G-CSF rescue of FOLFIRINOX-induced neutropenia leads to systemic immune suppression in mice and humans.

BACKGROUND: Recombinant granulocyte colony-stimulating factor (G-CSF) is routinely administered for prophylaxis or treatment of chemotherapy-induced neutropenia. Chronic myelopoiesis and granulopoiesis in patients with cancer has been shown to induce immature monocytes and neutrophils that contribute to both systemic and local immunosuppression in the tumor microenvironment. The effect of recombinant G-CSF (pegfilgrastim or filgrastim) on the production of myeloid-derived suppressive cells is unknown. Here we examined patients with pancreatic cancer, a disease known to induce myeloid-derived suppressor cells (MDSCs), and for which pegfilgrastim is routinely administered concurrently with FOLFIRINOX but not with gemcitabine-based chemotherapy regimens. METHODS: Serial blood was collected from patients with pancreatic ductal adenocarcinoma newly starting on FOLFIRINOX or gemcitabine/n(ab)paclitaxel combination chemotherapy regimens. Neutrophil and monocyte frequencies were determined by flow cytometry from whole blood and peripheral blood mononuclear cell fractions. Serum cytokines were evaluated pretreatment and on-treatment. Patient serum was used in vitro to differentiate healthy donor monocytes to MDSCs as measured by downregulation of major histocompatibility complex II (HLA-DR) and the ability to suppress T-cell proliferation in vitro. C57BL/6 female mice with pancreatic tumors were treated with FOLFIRINOX with or without recombinant G-CSF to directly assess the role of G-CSF on induction of immunosuppressive neutrophils. RESULTS: Patients receiving FOLFIRINOX with pegfilgrastim had increased serum G-CSF that correlated with an induction of granulocytic MDSCs. This increase was not observed in patients receiving gemcitabine/n(ab)paclitaxel without pegfilgrastim. Interleukin-18 also significantly increased in serum on FOLFIRINOX treatment. Patient serum could induce MDSCs as determined by in vitro functional assays, and this suppressive effect increased with on-treatment serum. Induction of MDSCs in vitro could be recapitulated by addition of recombinant G-CSF to healthy serum, indicating that G-CSF is sufficient for MDSC differentiation. In mice, neutrophils isolated from spleen of G-CSF-treated mice were significantly more capable of suppressing T-cell proliferation. CONCLUSIONS: Pegfilgrastim use contributes to immune suppression in both humans and mice with pancreatic cancer. These results suggest that use of recombinant G-CSF as supportive care, while critically important for mitigating neutropenia, may complicate efforts to induce antitumor immunity.

The association between non-English primary language and COVID-19 clinical trial eligibility and enrollment: A retrospective cohort study.

BACKGROUND: Establishing equitable access to COVID-19 clinical trials is an important step in mitigating outcomes disparities. Historically, language has served as a barrier to equitable clinical trial participation. METHODS: A centralized research infrastructure was established at our institution to screen potential trial participants and to promote efficient and equitable access to COVID-19 clinical trials. Rates of eligibility and enrollment in COVID-19 clinical trials by primary language between April 9 and July 31, 2020 (during the first regional COVID-19 surge) were evaluated using logistic regression. Estimates were adjusted for potential confounders including age, sex, and time. RESULTS: A total of 1245 patients were admitted to the hospital with COVID-19 during the study period and screened for clinical trial eligibility. Among all screened patients, 487 (39%) had a non-English primary language. After adjustment, patients with a non-English primary language had 1.98 times higher odds (CI 1.51 to 2.59) of being eligible for 1 or more COVID-19 clinical trials. Among eligible patients, those with a non-English primary language had 1.83 times higher odds (CI 1.36 to 2.47) of enrolling in COVID-19 clinical trials than patients with English as the primary language. CONCULSION: These findings suggest that there are modifiable barriers that can be addressed to lessen the impact of language discordance on access to clinical trials and provide an opportunity to further investigate factors associated with clinical trial participation for patients whose primary language is not English.

Performance of a Triage Protocol for Monoclonal Antibodies in a Mixed Vaccinated and Unvaccinated Cohort of COVID-19 Patients Treated With Intravenous Infusion or Subcutaneous Injection.

