activation in relapse. T-cell subsets and activation markers were analysed using two-colour flow cytometry. Soluble IL2 receptor (sIL2R) was measured in serum and urine by enzyme-linked immunosorbent assay (ELISA). Fifteen children were examined in remission and subsequent relapse (group A) and fourteen remained in remission (group B). In group A the proportion of CD4 + cells expressing the activation marker CD25 (alpha-chain of the IL2 receptor) increased significantly from remission to relapse : CD4 + 25 + cells rose from 5.6 to 7.0% of total lymphocytes, and from 15.8 to 19.1% of CD4 + lymphocytes (paired t test : P