Human herpesvirus-6, HHV-8 and parvovirus B19 after allogeneic hematopoietic cell transplant: the lesser-known viral complications.

PURPOSE OF REVIEW: Viral infections continue to burden allogeneic hematopoietic cell transplant (HCT) recipients. We review the epidemiology, diagnosis, and management of human herpesvirus (HHV)-6, HHV-8 and parvovirus B19 following HCT. RECENT FINDINGS: Advances in HCT practices significantly improved outcomes but impact viral epidemiology: post-transplant cyclophosphamide for graft-versus-host disease prevention increases HHV-6 reactivation risk while the impact of letermovir for CMV prophylaxis - and resulting decrease in broad-spectrum antivirals - is more complex. Beyond the well established HHV-6 encephalitis, recent evidence implicates HHV-6 in pneumonitis. Novel less toxic therapeutic approaches (brincidofovir, virus-specific T-cells) may enable preventive strategies in the future. HHV-8 is the causal agent of Kaposi's sarcoma, which is only sporadically reported after HCT, but other manifestations are possible and not well elucidated. Parvovirus B19 can cause severe disease post-HCT, frequently manifesting with anemia, but can also be easily overlooked due to lack of routine screening and ambiguity of manifestations. SUMMARY: Studies should establish the contemporary epidemiology of HHV-6, and other more insidious viruses, such as HHV-8 and parvovirus B19 following HCT and should encompass novel cellular therapies. Standardized and readily available diagnostic methods are key to elucidate epidemiology and optimize preventive and therapeutic strategies to mitigate the burden of infection.

Phage Therapy of Mycobacterium Infections: Compassionate Use of Phages in 20 Patients With Drug-Resistant Mycobacterial Disease.

BACKGROUND: Nontuberculous Mycobacterium infections, particularly Mycobacterium abscessus, are increasingly common among patients with cystic fibrosis and chronic bronchiectatic lung diseases. Treatment is challenging due to intrinsic antibiotic resistance. Bacteriophage therapy represents a potentially novel approach. Relatively few active lytic phages are available and there is great variation in phage susceptibilities among M. abscessus isolates, requiring personalized phage identification. METHODS: Mycobacterium isolates from 200 culture-positive patients with symptomatic disease were screened for phage susceptibilities. One or more lytic phages were identified for 55 isolates. Phages were administered intravenously, by aerosolization, or both to 20 patients on a compassionate use basis and patients were monitored for adverse reactions, clinical and microbiologic responses, the emergence of phage resistance, and phage neutralization in serum, sputum, or bronchoalveolar lavage fluid. RESULTS: No adverse reactions attributed to therapy were seen in any patient regardless of the pathogen, phages administered, or the route of delivery. Favorable clinical or microbiological responses were observed in 11 patients. Neutralizing antibodies were identified in serum after initiation of phage delivery intravenously in 8 patients, potentially contributing to lack of treatment response in 4 cases, but were not consistently associated with unfavorable responses in others. Eleven patients were treated with only a single phage, and no phage resistance was observed in any of these. CONCLUSIONS: Phage treatment of Mycobacterium infections is challenging due to the limited repertoire of therapeutically useful phages, but favorable clinical outcomes in patients lacking any other treatment options support continued development of adjunctive phage therapy for some mycobacterial infections.

Metabolomics of bacterial-fungal pairwise interactions reveal conserved molecular mechanisms.

Bacterial-fungal interactions (BFIs) can shape the structure of microbial communities, but the small molecules mediating these BFIs are often understudied. We explored various optimization steps for our microbial culture and chemical extraction protocols for bacterial-fungal co-cultures, and liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed that metabolomic profiles are mainly comprised of fungi derived features, indicating that fungi are the key contributors to small molecules in BFIs. LC-inductively coupled plasma MS (LC-ICP-MS) and MS/MS based dereplication using database searching revealed the presence of several known fungal specialized metabolites and structurally related analogues in these extracts, including siderophores such as desferrichrome, desferricoprogen, and palmitoylcoprogen. Among these analogues, a novel putative coprogen analogue possessing a terminal carboxylic acid motif was identified from Scopulariopsis sp. JB370, a common cheese rind fungus, and its structure was elucidated via MS/MS fragmentation. Based on these findings, filamentous fungal species appear to be capable of producing multiple siderophores with potentially different biological roles (i.e. various affinities for different forms of iron). These findings highlight that fungal species are important contributors to microbiomes via their production of abundant specialized metabolites and that elucidating their role in complex communities should continue to be a priority.

