Human Herpesvirus-6 Reactivation and Disease Are Infrequent in Chimeric Antigen Receptor T-cell Therapy Recipients.

Human herpesvirus-6B (HHV-6B) reactivation and disease are increasingly reported after CAR-T-cell therapy (CARTx). HHV-6 reactivation in the CAR-T-cell product was recently reported, raising questions about product and patient management. Due to overlapping manifestations with immune effector cell-associated neurotoxicity syndrome, diagnosing HHV-6B encephalitis is challenging. We provide two lines of evidence assessing the incidence and outcomes of HHV-6B after CARTx. First, in a prospective study with weekly HHV-6B testing for up to 12 weeks post-infusion, HHV-6B reactivation occurred in eight of 89 participants; three had chromosomally integrated HHV-6 and were excluded, resulting in a cumulative incidence of HHV-6B reactivation of 6% (95% confidence interval (CI), 2.2-12.5%). HHV-6B detection was low level (median peak, 435 copies/mL; IQR, 164-979) and did not require therapy. Second, we retrospectively analyzed HHV-6B detection in blood and/or cerebrospinal fluid (CSF) within 12 weeks post-infusion in CARTx recipients. Of 626 patients, 24 had symptom-driven plasma testing with detection in one. Among 34 patients with CSF HHV-6 testing, one patient had possible HHV-6 encephalitis for a cumulative incidence of 0.17% (95% CI, 0.02-0.94%), although symptoms improved without treatment. Our data demonstrate that HHV-6B reactivation and disease are infrequent after CARTx. Routine HHV-6 monitoring is not warranted.

Late Cytomegalovirus Disease after Hematopoietic Cell Transplantation: Significance of Novel Transplantation Techniques.

Pre-emptive therapy (PET) and letermovir prophylaxis are effective in preventing CMV disease within the first 100 days after allogeneic hematopoietic cell transplantation (HCT) but are associated with late-onset CMV disease. We retrospectively examined the clinical manifestations, risk factors, prevention algorithm, and outcome of late CMV disease in CMV seropositive day 100 survivors transplanted between 2001-2017 (PET cohort) and 2018-2021 (letermovir cohort). There were 187 episodes of late CMV disease among 2469 day 100 survivors and the estimated cumulative incidence of first late CMV disease was 6.7% (95% CI 5.6-%-7.6%) with no difference between the PET 6.7% (95% CI 5.7%-7.8%) and the letermovir group 5.4% (95% CI 3.2%-8.3%). 32 (1.3%) patients had a second episode of late CMV disease. In multivariable Cox regression models, post-transplant cyclophosphamide was associated with an increased risk of gastrointestinal CMV disease. CMV viremia detected before day 100, corticosteroid treatment after day 100 at dose ≥1mg/kg, acute and chronic GvHD, lymphopenia, HLA mismatched related donors status and recipient age were also associated with late CMV disease. HLA mismatched donor status and late use of corticosteroids (≥1 mg/kg) were risk factors for late CMV disease recurrence. Late CMV disease occurred most frequently in a setting of prolonged low-level untreated viremia and was independently associated with death by year two after HCT. In summary, late CMV disease continues to occur in the current era. Improved prevention strategies for late CMV disease are needed.

HHV-6B detection and host gene expression implicate HHV-6B as pulmonary pathogen after hematopoietic cell transplant.

Limited understanding of the immunopathogenesis of human herpesvirus 6B (HHV-6B) has prevented its acceptance as a pulmonary pathogen after hematopoietic cell transplant (HCT). In this prospective multicenter study of patients undergoing bronchoalveolar lavage (BAL) for pneumonia after allogeneic HCT, we test blood and BAL fluid (BALF) for HHV-6B DNA and mRNA transcripts associated with lytic infection and perform RNA-seq on paired blood. Among 116 participants, HHV-6B DNA is detected in 37% of BALs, 49% of which also have HHV-6B mRNA detection. We establish HHV-6B DNA viral load thresholds in BALF that are highly predictive of HHV-6B mRNA detection and associated with increased risk for overall mortality and death from respiratory failure. Participants with HHV-6B DNA in BALF exhibit distinct host gene expression signatures, notable for enriched interferon signaling pathways in participants clinically diagnosed with idiopathic pneumonia. These data implicate HHV-6B as a pulmonary pathogen after allogeneic HCT.

