Semaphorin 4D (Sema4D) is highly expressed in a variety of tumors and is associated with high invasion, poor prognosis and poor therapeutic response. However, the expression and role of Sema4D in leukemia remains unclear. The present study investigated the expression of Sema4D in pediatric leukemia and its effects in leukemia cells. The results demonstrated that Sema4D protein was highly expressed in peripheral blood mononuclear cells of patients with pediatric leukemia, and high levels of soluble Sema4D were also observed in the plasma of these patients. Sema4D knockdown induced cell cycle arrest in G 0 /G 1 phase, inhibited proliferation and promoted apoptosis in BALL-1 cells, while Sema4D overexpression exhibited the opposite effect. In Jurkat cells, Sema4D knockdown inhibited proliferation and promoted apoptosis, while Sema4D overexpression decreased the abundance of the cells in the G 0 /G 1 phase of the cell cycle and promoted proliferation. Sema4D overexpression also increased the migratory capacity of Jurkat cells and the invasive capacity of BALL-1 cells. The phosphorylation level of PI3K was decreased in both Sema4D knocked-down Jurkat and BALL-1 cells, and the phosphorylation level of ERK was decreased in Sema4D knocked-down BALL-1 cells. The phosphorylation levels of PI3K, ERK and AKT were elevated in patients with pediatric leukemia, and were correlated to the increased Sema4D expression. Sema4D overexpression was associated with a shorter overall survival in patients with acute myeloid leukemia. Overall, the results of the present study indicated that Sema4D serves an important role in leukemia development by activating PI3K/AKT and ERK signaling, and it may be used as a potential target for the diagnosis and treatment of leukemia.

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Background Hereditary spherocytosis (HS) is a type of hemolytic anemia caused by abnormal red cell membrane skeletal proteins with few unique clinical manifestations in the neonate and infant. An ANK1 gene mutation is the most common cause of HS. Case presentation The patient was a 11-month-old boy who suffered from anemia and needed a regular transfusion therapy at an interval of 2–3 months. Hematological investigations showed moderate anemia (Hb80 g/L). Red cells displayed microcytosis (MCV76.4 fl, MCH25.6 pg, MCHC335 g/L). The reticulocytes were elevated (4.8%) and the spherocytes were increased (10%). Direct antiglobulin test was negative. Biochemical test indicated a slight elevation of bilirubin, mainly indirect reacting (TBIL32.5 μmol/L, IBIL24 μmol/L). The neonatal HS ratio is 4.38, obviously up the threshold. Meanwhile, a de novo ANK1 mutation (exon 25:c.2693dupC:p.A899Sfs*11) was identified by next-generation sequencing (NGS). Thus, hereditary spherocytosis was finally diagnosed. Conclusions Gene detection should be considered in some hemolytic anemia which is difficult to diagnose by routine means. We identified a novel de novo ANK1 heterozygous frameshift mutation in a Yi nationality patient while neither of his parents carried this mutation. Electronic supplementary material The online version of this article (10.1186/s12887-019-1436-4) contains supplementary material, which is available to authorized users.

Brucellosis is a zoonotic disease. Severe refractory thrombocytopenia caused by brucellosis is very rare and easily misdiagnosed. We reported a 5-year-old girl who developed severe refractory thrombocytopenia secondary to brucellosis. The first-line treatment including corticosteroids and intravenous immunoglobulin did not elevate her platelets, but eltrombopag worked well and her platelet count recovered rapidly.