Systemic disease characterized by platelet aggregation into widespread platelet thrombi and resulting occlusion of the microvasculature. This disease is closely related to and overlaps with Hemolytic Uremic Syndrome (HUS) within the broader definition of thrombotic microangiopathies. Clinical features include seizure, hemiplegia, fatigue, abdominal pain, arthralgias, neurological deficit, and renal insufficiency. Idiopathic presentation with a 60% female preponderance.
Moschcowitz Syndrome; Thrombotic Microangiopathic Hemolytic Anemia.
First described by Eli Moschcowitz, an American pathologist, in 1924.
Approximately 3.7 cases per 1 million people. The mortality rate was 100% until 1980, but a major drop has been observed with early diagnosis and improvement in therapy with plasma exchange. Untreated, mortality remains high at 95%, whereas survival is 90% if treated. Approximately 60% of patients are female. The female-to-male ratio is 3:2.
Most familial cases are recessive, but dominant pedigrees have also been reported. The phenotypes might be identical, but mutations in the ADAMTS13 gene are involved for Moschcowitz disease; the locus is at 9q34.
Characterized by microangiopathic hemolysis and idiopathic platelet aggregation/hyaline thrombi leading to diffuse thrombosis of small blood vessels, with organ ischemia and microangiopathic hemolytic anemia. Platelet transfusion can actually cause deterioration secondary to increased activation and deposition. The thrombi partially occlude the vascular lumina with overlying proliferative endothelial cells. The endothelia of the kidneys and brain are particularly vulnerable to TTP. However, the lungs and liver are affected to a lesser extent. The megakaryocytes and endothelial cells produce and release the ultra-large von Willebrand factor multimer, which favors binding to platelets in the microcirculation. Treatment includes plasmapheresis, which either removes a platelet activator or adds an inhibitor, and immunosuppression. Splenectomy follows failure of medical therapy.
Based on clinical and laboratory findings, including the hemolytic anemia, consumptive thrombocytopenia, central nervous system (CNS) dysfunction, and petechiae.
Peak prevalence in third decade of life, hemolytic anemia, consumptive thrombocytopenia, CNS dysfunction, and petechiae. Seizure activity (16%), hemiplegia (12%), and paresthesias have been reported. Also, the possibility of heart failure and arrhythmias must be considered. Twenty-five percent of patients present with abdominal pain due to gastrointestinal ischemia.
Precautions before anesthesia
The heterogenicity of the patients—adults and children—renders the evaluation difficult. Obtain a full history of the concomitant illnesses (if any) and assess thoroughly the involvement of the kidneys and the CNS. The severity of the infection associated (if any) must be known. Aseptic technique, especially with immunosuppression. Supplemental steroids as needed. Check baseline renal and CNS function and obtain a complete cell blood count. Myopathy/neurotoxicity is possible with vincristine therapy.