Single-cell atlas of the liver myeloid compartment before and after cure of chronic viral hepatitis.

BACKGROUND & AIMS: Chronic viral infections present serious public health challenges; however, direct-acting antivirals (DAAs) are now able to cure nearly all patients infected with hepatitis C virus (HCV), representing the only cure of a human chronic viral infection to date. DAAs provide a valuable opportunity to study immune pathways in the reversal of chronic immune failures in an in vivo human system. METHODS: To leverage this opportunity, we used plate-based single-cell RNA-seq to deeply profile myeloid cells from liver fine needle aspirates in patients with HCV before and after DAA treatment. We comprehensively characterised liver neutrophils, eosinophils, mast cells, conventional dendritic cells, plasmacytoid dendritic cells, classical monocytes, non-classical monocytes, and macrophages, and defined fine-grained subpopulations of several cell types. RESULTS: We discovered cell type-specific changes post-cure, including an increase in MCM7+STMN1+ proliferating CD1C+ conventional dendritic cells, which may support restoration from chronic exhaustion. We observed an expected downregulation of interferon-stimulated genes (ISGs) post-cure as well as an unexpected inverse relationship between pre-treatment viral load and post-cure ISG expression in each cell type, revealing a link between viral loads and sustained modifications of the host's immune system. We found an upregulation of PD-L1/L2 gene expression in ISG-high neutrophils and IDO1 expression in eosinophils, pinpointing cell subpopulations crucial for immune regulation. We identified three recurring gene programmes shared by multiple cell types, distilling core functions of the myeloid compartment. CONCLUSIONS: This comprehensive single-cell RNA-seq atlas of human liver myeloid cells in response to cure of chronic viral infections reveals principles of liver immunity and provides immunotherapeutic insights. CLINICAL TRIAL REGISTRATION: This study is registered at ClinicalTrials.gov (NCT02476617). IMPACT AND IMPLICATIONS: Chronic viral liver infections continue to be a major public health problem. Single-cell characterisation of liver immune cells during hepatitis C and post-cure provides unique insights into the architecture of liver immunity contributing to the resolution of the first curable chronic viral infection of humans. Multiple layers of innate immune regulation during chronic infections and persistent immune modifications after cure are revealed. Researchers and clinicians may leverage these findings to develop methods to optimise the post-cure environment for HCV and develop novel therapeutic approaches for other chronic viral infections.

Preventing inadvertent drain removal using a novel catheter securement device.

Percutaneous drains have provided a minimally invasive way to treat a wide range of disorders from abscess drainage to enteral feeding solutions to treating hydronephrosis. These drains suffer from a high rate of dislodgement of up to 30% resulting in emergency room visits, repeat hospitalizations, and catheter repositioning/replacement procedures, which incur significant morbidity and mortality. Using ex vivo and in vivo models, a force body diagram was utilized to determine the forces experienced by a drainage catheter during dislodgement events, and the individual components which contribute to drainage catheter securement were empirically collected. Prototypes of a skin level catheter securement and valved quick release system were then developed. The system was inspired by capstans used in boating for increasing friction of a line around a central spool and quick release mechanisms used in electronics such as the Apple MagSafe computer charger. The device was tested in a porcine suprapubic model, which demonstrated the effectiveness of the device to prevent drain dislodgement. The prototype demonstrated that the miniaturized versions of technologies used in boating and electronics industries were able to meet the needs of preventing dislodgement of patient drainage catheters.

Characterization of an Iodinated Rectal Spacer for Prostate Photon and Proton Radiation Therapy.

