Monocytes Take Their Own Path to IL-1ß.

Generally, two signals are required to activate the NLRP3 inflammasome. In this issue of Immunity, Hornung and colleagues (2016) describe an alternative inflammasome activation pathway in human monocytes triggering activation of the NLRP3 inflammasome in response to a single stimulus.

Mitochondrial cardiolipin is required for Nlrp3 inflammasome activation.

Nlrp3 inflammasome activation occurs in response to numerous agonists but the specific mechanism by which this takes place remains unclear. All previously evaluated activators of the Nlrp3 inflammasome induce the generation of mitochondrial reactive oxygen species (ROS), suggesting a model in which ROS is a required upstream mediator of Nlrp3 inflammasome activation. Here we have identified the oxazolidinone antibiotic linezolid as a Nlrp3 agonist that activates the Nlrp3 inflammasome independently of ROS. The pathways for ROS-dependent and ROS-independent Nlrp3 activation converged upon mitochondrial dysfunction and specifically the mitochondrial lipid cardiolipin. Cardiolipin bound to Nlrp3 directly and interference with cardiolipin synthesis specifically inhibited Nlrp3 inflammasome activation. Together these data suggest that mitochondria play a critical role in the activation of the Nlrp3 inflammasome through the direct binding of Nlrp3 to cardiolipin.

Cutting Edge: Mitochondrial Assembly of the NLRP3 Inflammasome Complex Is Initiated at Priming.

The NLRP3 inflammasome is activated in response to microbial and danger signals, resulting in caspase-1-dependent secretion of the proinflammatory cytokines IL-1ß and IL-18. Canonical NLRP3 inflammasome activation is a two-step process requiring both priming and activation signals. During inflammasome activation, NLRP3 associates with mitochondria; however, the role for this interaction is unclear. In this article, we show that mouse NLRP3 and caspase-1 independently interact with the mitochondrial lipid cardiolipin, which is externalized to the outer mitochondrial membrane at priming in response to reactive oxygen species. An NLRP3 activation signal is then required for the calcium-dependent association of the adaptor molecule ASC with NLRP3 on the mitochondrial surface, resulting in inflammasome complex assembly and activation. These findings demonstrate a novel lipid interaction for caspase-1 and identify a role for mitochondria as supramolecular organizing centers in the assembly and activation of the NLRP3 inflammasome.

Primary Care Provider Awareness of IR: A Single-Center Analysis.

PURPOSE: To evaluate primary care provider awareness of interventional radiology (IR) services at a tertiary care academic medical center to identify areas of IR practice that require additional education and awareness initiatives. MATERIAL AND METHODS: An internet-based survey was distributed via email to primary care providers, including internal medicine (IM), family medicine (FM), obstetrics and gynecology (OBGYN), and hospital medicine (HM) physicians in the region. The survey consisted of 17 questions regarding provider demographics, experiences with IR in their practice, awareness of IR training, and awareness of IR procedures and services. RESULTS: A total of 234 of 533 invited physicians completed the survey (40% IM, 22% FM, 22% HM, and 16% OBGYN). Providers rated their knowledge of IR as poor (49, 20.3%), adequate (137, 56.9%), good (49, 20.3%), and excellent (6, 2.5%). Although 235 (97.5%) had consulted IR previously, only 141 (58.5%) had referred a patient directly to IR for an elective procedure. IR was offered as an alternative to surgical procedures never (42, 17.6%), a quarter of the time (101, 42.3%), half of the time (61, 25.5%), three-quarters of the time (27, 11.3%), and every time (8, 3.35%). Most respondents (161, 67.4%) learned the most about IR procedures during residency. Most (180, 75.3%) indicated that they would like to learn more about IR. CONCLUSIONS: These findings indicate that more can be done to educate providers about the potential role of IR in patient care. Provider awareness is limited regarding procedures that are increasingly popular in the IR community. This study helps to identify specific areas of IR in which awareness of can be increased.

Nationwide Trends in Use of Catheter-Directed Therapy for Treatment of Pulmonary Embolism in Medicare Beneficiaries from 2004 to 2016.

