Antibody-mediated rejection : importance of lactate dehydrogenase and neutrophilia in early diagnosis

We report the importance of elevated serum lactate dehydrogenase (LDH) and neutrophil a (NT) in two renal transplant recipients who developed renal impairment in the early post-operative period. One of our recipients developed oliguria and increased serum cretonne with unexplained elevation of LDH and NT. The biopsy was C4d positive with platelet and fibrin thrombi in the glomerular capillaries and arterioles and interpreted as acute vacuities or thrombotic form of antibody-mediated rejection (VAMR) with positive donor-specific antibodies (DSA). Despite intensive treatment, this graft was lost. When another patient developed a similar picture, prompt immunoadsorption was started without waiting for a confirmatory biopsy or DSA, and both were later reported as positive. Improvement in renal function was associated with decreasing levels of LDH and NT. Neither of these was elevated in cases of acute cellular rejection (ACR) or antibody mediated rejection (AMR) with isolated tubular injury (TAMR). It may therefore be reasonable to assume that LDH and NT are potential diagnostic and prognostic markers of VAMR.