Infections after chimeric antigen receptor (CAR)-T-cell therapy for hematologic malignancies.

BACKGROUND: Chimeric antigen receptor (CAR)-T-cell therapies have revolutionized the management of acute lymphoblastic leukemia, non-Hodgkin lymphoma, and multiple myeloma but come at the price of unique toxicities, including cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, and long-term "on-target off-tumor" effects. METHODS: All of these factors increase infection risk in an already highly immunocompromised patient population. Indeed, infectious complications represent the key determinant of non-relapse mortality after CAR-T cells. The temporal distribution of these risk factors shapes different infection patterns early versus late post-CAR-T-cell infusion. Furthermore, due to the expression of their targets on B lineage cells at different stages of differentiation, CD19, and B-cell maturation antigen (BCMA) CAR-T cells induce distinct immune deficits that could require different prevention strategies. Infection incidence is the highest during the first month post-infusion and subsequently decreases thereafter. However, infections remain relatively common even a year after infusion. RESULTS: Bacterial infections predominate early after CD19, while a more equal distribution between bacterial and viral causes is seen after BCMA CAR-T-cell therapy, and fungal infections are universally rare. Cytomegalovirus (CMV) and other herpesviruses are increasingly breported, but whether routine monitoring is warranted for all, or a subgroup of patients, remains to be determined. Clinical practices vary substantially between centers, and many areas of uncertainty remain, including CMV monitoring, antibacterial and antifungal prophylaxis and duration, use of immunoglobulin replacement therapy, and timing of vaccination. CONCLUSION: Risk stratification tools are available and may help distinguish between infectious and non-infectious causes of fever post-infusion and predict severe infections. These tools need prospective validation, and their integration in clinical practice needs to be systematically studied.

Loss of Coiled-Coil Protein Cep55 Impairs Neural Stem Cell Abscission and Results in p53-Dependent Apoptosis in Developing Cortex.

To build the brain, embryonic neural stem cells (NSCs) tightly regulate their cell divisions, undergoing a polarized form of cytokinesis that is poorly understood. Cytokinetic abscission is mediated by the midbody to sever the daughter cells at the apical membrane. In cell lines, the coiled-coil protein Cep55 was reported to be required for abscission. Mutations of Cep55 in humans cause a variety of cortical malformations. However, its role in the specialized divisions of NSCs is unclear. Here, we elucidate the roles of Cep55 in abscission and brain development. KO of Cep55 in mice causes abscission defects in neural and non-neural cell types, and postnatal lethality. The brain is disproportionately affected, with severe microcephaly at birth. Quantitative analyses of abscission in fixed and live cortical NSCs show that Cep55 acts to increase the speed and success rate of abscission, by facilitating ESCRT recruitment and timely microtubule disassembly. However, most NSCs complete abscission successfully in the absence of Cep55 Those that fail show a tissue-specific response: binucleate NSCs and neurons elevate p53, but binucleate fibroblasts do not. This leads to massive apoptosis in the brain, but not other tissues. Double KO of both p53 and Cep55 blocks apoptosis but only partially rescues Cep55-/- brain size. This may be because of the persistent NSC cell division defects and p53-independent premature cell cycle exit. This work adds to emerging evidence that abscission regulation and error tolerance vary by cell type and are especially crucial in neural stem cells as they build the brain.SIGNIFICANCE STATEMENT During brain growth, embryonic neural stem cells (NSCs) must divide many times. In the last step of cell division, the daughter cell severs its connection to the mother stem cell, a process called abscission. The protein Cep55 is thought to be essential for recruiting proteins to the mother-daughter cell connection to complete abscission. We find that Cep55 mutants have very small brains with disturbed structure, but almost normal size bodies. NSC abscission can occur, but it is slower than normal, and failures are increased. Furthermore, NSCs that do fail abscission activate a signal for programmed cell death, whereas non-neural cells do not. Blocking this signal only partly restores brain growth, showing that regulation of abscission is crucial for brain development.

