Vaccine response after pneumococcal vaccination in allogeneic hematopoietic stem cell transplant recipients.

Current guidelines for vaccination in allogeneic hematopoietic stem cell transplant (HCT) recipients recommend initiation of pneumococcal vaccination series three to six months post-HCT, with most data supporting initiation at six months due to a more robust immune response. This single-center, retrospective, observational chart review aimed to evaluate the impact of initiating the pneumococcal vaccine series at three months post-HCT compared to six months post-HCT. The primary endpoints were defined as a percentage of patients with a serologic response of >1 and >1.3 µg/mL for over 50% of the defined serotypes. Outcomes showed no difference in immunologic response between the two groups.

Development of Host Immune Response to Bacteriophage in a Lung Transplant Recipient on Adjunctive Phage Therapy for a Multidrug-Resistant Pneumonia.

Bacteriophage therapy is the use of viruses to kill bacteria for the treatment of antibiotic-resistant infections. Little is known about the human immune response following phage therapy. We report the development of phage-specific CD4 T cells alongside rising phage-specific immunoglobulin G and neutralizing antibodies in response to adjunctive bacteriophage therapy used to treat a multidrug-resistant Pseudomonas aeruginosa pneumonia in a lung transplant recipient. Clinically, treatment was considered a success despite the development phage-specific immune responses.

Neutropenia and antibiotics: when, what, how and why?

PURPOSE OF REVIEW: Our aim is to review recent literature on antibiotic use in patients with neutropenia. RECENT FINDINGS: Prophylactic antibiotics are associated with risks and have limited mortality benefit. While early antibiotic use in febrile neutropenia (FN) is critical, early de-escalation or discontinuation may be safe in many patients. SUMMARY: With an increasing understanding of potential risks and benefits of use and improved risk assessment, paradigms of antibiotic use in neutropenic patients are changing.

Effectiveness of letermovir for cytomegalovirus prophylaxis in allogeneic hematopoietic stem cell transplant recipients: A global systematic review.

OBJECTIVE(S): Letermovir (LET), a novel antiviral, has largely supplanted more traditional preemptive therapy (PET) for cytomegalovirus (CMV) prophylaxis in allogeneic hematopoietic stem cell transplant (allo-HCT) patients. Use of LET demonstrated efficacy against placebo in phase III randomized controlled trials, but is considerably more expensive than PET. This review aimed to evaluate the real-world effectiveness of LET in preventing clinically significant CMV infection (csCMVi) for allo-HCT recipients and related outcomes. DESIGN: A systematic literature review was performed using an a priori protocol using PubMed, Scopus, and ClinicalTrials.gov from January 2010 to October 2021. SETTING AND PARTICIPANTS: Studies were included if they met the following criteria: LET compared with PET, CMV-related outcomes, patients aged 18 years or older, and English language-only articles. Descriptive statistics were used to summarize study characteristics and outcomes. OUTCOME MEASURES: CMV viremia, csCMVi, CMV end-organ disease, graft-versus-host-disease, all-cause mortality. RESULTS: A total of 233 abstracts were screened, with 30 included in this review. Randomized trials demonstrated efficacy of LET prophylaxis in preventing csCMVi. Observational studies demonstrated varying degrees of effectiveness of LET prophylaxis compared with use of PET alone. All studies with a comparator group resulted in lower rates of csCMVi for patients using LET. Included studies varied widely by CMV viral load threshold cutoff and CMV test units, limiting synthesis of results owing to high heterogeneity. CONCLUSION: LET reduces risk of csCMVi, but lack of standardized clinical definitions on how to evaluate csCMVi and related outcomes largely prevent synthesis of results. Clinicians must consider this limitation in the context of evaluating the effectiveness of LET to other antiviral therapies, especially for patients at risk of late-onset CMV. Future studies should focus on prospective data collection through registries and concordance of diagnostic definitions to mitigate study heterogeneity.

Cost-effectiveness of using hepatitis C viremic hearts for transplantation into HCV-negative recipients.