PURPOSE: To evaluate changes in the use of catheter-directed therapy (CDT) for pulmonary embolism (PE) treatment with attention to primary operator specialty in the Medicare population. METHODS: Using a 5% national sample of Medicare claims data from 2004 to 2016, all claims associated with PE were identified. The annual volume of 2 billable CDT services-arterial mechanical thrombectomy and transcatheter arterial infusion for thrombolysis-were determined to evaluate changes in CDT use and primary CDT operator specialty over time. RESULTS: The total number of CDT procedures increased over the course of the study period, representing 0.457 and 5.057 service counts per 100,000 Medicare beneficiaries in 2004 and 2016, respectively. The proportion of PEs treated with CDT increased 10-fold from 2004 to 2016, increasing from 0.1% to 1.0%. Interventional radiologists performed most CDT therapies each year, with the exception of 2010 when vascular surgeons performed more. In 2016, interventional radiologists performed 3.54 CDT services for PE per 100,000 Medicare beneficiaries, which was 70% of total CDT for PE procedures, followed by interventional cardiologists and vascular surgeons performing 0.92 services (18%) and 0.60 services (12%), respectively. CONCLUSIONS: CDT is an increasingly used treatment for PE, with a 10-fold increase from 2004 to 2016. Interventional radiologists are the dominant providers of these services, followed by interventional cardiologists and vascular surgeons.

Initiation and perpetuation of NLRP3 inflammasome activation and assembly.

The NLRP3 (NOD-like receptor family, pyrin domain containing 3) inflammasome is a multiprotein complex that orchestrates innate immune responses to infection and cell stress through activation of caspase-1 and maturation of inflammatory cytokines pro-interleukin-1ß (pro-IL-1ß) and pro-IL-18. Activation of the inflammasome during infection can be protective, but unregulated NLRP3 inflammasome activation in response to non-pathogenic endogenous or exogenous stimuli can lead to unintended pathology. NLRP3 associates with mitochondria and mitochondrial molecules, and activation of the NLRP3 inflammasome in response to diverse stimuli requires cation flux, mitochondrial Ca(2+) uptake, and mitochondrial reactive oxygen species accumulation. It remains uncertain whether NLRP3 surveys mitochondrial integrity and senses mitochondrial damage, or whether mitochondria simply serve as a physical platform for inflammasome assembly. The structure of the active, caspase-1-processing NLRP3 inflammasome also requires further clarification, but recent studies describing the prion-like properties of ASC have advanced the understanding of how inflammasome assembly and caspase-1 activation occur while raising new questions regarding the propagation and resolution of NLRP3 inflammasome activation. Here, we review the mechanisms and pathways regulating NLRP3 inflammasome activation, discuss emerging concepts in NLRP3 complex organization, and expose the knowledge gaps hindering a comprehensive understanding of NLRP3 activation.

A consortium-driven framework to guide the implementation of ICH M7 Option 4 control strategies.

The ICH M7 Option 4 control of (potentially) mutagenic impurities is based on the use of scientific principles in lieu of routine analytical testing. This approach can reduce the burden of analytical testing without compromising patient safety, provided a scientifically rigorous approach is taken which is backed up by sufficient theoretical and/or analytical data. This paper introduces a consortium-led initiative and offers a proposal on the supporting evidence that could be presented in regulatory submissions.

A Nitrogen-Assisted One-Pot Heteroaryl Ketone Synthesis from Carboxylic Acids and Heteroaryl Halides.

A practical and highly effective one-pot synthesis of versatile heteroaryl ketones directly from carboxylic acids and heteroaryl halides under mild conditions is reported. This method does not require derivatization of carboxylic acids (preparation of acid chlorides, Weinreb amides, etc.) or the use of any additives/catalysts. A wide substrate scope of carboxylic acids with high functional group tolerance has also been demonstrated. The results reveal that the presence of an α-nitrogen on the halide substrate greatly improves the desired ketone formation.

The impact of bowel cleansing on follow-up recommendations in average-risk patients with a normal colonoscopy.

OBJECTIVES: Repeat colonoscopy in 10 years after a normal screening colonoscopy is recommended in an average-risk patient, and it has been proposed by American Gastroenterological Association (AGA), American College of Gastroenterology (ACG), and American Society for Gastrointestinal Endoscopy (ASGE) as a quality measure. However, there are little quantitative data about adherence to this recommendation or factors that may improve adherence. Our study quantifies adherence to this recommendation and the impact of suboptimal bowel preparation on adherence. METHODS: In this retrospective database study, endoscopy reports of average-risk individuals ≥50 years old with a normal screening colonoscopy were reviewed. Quality of colon cleansing was recorded using the Aronchick scale as excellent, good, fair, or poor. Main outcome measurements were quality of bowel preparation and recommendation for timing of repeat colonoscopy. Recommendations were considered consistent with guidelines if 10-year follow-up was documented after excellent, good, or fair prep or if ≤1-year follow-up was recommended after poor prep. RESULTS: Among 1,387 eligible patients, recommendations for follow-up colonoscopy inconsistent with guidelines were seen in 332 (23.9%) subjects. By bowel preparation quality, 15.3% of excellent/good, 75% of fair, and 31.6% of poor bowel preparations were assigned recommendations inconsistent with guidelines (P<0.001). Patients with fair (odds ratio=18.0; 95% confidence interval 12.0-28.0) were more likely to have recommendations inconsistent with guidelines compared with patients with excellent/good preps. CONCLUSIONS: Recommendations inconsistent with guidelines for 10-year intervals after a normal colonoscopy occurred in >20% of patients. Minimizing "fair" bowel preparations may be a helpful intervention to improve adherence to these recommendations.

