Giant mitochondria in "zero-hour" transplant biopsies

Giant mitochondria in kidneys have increasingly been observed since the introduction of Cyclosporin A (CSA) as immunosuppressant in kidney transplants and in patients with autoimmune disorders. In animals treated with CSA, giant mitochondria were also described. In a study of "zero-hour" biopsies taken immediately before or after reperfusion of the renal transplant, giant mitochondria were often unexpectedly found. Retrospective analysis revealed that a significant increase in the number of giant mitochondria is more often associated with CSA therapy than ischemia. Giant mitochondria with sparse cristae seem to prevail in ischemia, whereas those with dense matrix and crystalloid structures predominate in CSA therapy.