title: De novo post-transplant thrombotic microangiopathy localized only to the graft in autosomal dominant polycystic kidney disease with thrombophilia.
abstract: BACKGROUND
  Thrombotic microangiopathy (TMA) is a serious complication of renal transplantation and is mostly related to the prothrombotic effect of calcineurin inhibitors (CNIs). A subset of TMA (29%-38%) is localized only to the graft. Case 1: A young woman suffering from autosomal dominant polycystic kidney disease (ADPKD) underwent kidney transplant. After 2 months, she showed slow renal deterioration (serum creatinine from 1.9 to 3.1 mg/dl), without hematological signs of hemolytic-uremic syndrome (HUS); only LDH enzyme transient increase was detected. Renal biopsy showed TMA: temporary withdraw of tacrolimus and plasmapheresis was performed. The renal function recovered (serum creatinine 1.9 mg/dl). From screening for thrombophilia, we found a mutation of the Leiden factor V gene. Case 2: A man affected by ADPKD underwent kidney transplantation, with delay graft function; first biopsy showed acute tubular necrosis, but a second biopsy revealed TMA, while no altered hematological parameters of HUS was detected. We observed only a slight increase of lactate dehydrogenase (LDH) levels. The tacrolimus was halved and plasmapheresis was performed: LDH levels normalized within 10 days and renal function improved (serum creatinine from 9 to 2.9 mg/dl). We found a mutation of the prothrombin gene. Only a renal biopsy clarifies the diagnosis of TMA, but it is necessary to pay attention to light increasing level of LDH.
  
  
  CONCLUSIONS
  Prothrombotic effect of CNIs and mTOR inhibitor, mutation of genes encoding factor H or I, anticardiolipin antibodies, vascular rejection, cytomegalovirus infection are proposed to trigger TMA; we detected mutations of factor II and Leiden factor V, as facilitating conditions for TMA in patients affected by ADPKD.
authors.affiliation: Divisione di Nefrologia - Dialisi -Trapianto, Ospedale Sant'Andrea, La Spezia, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Rolla
authors.affiliation: Divisione di Chirurgia Vascolare e Trapianto di rene, Azienda Ospedaliera Universitaria San Martino, Genova, Italy.
authors.forename: Iris
authors.initials: I
authors.lastname: Fontana
authors.affiliation: Servizio di Anatomia Patologica, Azienda Ospedaliera Universitaria San Martino, Genova, Italy.
authors.forename: Jean Louis
authors.initials: JL
authors.lastname: Ravetti
authors.affiliation: Clinica Nefrologica, Azienda Ospedaliera Universitaria San Martino, Genova, Italy.
authors.forename: Luigina
authors.initials: L
authors.lastname: Marsano
authors.affiliation: Clinica Nefrologica, Azienda Ospedaliera Universitaria San Martino, Genova, Italy.
authors.forename: Diego
authors.initials: D
authors.lastname: Bellino
authors.affiliation: Clinica Nefrologica, Azienda Ospedaliera Universitaria San Martino, Genova, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Panaro
authors.affiliation: Clinica Nefrologica, Azienda Ospedaliera Universitaria San Martino, Genova, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Ansaldo
authors.affiliation: Estor Spa, Pero, Milan, Italy.
authors.forename: Lisa
authors.initials: L
authors.lastname: Mathiasen
authors.affiliation: Divisione di Nefrologia - Dialisi -Trapianto, Ospedale Sant'Andrea, La Spezia, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Storace
authors.affiliation: Divisione di Nefrologia - Dialisi -Trapianto, Ospedale Sant'Andrea, La Spezia, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Trezzi
keywords: Kidney transplantation; Leiden factor V; Protrombin gene; Thrombotic miocroangiopathy