ABSTRACT
Serum creatinine is an unreliable marker of renal function in neonates because it freely crosses the placental barrier and maternal creatinine is present in the neonate's circulation. Furthermore, there is a variable degree of proximal tubular reabsorption of creatinine in the immature kidneys. Elevated serum potassium levels may be a consequence of hypoxia, metabolic acidosis, catabolic stress, oliguric renal failure and inadequate excretion by the immature distal nephron. Low calcitriol levels result in reduced calcium absorption from the gut and reduced renal calcium reabsorption. Coupled with hyperphosphataemia (resulting from reduced renal excretion of phosphate) this stimulates increased secretion of parathyroid hormone from the parathyroid glands. Acute rejection is an important cause of early graft dysfunction and may be due to either T-cell mediated rejection or antibody-mediated rejection. The diagnosis is made by renal biopsy and identifying donor specific antibodies in the recipient's blood.