CMV Reactivation and CMV-Specific Cell-Mediated Immunity after Chimeric Antigen Receptor T-Cell Therapy.

BACKGROUND: The epidemiology of cytomegalovirus (CMV) after chimeric antigen receptor-modified T-cell immunotherapy (CARTx) is poorly understood due to lack of routine surveillance. METHODS: We prospectively enrolled 72 adult CMV-seropositive CD19-, CD20-, or BCMA-targeted CARTx-recipients and tested plasma for CMV pre- and weekly up to twelve weeks post-CARTx. We assessed CMV-cell mediated immunity (CMI) pre-, and at week two and four post-CARTx using an interferon-γ release assay quantifying T-cell responses to IE-1 and pp65. We tested pre-CARTx samples to calculate a risk score for cytopenias and infection (CAR-HEMATOTOX). We used Cox regression to evaluate CMV risk factors and evaluated the predictive performance of CMV-CMI for CMV reactivation in receiver operator characteristic curves. RESULTS: CMV was detected in one patient (1.4%) pre- and 18 patients (25%) post-CARTx for a cumulative incidence of 27% (95% CI, 16.8-38.2). Median CMV viral load was 127 IU/mL (interquartile range (IQR), 61-276), with no end-organ disease observed; five patients received preemptive therapy based on clinical results. CMV-CMI values reached a nadir two weeks post-infusion and recovered to baseline levels by week four. In adjusted models, BCMA-CARTx (versus CD19/CD20) and corticosteroid use for >3 days were significantly associated with CMV reactivation, and possible associations were detected for lower week 2 CMV-CMI and more prior antitumor regimens. The cumulative incidence of CMV reactivation almost doubled when stratified by BCMA CARTx-target and use of corticosteroids for >3 days (46% and 49%, respectively). CONCLUSIONS: CMV testing could be considered between 2-6 weeks in high-risk CARTx-recipients.

Exploring the pathogenesis of osteomyelitis accompanied by diabetic foot ulcers using microarray data analysis.

Although numerous studies have shown distinctive similarities between osteomyelitis and diabetic foot ulcers (DFU), the common pathogenesis of both is not fully understood. The current research focuses on an in-depth study of the molecular and pathway mechanisms involved in the complication of these 2 diseases. We downloaded clinical information on osteomyelitis (GSE30119) and DFU (GSE29221) from the GEO database, along with gene expression matrices. Differentially expressed genes (DEGs) among normal individuals and patients with osteomyelitis; normal individuals and patients with DFU were identified by R software, and thus common DEGs were confirmed. We then analyzed these differential genes, including the functional pathway analysis, protein-protein interaction (PPI), modules and hub genes establishment, and transcription factor regulatory networks. We identified 109 common DEGs (46 up-regulated and 63 down-regulated genes) for subsequent analysis. The results of PPI network and the functional pathway analysis revealed the importance of immune response and inflammatory response in both diseases. Among them, chemokines and cytokines were found to be closely related to both osteomyelitis and DFU. In addition, the tumor necrosis factor (TNF) pathway and Staphylococcus aureus infection were found to have more significant roles too. The 12 most essential key genes were later screened by cytoHubba, including matrix metalloproteinases (MMP) 1, MMP3, MMP9, IL8, C-X-C chemokine receptor (CXCR) 2, C-X-C motif chemokine ligand (CXCL) 9, CXCL10, CXCL13, FCGR3B, IL1B, LCN2, S100A12. CXCL10, and MMP1 were validated using the least absolute shrinkage and selection operator (LASSO) and support vector machine-recursive feature elimination (SVM-RFE) algorithms. Osteomyelitis and DFU share similar molecular and pathway mechanisms. These common key genes and pathways may provide new directions toward the future study of osteomyelitis and DFU.

[Content determination of ten flavonoids and alkaloids in Gleditsiae Sinensis Fructus, Gleditsiae Fructus Abnormalis, and Gleditsiae Spina].