Outcomes following hepatitis C virus (HCV)-viremic heart transplantation into HCV-negative recipients with HCV treatment are good. We assessed cost-effectiveness between cohorts of transplant recipients willing and unwilling to receive HCV-viremic hearts. Markov model simulated long-term outcomes among HCV-negative patients on the transplant waitlist. We compared costs (2018 USD) and health outcomes (quality-adjusted life-years, QALYs) between cohorts willing to accept any heart and those willing to accept only HCV-negative hearts. We assumed 4.9% HCV-viremic donor prevalence. Patients receiving HCV-viremic hearts were treated, assuming $39 600/treatment with 95% cure. Incremental cost-effectiveness ratios (ICERs) were compared to a $100 000/QALY gained willingness-to-pay threshold. Sensitivity analyses included stratification by blood type or region and potential negative consequences of receipt of HCV-viremic hearts. Compared to accepting only HCV-negative hearts, accepting any heart gained 0.14 life-years and 0.11 QALYs, while increasing costs by $9418/patient. Accepting any heart was cost effective (ICER $85 602/QALY gained). Results were robust to all transplant regions and blood types, except type AB. Accepting any heart remained cost effective provided posttransplant mortality and costs among those receiving HCV-viremic hearts were not >7% higher compared to HCV-negative hearts. Willingness to accept HCV-viremic hearts for transplantation into HCV-negative recipients is cost effective and improves clinical outcomes.

Post-transplant survey to assess patient experiences with donor-derived HCV infection.

BACKGROUND: Despite increased utilization of hepatitis C virus-infected (HCV+) organs for transplantation into HCV-uninfected recipients, there is lack of standardization in HCV-related patient education/consent and limited data on financial and social impact on patients. METHODS: We conducted a survey on patients with donor-derived HCV infection at our center transplanted between 4/1/2017 and 11/1/2019 to assess: why patients chose to accept HCV+ organ(s), the adequacy of their pre-transplant HCV education and informed consent process, financial issues related to copays after discharge, and social challenges they faced. RESULTS: Among 49 patients surveyed, transplanted organs included heart (n = 19), lung (n = 9), kidney (n = 11), liver (n = 4), heart/kidney (n = 4), and liver/kidney (n = 2). Many recipients accepted an HCV-viremic (HCV-V) organ due to perceived reduction in waitlist time (n = 33) and/or trust in their physician's recommendation (n = 29). Almost all (n = 47) felt that pre-transplant education and consent was appropriate. Thirty patients had no copay for direct-acting antivirals (DAA) for HCV, including 21 with household income <$20 000; seven had copays of <$100 and one had a copay >$1000. Two patients reported feeling isolated due to HCV infection and eight reported higher than anticipated medication costs. Patients' biggest concern was potential HCV transmission to partners (n = 18) and family/friends (n = 15). Overall almost all (n = 47) patients reported a positive experience with HCV-V organ transplantation. CONCLUSION: We demonstrate that real-world patient experiences surrounding HCV-V organ transplantation have been favorable. Almost all patients report comprehensive HCV-related pre-transplant consent and education. Additionally, medication costs and social isolation/exclusion were not barriers to the use of these organs.

Early clinical experience of bacteriophage therapy in 3 lung transplant recipients.

Bacteriophage therapy (BT) uses bacteriophages to treat pathogenic bacteria and is an emerging strategy against multidrug-resistant (MDR) infections. Experience in solid organ transplant is limited. We describe BT in 3 lung transplant recipients (LTR) with life-threatening MDR infections caused by Pseudomonas aeruginosa (n = 2) and Burkholderia dolosa (n = 1). For each patient, lytic bacteriophages were selected against their bacterial isolates. BT was administered for variable durations under emergency Investigational New Drug applications and with patient informed consent. Safety was assessed using clinical/laboratory parameters and observed clinical improvements described, as appropriate. All patients received concurrent antibiotics. Two ventilator-dependent LTR with large airway complications and refractory MDR P. aeruginosa pneumonia received BT. Both responded clinically and were discharged from the hospital off ventilator support. A third patient had recurrent B. dolosa infection following transplant. Following BT initiation, consolidative opacities improved and ventilator weaning was begun. However, infection relapsed on BT and the patient died. No BT-related adverse events were identified in the 3 cases. BT was well tolerated and associated with clinical improvement in LTRs with MDR bacterial infection not responsive to antibiotics alone. BT may be a viable adjunct to antibiotics for patients with MDR infections.

Successful adjunctive use of bacteriophage therapy for treatment of multidrug-resistant Pseudomonas aeruginosa infection in a cystic fibrosis patient.

INTRODUCTION: We describe the use of bacteriophage therapy in a 26-year-old cystic fibrosis (CF) patient awaiting lung transplantation. HOSPITAL COURSE: The patient developed multidrug resistant (MDR) Pseudomonas aeruginosa pneumonia, persistent respiratory failure, and colistin-induced renal failure. We describe the use of intravenous bacteriophage therapy (BT) along with systemic antibiotics in this patient, lack of adverse events, and clinical resolution of infection with this approach. She did not have recurrence of pseudomonal pneumonia and CF exacerbation within 100 days following the end of BT and underwent successful bilateral lung transplantation 9 months later. CONCLUSION: Given the concern for MDR P. aeruginosa infections in CF patients, BT may offer a viable anti-infective adjunct to traditional antibiotic therapy.