Mechanism of APTX nicked DNA sensing and pleiotropic inactivation in neurodegenerative disease.

The failure of DNA ligases to complete their catalytic reactions generates cytotoxic adenylated DNA strand breaks. The APTX RNA-DNA deadenylase protects genome integrity and corrects abortive DNA ligation arising during ribonucleotide excision repair and base excision DNA repair, and APTX human mutations cause the neurodegenerative disorder ataxia with oculomotor ataxia 1 (AOA1). How APTX senses cognate DNA nicks and is inactivated in AOA1 remains incompletely defined. Here, we report X-ray structures of APTX engaging nicked RNA-DNA substrates that provide direct evidence for a wedge-pivot-cut strategy for 5'-AMP resolution shared with the alternate 5'-AMP processing enzymes POLß and FEN1. Our results uncover a DNA-induced fit mechanism regulating APTX active site loop conformations and assembly of a catalytically competent active center. Further, based on comprehensive biochemical, X-ray and solution NMR results, we define a complex hierarchy for the differential impacts of the AOA1 mutational spectrum on APTX structure and activity. Sixteen AOA1 variants impact APTX protein stability, one mutation directly alters deadenylation reaction chemistry, and a dominant AOA1 variant unexpectedly allosterically modulates APTX active site conformations.

p53 deletion rescues lethal microcephaly in a mouse model with neural stem cell abscission defects.

Building a cerebral cortex of the proper size involves balancing rates and timing of neural stem cell (NSC) proliferation, neurogenesis and cell death. The cellular mechanisms connecting genetic mutations to brain malformation phenotypes are still poorly understood. Microcephaly may result when NSC divisions are too slow, produce neurons too early or undergo apoptosis but the relative contributions of these cellular mechanisms to various types of microcephaly are not understood. We previously showed that mouse mutants in Kif20b (formerly called Mphosph1, Mpp1 or KRMP1) have small cortices that show elevated apoptosis and defects in maturation of NSC midbodies, which mediate cytokinetic abscission. Here we test the contribution of intrinsic NSC apoptosis to brain size reduction in this lethal microcephaly model. By making double mutants with the pro-apoptotic genes Bax and Trp53 (p53), we find that p53-dependent apoptosis of cortical NSCs accounts for most of the microcephaly, but that there is a significant apoptosis-independent contribution as well. Remarkably, heterozygous p53 deletion is sufficient to fully rescue survival of the Kif20b mutant into adulthood. In addition, the NSC midbody maturation defects are not rescued by p53 deletion, showing that they are either upstream of p53 activation, or in a parallel pathway. Accumulation of p53 in the nucleus of mutant NSCs at midbody stage suggests the possibility of a novel midbody-mediated pathway for p53 activation. This work elucidates both NSC apoptosis and abscission mechanisms that could underlie human microcephaly or other brain malformations.

A eulogy for Dr Francisco Miguel Marty Forero.

As some of those who were lucky enough to have been mentored by Dr Francisco Marty in transplant infectious diseases, we stand with the larger medical community in mourning his untimely death and in commemorating him as a uniquely exceptional and talented physician, investigator, teacher, mentor, friend, artist, and human being.

Influence of maternal obesity on Bishop Score and failed induction of labour: A retrospective cohort study in a regional tertiary centre.

BACKGROUND: Maternal obesity is a growing health concern that has previously been associated with increased need for induction of labour (IOL) and caesarean section (CS) rates. Currently, limited evidence explores the influence of maternal body mass index (BMI) on Bishop Score (BS) and outcome of IOL. This study hypothesises that maternal obesity will lead to a lower BS at presentation, higher rates of failed IOL, and increased CS rates. AIMS: To explore the influence of maternal obesity on BS and likelihood of failed IOL. METHODS: A retrospective cohort analysis was conducted of all live, term, singleton, cephalic deliveries initiated with IOL across normal BMI (18.00-24.99), overweight BMI (25.00-29.99), and obese BMI (>30.00) at the Townsville Hospital and Health Service (THHS) between July 2011 to June 2016. Student's t-test, χ2 test, and binary logistic regression were used for statistical analysis. BS and failed IOL, defined as CS with cervical dilatation <3 cm, were the primary outcome measures. Delivery mode was the secondary outcome measure. RESULTS: A total of 1543 women were included, 678 with normal BMI, 370 with overweight BMI, and 495 with obese BMI. Obese women are more likely to have a low BS (<5) at presentation (unadjusted odds ratio (OR) 1.5 (1.1-2.0), P < 0.05), an increased rate of failed IOL (adjusted OR (aOR) 1.6 (1.0-2.5), P < 0.05) and increased CS rate (aOR 1.1 (1.0-1.9), P < 0.05), compared to normal weight women. CONCLUSIONS: Maternal obesity is associated with a lower BS, more difficult IOL process, and increased risk of failed IOL and CS.