To study the quality control of three traditional Chinese medicines derived from Gleditsia sinensis [Gleditsiae Sinensis Fructus(GSF), Gleditsiae Fructus Abnormalis(GFA), and Gleditsiae Spina(GS)], this paper established a multiple reaction monitoring(MRM) approach based on ultra-high performance liquid chromatography-triple quadrupole-linear ion-trap mass spectrometry(UHPLC-Q-Trap-MS). Using an ACQUITY UPLC BEH C_(18) column(2.1 mm × 100 mm, 1.7 µm), gradient elution was performed at 40 ℃ with water containing 0.1% formic acid-acetonitrile as the mobile phase running at 0.3 mL·min~(-1), and the separation and content determination of ten chemical constituents(e.g., saikachinoside A, locustoside A, orientin, taxifolin, vitexin, isoquercitrin, luteolin, quercitrin, quercetin, and apigenin) in GSF, GFA, and GS were enabled within 31 min. The established method could quickly and efficiently determine the content of ten chemical constituents in GSF, GFA, and GS. All constituents showed good linearity(r>0.995), and the average recovery rate was 94.09%-110.9%. The results showed that, the content of two alkaloids in GSF(2.03-834.75 µg·g~(-1)) was higher than that in GFA(0.03-10.41 µg·g~(-1)) and GS(0.04-13.66 µg·g~(-1)), while the content of eight flavonoids in GS(0.54-2.38 mg·g~(-1)) was higher than that in GSF(0.08-0.29 mg·g~(-1)) and GFA(0.15-0.32 mg·g~(-1)). These results provide references for the quality control of G. sinensis-derived TCMs.

Impact of GVHD prophylaxis on CMV reactivation and disease after HLA-matched peripheral blood stem cell transplantation.

The kinetics of early and late cytomegalovirus (CMV) reactivation after hematopoietic cell transplantation using various methods of graft-versus-host-disease (GVHD) prophylaxis are poorly defined. We retrospectively compared CMV reactivation and disease among 780 seropositive patients given HLA-matched peripheral blood stem cell (PBSC) grafts and calcineurin inhibitor plus posttransplantation cyclophosphamide (PTCy; n = 44), mycophenolate mofetil (MMF; n = 414), or methotrexate (MTX; n = 322). Transplantation occurred between 2007 and 2018; CMV monitoring/management followed uniform standard practice. Hazards of CMV reactivation at various thresholds were compared. Spline curves were fit over average daily viral load and areas under the curve (AUC) within 1 year were calculated. PTCy and MMF were associated with an increased risk of early (day ≤100) CMV reactivation ≥250 IU/mL after multivariate adjustment. The viral load AUC at 1 year was highest with MMF (mean difference = 0.125 units vs MTX group) and similar between PTCy and MTX (mean difference = 0.016 units vs MTX group). CMV disease risk was similar across groups. There was no interaction between GVHD prophylaxis and CMV reactivation on chronic GVHD risk. Despite PTCy-associated increased risk of early CMV reactivation, the CMV disease risk by 1 year was low in HLA-matched PBSC transplant recipients. In contrast, MMF was associated with higher overall CMV viral burden in the 1 year posttransplant. Although different mechanisms of immunosuppressive agents may affect CMV reactivation risk, effective prevention of GVHD may reduce corticosteroid exposure and mitigate infection risk over time.

Cytomegalovirus breakthrough and resistance during letermovir prophylaxis.

Letermovir is a relatively new antiviral for prophylaxis against cytomegalovirus (CMV) after allogeneic hematopoietic cell transplantation (HCT). CMV-seropositive HCT recipients who received letermovir prophylaxis from 2018 to 2020 at our center were evaluated for letermovir resistance and breakthrough CMV reactivation. Two-hundred twenty-six letermovir recipients were identified and 7/15 (47%) with CMV DNAemia ≥200 IU/mL were successfully genotyped for UL56 resistance. A single C325Y resistance mutation was identified in an umbilical cord blood recipient. Ninety-five (42%), 43 (19%), and 15 (7%) patients had breakthrough CMV at any level, ≥150 IU/mL, and ≥500 IU/mL, respectively. Risk factors for breakthrough CMV reactivation at each viral threshold were examined. Cumulative steroid exposure was the strongest risk factor for CMV at all evaluated viral thresholds. Graft-versus-host disease prophylaxis with post-transplantation cyclophosphamide (aHR 2.34, 95% CI 1.28-4.28, p = 0.001) or calcineurin inhibitors plus mycophenolate (aHR 2.24, 95% CI 1.30-3.86, p = 0.004) were also associated with an increased risk of CMV reactivation at any level. De novo letermovir resistance is rare and can be successfully treated using other antivirals. Letermovir effectively prevents clinically significant CMV, however, subclinical CMV reactivation occurs frequently at our center.

