Kịch phát LẠNH HEMOGLOBINURIA (PCH) Một hình thức rất hiếm gặp của thiếu máu tán huyết tự miễn lạnh đặc trưng bởi các giai đoạn cấp tính của tán huyết lớn sau khi tiếp xúc với lạnh. Bệnh thường được chẩn đoán trong nửa cuối của thế kỷ 19 do hiệp hội phải của nó với bệnh giang mai bẩm sinh hoặc đại học. | PAROXYSMAL COLD HEMOGLOBINURIA 691 PAPPENHEIMER BODIES Basophilic red blood cell inclusions often in small clusters near the periphery of the cell. They are composed of ferritin aggregates or of mitochondria or phagosomes containing aggregated ferritin. They often occur in reticulocytes. The associated disorders include Splenectomy post Sideroblastic anemia Lead toxicity PARAPROTEINEMIA See Monoclonal gammopathies. PARIETAL CELL ANTIBODIES See Gastric disorders. PAROXYSMAL COLD HEMOGLOBINURIA PCH A very rare form of cold autoimmune hemolytic anemia characterized by acute episodes of massive hemolysis following cold exposure. The disease was frequently diagnosed during the latter half of the 19th century because of its supposed association with congenital or tertiary syphilis. Now PCH occurs as an acute febrile illness associated with viral syndromes particularly the childhood exanthems. There is usually one self-limited attack of acute intravascular hemolysis with hemoglobinuria. The prognosis is good. A chronic form of the disorder is characterized by recurrent episodes of hemolysis precipitated by exposure to cold temperature. The cause of autoantibody production in PCH is unknown. There are no known racial or genetic predispositions. During severe chilling blood flowing through skin capillaries is exposed to low temperatures. The antibody see Donath-Landsteiner test is biphasic and early-acting complement components bind to red blood cells at lowered temperatures. Upon return of the cells to 37 C in the central circulation the cells are rapidly lysed by activation of the terminal complement sequence through C9. The Donath-Landsteiner antibody dissociates from the red blood cells at body temperature. Constitutional symptoms are prominent during the paroxysm. After cold exposure the patient develops aching pains in the back or legs and abdominal cramps. Chills and fever follow. Urine passed after onset of symptoms typically shows hemoglobinuria which with the .
