An 8-year-old Burmese male presented to the emergency department with a 7-day history of dizziness, jaundice, and worsening ecchymoses/petechiae on the extremities and trunk. This was preceded by 2 months of fatigue and nausea, without diarrhea. Ecchymoses gradually increased in number and size, without history of trauma.
The patient was born at term in a resource-limited Thai refugee camp, and spent 1 month in the hospital for neonatal feeding support and weight gain. At 7 years of age (8 months prior to hospital presentation), the patient immigrated with his immediate family to the United States. Thrombocytopenia (platelet count: 120 x 103/muL) and borderline anemia (hemoglobin: 11.9 g/dL) were noted at a refugee health exam, with negative screening for hepatitis B, human immunodeficiency virus, and tuberculosis. Neither the patient nor his family members have experienced similar symptoms.
The differential diagnosis for this patient included pathologies that manifest as or mimic a coagulopathy. These included severe nutritional deficiencies (e.g., iron, vitamin B12, and folate), systemic disease (e.g., hepatitis, hemolytic uremic syndrome, and disseminated intravascular coagulopathy), blood dyscrasias (e.g., leukemia, idiopathic thrombocytopenic purpura, and inherited/acquired TTP), and non-accidental trauma.
Initial values (Table 1) demonstrated thrombocytopenia, anemia, an elevated reticulocyte count, and a peripheral smear positive for schistocytes and spherocytes. Coagulation studies were normal with an elevated D-dimer. A comprehensive metabolic panel was normal for age and indicated normal kidney function. Coombs' test was negative. The patient was admitted to the hospital, where a low ADAMTS13 (<5%), and a positive inhibitor antibody confirmed the diagnosis of acquired TTP.
In consultation with the hospital's hematology team, the patient received a unit of packed red blood cells and platelets prior to the urgent placement of an internal jugular pheresis catheter for daily plasma exchange therapy (PLASMIC score of 7). In addition, the patient was started on prednisolone (0.5 mg/kg by mouth, twice daily) and rituximab (375 mg/m2 intravenous, once weekly for four doses).
As TTP's microangiopathy can manifest in multiorgan damage, cardiac monitoring was initiated. The patient was found to have an elevated cardiac troponin I (peak: 0.081 ng/mL; reference range [RR]: <=0.016 ng/mL) and intermittent ventricular tachycardia (VT)/premature ventricular contractions (Figure 1). On day 4 of admission, there was an asymptomatic 15-beat run of monomorphic VT at rest, with the shortest R-R cycle length of 330 ms.
Serum electrolytes were monitored via serial comprehensive metabolic panels, which demonstrated hypocalcemia (total serum calcium 8.6 mg/dL; ionized calcium 1.20 mmol/L). All other electrolytes were within normal limits for age. Additionally, a screening echocardiogram demonstrated normal segmental cardiac anatomy and normal biventricular size and systolic function with an anomalous origin of the right coronary artery from the left sinus of Valsalva and a small patent foramen ovale with left-to-right flow. Due to the patient's elevated cardiac troponin, prophylactic heparin was initiated and was transitioned to aspirin for oral anti-platelet therapy upon resolution of the cardiac troponinemia.
To evaluate for a potential rheumatologic etiology of the patient's symptoms, further investigation found a positive antinuclear antibody (ANA), positive anti-double stranded DNA (anti-dsDNA) antibodies, positive SSA 60, and a low C3 but normal C4. Additional lab tests demonstrated no renal (negative urinalysis and urine protein/creatinine ratio within normal limits), respiratory (pulmonary function test with spirometry, lung volumes, and diffusion capacity within normal limits), or neurovascular (unremarkable magnetic resonance imaging/magnetic resonance angiography of the brain) abnormalities. With these findings, the patient was diagnosed with systemic lupus erythematosus and was started on pulse-dosed steroids with solumedrol 30 mg/kg/day for three doses, followed by a 3-day course of high-dose, intravenous methylprednisolone 30 mg/kg/day.
Troponin levels were trended and returned to normal on day 4 of admission. Improvement in troponin levels were likely multifactorial in the setting of the patient's pharmacologic and plasma exchange treatments. Prior to hospital discharge on day 16 of admission, cardiac magnetic resonance imaging (MRI) showed no evidence of delayed gadolinium enhancement, but confirmed the anomalous origin of the right coronary artery from the left sinus of Valsalva. The patient was discharged from hospital to home and prescribed aspirin, prednisolone, nizatidine, ondansetron, and acetaminophen.
The patient was scheduled for a 6-month outpatient follow-up appointment with a pediatric cardiac electrophysiologist. The patient reported no symptoms, and a Holter monitor at 6 months demonstrated sinus rhythm throughout, without evidence of ectopy or ventricular arrhythmia. Due to the patient's temporarily elevated troponin, inpatient electrophysiological derangements, and the abnormal coronary artery anatomy, he will require ongoing evaluation with a pediatric cardiologist, sequential transthoracic echocardiograms, and exercise stress testing. This patient was diagnosed with systemic lupus erythematosus following the acute presentation with TTP, which is a known association in pediatric patients.