Individuals with alcohol use disorder (AUD) show elevated brain metabolism of acetate at the expense of glucose. We hypothesized that a shift in energy substrates during withdrawal may contribute to withdrawal severity and neurotoxicity in AUD and that a ketogenic diet (KD) may mitigate these effects. We found that inpatients with AUD randomized to receive KD (n = 19) required fewer benzodiazepines during the first week of detoxification, in comparison to those receiving a standard American (SA) diet (n = 14). Over a 3-week treatment, KD compared to SA showed lower “wanting” and increased dorsal anterior cingulate cortex (dACC) reactivity to alcohol cues and altered dACC bioenergetics (i.e., elevated ketones and glutamate and lower neuroinflammatory markers). In a rat model of alcohol dependence, a history of KD reduced alcohol consumption. We provide clinical and preclinical evidence for beneficial effects of KD on managing alcohol withdrawal and on reducing alcohol drinking.

The inappropriate retention of neutrophils at inflammatory sites is a major driver of the excessive tissue damage characteristic of respiratory inflammatory diseases including COPD, ARDS, and cystic fibrosis. The molecular programmes which orchestrate neutrophil recruitment to inflammatory sites through chemotactic guidance have been well-studied. However, how neutrophil sensitivity to these cues is modulated during inflammation resolution is not understood. The identification of neutrophil reverse migration as a mechanism of inflammation resolution and the ability to modulate this therapeutically has identified a new target to treat inflammatory disease. Here we investigate the role of the CXCL12/CXCR4 signaling axis in modulating neutrophil retention at inflammatory sites. We used an in vivo tissue injury model to study neutrophilic inflammation using transgenic zebrafish larvae. Expression of cxcl12a and cxcr4b during the tissue damage response was assessed using in situ hybridization and analysis of RNA sequencing data. CRISPR/Cas9 was used to knockdown cxcl12a and cxcr4b in zebrafish larvae. The CXCR4 antagonist AMD3100 was used to block the Cxcl12/Cxcr4 signaling axis pharmacologically. We identified that cxcr4b and cxcl12a are expressed at the wound site in zebrafish larvae during the inflammatory response. Following tail-fin transection, removal of neutrophils from inflammatory sites is significantly increased in cxcr4b and cxcl12a CRISPR knockdown larvae. Pharmacological inhibition of the Cxcl12/Cxcr4 signaling axis accelerated resolution of the neutrophil component of inflammation, an effect caused by an increase in neutrophil reverse migration. The findings of this study suggest that CXCR4/CXCL12 signaling may play an important role in neutrophil retention at inflammatory sites, identifying a potential new target for the therapeutic removal of neutrophils from the lung in chronic inflammatory disease.

Neutrophilic inflammation with prolonged neutrophil survival is common to many inflammatory conditions, including chronic obstructive pulmonary disease (COPD). There are few specific therapies that reverse neutrophilic inflammation, but uncovering mechanisms regulating neutrophil survival is likely to identify novel therapeutic targets. Screening of 367 kinase inhibitors in human neutrophils and a zebrafish tail fin injury model identified ErbBs as common targets of compounds that accelerated inflammation resolution. The ErbB inhibitors gefitinib, CP-724714, erbstatin and tyrphostin AG825 significantly accelerated apoptosis of human neutrophils, including neutrophils from people with COPD. Neutrophil apoptosis was also increased in Tyrphostin AG825 treated-zebrafish in vivo. Tyrphostin AG825 decreased peritoneal inflammation in zymosan-treated mice, and increased lung neutrophil apoptosis and macrophage efferocytosis in a murine acute lung injury model. Tyrphostin AG825 and knockdown of egfra and erbb2 by CRISPR/Cas9 reduced inflammation in zebrafish. Our work shows that inhibitors of ErbB kinases have therapeutic potential in neutrophilic inflammatory disease.

20The inappropriate retention of neutrophils in the lung is a major driver of the excessive tissue 21 damage characteristic of respiratory inflammatory diseases including COPD, ARDS and cystic 22 42

3173 Background: We evaluated the utility of screening for VTE using a previously developed clinical risk score (Khorana et al, Blood 2008) in a prospective cohort of cancer patients initiating outpatient chemotherapy but not receiving thromboprophylaxis. Methods: Cancer patients initiating a new chemotherapy regimen and deemed high-risk based on a predictive risk model (score ≥3) were enrolled on an ongoing prospective cohort study with informed consent. Patients were evaluated with baseline and Q4 (± 1) week serial ultrasonography for upto 16 weeks; additionally, computed tomography scans for restaging were also evaluated for VTE. Results: Of 30 patients enrolled on study, 8 (27%) developed a VTE. This included 5 patients with DVT alone (17%), 1 patient with PE alone (3%) and 2 (7%) with both. Twenty-seven patients underwent a baseline ultrasound. Of these, 3 asymptomatic DVTs were identified (11%). Subsequent ultrasounds were performed in 18 patients at week 4 (0 DVT), 17 patients at week 8 (0 DVT) and 15 patients at week 12 (1 DVT, 7%). An additional two patients developed symptomatic DVT between weeks 1 and 4. Restaging CT scans identified an asymptomatic PE in 1 patient at week 6 and asymptomatic PE in 1 patient at week 9 with subsequent symptomatic DVT at week 10. Conclusions: In a prospective observational study, 27% of cancer outpatients deemed high-risk using a clinical risk score developed VTE, a rate much higher than observed even in hospitalized acutely ill patients. Thus, this study confirms the validity of a previously described risk score. The role of thromboprophylaxis in this population is currently being tested. The value of screening ultrasonography should be considered in high-risk patients based on this risk score. Disclosures: No relevant conflicts of interest to declare.