Initial experience of an algorithm-based protocol for the community follow-up of men with prostate cancer.

OBJECTIVE: To evaluate the implementation of a novel algorithm-based discharge programme for the community follow-up of men with prostate cancer. PATIENTS AND METHODS: Men with prostate cancer considered suitable for discharge were identified from consultant-led and clinical nurse-specialist telephone clinics at Nottingham University Hospitals National Health Service Trust. Patients were discharged on to one of four discharge pathways: watchful waiting, androgen-deprivation therapy (ADT), post-prostatectomy, and post-radiotherapy. Primary care providers were asked to adhere to specific surveillance measures and refer patients back to secondary care after breach of pre-defined prostate-specific antigen (PSA) level threshold criteria. Reasons for non-compliance, re-referral, and cause of death were determined for all discharged men. RESULTS: In all, 573 men were discharged across all four pathways; 169 on the watchful-waiting pathway, 229 on the ADT pathway, 95 on the post-prostatectomy pathway, and 80 on the post-radiotherapy pathway. All patients had ≥12 months of follow-up. In all, 48 of 54 (88.9%) men were re-referred promptly after a PSA-threshold breach. Of the remaining six patients there were three refusals, one unrelated death before referral, and two late referrals at 4 months. Three patients were lost to follow-up due to database non-registration and were subsequently recalled, none of whom had a PSA-threshold breach. There were three unexpected deaths attributed to prostate cancer: two were community deaths with no biochemical or clinical evidence of prostate cancer progression, while one was due to a likely progressive PSA non-secreting tumour. CONCLUSION: Initial results suggest the algorithm-based protocol is a viable, effective, and oncologically safe method for the controlled discharge of men from secondary to primary care. Longer-term follow-up, patient satisfaction and cost-effectiveness data are required to assess the true impact of the initiative.

Simulation as an effective means of preparing trainees for active participation in MDT meetings.

Introduction: Cancer multi-disciplinary team (MDT) meetings are an important component of consultant workload, however previous literature has suggested trainees are not satisfied with their current curriculum in preparing for MDT working. Methods: This educational pilot assessed whether multi-speciality simulated scenarios with pre-defined learning objectives, could prepare specialist registrars for interacting within an MDT. Participants completed pre- and post-questionnaires assessing a number of areas including: current experience of training, confidence presenting patients and whether the course would alter future practice. Results: Trainee confidence increased significantly from a mean of 5 to 7 (mean to nearest whole number, p < 0.01). Trainees rated the session highly for utility and altering their future practice (mean scores of 9 for both respectively, out of 10). Conclusion: Simulation has shown success in other multidisciplinary teaching, however to our knowledge there are no cancer specific training programmes. Our results highlight a potential gap in UK specialist training, and suggest simulation may be beneficial in preparing trainees to present in MDT meetings.

The Burden of Invasive Fungal Disease Following Chimeric Antigen Receptor T-Cell Therapy and Strategies for Prevention.

Chimeric antigen receptor (CAR) T-cell therapy is a novel immunotherapy approved for the treatment of hematologic malignancies. This therapy leads to a variety of immunologic deficits that could place patients at risk for invasive fungal disease (IFD). Studies assessing IFD in this setting are limited by inconsistent definitions and heterogeneity in prophylaxis use, although the incidence of IFD after CAR T-cell therapy, particularly for lymphoma and myeloma, appears to be low. This review evaluates the incidence of IFD after CAR T-cell therapy, and discusses optimal approaches to prevention, highlighting areas that require further study as well as future applications of cellular therapy that may impact IFD risk. As the use of CAR T-cell therapy continues to expand for hematologic malignancies, solid tumors, and most recently to include non-oncologic diseases, understanding the risk for IFD in this uniquely immunosuppressed population is imperative to prevent morbidity and mortality.