Background: Several monoclonal antibodies (mAbs) have been shown to reduce rates of hospitalization in patients with coronavirus disease 2019 (COVID-19) who have risk factors for severe disease. Due to capacity constraints, many health systems have been unable to provide mAbs to all eligible patients. There is little evidence regarding the performance of triage protocols for allocation or the relative effectiveness of subcutaneous administration vs intravenous infusion. Methods: This was a retrospective cohort study of 1063 patients with COVID-19 consecutively referred for monoclonal antibody therapy in a single large academic health care system, who were prioritized for mAb therapy using an allocation protocol grouping patients by risk. Results: A triage protocol prioritizing patients who were not fully vaccinated and were at high risk of severe COVID-19 and patients who were heavily immunosuppressed performed well in terms of differentiating between groups of patients by risk of severe disease. The number needed to treat (NNT) to prevent 1 hospitalization was 4.4 for the highest priority group, 8.5 for the next highest priority group, and 21.7 for the third highest priority group. There was no significant correlation between route of administration and hospitalization for symptoms related to COVID-19 (odds ratio, 1.26 in the intravenous group compared with the subcutaneous group; 95% CI, 0.56-2.8; P = .58). Conclusions: This study demonstrates that triaging mAbs for patients with COVID-19 by risk can optimize benefit in terms of reducing rates of hospitalization and that rates of hospitalization may be no different between patients treated with subcutaneous injection and patients treated with intravenous infusion.

Exploiting telerobotics for sensorimotor rehabilitation: a locomotor embodiment.

BACKGROUND: Manual treadmill training is used for rehabilitating locomotor impairments but can be physically demanding for trainers. This has been addressed by enlisting robots, but in doing so, the ability of trainers to use their experience and judgment to modulate locomotor assistance on the fly has been lost. This paper explores the feasibility of a telerobotics approach for locomotor training that allows patients to receive remote physical assistance from trainers. METHODS: In the approach, a trainer holds a small robotic manipulandum that shadows the motion of a large robotic arm magnetically attached to a locomoting patient's leg. When the trainer deflects the manipulandum, the robotic arm applies a proportional force to the patient. An initial evaluation of the telerobotic system's transparency (ability to follow the leg during unassisted locomotion) was performed with two unimpaired participants. Transparency was quantified by the magnitude of unwanted robot interaction forces. In a small six-session feasibility study, six individuals who had prior strokes telerobotically interacted with two trainers (separately), who assisted in altering a targeted gait feature: an increase in the affected leg's swing length. RESULTS: During unassisted walking, unwanted robot interaction forces averaged 3-4 N (swing-stance) for unimpaired individuals and 2-3 N for the patients who survived strokes. Transients averaging about 10 N were sometimes present at heel-strike/toe-off. For five of six patients, these forces increased with treadmill speed during stance (R2 = .99; p < 0.001) and increased with patient height during swing (R2 = .71; p = 0.073). During assisted walking, the trainers applied 3.0 ± 2.8 N (mean ± standard deviation across patients) and 14.1 ± 3.4 N of force anteriorly and upwards, respectively. The patients exhibited a 20 ± 21% increase in unassisted swing length between Days 1-6 (p = 0.058). CONCLUSIONS: The results support the feasibility of locomotor assistance with a telerobotics approach. Simultaneous measurement of trainer manipulative actions, patient motor responses, and the forces associated with these interactions may prove useful for testing sensorimotor rehabilitation hypotheses. Further research with clinicians as operators and randomized controlled trials are needed before conclusions regarding efficacy can be made.

Molecular Pathways of Colon Inflammation Induced by Cancer Immunotherapy.