Infectious complications after intensive chemotherapy with CLAG-M versus 7+3 for AML and other high-grade myeloid neoplasms.

Contemporary data on infections after intensive chemotherapy for acute myeloid leukemia (AML) are scarce. Cladribine, high-dose cytarabine, G-CSF, and dose-escalated mitoxantrone ("CLAG-M") may result in higher remission rates than standard-dose cytarabine plus anthracycline ("7 + 3") but may result in more infections. We compared moderate to severe infections occurring up to 90 days after the first induction cycle for AML or other high-grade myeloid neoplasms in patients receiving CLAG-M for newly diagnosed (n = 196) or relapsed/refractory disease (n = 131) or 7 + 3 for newly diagnosed disease (n = 115). For newly diagnosed disease, microbiologically documented infections were more frequent after CLAG-M compared to 7 + 3 (adjusted rate ratio, 1.65 [95% CI, 1.06-2.58]; P = 0.03), with a cumulative incidence of 27.8% and 16.5% by day 90, respectively. Patients receiving CLAG-M for relapsed/refractory disease had the highest cumulative incidence of 50.7%. Bacterial bloodstream infections were the most frequent followed by respiratory tract infections. Among 29 patients (7%) who died, infection was a primary or contributing cause of death in 59%. These data indicate that infections continue to cause substantial morbidity in patients treated for AML, especially those treated for relapsed/refractory disease, and are more common with newer, more myelosuppressive regimens such as CLAG-M. Improved strategies for infection prevention are needed.

[Neuromodulation: Past, Present, and Future].

Neuromodulation technology is one of the medical fields currently experiencing the most rapid development, witnessing a surge in the types of modulation techniques and a constant expansion of indications. Consequently, hundreds of thousands of patients with functional neurological disorders have benefited from the advancements in the field all over the world. Nevertheless, some challenges remain, for exmaple, the lack of a thorough understanding of the mechanism of neuromodulation, the long-standing controversy over the optimal targets of neuromodulation, the lack of reliable efficacy predictors, and the cumbersome and inefficient mode of postoperative programming. We anticipate that these issues will be resolved with the continued advancement in medical technology and the gradual revelation of the neural network mechanism of brain disorders. More individualized, precise, and intelligent neuromodulation technology will be the main direction of development in the future. Herein, we reviewed and commented on the evolution of neuromodulation technology, the current status of its applications, and its prospective development.

Respiratory viruses in hematopoietic cell transplant candidates: impact of preexisting lower tract disease on outcomes.

Pretransplant respiratory virus infections (RVIs) have been shown to negatively affect hematopoietic cell transplantation (HCT) outcomes. The impact of and need for delay of HCT for pretransplant infection with human rhinovirus (HRV) or endemic human coronavirus (HCoV; 229E, OC43, NL63, and HKU1) remain controversial. We analyzed the impact of symptomatic RVI within ≤90 days before HCT on overall mortality, posttransplant lower respiratory tract disease (LRD), and days alive and out of hospital (DAOH) by day 100 post-HCT in multivariable models. Among 1,643 adult HCT recipients (58% allogeneic recipients), 704 (43%) were tested for RVI before HCT, and 307 (44%) tested positive. HRV was most commonly detected (56%). Forty-five (15%) of 307 HCT recipients had LRD with the same virus early after HCT. Pretransplant upper respiratory tract infection (URI) with influenza, respiratory syncytial virus, adenovirus, human metapneumovirus, parainfluenza virus, HRV, or endemic HCoV was not associated with increased overall mortality or fewer DAOH. However, in allogeneic recipients who received myeloablative conditioning, LRD due to any respiratory virus, including HRV alone, was associated with increased overall mortality (adjusted hazard ratio, 10.8 [95% confidence interval, 3.29-35.1] for HRV and 3.21 [95% confidence interval, 1.15-9.01] for all other viruses). HRV LRD was also associated with fewer DAOH. Thus, the presence of LRD due to common respiratory viruses, including HRV, before myeloablative allogeneic HCT was associated with increased mortality and hospitalization. Pretransplant URI due to HRV and endemic HCoV was not associated with these outcomes. Improved management strategies for pretransplant LRD are warranted.

