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Purpose:Myelodysplastic syndrome (MDS) is associated with a dysregulated innate immune system. The purpose of this study was to determine whether modulation of the innate immune system via high mobility group box-1 (HMGB1) could reduce cell viability in MDS.Experimental Design:We quantified HMGB1 in an MDS cell line MDS-L and in primary MDS cells compared with nonmalignant hematopoietic cells. We performed loss-of-function studies of HMGB1 using pooled siRNAs and a small-molecule inhibitor sivelestat compared with standard chemotherapy. We measured levels of engraftment of MDS-L cells in NOD-scidIL2Rgnull (NSG) mice following treatment with sivelestat. Mechanistically, we interrogated cell survival pathways and 45 targets within the NFκB pathway using both protein analysis and a proteome profiler array.Results:We discovered that HMGB1 had increased expression in both MDS-L cells and in primary CD34+ MDS cells compared with healthy CD34+ hematopoietic cells. Sivelestat impaired MDS cell expansion, increased cellular death, and spared healthy hematopoietic cells. MDS-L marrow engraftment is reduced significantly at 17 weeks following treatment with sivelestat compared with control mice. Treatment of CD34+ MDS cells with sivelestat and azacitidine or decitabine was additive to increase apoptotic cell death compared with chemotherapy alone. Sivelestat promoted apoptosis with increased expression of PUMA, activated caspase 3, and increased DNA double-strand breaks. Inhibition of HMGB1 reduced levels of Toll-like receptors (TLR) and suppressed activation of NFκB in MDS-L cells.Conclusions:Inhibition of HMGB1 could promote MDS cell death and alter innate immune responses via suppression of NFκB pathways.

The association of maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) status before delivery with breastfeeding is unknown. This study compares breastfeeding initiation, exclusivity, and duration between SARS-CoV-2-positive (+) and SARS-CoV-2-negative (-) mothers during the first 2 months of their newborns' lives.A single center, retrospective cohort study of pediatric contacts during the first 2 months in a diverse mother-infant population (n = 285) compared breastfeeding outcomes by maternal SARS-CoV-2 status during a pandemic surge. Infants of SARS-CoV-2 positive mothers were also tested before discharge. Comparison of maternal demographics (age, race, ethnicity), maternal/infant characteristics (parity, insurance, delivery mode, infant sex, hospital length of stay), and pediatric contacts by maternal SARS-CoV-2 status included Fisher's exact and Wilcoxon tests and Poisson regression for count outcomes. Logistic regression compared breastfeeding outcomes between the 2 groups, adjusting for potential confounders and effect modifiers.Maternal demographics and maternal/infant characteristics were similar. While 19% of mothers tested positive for SARS-CoV-2 (n = 54), their infants were all negative. SARS-CoV-2 positive mothers had fewer in-person, but more virtual pediatric contacts. After controlling for the above variables, SARS-CoV-2 positive mothers had lower odds of breastfeeding initiation within 1 to 7 days of life (78% vs 88%; adjusted odds ratio [aOR] = 0.40, 95% confidence interval [CI]: 0.17, 0.96) and of any breastfeeding during month 2 (54% vs 76%; aOR = 0.37, 95% CI: 0.16, 0.86) compared with SARS-CoV-2 negative mothers.Maternal SARS-CoV-2 positivity at delivery was independently associated with less initiation and shorter duration of any breastfeeding during month 2. SARS-CoV-2 positive women would likely benefit from additional breastfeeding support during pandemic surges.