Adherence to recommended intervals for surveillance colonoscopy in average-risk patients with 1 to 2 small (<1 cm) polyps on screening colonoscopy.

BACKGROUND: Among average-risk patients, repeat colonoscopy in 5 years is recommended after 1 to 2 small (<1 cm) adenomas are found on screening colonoscopy or in 10 years if hyperplastic polyps are found. However, sparse quantitative data are available about adherence to these recommendations or factors that may improve adherence. OBJECTIVE: To quantify adherence to recommended intervals and to identify factors associated with lack of adherence. DESIGN: Retrospective endoscopic database analysis. SETTING: Tertiary-care institution and Veterans Affairs Health System. PATIENTS: Average-risk individuals undergoing screening colonoscopy found to have 1 to 2 small polyps on screening colonoscopy. MAIN OUTCOME MEASUREMENTS: Frequency of recommending repeat colonoscopy in 5 years if 1 to 2 small adenomas are found and in 10 years if hyperplastic polyps are found. RESULTS: Of 922 outpatient screening colonoscopies with 1 to 2 small polyps found, 90.2% received appropriate recommendations for timing of repeat colonoscopy. Eighty-four percent of patients with 1 to 2 small adenomas and 94% of patients with 1 to 2 hyperplastic polyps received recommendations that were consistent with guidelines. Based on logistic regression analysis, patients aged >70 years (odds ratio [OR] 2.4, 95% confidence interval [CI], 1.0-5.7), fair bowel preparation (OR 12.7; 95% CI, 7.3-22.4), poor bowel preparation (OR 10.0; 95% CI, 4.3-23.6), and the presence of 2 small adenomas versus 1 small adenoma (OR 3.6; 95% CI, 2.2-6.0) were factors associated with "overuse" or recommendations inconsistent with guidelines. LIMITATIONS: Retrospective study design. CONCLUSION: More than 90% of endoscopists' recommendations for timing of surveillance colonoscopy in average-risk patients with 1 to 2 small polyps are consistent with guideline recommendations. Quality of preparation is strongly associated with deviation from guideline recommendations.

Characterization of Thrombate III®, a pasteurized and nanofiltered therapeutic human antithrombin concentrate.

Thrombate III(®) is a highly purified antithrombin concentrate that has been used by clinicians worldwide for more than two decades for the treatment of hereditary antithrombin deficiency. The manufacturing process is based on heparin-affinity chromatography and pasteurization. To modernize the process and to further enhance the pathogen safety profile of the final product, despite the absence of infectious disease transmission, a nanofiltration step was added. The biochemical characterization and pathogen safety evaluation of Thrombate III(®) manufactured using the modernized process are presented. Bioanalytical data demonstrate that the incorporation of nanofiltration has no impact on the antithrombin content, potency, and purity of the product. Scaledown models of the manufacturing process were used to assess virus and prion clearance under manufacturing setpoint conditions. Additionally, robustness of virus clearance was evaluated at or slightly outside the manufacturing operating limits. The results demonstrate that pasteurization inactivated both enveloped and non-enveloped viruses. The addition of nanofiltration substantially increased clearance capacities for both enveloped and non-enveloped viruses by approximately 4-6 log10. In addition, the process achieves 6.0 log10 ID50 prion infectivity clearance. Thus, the introduction of nanofiltration increased the pathogen safety margin of the manufacturing process without impacting the key biochemical characteristics of the product.

Synthesis of isotope-labeled HSP90 inhibitor: [(13) CD3 ] and [(14) C]-TAK-459.

[(13) CD3 ]-TAK-459 (1A), an HSP90 inhibitor, was synthesized from [(13) CD3 ]-sodium methoxide in three steps in an overall yield of 29%. The key intermediate [(13) CD3 ]-2-methoxy-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine was synthesized in two steps from 2,6-dibromopyridine and stable isotope-labeled sodium methoxide. [(14) C]-TAK-459 (1B) was synthesized from [(14) C(U)]-guanidine hydrochloride in five steps in an overall radiochemical yield of 5.4%. The key intermediate, [(14) C]-(R)-2-amino-7-(2-bromo-4-fluorophenyl)-4-methyl-7,8-dihydropyrido[4,3-d]pyrimidin-5(6H)-one, was prepared by microwave-assisted condensation.

