[Kidney injury in transplantation-associated thrombotic microangiopathy]

To study clinicopathological features and mechanism of renal injury in transplantation-associated thrombotic microangiopathy (TA-TMA).

The renal biopsies obtained from patients after hematopoietic cell transplantation or kidney transplantation were observed by immunofluorescence, light microscopy and electron microscopy (EM).

The patients presented hypertension, massive proteinuria, intravascular haemolysis and renal insufficiency some time after transplantation. Various immunoglobulins and complements were negative in immunofluorescent staining. Light microscopy showed endothelial cell proliferation and swelling of glomerular capillary and small arteries, irregular thickened glomerular basement membrane and microthrombosis. EM revealed endothelial cell proliferation and swelling with thickened lamina rara interna of glomerular basement membrane.

TA-TMA is a rare complication after organ or tissue transplantation. Kidney is often involved in TA-TMA with massive proteinuria, anemia and renal failure. Differential diagnosis should be made between TA-TMA and rejection or other renal diseases. Renal biopsy is a major method for accurate diagnosis. TA-TMA correlates to endothelial cell injury caused by viral infection and/or immunosuppressive drugs for anti-rejection.