Tuberculosis-associated hemophagocytic lymphohistiocytosis in an umbilical cord blood transplant recipient.

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is a rare and potentially fatal condition that can be primary or secondary. Secondary HLH due to Mycobacterium tuberculosis (TB) is uncommon. We report a case of tuberculosis-associated HLH in an umbilical cord blood transplant (UCBT) recipient and discuss its clinical characteristics and challenges. METHODS: Hematologic investigations, bone marrow aspirates, Xpert MTB/RIF test of TB with peripheral blood were performed. Immune modulation with anti-TB therapy was initiated. RESULTS: Subsequent treatment with anti-TB treatment resulted rapid clinical response and disease remission. CONCLUSION: It is important to consider TB as one of the underlying cause of HLH in high-risk patients, particularly those in immunodeficient states. Early diagnosis and treatment can improve the survival rates of patients with tuberculosis-associated HLH.

Targeting GLI1 Suppresses Cell Growth and Enhances Chemosensitivity in CD34+ Enriched Acute Myeloid Leukemia Progenitor Cells.

BACKGROUND/AIMS: Resistance of leukemia stem cells (LSCs) to chemotherapy in patients with acute myeloid leukemia (AML) causes relapse of disease. Hedgehog (Hh) signaling plays a critical role in the maintenance and differentiation of cancer stem cells. Yet its role in AML remains controversial. The purpose of the present study is to investigate the role of GLI1, the transcriptional activator of Hh signaling, in AML progenitor cells and to explore the anti-AML effects of GLI small-molecule inhibitor GANT61. METHODS: The expression of GLI1 mRNA and protein were examined in AML progenitor cells and normal cells. The proliferation, colony formation, apoptosis and differentiation of AML progenitor cells were also analyzed in the presence of GANT61. RESULTS: Kasumi-1 and KG1a cells, containing more CD34+ cells, expressed higher level of GLI1 compared to U937 and NB4 cells with fewer CD34+ cells. Consistently, a positive correlation between the protein levels of GLI1 and CD34 was validated in the bone marrow mononuclear cells (BMMC) of AML patients tested. GANT61 inhibited the proliferation and colony formation in AML cell lines. Importantly, GANT61 induced apoptosis in CD34+ enriched Kasumi-1 and KG1a cells, whereas it induced differentiation in U937 and NB4 cells. Furthermore, GANT61 enhanced the cytotoxicity of cytarabine (Ara-c) in primary CD34+ AML cells, indicating that inhibition of GLI1 could be a promising strategy to enhance chemosensitivity. CONCLUSIONS: The present findings suggested that Hh signaling was activated in AML progenitor cells. GLI1 acted as a potential target for AML therapy.