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We report the case of a 67 years old patient with a history of gastric adenocarcinoma who died in a context of severe dyspnea and whose autopsy will confirm the diagnosis of a Pulmonary Tumor Thrombotic Microangiopathy (PTTM). PTTM is a fatal pulmonary complication associated to multiple cancers. It starts with an acute or subacute respiratory failure quickly evolving towards fatal thrombo-embolic pulmonary hypertension and right heart failure. Pre-mortem diagnosis is difficult and not frequent because the pathology is rare, the underlying neoplastic disease is not always known, clinical and radiological signs are not specific and progression is fast. When made soon enough, PTTM diagnosis avoids useless and sometimes harmful medication. In some cases, an improvement of patient's symptoms and comfort is observed. Some studies described several months of extended survival.

The most frequent causes of hemolytic anemias are immune or infectious diseases, drug induced hemolysis, thrombotic microangiopathies, hereditary spherocytosis, glucose-6-phosphate dehydrogenase or pyruvate kinase deficiencies, thalassemia's and sickle cell disease. Sometimes no cause is found because a rarer etiology is involved. The goal of this review is to remember some unfrequent constitutional or acquired causes and to point out difficulties to avoid wrong interpretations of analysis results.

Thrombotic microangiopathy includes a set of conditions characterized by the association of mechanical hemolytic anemia, thrombocytopenia and organ failure which accurate diagnosis is sometimes difficult. We report the case of a patient who presented a thrombotic microangiopathy (TMA) due to an atypical hemolytic and uremic syndrome (HUS) associated with an immunoglobulin A (IgA) nephropathy with a favorable outcome under corticosteroid.

Acute pancreatitis and thrombotic microangiopathy is an established association: but which is the cause, which is the consequence? Thanks to two case reports and a literature review, we put to light an unequivocal link. Indeed, thrombotic microangiopathy may be responsible for ischemic pancreatitis. On the other hand, acute pancreatitis, whatever its cause, may trigger thrombotic microangiopathy. In either case, an anti-ADAMTS-13 antibody can be detected: its research is mandatory., (Copyright © 2011 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.)

Hemolytic uremic syndrome (HUS) is related to a renal thrombotic microangiopathy, inducing hypertension and acute renal failure (ARF). Its pathogenesis involves an activation/lesion of microvascular endothelial cells, mainly in the renal vasculature, secondary to bacterial toxins, drugs, or autoantibodies. An overactivation of the complement alternate pathway secondary to a heterozygote deficiency of regulatory proteins (factor H, factor I or MCP) or to an activating mutation of factor B or C3 can also result in HUS. Less frequently, renal microthrombi are due to an acquired or a constitutional deficiency in ADAMTS-13, the protease cleaving von Wilebrand factor. Hemolytic anemia with schistocytes, thrombocytopenia without evidence of disseminated intravascular coagulation, and renal failure are consistently found. In typical HUS, a prodromal diarrhea, with blood in the stools, is observed, related to pathogenic enterobacteria, most frequently E. Coli O157:H7. HUS may also occur in the post partum period, and is then related to a factor H or factor I deficiency. HUS may also occur after various treatments such as mitomycin C, gemcitabine, ciclosporin A, or tacrolimus, and as reported more recently bevacizumab, an anti VEGF antibody. Atypical HUS are not associated with diarrhea, may be sporadic or familial, and can be related to an overactivation of the complement alternate pathway. More recently, some of them have been related to a mutation of thrombomodulin, which also regulates the alternate pathway of complement. In adults, several HUS are encountered in the course of chronic nephropathies: nephroangiosclerosis, chronic glomerulonephritis, post irradiation nephropathy, scleroderma, disseminated lupus erythematosus, antiphospholipid syndrome. Overall the prognosis of HUS has improved, with a patient survival greater than 85% at 1 year. Chronic renal failure is observed as a sequella in 20 to 65% of the cases. Plasma infusions and plasma exchanges are effective in most of the cases to treat hemolysis and thrombocytopenia. Steroid therapy is debated, as well as immunosuppressive drugs, including rituximab, in autoimmune forms. A new monoclonal anti-C5 antibody is tested, and seems to be effective in atypical HUS with abnormal complement alternate pathway activation. If terminal renal failure occurs, renal transplantation can be performed but the risk of recurrence, which very low in post infectious forms of HUS, is about 70 to 80% in genetic forms of complement regulatory protein deficiency., (Copyright 2010 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.)