Checkpoint blockade with antibodies specific for the PD-1 and CTLA-4 inhibitory receptors can induce durable responses in a wide range of human cancers. However, the immunological mechanisms responsible for severe inflammatory side effects remain poorly understood. Here we report a comprehensive single-cell analysis of immune cell populations in colitis, a common and severe side effect of checkpoint blockade. We observed a striking accumulation of CD8 T cells with highly cytotoxic and proliferative states and no evidence of regulatory T cell depletion. T cell receptor (TCR) sequence analysis demonstrated that a substantial fraction of colitis-associated CD8 T cells originated from tissue-resident populations, explaining the frequently early onset of colitis symptoms following treatment initiation. Our analysis also identified cytokines, chemokines, and surface receptors that could serve as therapeutic targets for colitis and potentially other inflammatory side effects of checkpoint blockade.

Intra- and Inter-cellular Rewiring of the Human Colon during Ulcerative Colitis.

Genome-wide association studies (GWAS) have revealed risk alleles for ulcerative colitis (UC). To understand their cell type specificities and pathways of action, we generate an atlas of 366,650 cells from the colon mucosa of 18 UC patients and 12 healthy individuals, revealing 51 epithelial, stromal, and immune cell subsets, including BEST4+ enterocytes, microfold-like cells, and IL13RA2+IL11+ inflammatory fibroblasts, which we associate with resistance to anti-TNF treatment. Inflammatory fibroblasts, inflammatory monocytes, microfold-like cells, and T cells that co-express CD8 and IL-17 expand with disease, forming intercellular interaction hubs. Many UC risk genes are cell type specific and co-regulated within relatively few gene modules, suggesting convergence onto limited sets of cell types and pathways. Using this observation, we nominate and infer functions for specific risk genes across GWAS loci. Our work provides a framework for interrogating complex human diseases and mapping risk variants to cell types and pathways.

Ceftaroline pharmacokinetics and pharmacodynamics in patients with cystic fibrosis.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is a prevalent pathogen in patients with cystic fibrosis (CF) associated with increased morbidity. Ceftaroline fosamil is an intravenous (IV) cephalosporin with activity against MRSA. There are minimal data regarding dosing in the CF population. The objective of this study was to determine the pharmacokinetic and pharmacodynamic profile of IV ceftaroline in patients with CF. METHODS: We conducted a single-center prospective study of children and young adults with CF receiving ceftaroline (15mg/kg IV up to 600mg every 8h) as part of treatment for a CF pulmonary exacerbation between June 2016 and April 2017. Seven patients were enrolled for a total of 10 treatment courses. For each treatment course, up to 8 plasma samples were assayed for ceftaroline using ultra-high performance liquid chromatography with mass spectrometry. Maximum plasma concentration, systemic clearance, and elimination half-life were calculated. The area under the curve (AUC) above the minimum inhibitory concentration (MIC) and the percent time above the MIC (%fT>MIC) were determined for each subject using MICs of 0.5, 1, and 2µg/mL and the measured MIC if available. RESULTS: The mean (SD) age for the 7 patients was 20.3 (8.0) years. Mean (SD) maximum plasma concentration of ceftaroline was 22.7 (9.6) µg/mL, systemic clearance 7.9 (3.3) L/h, and half-life 1.1 (0.4) hours. Using a MIC of 1 µg/mL, accepted as the MIC 90 of MRSA isolates, AUC above MIC mean (SD) was 53.6 (19.5) µg·h/mL, mean (SD) %fT>MIC was 75.7 (10.4), and all subjects had >60%fT>MIC. CONCLUSIONS: In this cohort of CF patients, mean ceftaroline half-life was 1.1h, which is notably lower than the general population. The dosing regimen studied, which exceeds the recommended dosing in the non-CF population, was adequate to achieve >60% time above the MIC in all patients.

A Comparison of Antibiotic Serum Concentrations Drawn Simultaneously from Peripherally Inserted Central Catheters and Peripheral Veins in Children with Respiratory Infection.

The purpose of the study was to evaluate serum concentration of antibiotics drawn from a peripherally inserted central catheter (PICC) compared with a peripheral venipuncture. This prospective comparative study included patients with ages 1month to 21years admitted with a respiratory infection requiring IV vancomycin or IV tobramycin via a newly placed PICC. The difference between the antibiotic levels from the venipuncture and PICC samples was statistically significant for both the peak and trough levels. However, the difference in values was not enough to impact antibiotic dosing and therefore was not clinically significant.