Learning from an equitable, data-informed response to COVID-19: Translating knowledge into future action and preparation.

Introduction: The COVID-19 pandemic revealed numerous barriers to effectively managing public health crises, including difficulties in using publicly available, community-level data to create learning systems in support of local public health decision responses. Early in the COVID-19 pandemic, a group of health care partners began meeting to learn from their collective experiences. We identified key tools and processes for using data and learning system structures to drive equitable public health decision making throughout different phases of the pandemic. Methods: In fall of 2021, the team developed an initial theory of change directed at achieving herd immunity for COVID-19. The theoretical drivers were explored qualitatively through a series of nine 45-min telephonic interviews conducted with 16 public health and community leaders across the United States. Interview responses were analyzed into key themes to inform potential future practices, tools, and systems. In addition to the interviews, partners in Dallas and Cincinnati reflected on their own COVID-19 experiences. Results: Interview responses fell broadly into four themes that contribute to effective, community driven responses to COVID-19: real-time, accessible data that are mindful of the tension between community transparency and individual privacy; a continued fostering of public trust; adaptable infrastructures and systems; and creating cohesive community coalitions with shared alignment and goals. These themes and partner experiences helped us revise our preliminary theory of change around the importance of community collaboration and trust building and also helped refine the development of the Community Protection Dashboard tool. Conclusions: There was broad agreement amongst public health and community leaders about the key elements of the data and learning systems required to manage public health responses to COVID-19. These findings may be informative for guiding the use of data and learning in the management of future public health crises or population health initiatives.

Rising Cardiac Troponin: A Prognostic Biomarker for Mortality After Acute Ischemic Stroke.

BACKGROUND: Elevated cardiac troponin (cTn) is detected in 10% to 30% of patients with acute ischemic stroke (AIS) and correlates with poor functional outcomes. Serial cTn measurements differentiate a dynamic cTn pattern (rise/fall >20%), specific for acute myocardial injury, from elevated but stable cTn levels (nondynamic), typically attributed to chronic cardiac/noncardiac conditions. We investigated if the direction of the cTn change (rising versus falling) affects mortality and outcome. METHODS AND RESULTS: We retrospectively screened consecutive patients with AIS admitted to 5 stroke centers for elevated cTn at admission and at least 1 additional cTn measurement within 48 hours. The pattern of cTn was defined as rising if >20% increase from baseline, falling if >20% decrease, or nondynamic if ≤20% change in either direction. Logistic regression analyses were performed to assess the association of cTn patterns and 7-day mortality and unfavorable discharge disposition. Of 3789 patients with AIS screened, 300 were included. Seventy-two had a rising pattern, 66 falling, and 162 nondynamic. In patients with AIS with rising cTn, acute ischemic myocardial infarction was present in 54%, compared with 33% in those with falling cTn (P<0.01). Twenty-two percent of patients with a rising pattern had an isolated dynamic cTn in the absence of any ECG or echocardiogram changes, compared with 53% with falling cTn. A rising pattern was associated with higher risk of 7-day mortality (adjusted odds ratio [OR]=32 [95% CI, 2.5-415.0] rising versus aOR=1.3 [95% CI, 0.1-38.0] falling versus nondynamic as reference) and unfavorable discharge disposition (aOR=2.5 [95% CI, 1.2-5.2] rising versus aOR=0.6 [95% CI, 0.2-1.5] versus falling). CONCLUSIONS: Rising cTn is independently associated with increased mortality and unfavorable discharge disposition in patients with AIS.

Opportunistic Infections in Patients Receiving Post-Transplantation Cyclophosphamide: Impact of Haploidentical versus Unrelated Donor Allograft.

