A 41-year-old female visited our emergency room for recurrent epigastric pain and diarrhea in the last 3 months after a general weakness and vague feeling of illness. The pain lasted for several hours to days and improved spontaneously. The patient had no history of spontaneous abortion or vaccination recently. She had normal blood pressure (110/70 mmHg), pulse (88/min), respiration (20/min), and body temperature (37.1°C). Her mentality was alert without focal neurologic deficit. Her hemoglobin (10.6 g/dL) and platelet count (9,000/μL) were decreased, but recovered completely to normal levels (15.2 g/dL, 255,000/mL) within several days, as abdominal pain disappeared. Serum haptoglobin was undetectable. Lactate dyhydrogenase level was high (851 IU/L) with poikylocytosis and red blood cell remnants on peripheral blood smears (Fig. 1A and 1B). Anti-Ro antibody (Ab) was positive. Prothrombin time, activated partial thromboplastin time, fibrinogen, fibrinogen degradation production, D-dimer for disseminated intravascular coagulation, FANA, anti-dsDNA/anti-Smith/anti-phospholipid Abs, anti-neutrophil cytoplasmic antibody for autoimmune diseases, direct/indirect Coomb’s tests for immune cytopenia, flow cytometry for paroxysmal nocturnal hemoglobinuria, human immunodeficiency virus tests, blood urea nitrogen/creatinine (9.9/0.59 mg/dL), C3/C4 (123.6/30.8 mg/dL), procalcitonin, C-reactive protein, a disintegrin and metalloproteinase with thrombospondin type 1 motif, 13 (ADAMTS-13), computed tomography, and positron emission tomography scans were all normal. Her stool cultures were negative for salmonella, shigella, and shiga toxin producing Escherichia coli. Bone marrow studies demonstrated erythroid karyorrhexis and increased megakaryocytes with hyperlobulated nuclei (Fig. 1C and 1D). With symptom free intervals, sudden bouts of abdominal pain and thrombocytopenia developed recurrently which recovered spontaneously. Under the diagnosis of atypical hemolytic uremic syndrome (HUS), associated genetic changes were tested but not identified (Table 1). During conservative treatment with glucocorticoids (20 mg/day) and hydroxychloroquine (400 mg/day), sudden onset of chest pain and cardiac arrest followed nausea and diarrhea. Coronary angiography showed diffuse stenosis of coronary arteries which recovered fully with intra-coronary nitrate injection (Fig. 2). Acute coronary syndrome of vasospastic variant angina was diagnosed, which was accompanied by acutely precipitating thrombocytopenia and anemia without haptoglobin as a HUS. Refractory to β-blocker and vasodilators, her acute coronary attacks occurred repeatedly which resulted in cardiac death.