Report of cold agglutinins in a patient with acute ischemic stroke

Stay Away From the Cold: An Unusual Case of Cold Agglutinin Disease Presenting as Recurrent Transient Ischemic Attacks

Cold agglutinin disease (CAD) is a rare autoimmune hemolytic anemia caused by cold-reactive IgM antibodies leading to complement-mediated hemolysis. While CAD-associated venous thromboembolism is recognized, its role in arterial thromboembolic events, particularly ischemic stroke, is poorly defined. We report an 84-year-old woman who developed acute onset upper left extremity weakness following exposure to sub-zero temperatures. She had a history of similar transient episodes during cold seasons and recurrent anemia. Physical examination revealed decreased muscle strength in the upper left extremity (Grade 4+ out of 5) and scleral icterus. Laboratory findings showed normocytic anemia, elevated reticulocytes, high lactate dehydrogenase, indirect hyperbilirubinemia, and undetectable haptoglobin levels. Peripheral smear showed erythrocyte agglutination. Direct antiglobulin test was positive for C3d and IgM, confirming CAD. Vascular imaging showed significant atherosclerotic disease with near-occlusive (>80%) stenosis of the right internal carotid artery. The patient's transient ischemic attacks were attributed to compromised cerebral perfusion due to severe carotid artery stenosis, exacerbated by anemia from cold-induced hemolysis in CAD. Cold exposure precipitated hemolysis, leading to acute anemia and increased blood viscosity, further reducing cerebral blood flow and oxygen delivery. Spontaneous resolution of symptoms upon rewarming supported the role of CAD in her neurological deficits. This case underscores the potential for CAD to induce neurological deficits in patients with significant carotid artery stenosis. Clinicians should consider CAD as a contributory factor in patients presenting with transient neurological deficits precipitated by cold exposure, especially when significant arterial stenosis is present.

[A case of autoimmune hemolytic anemia diagnosed by occurrence of cardioembolic stroke]

A 79-year-old woman came to us because of sudden onset of dysarthria. She had taken apixaban due to her non-valvular atrial fibrillation. A neurological examination revealed mild facial palsy of her right side, and magnetic resonance imaging showed acute brain infarction at the left frontal lobe. There were no stenotic lesions on intracranial or extracranial magnetic resonance angiography, and she was diagnosed with cardioembolic stroke. Intravenous infusion of heparin and edaravone was initiated, and her neurological symptoms improved. However, she gradually developed jaundice and anemia. Gastro-intestinal bleeding was not observed, and her blood test met the diagnostic criteria for hemolytic anemia. Because both the direct Coombs test and cold agglutinin were positive, she was diagnosed with mixed-type autoimmune hemolytic anemia. Although her serum hemoglobin level decreased to 7.0 g/dl on the 12th hospital day, her anemia gradually improved after steroidal therapy with transfusion. It was revealed that she had shown mild anemia (hemoglobin: 9.2-10.9 g/dl) and hyperbilirubinemia (total bilirubin: 1.8-2.6 mg/dl) for 6 months. Therefore, her latent autoimmune hemolytic anemia became activated with the occurrence of cardioembolic stroke. Autoimmune hemolytic anemia might have promoted cardiac thrombus formation despite the administration of an anticoagulant in this case. It should be noted that autoimmune hemolytic anemia can develop as thrombotic disease. In the present case, autoimmune hemolytic anemia was diagnosed based on the development of cardioembolic stroke.

Unusual underlying disorder for pulmonary embolism: Cold agglutinin disease

Cold agglutinin disease (CAD) is a form of autoimmune hemolytic anemia caused by cold-reacting autoantibodies. The manifestations of CAD are commonly anemia, acrocyanosis, and fatigue caused by hemolysis and agglutination of red blood cells (RBCs) at a temperature lower than normal body temperature. We report a case of CAD presenting with pulmonary embolisms in an 86-year-old man. The patient visited our emergency department complaining of acute chest pain and respiratory distress. Laboratory data showed decreased RBC and hematocrit and markedly elevated mean corpuscular hemoglobin (MCH) and MCH concentration (MCHC). A contrast-enhanced computed tomographic scan demonstrated bilateral massive pulmonary embolisms. After admission, diagnosis of CAD was made on the basis of a high cold agglutinin titer without other factors of coagulation. CAD can contribute to the onset of pulmonary embolisms. It is necessary to incubate blood samples at 37 °C when laboratory data show markedly elevated MCH and MCHC and to consider the presence of cold agglutinins as an underlying disorder for the formation of venous thrombosis. <Learning objective: Cold agglutinin disease can contribute to the onset of pulmonary embolisms. It is necessary to incubate blood samples at 37 °C when laboratory data showed markedly elevated mean corpuscular hemoglobin (MCH) and MCH concentration (MCHC) and to consider the presence of cold agglutinins as an underlying disorder for the formation of venous thrombosis. Complete blood count including MCH and MCHC is always ordered, but we may have overlooked the meaning of abnormal results. We must be aware of these parameters and carefully examine the underlying mechanisms of thrombosis.>.