Lymphocyturia: an important diagnostic and prognostic marker in renal allograft rejection

We examined the urine for lymphocytes in 60 renal allograft recipients in the immediate posttransplant period using a simple staining technique with methylene blue. 37 acute rejection episodes associated with deterioration in renal function were observed. Other causes of decreased renal function, such as acute tubular necrosis, vascular occlusion or urologic obstruction were carefully excluded. 34 (92%) of the 37 acute rejection episodes were accompanied by significant lymphocyturia. Lymphocyturia was recognized concomitantly with the rise in serum creatinine in 20 of the 34, whereas in 14 it preceded the rise in serum creatinine by a period of 3.5 +/- 2.5 days. 24 (71%) of the 34 acute rejection episodes were reversed by high dose steroid administration and only 2 of them showed persistent lymphocyturia following treatment. On the other hand, 9 of the 10 nonresponders to steroid therapy showed persistent lymphocyturia. All the nonresponders eventually required maintenance dialysis. Detection of lymphocyturia is not only of value in the diagnosis of acute allograft rejection, but is also useful in determining allograft survival in the immediate posttransplant period.