Successful optimization of antiretroviral regimens in treatment-experienced people living with HIV undergoing liver transplantation.

Modern antiretroviral therapy (ART) extends life expectancy for people living with HIV (PLWH). However, most older PLWH (≥50 years) "aged" with HIV and were exposed to historical HIV care practices and older, more toxic ART. In PLWH with exposure to older and multiple ART regimens, the drug interactions between ART frequently used in treatment-experienced persons and commonly used immunosuppressants remain a significant challenge. However, the advent of newer ART classes (eg, integrase non-strand transfer inhibitors) and more advanced HIV genetic resistance testing may allow optimization of ART regimens with minimal drug interactions. Here, we present a case series of three PLWH whose complicated ART interacted (or was at risk for interacting) with their post-liver transplant immunosuppression. After a review of their proviral DNA resistance testing, they successfully transitioned onto safer integrase non-strand transfer inhibitor-containing ART regimens without viral blips or evidence of organ rejection.

S.T.I.C.K.: A Quality Improvement Pediatric IV Infiltration Prevention Bundle.

Peripheral intravenous (PIV) catheters are commonly used in pediatric medical-surgical orthopedic and neurology populations but are at risk of dislodgement with subsequent infiltration of fluids and/or medications. This quality improvement project sought to decrease the incidence of infiltration by creating an educational awareness program for both staff nurses and families using the S.T.I.C.K. mnemonic bundle. Rates of PIV catheter infiltration on a pediatric medical-surgical orthopedic and neurology unit were found to decrease when staff nurses utilized the S.T.I.C.K. mnemonic bundle while managing PIV catheter care for pediatric medical-surgical orthopedic and neurology patients.

Use of organs from donors with bloodstream infection, pneumonia, and influenza: Results of a survey of infectious diseases practitioners.

BACKGROUND: Potential organ donors may be admitted with an infection to an intensive care unit, or contract a nosocomial infection during their stay, increasing the risk of potential transmission to the recipient. Because of a lack of practice guidelines and large-scale data on this topic, we undertook a survey to assess the willingness of transplant infectious diseases (ID) physicians to accept such organs. METHODS: We performed a 10-question survey of ID providers from the American Society of Transplantation Infectious Disease Community of Practice to determine the scope of practice regarding acceptance of organs from donors with bloodstream infection, pneumonia, and influenza prior to organ procurement, as well as management of such infections following transplantation. RESULTS: Among 60 respondents to our survey, a majority indicated that organs would be accepted from donors bacteremic with streptococci (76%) or Enterobacteriaceae (73%) without evidence of drug resistance. Acceptance rates varied based on infecting organism, type of organ, and center size. Ten percent of respondents would accept an organ from a donor bacteremic with a carbapenem-resistant organism. Over 90% of respondents would accept an organ other than a lung from a donor with influenza on treatment, compared with 52% that would accept a lung in the same setting. CONCLUSIONS: This study is the first to our knowledge to survey transplant ID providers regarding acceptance of organs based on specific infections in the donor. These decisions are often based on limited published data and experience. Better characterization of the outcomes from donors with specific types of infection could lead to liberalization of organ acceptance practices across centers.

Cost Effectiveness of Letermovir for Cytomegalovirus Prophylaxis Compared with Pre-Emptive Therapy in Allogeneic Hematopoietic Stem Cell Transplant Recipients in the United States.

PURPOSE: The aim of this study was to assess the cost effectiveness of letermovir prophylaxis with the option for subsequent pre-emptive therapy (PET) for the prevention of cytomegalovirus (CMV) infection compared with a PET-only scenario in adult allogeneic hematopoietic stem cell transplant (allo-HCT) recipients in the United States over a 10-year time horizon. MATERIALS AND METHODS: A publicly available decision tree model was constructed using a commercial third-party payer perspective to simulate an allo-HCT recipient's clinical trajectory in the first-year post-transplant, followed by entry to a Markov model to simulate years 2 through 10. Clinical inputs and utility estimates were derived from published literature. Costs were derived from published literature and US Department of Veterans Affairs Federal Supply Schedule drug pricing. Outcomes assessed included life expectancy, quality-adjusted life-years (QALYs), direct medical costs, and the incremental cost-effectiveness ratio (ICER). One-way and probabilistic sensitivity analyses (PSA) were performed to test the robustness of the findings. RESULTS: Compared with PET alone, letermovir prophylaxis was projected to increase life-years per person (4.99 vs. 4.70 life-years), and increase QALYs (3.29 vs. 3.08) and costs (US$83.411 vs. US$70,698), yielding an ICER of US$59,356 per QALY gained. One-way sensitivity analyses indicated our model was sensitive to mortality (ICER: $164,771/QALY) and utility (letermovir ICER: $117,447/QALY; PET ICER: $107,290/QALY) in the first-year post-transplant. In 57.1% of the PSA simulations, letermovir was a cost-effective option using a willingness-to-pay threshold of US$100,000 per QALY. CONCLUSIONS: Letermovir prophylaxis is cost effective compared with PET alone with a willingness-to-pay threshold of US$100,000 per QALY gained. Sensitivity analysis results indicate future research is required to understand the impact of mortality and quality of life in the first-year post-transplant to arrive at a conclusive decision on letermovir adoption.