PURPOSE: Conventional rectal spacers (nonI-SPs) are low-contrast on computed tomography (CT), often necessitating magnetic resonance imaging for accurate delineation. A new formulation of spacers (I-SPs) incorporates iodine to improve radiopacity and CT visualization. We characterized placement, stability, and plan quality of I-SPs compared to nonI-SPs. METHODS AND MATERIALS: Patients with intact prostate cancer (n = 50) treated with I-SPs and photons were compared to randomly selected patients (n = 50) with nonI-SPs (photon or proton therapy). The I-SP was contoured on the planning CT and cone beam CTs at 3 timepoints: first, middle, and final treatment (n = 200 scans). I-SPs Hounsfield units (HU), volume, surface area (SA), centroid position relative to prostate centroid, and distance between prostate/rectum centroids were compared on the planning CTs between each cohort. I-SP changes were evaluated on cone beam CTs over courses of treatment. Dosimetric evaluations of plan quality and robustness were performed. I-SP was tested in a phantom to characterize its relative linear stopping power for protons. RESULTS: I-SPs yielded a distinct visible contrast on planning CTs compared to nonI-SPs (HU 138 vs 12, P < .001), allowing delineation on CT alone. The delineated volume and SA of I-SPs were smaller than nonI-SPs (volume 8.9 vs 10.6 mL, P < .001; SA 28 vs 35 cm2, P < .001), yet relative spacer position and prostate-rectal separation were similar (P = .79). No significant change in HU, volume, SA, or relative position of the I-SPs hydrogel occurred over courses of treatment (all P > .1). Dosimetric analysis concluded there were no significant changes in plan quality or robustness for I-SPs compared to nonI-SPs. The I-SP relative linear stopping power was 1.018, necessitating HU override for proton planning. CONCLUSIONS: I-SPs provide a manifest CT contrast, allowing for delineation on planning CT alone with no magnetic resonance imaging necessary. I-SPs radiopacity, size, and relative position remained stable over courses of treatment from 28 to 44 fractions. No changes in plan quality or robustness were seen comparing I-SPs and nonI-SPs.

Magnetic resonance imaging/transrectal ultrasonography fusion guided seed placement in a phantom: Accuracy between 2-seed versus 1-seed strategies.

PURPOSE: To investigate whether the 2-seed placement per Magnetic Resonance Imaging (MRI) suspicious lesion yields a higher seed placement accuracy than a 1-seed strategy on a phantom. METHODS: Eight olives embedded in gelatin, each simulating a prostate, underwent MRI. Three virtual spherical lesions (3, 5, and 8 mm diameters) were marked in each olive on the MRI images and co-registered to the MRI/Transrectal Ultrasonography (TRUS) fusion biopsy system. Two radiologists placed 0.5 mm fiducials, targeting the center of each virtual lesion under fusion image guidance. Half of the 8 olives in each phantom were assigned either to the 1-seed or 2-seeds per lesion strategy. Post-procedure Computed Tomography (CT) images identified each seed and were fused with MR to localize each virtual lesion and collected the seed placement error - distance between the virtual target and the corresponding seed (using the closer seed for the 2-seed strategy). Seed placement success is defined as fiducial placement within a lesion boundary. RESULTS: Each operator repeated the procedure on three different phantoms, and data from 209 seeds placed for 137 lesions were analyzed, with an overall error of 3.03 ±â€¯1.52 mm. The operator skill, operator phantom procedural experience, lesion size, and number of seeds, were independently associated with the seed placement error. Seed placement success rate was higher for the 2-seed group compared to 1-seed, although the difference was not statistically significant. CONCLUSIONS: Placing 2 seeds per MRI lesion yielded a significantly lower error compared to 1-seed strategy, although seed placement success rate was not significantly different.

Improved Mortality in Necrotizing Pancreatitis with a Multidisciplinary Minimally Invasive Step-Up Approach: Comparison with a Modern Open Necrosectomy Cohort.

BACKGROUND: A minimally invasive step-up (MIS) approach has been associated with reduced morbidity compared with open surgical necrosectomy (OSN) for treatment of necrotizing pancreatitis. We sought to determine whether transitioning from an OSN to an MIS-based approach would result in reduced mortality. MIS interventions included percutaneous drainage, endoscopic transgastric necrosectomy, video-assisted retroperitoneal debridement, sinus tract endoscopic necrosectomy, or a combination of techniques, with selective use of OSN. STUDY DESIGN: We conducted an observational cohort study with retrospective comparison at a single tertiary referral center (2006 through 2019). Eighty-eight patients were treated with OSN and 91 were treated with an MIS-based approach. Baseline characteristics and clinical outcomes were compared between groups. The primary end point was 90-day mortality. RESULTS: There was no difference in baseline characteristics. Ninety-day mortality was 2% with MIS compared with 10% with OSN (p = 0.03). One-year mortality was 3% with MIS compared with 15% with OSN (p = 0.012). The rate of organ failure was lower with MIS (30% vs 45%; p = 0.029), but there was a higher bleeding rate (19% vs 9%; p = 0.064). In the MIS group, 9% were treated with percutaneous drainage, 32% with endoscopic transgastric necrosectomy, 8% with video-assisted retroperitoneal debridement, 15% with sinus tract endoscopic necrosectomy, and 27% with a combination of techniques. CONCLUSIONS: Adoption of a multidisciplinary MIS-based approach to necrotizing pancreatitis resulted in a 5-fold decrease in mortality compared with OSN.