Correlation of initial upper respiratory tract viral burden with progression to lower tract disease in adult allogeneic hematopoietic cell transplant recipients.

BACKGROUND: Some respiratory viruses have been evaluated for the association between viral burden and respiratory disease progression in hematopoietic cell transplant (HCT) recipients, and no significant association has been reported. OBJECTIVES: To assess whether initial viral burden of respiratory viruses predicts risk of progression to lower respiratory tract infection (LRTI) among adult allogeneic HCT recipients who presented with upper respiratory tract infection (URTI) with 12 viruses in the PCR era. STUDY DESIGN: We reviewed adult allogeneic HCT recipients (4/2008-9/2018) who presented with their first symptomatic respiratory viral infection following transplantation at the Fred Hutchinson Cancer Center. Cox proportional hazards models were used to investigate whether viral burden as measured by initial Ct values at the diagnosis of URTI is associated with progression to LRTI within 90 days for each virus, treating death as a competing risk. RESULTS: Among 2,148 adult HCT recipients during the study periods, 1,102 episodes of URTI met the study inclusion criteria. Higher viral burden (lower Ct value) were associated with an increased risk of progression to LRTI for influenza after adjusting for immunodeficiency scoring index and initiation of antiviral therapy, respectively. The association between viral burden and progression to LRTI was not found for other viruses. CONCLUSIONS: Our findings suggest that routine reporting of viral burden in current molecular diagnostic platforms may be beneficial. Further studies are needed to investigate the impact of viral burden on LRTI in other populations including pediatric HCT recipients.

Novel factors to predict respiratory viral disease progression in allogeneic hematopoietic cell transplant recipients.

We assessed novel factors and the immunodeficiency scoring index (ISI) to predict progression to lower respiratory tract infection (LRTI) among hematopoietic cell transplant (HCT) recipients presenting with upper respiratory tract infection (URTI) with 12 viruses in the PCR era. We retrospectively analyzed the first respiratory virus detected by multiplex PCR in allogeneic HCT recipients (4/2008-9/2018). We used Cox proportional hazards models to examine factors for progression to LRTI within 90 days among patients presenting with URTI. A total of 1027 patients (216 children and 811 adults) presented with URTI only. Among these, 189 (18%) progressed to LRTI (median: 12 days). Multivariable models demonstrated a history of >1 transplant, age ≥40 years, time post-HCT (≤30 days), systemic steroids, hypoalbuminemia, hyperglycemia, cytopenia, and high ISI (scores 7-12) were associated with an increased risk of progression to LRTI. Respiratory syncytial virus and human metapneumovirus showed the highest progression risk. Patients with ≥3 independent risk factors or high ISI scores were highly likely to progress to LRTI. We identified novel risk factors for progression to LRTI, including history of multiple transplants and hyperglycemia, suggesting an intervention opportunity with glycemic control. ISI and number of risk factors appear to predict disease progression across several viruses.

Quantitative proteomics reveals the relationship between protein changes and off-flavor in Russian sturgeon (Acipenser gueldenstaedti) fillets treated with low temperature vacuum heating.

This study aimed to reveal the molecular mechanisms associated with off-flavor generation in sturgeon fillets treated by low temperature vacuum heating (LTVH). Label-free quantitative proteomics was used to identify 120 favor-related proteins, 27 proteins were screened as differentially expressed for bioinformatics analysis. 17 of KEGG pathways were identified. Particularly, proteins involved in proteasome and peroxisome were highly correlated with off-flavor formation. They were primarily implicated in the structures of proteins, including binding and proteasome pathways. The results indicated that the LTVH reduced the binding sites by down-regulating protease and superoxide dismutase expression. LTVH increased the myofibrillar protein and sulfhydryl content and decreased the total volatile basic nitrogen and thiobarbituric acid reactive substance, which confirmed that protein oxidation was related to off-flavor. This proteomics study provided new insights into the off-flavor of sturgeon with LTVH, and proposed potential link between biological processes and off-flavor formation.

Delayed-onset cytomegalovirus infection is frequent after discontinuing letermovir in cord blood transplant recipients.

