Concurrent IRF4 Rearrangements in a Patient with B Cell and T Cell Disorders

Introduction/Objective

IRF4 is a regulatory protein which required at several stages of B and T cell development and differentiation. Rearrangements of the IRF4 chromosomal region have been detected in various B and T cell neoplasms including a distinct entity in the WHO tumor classification for diffuse large B cell lymphoma (DLBCL) with IRF4 rearrangement and another for an IRF4 rearranged subtype of the CD30-positive T cell lymphoproliferative disorder, lymphomatoid papulosis (LyP).

Methods/Case Report

We present the case of a 52-year-old man with a past medical history of treated Hodgkin disease in remission who now presents with a DLBCL of the tonsil as well a cutaneous LyP, both of which demonstrate the IRF4 gene rearrangement. Immunohistochemical stains support the morphologic diagnoses and the rearrangement is detected in both cases using fluorescence in situ hybridization (FISH).

Results (if a Case Study enter NA)

NA.

Conclusion

The detection of IRF4 translocation in two separate cell lineages may result from one of a handful of possible explanations that we explore. First, a mutation in a multipotent hematopoietic progenitor cell may give rise to common lymphoid progenitors which pass the mutation on to subsequent B and T differentiated lymphocytes. Second, de novo mutations may be occurring in both B and T cell lines leading to the mature lesions. Finally, it may be possible that one of the two lesions is not truly positive for IRF4 rearrangement, but rather the background B cells in the skin or T cells in the tonsil are the cells positive for the aberration. This is a unique case of a B and T cell lesion in the same patient which both possess the same rare genetic rearrangement. The implications on our understanding of the genetic development of such lesions is significant and may subsequently impact diagnosis and therapy going forward.

Structure of the MRAS-SHOC2-PP1C phosphatase complex

RAS-MAPK signalling is fundamental for cell proliferation and is altered in most human cancers1-3. However, our mechanistic understanding of how RAS signals through RAF is still incomplete. Although studies revealed snapshots for autoinhibited and active RAF-MEK1-14-3-3 complexes4, the intermediate steps that lead to RAF activation remain unclear. The MRAS-SHOC2-PP1C holophosphatase dephosphorylates RAF at serine 259, resulting in the partial displacement of 14-3-3 and RAF-RAS association3,5,6. MRAS, SHOC2 and PP1C are mutated in rasopathies-developmental syndromes caused by aberrant MAPK pathway activation6-14-and SHOC2 itself has emerged as potential target in receptor tyrosine kinase (RTK)-RAS-driven tumours15-18. Despite its importance, structural understanding of the SHOC2 holophosphatase is lacking. Here we determine, using X-ray crystallography, the structure of the MRAS-SHOC2-PP1C complex. SHOC2 bridges PP1C and MRAS through its concave surface and enables reciprocal interactions between all three subunits. Biophysical characterization indicates a cooperative assembly driven by the MRAS GTP-bound active state, an observation that is extendible to other RAS isoforms. Our findings support the concept of a RAS-driven and multi-molecular model for RAF activation in which individual RAS-GTP molecules recruit RAF-14-3-3 and SHOC2-PP1C to produce downstream pathway activation. Importantly, we find that rasopathy and cancer mutations reside at protein-protein interfaces within the holophosphatase, resulting in enhanced affinities and function. Collectively, our findings shed light on a fundamental mechanism of RAS biology and on mechanisms of clinically observed enhanced RAS-MAPK signalling, therefore providing the structural basis for therapeutic interventions.

Non-adherence to LDV/SOF did not predict SVR in a randomized controlled trial of HIV/HCV coinfected persons who use drugs

BACKGROUND

Eliminating Hepatitis C Virus (HCV) will require effective treatment delivery to persons with substance use disorders (SUDs). We evaluated the relationship between ledipasvir/sofosbuvir treatment persistence (receiving 84 tablets), adherence, and sustained virologic response (SVR) in persons with HIV/HCV coinfection.

METHODS

Of the 144 participants with HIV/HCV and SUDs, 110 initiated a 12-week treatment course under one of three conditions (usual care, peer mentors, and cash incentives). We used self-report, pharmacy pill counts, and expected date of refill to examine adherence. Persistent participants were categorized as high adherence (taking ≥90% of doses) or low adherence (taking <90% of doses).

RESULTS

Most participants persisted on treatment after initiation (n=105), with 95% (n=100) achieving SVR. One-third (34%) of participants had moderate/heavy alcohol use by the biomarker phosphatidylethanol (PEth ≥50 ng/mL), and 44% had urine toxicology positive for cocaine or heroin at enrollment. The proportion of persons with high adherence was 72% (n=76) and low adherence, 28%. Although low adherence was associated with moderate/heavy alcohol use by PEth (RR 2.77, 95% CI 1.50-5.12), SVR did not vary according to adherence (p=0.702), and most participants (97%) with low adherence achieved SVR.