Serial ctDNA Monitoring to Predict Response to Systemic Therapy in Metastatic Gastrointestinal Cancers.

PURPOSE: ctDNA offers a promising, noninvasive approach to monitor therapeutic efficacy in real-time. We explored whether the quantitative percent change in ctDNA early after therapy initiation can predict treatment response and progression-free survival (PFS) in patients with metastatic gastrointestinal cancer. EXPERIMENTAL DESIGN: A total of 138 patients with metastatic gastrointestinal cancers and tumor profiling by next-generation sequencing had serial blood draws pretreatment and at scheduled intervals during therapy. ctDNA was assessed using individualized droplet digital PCR measuring the mutant allele fraction in plasma of mutations identified in tumor biopsies. ctDNA changes were correlated with tumor markers and radiographic response. RESULTS: A total of 138 patients enrolled. A total of 101 patients were evaluable for ctDNA and 68 for tumor markers at 4 weeks. Percent change of ctDNA by 4 weeks predicted partial response (PR, P < 0.0001) and clinical benefit [CB: PR and stable disease (SD), P < 0.0001]. ctDNA decreased by 98% (median) and >30% for all PR patients. ctDNA change at 8 weeks, but not 2 weeks, also predicted CB (P < 0.0001). Four-week change in tumor markers also predicted response (P = 0.0026) and CB (P = 0.022). However, at a clinically relevant specificity threshold of 90%, 4-week ctDNA change more effectively predicted CB versus tumor markers, with a sensitivity of 60% versus 24%, respectively (P = 0.0109). Patients whose 4-week ctDNA decreased beyond this threshold (≥30% decrease) had a median PFS of 175 days versus 59.5 days (HR, 3.29; 95% CI, 1.55-7.00; P < 0.0001). CONCLUSIONS: Serial ctDNA monitoring may provide early indication of response to systemic therapy in patients with metastatic gastrointestinal cancer prior to radiographic assessments and may outperform standard tumor markers, warranting further evaluation.

A Step-Up Approach to Infected Abdominal Fluid Collections: Not Just for Pancreatitis.

Background: More than 145,500 abdominal abscesses occur annually in the U.S. Percutaneous catheter drainage (PCD) is the primary treatment for clinically significant intra-abdominal collections (IACs), but only approximately 90% of all IACs are treatable with PCD. This leaves a significant number of patients facing long courses of management, including multiple interventions. Minimally invasive debridement techniques are now employed regularly for the treatment of infected necrosis caused by acute pancreatitis. We describe the use of minimally invasive videoscopic debridement techniques employed as part of a "step-up" approach to resolve IACs of other etiologies that are unresponsive to PCD. Methods: Data of all patients undergoing this procedure at a tertiary referral academic center from 2015 to 2017 after failure of different PCD techniques were analyzed retrospectively. Results: Four men and two women, mean age 54.6 years (range 26-70 years), with refractory IACs (mean drainage time 91.3 days; mean number of drainage procedures 4.6) following a variety of surgical interventions and inflammatory conditions underwent either video-assisted retroperitoneal debridement or sinus tract endoscopic debridement with a rigid or flexible endoscope. Technical success was achieved in all cases, and clinical success was observed in five cases. No immediate procedural complications were detected. The mean hospital stay and post-procedure drainage times were 5.5 and 25.2 days, respectively. There were no recurrent IACs. Conclusion: Minimally invasive debridement techniques can safely resolve IACs refractory to standard PCD techniques. Employment of these techniques as part of a step-up approach may reduce the morbidity and duration of drainage for the thousands of patients treated annually who have refractory IACs, whatever their etiology.

