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.

Convergent loss of PTEN leads to clinical resistance to a PI(3)Kα inhibitor.

Broad and deep tumour genome sequencing has shed new light on tumour heterogeneity and provided important insights into the evolution of metastases arising from different clones. There is an additional layer of complexity, in that tumour evolution may be influenced by selective pressure provided by therapy, in a similar fashion to that occurring in infectious diseases. Here we studied tumour genomic evolution in a patient (index patient) with metastatic breast cancer bearing an activating PIK3CA (phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha, PI(3)Kα) mutation. The patient was treated with the PI(3)Kα inhibitor BYL719, which achieved a lasting clinical response, but the patient eventually became resistant to this drug (emergence of lung metastases) and died shortly thereafter. A rapid autopsy was performed and material from a total of 14 metastatic sites was collected and sequenced. All metastatic lesions, when compared to the pre-treatment tumour, had a copy loss of PTEN (phosphatase and tensin homolog) and those lesions that became refractory to BYL719 had additional and different PTEN genetic alterations, resulting in the loss of PTEN expression. To put these results in context, we examined six other patients also treated with BYL719. Acquired bi-allelic loss of PTEN was found in one of these patients, whereas in two others PIK3CA mutations present in the primary tumour were no longer detected at the time of progression. To characterize our findings functionally, we examined the effects of PTEN knockdown in several preclinical models (both in cell lines intrinsically sensitive to BYL719 and in PTEN-null xenografts derived from our index patient), which we found resulted in resistance to BYL719, whereas simultaneous PI(3)K p110ß blockade reverted this resistance phenotype. We conclude that parallel genetic evolution of separate metastatic sites with different PTEN genomic alterations leads to a convergent PTEN-null phenotype resistant to PI(3)Kα inhibition.

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.

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.

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.

A Quality Improvement Initiative to Reduce Catheter Exchange Rates for Fluoroscopically Guided Gastrostomy Tubes.

PURPOSE: To evaluate the effectiveness of a data-driven quality improvement initiative to reduce catheter exchange rates. MATERIALS AND METHODS: A single-institution retrospective analysis of all percutaneous radiologic gastrostomy (PRG) placement and replacement procedures between January 2010 and July 2015 was conducted. A statistical model predicting the risk for catheter exchange for any reason and exchanges specifically for tube malfunction was created; a quality improvement plan to reduce catheter exchanges was designed and implemented in June 2014. The outcomes for subsequent PRG procedures from July 2014 through March 2015 were followed until July 2015. RESULTS: Between 2010 and June 2014, 1,144 primary PRG procedures and 442 replacement procedures were performed in 1,112 patients. Of the 442 exchange procedures, 289 were "rescue" procedures secondary to catheter malfunction. A quality improvement plan was implemented in June 2014 that encouraged primary gastrojejunostomy catheter and balloon-retained PRG catheter placement and placement of skin sutures in patients considered high risk for catheter dislodgment. From July 2014 through March 2015, 229 PRG catheters were placed, and 71 exchange procedures were performed through July 2015. There was a statistically significant decrease in the number of rescue exchanges performed secondary to catheter malfunction (P = .036). CONCLUSIONS: Procedural and patient-specific risk factors for PRG complications were identified, and a statistical model to predict rates of minor complications was created. These findings were used to implement a quality improvement program that resulted in a decrease in PRG exchanges secondary to catheter malfunction.

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.

Image-guided ovarian mass biopsy: efficacy and safety.

PURPOSE: Image-guided needle biopsy represents a minimally invasive method for pathologic diagnosis of a mass. This study evaluates the diagnostic yield, accuracy, and safety of ovarian mass biopsy with combined core and fine-needle technique. MATERIALS AND METHODS: Medical records of all women at least 18 years of age, referred from gynecologic oncology, who underwent image-guided ovarian mass biopsy from 2001 through 2011 were reviewed. Among 27 patients, ultrasound guidance was used in 13 (48%), six transabdominal and seven transvaginal; computed tomography guidance was used in 14 (52%), nine transabdominal and five transgluteal. Biopsy indications were suspected metastasis (n = 15; 56%), suspected ovarian cancer to be treated with neoadjuvant chemotherapy (n = 10; 37%), and relative contraindication to surgery (n = 2; 7%). Mean maximum lesion dimension was 9.9 cm (range, 2-23 cm), with solid composition in nine (33%), cystic in six (22%), and mixed in 12 (44%). Biopsy pathologic findings were compared versus those of the surgical specimen or, for masses that were not resected, versus the stability of benign masses and response to chemotherapy of malignant masses on follow-up. RESULTS: All biopsies yielded a diagnosis. No biopsy-related complications were noted. Eleven patients (41%) did not undergo lesion resection and were followed for an average of 28.8 months (range, 0.3-118.4 mo). In no patient did malignancy develop during clinical follow-up after a benign biopsy diagnosis. Sensitivity and specificity for diagnosis of malignancy were 100% ± 0 (19 of 19) and 88% ± 26 (seven of eight), respectively, for cancer detection. In nine patients (33%) with final pathologic diagnosis of epithelial ovarian cancer, tumor seeding was not observed during a mean follow-up of 44.6 months (range, 1.3-110.2 mo). CONCLUSIONS: Image-guided ovarian mass core needle biopsy results in a pathologic diagnosis of benign and malignant masses with high yield, accuracy, and safety.