CONCLUSION

Treatment persistence led to high SVR rates among persons with HIV/HCV, despite imperfect adherence and SUDs.

Social Determinants of Health Challenges Are Prevalent Among Commercially Insured Populations

OBJECTIVES

To evaluate the prevalence of social determinants of health (SDoH) factors in a large commercially-insured population and to characterize the prevalence of common conditions (eg, diabetes, behavioral health issues) and addressable health services utilization concerns (eg, lack of preventive care) for which employers offer no- and low-cost benefit programs.

METHODS

We identified groups with SDoH challenges within a commercially-insured population of 5.1 M through administrative data and self-report. Using medical claims and health assessment data, we identified populations with SDoH needs who had common conditions for which employers often provide no- or low-cost benefit programs (ie, diabetes, behavioral health conditions, high-risk pregnancy, overweight/obesity). Additionally, we sought populations with common addressable health services utilization concerns such as avoidable emergency room visits, lack of preventive care services, or non-adherence to medications. We used univariate analyses to describe the prevalence of SDoH risks in the population of interest.

RESULTS

Twenty-seven percent of this commercially-insured population live in a zip code where the median income is at or below 200% of the Federal Poverty Line. Respondents identified cost (55%) and family, school, or work responsibilities (26%) as key barriers to care. ER overutilization rates are higher in lower income zip codes than wealthier zip codes (34% vs 9%) as is the prevalence of diabetes, overweight/obesity, and behavioral issues, and decreased use of preventive services. Fifteen percent of the study population live in a low-access food area. There is considerable variability in access to employer-sponsored resources to address these needs (70% of employers provide behavioral health programs; 63% provide telehealth programs, but only 1% offer healthy food programs and less than 0.5% offer either child care or transportation support programs).

CONCLUSIONS

Commercially insured populations could benefit from employer-sponsored programs or benefits that address key SDoH barriers such as financial support, healthy food programs, child-care, and transportation.

InterCarb: A Community Effort to Improve Interlaboratory Standardization of the Carbonate Clumped Isotope Thermometer Using Carbonate Standards

Increased use and improved methodology of carbonate clumped isotope thermometry has greatly enhanced our ability to interrogate a suite of Earth-system processes. However, interlaboratory discrepancies in quantifying carbonate clumped isotope (Δ47) measurements persist, and their specific sources remain unclear. To address interlaboratory differences, we first provide consensus values from the clumped isotope community for four carbonate standards relative to heated and equilibrated gases with 1,819 individual analyses from 10 laboratories. Then we analyzed the four carbonate standards along with three additional standards, spanning a broad range of δ47 and Δ47 values, for a total of 5,329 analyses on 25 individual mass spectrometers from 22 different laboratories. Treating three of the materials as known standards and the other four as unknowns, we find that the use of carbonate reference materials is a robust method for standardization that yields interlaboratory discrepancies entirely consistent with intralaboratory analytical uncertainties. Carbonate reference materials, along with measurement and data processing practices described herein, provide the carbonate clumped isotope community with a robust approach to achieve interlaboratory agreement as we continue to use and improve this powerful geochemical tool. We propose that carbonate clumped isotope data normalized to the carbonate reference materials described in this publication should be reported as Δ47 (I-CDES) values for Intercarb-Carbon Dioxide Equilibrium Scale.

Network-based recruitment of people who inject drugs for hepatitis C testing and linkage to care

Although oral direct-acting agent (DAA) therapies have the potential to reduce the burden of hepatitis C virus (HCV) infection, treatment uptake remains low, particularly among people who inject drugs (PWID). This study examined the feasibility of an innovative peer-based recruitment strategy to engage PWID in HCV testing and treatment. We interviewed an initial set of HCV antibody-positive PWID as 'primary indexes' to gather demographic, drug use, health information and drug network characteristics. Primary indexes were then briefly educated on HCV and its treatment and encouraged to recruit their injection drug 'network members' for HCV testing and linkage to care. Eligible network members were enrolled as 'secondary indexes' and completed the same index study procedures. In sum, 17 of 36 primary indexes initiated the recruitment of 64 network members who were HCV antibody positive and eligible to become indexes. In multivariable analysis, successful recruitment of at least one network member was positively associated with prior HCV treatment (OR 2.80; CI [1.01, 7.72]), daily or more injection drug use (OR 2.38; CI [1.04, 5.47]), and a higher number of injection drug network members (OR 1.20; CI [1.01, 1.42]). Among the 69 participants with chronic HCV not previously linked to HCV care at enrolment, 91% (n = 63) completed a linkage to HCV care appointment, 45% (n = 31) scheduled an appointment with an HCV provider, and 20% (n = 14) initiated HCV therapy. These findings suggest a potential benefit for peer-driven, network-based interventions focused on HCV treatment-experienced PWID as a mechanism to increase HCV linkage to care.

