A lot of attention has been paid to evaluation of host immune system status for prognosis of acute pyelonephritis and system inflammatory response. It is known that strength and quality of the host immune response depend on balance between apoptosis and cell proliferation processes. It is known from literature that in patients with purulent and septic diseases a rise of apoptotic readiness is observed in both fresh isolated and cultured lymphocytes. Absence of studies of peripheral blood lymphocytes apoptosis nature in patients with acute pyelonephritis was the reason for the present study.

Assay of lymphocyte apoptosis dynamics in cell cultures of healthy humans and patients with various forms of acute pyelonephritis was performed. 28 patients with acute upper urinary tract infection were enrolled in the study. There were 12 patients with acute purulent destructive process and 16 patients with non-complicated pyelonephritis. A control group consisted of 14 healthy donors.

It was demonstrated that purulent complications are accompanied by significant increase in apoptotic cells among the fresh isolated lymphocytes. In vivo incubation detected significant difference in dynamics of lymphocyte apoptosis rising depending on severity of the disease: in case of purulent complications it was much higher than in healthy individuals, and reduction of activation apoptosis was observed in patients without complications. Therefore the assay of lymphocyte apoptosis may provide important information for prognosis determination and management of patients with acute pyelonephritis.