Case report: Microangiopathic hemolytic anemia and thrombocytopenia in a child with Brucella infection.

Thrombotic thrombocytopenic purpura (TTP) is a diffused microvascular occlusive disorder characterized by microangiopathic hemolytic anemia (MAHA), thrombocytopenia, and ischemic organ dysfunction. In addition, this condition has been linked to an absence or dysfunction of ADAMTS13. Although TTP can occur due to various factors, such as bacteria, viruses, autoimmune disorders, drugs, connective tissue conditions, and solid tumors, it is a rare hematological complication associated with brucellosis. We describe the first case of a 9-year-old boy with acquired TTP with undetectable ADAMTS-13 assay secondary to Brucella infection. After initiating antimicrobial therapy, symptoms and laboratory abnormalities improved dramatically, with no recurrence of TTP in subsequent follow-ups.

Refractory Auto-Immune Thrombotic Thrombocytopenic Pupura Successfully Treated With Caplacizumab.

Thrombotic thrombocytopenic purpura (TTP) is a rare thrombotic microangiopathy characterized by mechanical hemolytic anemia, profound thrombocytopenia, and neurological manifestations. Acquired auto-immune TTP, the most prevalent cause of TTP, is induced by the presence of inhibitory anti-ADAMTS13 auto-antibodies. Modern treatment of acquired TTP relies on plasma exchange, rituximab, and steroids. Caplacizumab (Cablivi®), a humanized single-variable domain immunoglobulin that targets the A1 domain of the ultra-large von Willebrand factor, inhibits the interaction between ultra-large vWFand platelets. In two clinical trials, caplacizumab, in addition to conventional treatment, shortened the delay to platelet count normalization in comparison to conventional treatment plus placebo, without increasing significantly hemorrhagic complications. Moreover, caplacizumab was associated with reduced occurrence of a secondary endpoint associating death, TTP recurrence, and major thromboembolic events. Here, we report the off-label use of caplacizumab in a 68-year-old patient with confirmed acquired TTP, severe thrombocytopenia, and generalized tonic-clonic seizures requiring mechanical ventilation and admission in the intensive care unit. Conventional treatment was rapidly started. Despite the intensification of plasma exchange treatment with twice-daily sessions, steroid continuation, and a second rituximab infusion on day 6, thrombotic microangiopathy worsened with thrombocytopenia at 21 g/L on day 8 from admission. We also considered using caplacizumab, which we could obtain and start on day 12 from admission, as it was available under a temporary authorization use in France. As soon as 12 h after caplacizumab initiation, we observed a significant increase of platelet count and improvement of other hemolytic parameters. We observed resolution of encephalopathy and complete recovery of motor paralysis, allowing us to stop mechanical ventilation on day 14. Caplacizumab was maintained for 128 days until day 139 from initial admission. The patient is going well 10 months after initial admission, without any neurological sequelae, and TTP did not relapse. To the best of our knowledge, this is the first reported use of caplacizumab in such a condition. This case report suggests that caplacizumab use may help to reduce the rate of refractory TTP episodes.

Púrpura trombocitopénica trombótica: Informe de un caso y revisión de la fisiopatología / Thrombotic thrombocytopenic purpura: A case and review of its physiopathology

Se informa un caso compatible con púrpura trombocitopénica trombótica así como los hallazgos de autopsia con una breve revisión de la literatura. Paciente de 19 años de edad con antecedente de HELLP en su primer embarazo, que cursó con alteraciones neurológicas, trombocitopenia y anemia hemolítica. Falleció a 15 días después de su hospitalización. El estudio posmortem reveló numerosos trombos en los vasos de pequeño calibre de diversos órganos. La púrpura trombocitopénica trombótica es un padecimiento raro cuya expresión morfológica es la formación de microtrombos que obliteran el lecho capilar de diversas estructuras vitales. Moschcowitz fue el primero en informar el hallazgo de múltiples trombos hialinos en los vasos de pequeño calibre en una autopsia parcial. Se consideró la posible existencia de "un veneno con capacidad trombótica y aglutinante", que más tarde se identificó como polímeros ultralargos del factor de Von Willebrand cuya persistencia se debe a la carencia de la metaloproteinasa ADAMTS13.

We report a case compatible with thrombotic thrombocytopenic purpura, autopsy findings and make a brief review of the literature. 19 year old woman with HELLP syndrome in her previous pregnancy who presented with neurological signs, thrombocytopenia and microangiopathic haemolytic anemia until her pass away fifteen days after being admitted to the hospital. Autopsy findings showed multiple thrombi in small sized vessels of several organs. Thrombotic thrombocitopenic purpura is a rare disease with a morphological expression featured of many microthrombi in the terminal arterioles of several vital structures. Moschcowitz was the first to inform multiple hyaline thrombi as the primordial finding of a partial autopsy case. He proposed that "a powerful poison with both agglutinative and hemolytic properties" was the causative agent but it was identified years later as unusually large fragments of Von Willebrand factor caused by a deficiency of ADAMTS13, a newly discovered metalloproteinase.