Development of a long-acting direct-acting antiviral system for hepatitis C virus treatment in swine

Chronic hepatitis C virus (HCV) infection is a leading cause of cirrhosis worldwide and kills more Americans than 59 other infections, including HIV and tuberculosis, combined. While direct-acting antiviral (DAA) treatments are effective, limited uptake of therapy, particularly in high-risk groups, remains a substantial barrier to eliminating HCV. We developed a long-acting DAA system (LA-DAAS) capable of prolonged dosing and explored its cost-effectiveness. We designed a retrievable coil-shaped LA-DAAS compatible with nasogastric tube administration and the capacity to encapsulate and release gram levels of drugs while resident in the stomach. We formulated DAAs in drug-polymer pills and studied the release kinetics for 1 mo in vitro and in vivo in a swine model. The LA-DAAS was equipped with ethanol and temperature sensors linked via Bluetooth to a phone application to provide patient engagement. We then performed a cost-effectiveness analysis comparing LA-DAAS to DAA alone in various patient groups, including people who inject drugs. Tunable release kinetics of DAAs was enabled for 1 mo with drug-polymer pills in vitro, and the LA-DAAS safely and successfully provided at least month-long release of sofosbuvir in vivo. Temperature and alcohol sensors could interface with external sources for at least 1 mo. The LA-DAAS was cost-effective compared to DAA therapy alone in all groups considered (base case incremental cost-effectiveness ratio $39,800). We believe that the LA-DAA system can provide a cost-effective and patient-centric method for HCV treatment, including in high-risk populations who are currently undertreated.

Unreported alcohol use was common but did not impact hepatitis C cure in HIV-infected persons who use drugs

We investigated the prevalence and impact of heavy alcohol use on the hepatitis C virus (HCV) care continuum amongst HIV/HCV co-infected persons who use drugs. In the CHAMPS study, 144 HIV/HCV co-infected persons were randomized to contingent cash incentives, peer mentors and usual care to evaluate the impact on HCV care. Alcohol use was ascertained using the 10-item AUDIT (hazardous: male ≥8, female ≥4) and phosphatidylethanol (PEth) (heavy: ≥50 ng/mL), an alcohol biomarker. Log binomial regression was used to evaluate the association between heavy alcohol use and failure to initiate treatment and to achieve sustained virologic response (SVR). Of the 135 participants with PEth data, median age was 55 years, 59% were male, 92% were Black, 91% reported a history of drug use, and 97% were on antiretroviral therapy. Hazardous drinking was reported on AUDIT by 28% of participants, and 35% had heavy alcohol use by PEth. Of the 47 individuals with a PEth ≥50 ng/mL, 23 (49%) reported no or minimal alcohol use by AUDIT. HCV treatment was initiated in 103 of 135 participants, and SVR was achieved in 92%. PEth ≥50 ng/mL (Relative Risk [RR] 0.72, 95% CI 0.35-1.48) was not significantly associated with failure to initiate HCV treatment or failure to achieve SVR (RR 0.85, 95% CI 0.46-1.57).In conclusion, alcohol use was common and frequently not detected by self-report. However, heavy alcohol use, even when measured objectively, was not associated with failure to initiate HCV treatment or to achieve cure.

A Randomized Controlled Trial of Cash Incentives or Peer Support to Increase HCV Treatment for Persons With HIV Who Use Drugs: The CHAMPS Study

Background

Despite access to direct-acting antivirals, barriers to a hepatitis C virus (HCV) cure persist, especially among persons living with human immunodeficiency virus (HIV) (PLWH) who use drugs. Interventions such as peer mentors or cash incentives may improve the care continuum.

Methods

The CHAMPS (Chronic HepAtitis C Management to ImProve OutcomeS) study randomized 144 PLWH, recruited from an outpatient clinic, with substance use disorders into three treatment groups: usual care (UC) (n = 36), UC plus cash incentives (n = 54), and UC plus peer mentors (n = 54) to evaluate HCV treatment uptake and cure. All participants received 12-weeks of ledipasvir/sofosbuvir (LDV/SOF). Trained peer mentors had well-controlled HIV and HCV. Cash incentives were contingent on visit attendance (maximum $220). The primary endpoint was HCV treatment initiation; secondary endpoints included sustained virologic response (SVR) and HCV reinfection.