Acute Hepatitis due to Primary Human Immunodeficiency Virus Infection.

The acute retroviral syndrome may present with diverse systemic manifestations and laboratory abnormalities. Here we present a rare case of primary human immunodeficiency virus (HIV) infection causing severe acute hepatitis. Liver histopathology demonstrated a pattern of lymphocytic inflammation consistent with acute hepatitis, high levels of HIV proviral DNA were detected within liver tissue, and immunofluorescence showed HIV p24 antigen within immune and parenchymal cells including hepatocytes. We review the literature pertaining to HIV infection of cell compartments within the liver and discuss the implications for HIV-associated acute liver disease.

The impact of fair colonoscopy preparation on colonoscopy use and adenoma miss rates in patients undergoing outpatient colonoscopy.

BACKGROUND: The impact of fair bowel preparation on endoscopists' recommendations and adenoma miss rates in average-risk patients undergoing colonoscopy is unknown. OBJECTIVE: To assess the impact of fair bowel preparation on endoscopists' interval colonoscopy recommendations and miss rates in colonoscopies performed within 3 years of the index colonoscopy in average-risk patients undergoing colorectal cancer screening. DESIGN: Retrospective chart review. SETTING: Tertiary-care center. PATIENTS: Average-risk patients undergoing index colonoscopy for colorectal cancer screening between 2004 and 2006. INTERVENTION: Colonoscopy. MAIN OUTCOME MEASUREMENTS: Endoscopists' interval recommendations, adenoma miss rates. RESULTS: A total of 16,251 colonoscopy records were reviewed over a 2-year period. Of these cases, 1943 colonoscopies were performed for the sole indication of average risk or screening. Of these, fair bowel preparation was reported in 619 patients (31.9%). A repeat colonoscopy within 5 years was recommended in 70.4% of patients. The follow-up colonoscopy compliance rate within 3 years was 55.9%. Adenoma detection rates at index and follow-up colonoscopy were 20.5% and 28.2%, respectively. Of the 39 patients with follow-up colonoscopy within 3 years, the overall adenoma miss rate was 28%. Of the patients with an adenoma identified on follow-up colonoscopy, 13.6% had normal colonoscopy results on index examination. LIMITATIONS: Retrospective design. CONCLUSION: Fair bowel preparation led to a deviation from national guidelines with early repeat colonoscopy follow-up recommendations in nearly 60% of average-risk patients with normal colonoscopy results. In patients who returned for repeat colonoscopy within 3 years, the overall adenoma miss rate was 28%. Further guidelines on timing for repeat colonoscopy for fair bowel preparation are needed.

Syntheses of C-13 and C-14-labeled versions of the investigational proteasome inhibitor MLN9708.

MLN9708 (ixazomib citrate) is an investigational, orally bioavailable proteasome inhibitor that is under development by Millennium in clinical studies in both hematologic and nonhematologic malignancies. The stable isotope-labeled MLN9708 was required for bio-analytical studies. [(13) C9 ]-MLN9708 (11) was synthesized in seven steps from the uniformly labeled [(13) C6 ]-1,4-dichlorobenzene (3) and [1-(13) C]-acetyl chloride. Because of the presence of two chlorine atoms and a boron atom, compound 6 was further reacted with [(13) C2 ]-glycine to provide an internal standard that is well separated from the parent compound during mass spectrometric analysis. The radiolabeled version was prepared to support metabolite profiling and whole body autoradiography studies in experimental animals. [(14) C]-MLN9708 (19) was synthesized in six steps from commercially available [(14) C]-barium carbonate. The key intermediate, [carboxyl-(14) C]-2,5-dichlorobenzoic acid (14), was prepared by selective lithiation of 1-bromo-2,5-dichlorobenzene (12) followed by carbonation with [(14) C]-barium carbonate. In preparation for a one-time human absorption, distribution, metabolism and excretion (ADME) study, the stability of [(14) C]-MLN9708 and its precursors were also evaluated.

Prevalence of adenomas and advanced adenomas in patients in the 40- to 49-year age group undergoing screening colonoscopy because of a family history of adenoma/polyp in a first-degree relative.

