Tubular antithrombin at transplantation determines subsequent renal allograft function.

Background: Antithrombin is found in the microvasculature and tubules of normal and transplanted human kidneys. Although depletion of vascular antithrombin is associated with renal allograft dysfunction, neither the distribution nor clinical significance of tubular antithrombin is known.

Methods: Changes in tubular antithrombin in biopsy specimens (n=41) obtained from donor kidneys at transplantation were studied immunohistochemically. The relationship between these changes and subsequent graft function was analyzed.

Results: Granular intracellular antithrombin was found only within the proximal tubular epithelium. Allografts with depleted tubular antithrombin at transplantation (n=20) had significantly greater plasma creatinine concentrations at posttransplant days 3 (P < 0.001) and 5 (P < 0.03) than allografts with normal tubular antithrombin (n=21). Indeed, depletion of tubular antithrombin at transplantation correlated with the degree of graft dysfunction at 3 days after transplantation.

Conclusions: Depleted tubular antithrombin at transplantation is associated with reduced early graft function, and this may identify patients at risk of a complicated follow-up.