Increased apoptosis of peripheral blood lymphocytes in children with nephrotic syndrome.

Nephrotic syndrome is accompanied by and probably related to abnormal T-lymphocyte function. Decreased stimulation of survival factors and increased levels of "dead signals" may lead to the malfunction of many cells, including lymphocytes. In our study, we investigated the process of apoptosis within T cells in children with a first attack of nephrotic syndrome (NS). We found that the number of apoptotic T cells is greater in these patients than in both children in remission from NS and in controls. The percentage of annexin-V-fluorescein isothiocyanate (FITC)-positive CD3+ cells was 27.30+/- 12.13% in children with a first attack of NS, 19.22+/- 15.16% (P=0.006) in children in remission and 16.20+/- 6.13% (P=0.004) in controls. The percentage of annexin-V-FITC-positive CD3+CD4+ cells was 7.35+/-7.72% in children with a first attack of NS, 3.80+/-3.75% (P=0.0001) in children in remission and 3.82+/-2.01% (P=0.0002) in controls. We conclude that abnormal number and function of T lymphocytes found in NS patients may be related to an increased apoptotic rate of circulating lymphocytes.