BACKGROUND: Per current guidelines, patients with a first-degree relative (FDR) with adenomas should get screened at age 40. Data on the prevalence of adenomas and advanced adenomas (AAs) in these patients are lacking. OBJECTIVE: To examine the prevalence of adenomas and AAs in 40- to 49-year-old individuals undergoing screening colonoscopy because of a family history (FH) of polyps and to compare these data with those of a control population of similar age. DESIGN: Retrospective cross-sectional study. SETTING: Tertiary care academic medical center and Veterans Affairs medical center. PATIENTS: Study subjects included all 40- to 49-year-old asymptomatic individuals undergoing initial screening colonoscopy at our institution from January 1, 2006, to June 1, 2009, because of an FDR with polyps. The control population consisted of all 40- to 49-year-old individuals who underwent their first colonoscopy during the same period because of abdominal pain, diarrhea, or constipation without an FH of polyps or colorectal cancer. INTERVENTION: Colonoscopy. MAIN OUTCOME MEASUREMENTS: The prevalence of adenomas of any size, AAs, and risk factors associated with adenomas. RESULTS: The prevalence of adenomas was greater in the FH of polyps group (n = 176) compared with the control sample (n = 178) (26.7% vs 13.5%; P = .002) but was not statistically greater for AAs (5.7% vs 3.4%; P = .3). After adjusting for confounders, FH of a polyp was associated with an increased prevalence of adenomas (odds ratio 2.8 [95% CI, 1.4-5.5]). LIMITATIONS: Limited data on polyp histology in FDRs and limited sample size. CONCLUSIONS: Among 40- to 49-year-old patients undergoing screening colonoscopy because of an FDR with polyps, the prevalence of adenomas was greater than in a control population. Prospective research is needed to quantify the prevalence of AAs in this group and to determine whether these individuals should undergo screening colonoscopy at age 40.

Legionella pneumophila and Staphylococcus aureus co-infections in a patient with SARS-CoV-2.

A man fully mRNA-vaccinated against COVID-19 presented to our hospital with an acute febrile illness, respiratory symptoms and a positive test for SARS-CoV-2. He was later found early into hospitalisation to have two morbid bacterial co-infections: Legionella pneumophila serogroup 1 and methicillin-resistant Staphylococcus aureus (MRSA). Although this patient was initially admitted for COVID-19 management, his initial presentation was remarkable for lobar pneumonia, hyponatraemia and rhabdomyolysis more compatible with Legionnaire's disease than severe COVID-19. On discovery of MRSA pneumonia as a second bacterial infection, immunosuppressive COVID-19 therapies were discontinued and targeted antibiotics towards both bacterial co-infections were initiated. The patient's successful recovery highlighted the need to have high suspicion for bacterial co-infections in patients presenting with community-acquired pneumonia and a positive SARS-CoV-2 test, as patients with serious bacterial co-infections may have worse outcomes with use of immunosuppressive COVID-19 therapies.

Prevalence of any size adenomas and advanced adenomas in 40- to 49-year-old individuals undergoing screening colonoscopy because of a family history of colorectal carcinoma in a first-degree relative.

BACKGROUND: Per current guidelines, patients with a first-degree relative (FDR) with colorectal cancer (CRC) should get screened at least at age 40. Data about the prevalence of adenomas and advanced adenomas (AAs) in these patients are lacking. OBJECTIVE: To examine the prevalence of adenomas and AAs in 40- to 49-year-old individuals undergoing screening colonoscopy for family history of CRC. DESIGN: Retrospective chart review. PATIENTS: Asymptomatic patients 40 to 49 years of age undergoing their first screening colonoscopy at the University of Michigan during the period 1999 to 2009 because of an FDR with CRC. MAIN OUTCOME MEASUREMENTS: Prevalence of adenomas (any size), AAs, and risk factors associated with adenomas. RESULTS: Among 640 study patients, the prevalence of adenomas (any size) was 15.4% and 3.3% for AAs. Adenoma prevalence was lower if the FDR with CRC was younger than 60 years of age versus an FDR with CRC older than 60 years of age (12.4% vs 19%, P = .034). Male sex (odds ratio 2.6; 95% CI, 1.06-4.4) and advancing age (odds ratio 1.16; 95% CI, 1.03-1.31) were associated with adenomas. LIMITATIONS: Limited data on risk factor exposure and insufficient sample size to assess risk factors for AAs. CONCLUSIONS: Among 40- to 49-year-old patients undergoing screening colonoscopy because of an FDR with CRC, the prevalence of adenomas and AAs is low. Further research should determine whether these individuals have a higher prevalence of adenomas compared with average-risk individuals.

Interferon gamma runs interference on persistent COVID-19.

COVID-19 represents a collection of disease endotypes stemming from infection with SARS-CoV-2 and thus requires precision medicine approaches to target specific viral variants and stages of illness. In this issue, van Laarhoven et al.1 describe five immunocompromised patients with prolonged COVID-19 successfully treated with interferon gamma (IFNγ).