Post-transplantation cyclophosphamide (PTCy) is an effective strategy for graft-versus-host disease (GVHD) prophylaxis and is the standard of care for haploidentical hematopoietic cell transplantation (HCT). It is increasingly used for matched and mismatched unrelated donor (MUD/MMUD) HCT, but infections remain a concern. The objective of this study was to evaluate the characteristics and risk factors for infections in haploidentical and unrelated donor HCT recipients treated with PTCy-based GVHD prophylaxis. This single-center retrospective study examined 354 consecutive adults undergoing HCT with PTCy-based GVHD prophylaxis (161 MUD/MMUD; 193 haploidentical) between 2015 and 2022. Opportunistic infections (OIs), including cytomegalovirus (CMV), adenovirus (AdV), Epstein-Barr virus (EBV), and invasive fungal disease (IFD), were assessed from day 0 through day +365. The 1-year cumulative incidence functions of OIs and nonrelapse mortality (NRM) were calculated using dates of relapse and repeat HCT as competing risks. Secondary analysis evaluated risk factors for OIs and NRM using univariate and multivariable Cox regression models. Haploidentical HCT recipients had an increased risk of OIs compared to unrelated donor allograft recipients (39% for haploidentical versus 25% for MUD/MMUD; hazard ratio [HR], 1.70; 95% confidence interval [CI], 1.16 to 2.49; P = .006). On multivariable analysis, haploidentical donor (HR, 1.50; 95% CI, 1.01 to 2.23; P = .046), prior HCT (HR, 1.99; 95% CI, 1.29 to 3.09; P = .002), and diagnosis of aGVHD (HR, 1.47; 95% CI, 1.02 to 2.14; P = .041) were associated with increased risk of OIs. NRM within the first year was not significantly different between the 2 cohorts (HR, 1.11; 95% CI, .64 to 1.93; P = .70). Overall, haploidentical donor was a significant risk factor for OIs in patients receiving PTCy, although 1-year NRM was not different between haploidentical HCT and MUD/MMUD HCT recipients. CMV and AdV infections were significantly increased among haploidentical HCT recipients, whereas the incidences of EBV infection and IFD were similar in the 2 cohorts. Our findings may have implications for infection monitoring and prophylaxis in the setting of PTCy, particularly in haploidentical HCT recipients.

Comprehensive analyses of a large human gut Bacteroidales culture collection reveal species and strain level diversity and evolution.

Species of the Bacteroidales order are among the most abundant and stable bacterial members of the human gut microbiome with diverse impacts on human health. While Bacteroidales strains and species are genomically and functionally diverse, order-wide comparative analyses are lacking. We cultured and sequenced the genomes of 408 Bacteroidales isolates from healthy human donors representing nine genera and 35 species and performed comparative genomic, gene-specific, mobile gene, and metabolomic analyses. Families, genera, and species could be grouped based on many distinctive features. However, we also show extensive DNA transfer between diverse families, allowing for shared traits and strain evolution. Inter- and intra-specific diversity is also apparent in the metabolomic profiling studies. This highly characterized and diverse Bacteroidales culture collection with strain-resolved genomic and metabolomic analyses can serve as a resource to facilitate informed selection of strains for microbiome reconstitution.

Active infection at the time of CD34+ selected stem cell boost is associated with treatment failure and poor survival.

BACKGROUND: The use of CD34+ selected stem cell boost (SCB) post allogeneic hematopoietic cell transplant (alloHCT) has been increasing. Predictors of treatment failure following SCB, both in the context of poor graft function (PGF) or other settings, are not well-characterized. We report among the largest single center retrospective experiences of the use of SCB and evaluate potential predictors of response and outcomes. METHODS: 58 patients who underwent HCT between 2015 and 2022 and who received SCB were identified. The indication for SCB was predominantly PGF, defined as the presence of 2 or more cytopenias for at least two consecutive weeks beyond day +14 after alloHCT in the presence of ≤ 30% bone marrow cellularity and ≥ 90% donor myeloid chimerism in the absence of morphological disease. RESULTS: The median dose of infused CD34+ selected SCB products was 3.88 x 106 CD34+ cells/kg (range: 0.99-9.92). The median 2-year OS and NRM following SCB was 47% and 38%, respectively. The cumulative incidences of 6-month grade III-IV acute and 2-year moderate-severe chronic GVHD following SCB were 3.4% and 12%, respectively. Overall response (CR + PR) was attained in 36/58 (62%) patients, and in 69% with PGF. On multivariable analysis, an active infection at the time of SCB was the greatest predictor of poor response and survival (p=0.013) following SCB. CONCLUSION: SCB can restore hematopoiesis in the majority of patients, particularly for those with poor graft function in whom there is no active infection at infusion.