Cytomegalovirus (CMV)-seropositive umbilical cord blood transplantation (CBT) recipients have a high incidence of CMV-associated complications. There are limited data regarding the efficacy of letermovir for preventing clinically significant CMV infection (CS-CMVi), and the impact of letermovir prophylaxis on delayed-onset CMV reactivation after letermovir discontinuation, in CBT recipients. We compared the cumulative incidence of CS-CMVi and CMV detection in 21 CMV-seropositive CBT recipients receiving letermovir prophylaxis with a historical cohort of 40 CBT recipients receiving high-dose valacyclovir prophylaxis. Letermovir was administered on day +1 up to day +98. The cumulative incidence of CS-CMVi was significantly lower by day 98 in the letermovir cohort (19% vs 65%). This difference was lost by 1 year due to a higher incidence of delayed-onset CMV reactivation in the letermovir cohort. No patients developed CMV disease in the letermovir cohort within the first 98 days compared with 2 cases (2.4%) in the high-dose valacyclovir cohort; 2 patients developed CMV enteritis after discontinuing letermovir. Median viral loads were similar in both cohorts. Thus, letermovir is effective at preventing CS-CMVi after CBT, but frequent delayed-onset infections after letermovir discontinuation mandate close monitoring and consideration for extended prophylaxis.

Association of Inherited Chromosomally Integrated Human Herpesvirus 6 with Neurologic Symptoms and Management after Allogeneic Hematopoietic Cell Transplantation.

Reactivation of human herpesvirus 6 (HHV-6) after allogeneic hematopoietic cell transplantation (HCT) is associated with neurologic complications, but the impact of donor and/or recipient inherited chromosomally integrated HHV-6 (iciHHV-6) on post-HCT central nervous system (CNS) symptoms and diagnostic and therapeutic interventions is not well understood. The aims of the present study were (1) to compare the cumulative incidence of CNS symptoms in the first 100 days following allogeneic HCT among patients with donor and/or recipient iciHHV-6 (iciHHV-6pos)with that of patients with neither donor nor recipient iciHHV-6 (iciHHV-6neg) and (2) to assess the role of HHV-6 detection in driving potentially unnecessary interventions in iciHHV-6pos patients. We performed a retrospective matched cohort study of 87 iciHHV-6pos and 174 iciHHV-6neg allogeneic HCT recipients. HHV-6 testing was performed at the discretion of healthcare providers, who were unaware of iciHHV-6 status. The cumulative incidence of CNS symptoms was similar in iciHHV-6pos (n = 37; 43%) and iciHHV-6neg HCT recipients (n = 81; 47%; P = .63). HHV-6 plasma testing was performed in similar proportions of iciHHV-6pos (n = 6; 7%) and iciHHV-6neg (9%) patients and was detected in all tested iciHHV-6pos HCTs and 2 (13%) iciHHV-6neg HCTs. This resulted in more frequent HHV-6-targeted antiviral therapy after iciHHV-6pos HCT (odds ratio, 12.8; 95% confidence interval, 1.5 to 108.2) with associated side effects. HHV-6 plasma detection in 2 iciHHV-6pos patients without active CNS symptoms prompted unnecessary lumbar punctures. The cumulative incidence of CNS symptoms was similar after allogeneic HCT involving recipients or donors with and without iciHHV-6. Misattribution of HHV-6 detection as infection after iciHHV-6pos HCT may lead to unnecessary interventions. Testing for iciHHV-6 may improve patient management.

Risk factors for seasonal human coronavirus lower respiratory tract infection after hematopoietic cell transplantation.

