LAUSR

A healthy 2-year-old male with a history of mild persistent asthma visited the outpatient hematology clinic to evaluate intermittent epistaxis. There was no history of recent illness. His exam was notable for left upper extremity bruising secondary to recent venipuncture, but no lymphadenopathy or hepatosplenomegaly. Complete blood count (CBC) revealed hemoglobin 9.3 g/dL, leukocyte count 20.7 10/L, and platelet count 33 k 10/L. Peripheral blood smear exhibited polychromasia, numerous large platelets, and a few reactive lymphocytes. The differential diagnosis for both thrombocytopenia and anemia include processes leading to impaired hematopoiesis, increased cell destruction, or abnormal cell pooling. Impaired hematopoiesis could stem from infectious suppression, infiltrative processes (leukemia, metabolic disorders, etc.), or inherited and acquired bone marrow failure syndromes. Possible destructive or consumptive processes included microangiopathy, disseminated intravascular coagulation (DIC), or immune destruction. Sequestration within the liver or spleen was considered, but he was without hepatosplenomegaly to suggest a site of abnormal pooling. We approached his work-up with a stepwise approach. Screening tests were normal for common infectious diseases implicated in marrow suppression (Table 1). Since the patient appeared well and did not exhibit any findings that would prompt an immediate evaluation for malignancy or sepsis, we decided to repeat a short interval CBC to see if his cytopenias self-resolved. When they did not, further evaluation of the bone marrow was warranted. Bone marrow biopsy and aspirate did not demonstrate marrow infiltration or failure (Table 1). Lab work was sent to investigate consumptive processes. Lactate dehydrogenase levels and reticulocyte counts were elevated (Table 1), suggesting a hemolytic process. A hemoglobinopathy screen and glucose-6-phosphate dehydrogenase testing were normal, though active hemolysis can skew results. In an ill-appearing child, the presence of hemolysis and thrombocytopenia should prompt an investigation for DIC or microangiopathy, but in this well appearing-child, an immune process was thought likelier. We, therefore, pursued an immunologic work-up, including screening for autoimmune lymphoproliferative syndrome (ALPS) (Table 1). The results were unrevealing except for a low IgG level at 228 (505–1280 mg/dL) with normal lymphocyte subsets. Low IgG is often associated with systemic autoimmune disorders, vasculitides, atopy, and asthma. We attributed the low IgG and eosinophilia to the patient's known history of asthma. A consumptive autoimmune process was high on the differential, and the involvement of two cell lines would be classified as Evans syndrome. Evans syndrome, though never a primary diagnosis, is treated upfront with Abbreviations: ALPS, autoimmune lymphoproliferative syndrome; CBC, complete blood count; CPP, cryoprecipitate; DIC, disseminated intravascular coagulation; FFP, fresh frozen plasma; IVIG, intravenous immunoglobulin; KHE, Kaposiform hemangioendothelioma; KMP, Kasabach-Merritt Phenomenon; MRI, magnetic resonance imaging; PRBC, packed red blood cell; PT, prothrombin time; PTT, partial thromboplastin time.