Results

The majority of participants were male (61%), Black (93%), and unemployed (85%). Depression and active drug and alcohol use were common. Overall, 110 of 144 (76%) participants initiated LDV/SOF. Although treatment initiation rates were higher in PLWH randomized to peers (83%, 45 of 54) or cash (76%, 41 of 54) compared to UC (67%, 24 of 36), these differences were not statistically significant (P = .11). Most PLWH who initiated treatment achieved SVR (100 of 110, 91%). LDV/SOF was well tolerated; peers and cash had no effect on drug and alcohol use during therapy. One individual from the cash cohort experienced HCV reinfection.

Conclusion

After removal of system barriers, one-third of PLWH in UC did not initiate HCV treatment. Among those who initiated, SVR rates were high. Research involving PLWH who use drugs should focus on overcoming barriers to treatment initiation.

Clinical trial information

The registration data for the trial are in the ClinicalTrials.gov database, number NCT02402218.

Glucocorticoid-induced osteoporosis preventive care in rheumatology patients

Glucocorticoid-induced osteoporosis (GIOP) is common in patients prescribed with long-term glucocorticoids. Guidelines suggest patients receiving moderate-dose glucocorticoid therapy receive GIOP preventive care. Previous studies have shown preventive care rates are not optimal. We look at GIOP preventive care rates in rheumatology patients and predictors of various components of care.

PURPOSE

Glucocorticoid-induced osteoporosis (GIOP) is a common concern in patients prescribed with long-term glucocorticoids. Studies have shown GIOP preventive care is not provided optimally in the general population; however, little is published on GIOP preventive care among patients with rheumatic disease. The objective of this study is to determine the proportion of rheumatology patients who received GIOP preventive care.

METHODS

A population-based retrospective quality assurance study of adults seen at the University of Alberta Rheumatology Clinic was performed using the electronic outpatient medical record. Records of adult patients prescribed with prednisone from January 1st to December 31st, 2016 by a rheumatologist were initially included for review. Those who had been prescribed ≥ 7.5 mg/day for ≥ 3 months were assessed for concurrent GIOP preventive care.

RESULTS

A total of 745 discreet courses of prednisone were prescribed in 433 patients with 113 meeting the above inclusion criteria. Following the prednisone prescription, 79% were taking vitamin D, 86% were taking calcium, and 50% were prescribed with osteoporosis pharmacotherapy. Twenty-five percent of patients had DXA imaging ordered by the rheumatologist within the first 6 months; of these, 86% of patients completed the DXA.

CONCLUSIONS

Overall, our study shows that patients under the care of rheumatologists receive better GIOP preventative care than previously reported care in the general population. However, there is still room for improvement. In particular, men, younger patients, and rural patients seem to be at the most at risk of not receiving optimal GIOP prevention.

Reversible light-dependent molecular switches on Ag/AgCl nanostructures

Nanostructured Ag/AgCl substrates were used to generate reversible and highly efficient light-dependent chemical switches based on adsorbed 4,4'-dimercaptoazobenzene (DMAB). DMAB was formed in situ via laser-induced dimerization either from 4-nitrothiophenol (4-NTP) or 4-aminothiophenol (4-ATP). The subsequent reaction pathways of DMAB, however, were quite different as monitored by surface enhanced Raman spectroscopy. In the 4-NTP/DMAB system, AgCl catalyses the reversal of the dimerization. Conversely, irradiation of adsorbed 4-ATP first generated cis-DMAB attached to the surface via two Ag-S bonds, followed by AgCl-catalysed cleavage of one Ag-S bond and cis → trans photoisomerisation of DMAB. In the dark, the trans-isomer thermally reverts to cis-DMAB. The here presented light-dark chemical switches, which work without changing other parameters (e.g., pH, anaerobic vs. aerobic), are based on the (photo)catalytic properties of the Ag/AgCl substrate and do not function on pure metal surfaces.

Vibrational spectroscopy reveals the initial steps of biological hydrogen evolution

[FeFe] hydrogenases are biocatalytic model systems for the exploitation and investigation of catalytic hydrogen evolution. Here, we used vibrational spectroscopic techniques to characterize, in detail, redox transformations of the [FeFe] and [4Fe4S] sub-sites of the catalytic centre (H-cluster) in a monomeric [FeFe] hydrogenase. Through the application of low-temperature resonance Raman spectroscopy, we discovered a novel metastable intermediate that is characterized by an oxidized [FeIFeII] centre and a reduced [4Fe4S]1+ cluster. Based on this unusual configuration, this species is assigned to the first, deprotonated H-cluster intermediate of the [FeFe] hydrogenase catalytic cycle. Providing insights into the sequence of initial reaction steps, the identification of this species represents a key finding towards the mechanistic understanding of biological hydrogen evolution.