Data are limited regarding risk factors for lower respiratory tract infection (LRTI) caused by seasonal human coronaviruses (HCoVs) and the significance of virologic documentation by bronchoalveolar lavage (BAL) on outcomes in hematopoietic cell transplant (HCT) recipients. We retrospectively analyzed patients undergoing allogeneic HCT (4/2008-9/2018) with HCoV (OC43/NL63/HKU1/229E) detected by polymerase chain reaction during conditioning or post-HCT. Risk factors for all manifestations of LRTI and progression to LRTI among those presenting with HCoV upper respiratory tract infection (URTI) were analyzed by logistic regression and Cox proportional hazard models, respectively. Mortality rates following HCoV LRTI were compared according to virologic documentation by BAL. A total of 297 patients (61 children and 236 adults) developed HCoV infection as follows: 254 had URTI alone, 18 presented with LRTI, and 25 progressed from URTI to LRTI (median, 16 days; range, 2-62 days). Multivariable logistic regression analyses showed that male sex, higher immunodeficiency scoring index, albumin <3 g/dL, glucose >150 mg/dL, and presence of respiratory copathogens were associated with occurrence of LRTI. Hyperglycemia with steroid use was associated with progression to LRTI (P < .01) in Cox models. LRTI with HCoV detected in BAL was associated with higher mortality than LRTI without documented detection in BAL (P < .01). In conclusion, we identified factors associated with HCoV LRTI, some of which are less commonly appreciated to be risk factors for LRTI with other respiratory viruses in HCT recipients. The association of hyperglycemia with LRTI might provide an intervention opportunity to reduce the risk of LRTI.

Cytomegalovirus-specific T-cell reconstitution following letermovir prophylaxis after hematopoietic cell transplantation.

Decreased cytomegalovirus (CMV)-specific immunity after hematopoietic cell transplantation (HCT) is associated with late CMV reactivation and increased mortality. Whether letermovir prophylaxis-associated reduction in viral exposure influences CMV-specific immune reconstitution is unknown. In a prospective cohort of allogeneic HCT recipients who received letermovir, we compared polyfunctional CMV-specific T-cell responses to those of controls who received PCR-guided preemptive therapy before the introduction of letermovir. Thirteen-color flow cytometry was used to assess T-cell responses at 3 months after HCT following stimulation with CMV immediate early-1 (IE-1) antigen and phosphoprotein 65 (pp65) antigens. Polyfunctionality was characterized by combinatorial polyfunctionality analysis of antigen-specific T-cell subsets. Use of letermovir and reduction of viral exposure were assessed for their association with CMV-specific T-cell immunity. Polyfunctional T-cell responses to IE-1 and pp65 were decreased in letermovir recipients and remained diminished after adjustment for donor CMV serostatus, absolute lymphocyte count, and steroid use. Among letermovir recipients, greater peak CMV DNAemia and increased viral shedding were associated with stronger CD8+ responses to pp65, whereas the CMV shedding rate was associated with greater CD4+ responses to IE-1. In summary, our study provided initial evidence that letermovir may delay CMV-specific cellular reconstitution, possibly related to decreased CMV antigen exposure. Evaluating T-cell polyfunctionality may identify patients at risk for late CMV infection after HCT.

Role of Human Bocavirus Respiratory Tract Infection in Hematopoietic Cell Transplant Recipients.

BACKGROUND: Limited data exist regarding the impact of human bocavirus (BoV) in hematopoietic cell transplant (HCT) recipients. METHODS: In a longitudinal surveillance study among allogeneic HCT recipients, pre-HCT and weekly post-HCT nasal washes and symptom surveys were collected through day 100, then at least every 3 months through 1 year post-HCT at the Fred Hutchinson Cancer Research Center (2005-2010). Samples were tested by multiplex semiquantitative polymerase chain reaction (PCR) for 12 viruses. Plasma samples from BoV + subjects were analyzed by PCR. Separately, we conducted a retrospective review of HCT recipients with BoV detected in lower respiratory tract specimens. RESULTS: Among 51 children and 420 adults in the prospective cohort, 21 distinct BoV respiratory tract infections (RTIs) were observed by 1 year post-HCT in 19 patients. Younger age and exposure to children were risk factors for BoV acquisition. Univariable models among patients with BoV RTI showed higher peak viral load in nasal samples (P = .04) and presence of respiratory copathogens (P = .03) were associated with presence of respiratory symptoms, but BoV plasma detection was not. Only watery eyes and rhinorrhea were associated with BoV RTI in adjusted models. With additional chart review, we identified 6 HCT recipients with BoV detected in lower respiratory tract specimens (incidence rate of 0.4% [9/2509] per sample tested). Although all cases presented with hypoxemia, 4 had respiratory copathogens or concomitant conditions that contributed to respiratory compromise. CONCLUSIONS: BoV RTI is infrequent in transplant recipients and associated with mild symptoms. Our studies did not demonstrate convincing evidence that BoV is a serious respiratory pathogen.