Clinical and pathological features of thrombotic microangiopathy influencing long-term kidney transplant outcomes

• Published in: PloS one 2020, Vol.15 (1), p.e0227445-e0227445
• Main Authors: Teixeira, Cínthia Montenegro, Tedesco Silva Junior, Hélio, Moura, Luiz Antônio Ribeiro de, Proença, Henrique Machado de Sousa, de Marco, Renato, Gerbase de Lima, Maria, Cristelli, Marina Pontello, Viana, Laila Almeida, Felipe, Cláudia Rosso, Medina Pestana, José Osmar
• Format: Article
• Language: English
• Subjects: Activation; Adult; Anemia; Antibodies; Biology and Life Sciences; Calcineurin; Calcineurin inhibitors; Cell activation; Cell survival; Endothelial cells; Etiology; Female; Glomerulus; Graft rejection; Graft Rejection - complications; Graft Rejection - immunology; Humans; Incidence; Infections - complications; Kidney diseases; Kidney Diseases - complications; Kidney Diseases - therapy; Kidney transplantation; Kidney Transplantation - adverse effects; Kidney transplants; Kidneys; Male; Medicine and Health Sciences; Middle Aged; Nephrology; Pathology; Patients; Pregnancy; Rejection; Retrospective Studies; Survival; Thrombocytopenia; Thrombosis; Thrombotic Microangiopathies - etiology; Thrombotic Microangiopathies - pathology; Thrombotic microangiopathy; Toxicity; Transplantation, Homologous - adverse effects; Transplants & implants
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0227445

Thrombotic microangiopathy (TMA) in post-transplant setting has heterogeneous clinical manifestations. We retrospectively studied data of 89 patients with post-transplant TMA, which was characterized by thrombi in at least one glomerulus and/or arteriole. Systemic TMA was defined by thrombocytopenia and microangiopathic anemia and early onset TMA, when occurred less than 90 days post transplant. The cumulative incidence was 0.93%. The majority of the recipients were young (mean age 39 years), female (52%) and Caucasian (48%) with primary kidney disease of unknown etiology (37%). Early TMA occurred in 51% of the patients and systemic TMA, in 25%. Underlying precipitating factors were: infection (54%), acute rejection (34%), calcineurin inhibitor toxicity (13%) and pregnancy (3%). 18% of the patients had several triggers. Glomerular TMA was observed in 50% of the biopsies and endothelial cell activation, in 61%. The 1-year patient survival was 97% and corresponding graft survival, 66%. Allograft survival was inferior when acute antibody mediated rejection (ABMR) occurred (with 41%; without 70%, p = 0.01), however no differences were determined by hemolysis, time of onset, thrombi location or endothelial cell activation. Our results suggest that post-transplant TMA is a rare but severe condition, regardless of its clinical and histological presentation, mainly when associated to ABMR.