A Low-Cost Highly Configurable Phantom for Simulation of Imaging-Guided Endocavitary Procedures.

We developed a method to create customizable phantoms suitable for endocavitary imaging and interventional research, based on the fabrication of an acrylic phantom mold, and development of a phantom matrix composed of gelatin, agar, graphite particles, and propanol. Our phantom was mechanically stable, easily fabricated, and highly adjustable, and its ultrasound (US) and magnetic resonance imaging (MRI) scans showed the qualification for the procedure guidance compared with the human prostate image using the same US system. To test the feasibility of the phantom for the research, the seeds placement guided by MRI/US fusion was performed, and the overall test error (distance from the seed center to the virtual lesion center in olives) was 2.59 ± 0.59 mm. We have created a simple, low-cost, configurable, gelatin-based phantom and tested its feasibility for simulating endorectal interventional US procedures. The design of the phantom mold and matrix is likely to be useful to the broader medical training community, and the preliminary data from the experiment of MRI/US-guided seeds placement showed its potential to test the clinical hypothesis in US research.

CT-Guided Percutaneous Needle Biopsy of Retroperitoneal and Pelvic Lymphadenopathy: Assessment of Technique, Diagnostic Yield, and Clinical Value.

PURPOSE: To assess the technical success rate, diagnostic yield, and clinical value of computed tomography (CT)-guided percutaneous needle biopsy (PNB) for retroperitoneal and pelvic lymphadenopathy. MATERIALS AND METHODS: This retrospective study included 344 patients evaluated for safety and technique and 334 patients evaluated for diagnostic yield and clinical analyses. PNBs were performed with fine-needle aspiration (FNA) in 315 patients and with core biopsy in 333 patients. Follow-up analyses, including repeat biopsy, open surgery, imaging, and clinical indicators, were conducted for 94 patients who had nonspecific malignant or benign results. Diagnostic yields were calculated based on biopsy and follow-up results. Factors associated with final diagnoses were compared and modeled by multivariate analysis. RESULTS: Technical success rate was 99.7%. Thirty-nine patients (11.3%) had minor complications. From biopsy results and follow-up analyses, final malignant diagnoses were determined for 281 patients (84.1%). Overall sensitivity, specificity, and accuracy rates of PNB were 91.5%, 100%, and 92.8%, respectively. For patients with a history of malignancy, the likelihood of nodal involvement was 84.6% and that of a new, different malignancy was 3.7%. Older age (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.00-1.05), history of malignancy (OR, 3.44; 95% CI, 1.71-6.92), multiple lymph nodes (LNs; OR, 2.65; 95% CI, 1.38-5.09), and new or enlarging LNs (OR, 2.62; 95% CI, 1.25-5.48) were independent risk factors for malignancy diagnosis. CONCLUSIONS: CT-guided PNB is a safe, effective procedure that can achieve high diagnostic yields for patients with retroperitoneal and pelvic lymphadenopathy.

Imaging guided percutaneous interventions in hepatic dome lesions: Tips and tricks.

Percutaneous hepatic interventions are generally safe given the fact that liver closely abuts the abdominal wall and hence it is easily accessible. However, the superior portion of liver, adjacent to the diaphragm, commonly referred as the "hepatic dome", presents unique challenges for interventionists. Percutaneous access to the hepatic dome may be restricted by anatomical factors and special considerations may be required to avoid injury to the surrounding organs. The purpose of this review article is to discuss certain specific maneuvers and techniques that can enhance the success and safety of interventions in the hepatic dome.

Combined endoscopic trangastric drainage and video assisted retroperitoneal pancreatic debridement - The best of both worlds for extensive pancreatic necrosis with enteric fistulae.

Enteric fistula is a serious complication of necrotizing pancreatitis. Endoscopic transluminal drainage and necrosectomy can significantly reduce the incidence of enterocutaneous fistula after pancreatic debridement. However, endoscopic necrosectomy may not be well-suited to debridement of necrosis that tracks laterally to the paracolic gutters, which is often more efficiently addressed by video-assisted retroperitoneal debridement (VARD). We report the combined use of endoscopic transgastric drainage and VARD for treatment of a 76 year old man with severe necrotizing acute pancreatitis complicated by infected, walled-off pancreatic necrosis. Computed tomography showed laterally tracking pancreatic necrosis and flouroscopic drain injection after percutaneous drainage demonstrated with fistulas to the stomach, duodenum, and colon. The infection and fistulas resolved completely. This approach combined the major advantage of VARD with the major advantage of endoscopic transluminal drainage. We are not aware of any reports of combining these techniques and believe the combination offers a minimally invasive approach for patients with extensive necrosis and a high likelihood of enteric or pancreatic fistulas.

CT-Guided Percutaneous Microwave Ablation of Tumors in the Hepatic Dome: Assessment of Efficacy and Safety.

PURPOSE: To evaluate the technique, efficacy, safety, and clinical outcomes of CT-guided microwave ablation of tumors in the hepatic dome. MATERIALS AND METHODS: Retrospective review was conducted of 46 consecutive patients (31 men and 15 women; mean age, 64 y) treated with CT-guided microwave ablation for hepatic-dome tumors between June 2011 and December 2014. Baseline demographics of sex, tumor diagnosis, tumor location, tumor size, and technical details were recorded. Technical success was evaluated. Treatment response was assessed per European Association for the Study of the Liver criteria. Overall success and overall survival were calculated, and complications were recorded. RESULTS: Forty-eight tumors were treated. Tumor locations included segments VIII (n = 32), VII (n = 10), and VIa (n = 6). Mean tumor size was 2.4 cm (range, 0.9-5.2 cm). Thirty-four tumors (70%) were treated following creation of artificial ascites with 0.9% normal saline solution (mean volume, 1,237 mL; range, 300-3,000 mL). The technical success rate was 100%, and the complete response rate was 94%. Overall survival rate was 73.9% over 24.7 months of follow-up. There were no major complications. Two patients experienced small, asymptomatic pneumothoraces that were aspirated at the time of the procedure and required no further treatment. CONCLUSIONS: CT-guided microwave ablation of tumors in the hepatic dome is associated with a high technical success rate, high complete response rate, and low complication rate.

Elevation of Urinary 2-Hydroxyglutarate in IDH-Mutant Glioma.

BACKGROUND: Recurrent mutations in the isocitrate dehydrogenase 1 (IDH1) and IDH2 genes, which are frequent in gliomas, result in marked accumulation of the metabolic by-product 2-hydroxyglutarate (2-HG) within tumors. In other malignancies, such as acute myeloid leukemia, presence of IDH mutation is associated with elevated 2-HG levels in serum or urine compartments. Circulating 2-HG in patients with glial malignancies has not been thoroughly investigated. METHODS: In this study, we analyzed 2-HG levels in the serum and urine of a large set of patients with IDH-mutant and IDH-wild-type glioma, and the cerebrospinal fluid (CSF) from a subset of this cohort. RESULTS: We found that 2-HG was elevated in the urine of patients with IDH-mutant versus IDH-wild-type glioma, although no significant differences in 2-HG levels were observed in the serum or the small set of CSF samples obtained. Among patients with IDH-mutant glioma, 2-HG levels did not differ based on the histopathologic grade, genetic subtype (TP53 mutant or 1p/19q codeleted), presence of a canonical (IDH1 R132H) or noncanonical (any other IDH variant) mutation, or treatment type. CONCLUSION: Our finding suggests that urinary 2-HG is increased among patients with IDH-mutant gliomas, and may represent a future surrogate, noninvasive biomarker to aid in diagnosis, prognosis, and management. IMPLICATIONS FOR PRACTICE: Patients with glioma who harbor mutations in isocitrate dehydrogenase genes showed selective elevation of the oncometabolite 2-hydroxyglutarate in the urine. Similar elevations were not identified in the serum or cerebrospinal fluid. 2-Hydroxyglutarate may serve as a useful, noninvasive biomarker to stratify patients newly diagnosed with glioma with regard to prognosis and management.

Catecholamine Surge during Image-Guided Ablation of Adrenal Gland Metastases: Predictors, Consequences, and Recommendations for Management.

PURPOSE: To identify retrospectively predictors of catecholamine surge during image-guided ablation of metastases to the adrenal gland. MATERIALS AND METHODS: Between 2001 and 2014, 57 patients (39 men, 18 women; mean age, 65 y ± 10; age range, 41-81 y) at two academic medical centers underwent ablation of 64 metastatic adrenal tumors from renal cell carcinoma (n = 27), lung cancer (n = 23), melanoma (n = 4), colorectal cancer (n = 3), and other tumors (n = 7). Tumors measured 0.7-11.3 cm (mean, 4 cm ± 2.5). Modalities included cryoablation (n = 38), radiofrequency (RF) ablation (n = 20), RF ablation with injection of dehydrated ethanol (n = 10), and microwave ablation (n = 4). Fisher exact test, univariate, and multivariate logistical regression analysis was used to evaluate factors predicting hypertensive crisis (HC). RESULTS: HC occurred in 31 sessions (43%). Ventricular tachycardia (n = 1), atrial fibrillation (n = 2), and troponin leak (n = 4) developed during HC episodes. HC was significantly associated with maximum tumor diameter ≤ 4.5 cm (odds ratio [OR], 26.36; 95% confidence interval [CI], 5.26-131.99; P < .0001) and visualization of normal adrenal tissue on CT or MR imaging before the procedure (OR, 8.38; 95% CI, 2.67-25.33; P < .0001). No HC occurred during ablation of metastases in previously irradiated or ablated adrenal glands. CONCLUSIONS: Patients at high risk of catecholamine surge during ablation of non-hormonally active adrenal metastases can be identified by the presence of normal adrenal tissue and tumor diameter ≤ 4.5 cm on pre-procedure CT or MR imaging.

Tumor Heterogeneity and Lesion-Specific Response to Targeted Therapy in Colorectal Cancer.

UNLABELLED: How genomic heterogeneity associated with acquired resistance to targeted agents affects response to subsequent therapy is unknown. We studied EGFR blockade in colorectal cancer to assess whether tissue and liquid biopsies can be integrated with radiologic imaging to monitor the impact of individual oncogenic alterations on lesion-specific responses. Biopsy of a patient's progressing liver metastasis following prolonged response to cetuximab revealed a MEK1(K57T) mutation as a novel mechanism of acquired resistance. This lesion regressed upon treatment with panitumumab and the MEK inhibitor trametinib. In circulating tumor DNA (ctDNA), mutant MEK1 levels declined with treatment, but a previously unrecognized KRAS(Q61H) mutation was also identified that increased despite therapy. This same KRAS mutation was later found in a separate nonresponding metastasis. In summary, parallel analyses of tumor biopsies and serial ctDNA monitoring show that lesion-specific radiographic responses to subsequent targeted therapies can be driven by distinct resistance mechanisms arising within separate tumor lesions in the same patient. SIGNIFICANCE: Molecular heterogeneity ensuing from acquired resistance drives lesion-specific responses to subsequent targeted therapies. Analysis of a single-lesion biopsy is inadequate to guide selection of subsequent targeted therapies. ctDNA profiles allow the detection of concomitant resistance mechanisms residing in separate metastases and assessment of the effect of therapies designed to overcome resistance.

Abscess due to perforated appendicitis: factors associated with successful percutaneous drainage.

BACKGROUND: Percutaneous drainage is the standard treatment for perforated appendicitis with abscess. We studied factors associated with complete resolution (CR) with percutaneous drainage alone. METHODS: Ninety-eight patients underwent percutaneous drainage for acute appendicitis complicated by abscess (October 1990 to September 2010). CR was defined as clinical recovery, resolution of the abscess on imaging, and drain removal without recurrence. Patients achieving CR were compared with patients not achieving CR. RESULTS: The rate of CR was 78.6% (n = 77). Abscess grade was the only radiological factor associated with CR (P = .007). The CR rate was higher with transgluteal drainage (90.9% vs 79.2%) than with other anatomic approaches (P = .018) and higher with computed tomography-guided drainage than with ultrasound-guided drainage (82.7% vs 64.3%, P = .046). CONCLUSION: CR was more likely to be achieved in patients with lower abscess grade, computed tomography-guided drainage, and a transgluteal approach.