Rapid multiplexed immunoassay for simultaneous serodiagnosis of HIV-1 and coinfections.

Diagnosis of opportunistic infections in HIV-infected individuals remains a major public health challenge, particularly in resource-limited settings. Here, we describe a rapid diagnostic system that delivers a panel of serologic immunoassay results using a single drop of blood, serum, or plasma. The system consists of disposable cartridges and a simple reader instrument, based on an innovative implementation of planar waveguide imaging technology. The cartridge incorporates a microarray of recombinant antigens and antibody controls in a fluidic channel, providing multiple parallel fluorescence immunoassay results for a single sample. This study demonstrates system performance by delivering antibody (Ab) reactivity results simultaneously for multiple antigens of HIV-1, Treponema pallidum (syphilis), and hepatitis C virus (HCV) in a collection of clinical serum, plasma, and whole-blood samples. By plotting antibody reactivity (fluorescence intensity) for known positive and negative samples, empirical reactivity cutoff values were defined. The HIV-1 assay shows 100% agreement with known seroreactivity for a collection of 82 HIV Ab-positive and 142 HIV Ab-negative samples, including multiple samples with HCV and syphilis coinfection. The treponema-specific syphilis assay correctly identifies 67 of 68 T. pallidum Ab-positive and 100 of 102 T. pallidum Ab-negative samples, and the HCV assay correctly identifies 59 of 60 HCV Ab-positive and 120 of 121 HCV Ab-negative samples. Multiplexed assay performance for whole-blood samples is also demonstrated. The ability to diagnose HIV and opportunistic infections simultaneously at the point of care should lead to more effective therapy decisions and improved linkage to care.

Near patient CD4 count in a hospitalized HIV patient population.

BACKGROUND: Point-of-care (POC) CD4 T-cell counting is increasingly recognized as providing improved linkage-to-care during management of HIV infection, particularly in resource-limited settings where disease burden is highest. This study evaluated prototype POC CD4 T-cell counters from MBio Diagnostics in the context of low CD4 count, hospitalized patients in Mozambique. This study measured system performance when presented with challenging, low count samples from HIV/AIDS patients with acute illnesses resulting in hospitalization. METHODS: Forty whole blood samples were collected from donors on the medical service at Maputo Central Hospital and absolute CD4 counts were generated on the MBio CD4 system and a reference laboratory using flow cytometry. RESULTS: The mean and median CD4 counts by the flow cytometry reference were 173 and 80 cells/µL, respectively. Correlation between the MBio CD4 System and the reference was good. Bland-Altman analysis showed a mean bias of +15 cells/µL (+9 to +21 cells/µL, 95% CI), and limits of agreement of -47 to 77 cells/µL. For samples with counts >100 cells/µL (N = 14), the mean coefficient of variation was 7.3%. For samples with counts <50 cells/µL, mean absolute bias of replicate samples was 4.8 cells/µL. When two MBio readers were compared, Bland-Altman bias was -4 cells/µL (-13 to +6 cells/µL, 95% CI), and limits of agreement of -63 and +55 cells/µL. CONCLUSIONS: The MBio System holds promise as a POC system for quantitation of CD4 T cells in resource-limited settings given system throughput (80-100 cartridges/day), design simplicity, and ease-of-use. © 2015 International Clinical Cytometry Society.

Rapid Multiplexed Immunoassay for Detection of Antibodies to Kaposi's Sarcoma-Associated Herpesvirus.

Diagnosis of KSHV-infected individuals remains a challenge. KSHV prevalence is high in several populations with high prevalence of HIV, leading to increased risk of development of Kaposi's sarcoma (KS). While current assays are reliable for detecting antibodies to KSHV, none are routinely utilized to identify individuals with KSHV infection and thus at increased risk for KS due to assay complexity, lack of access to testing, and cost, particularly in resource-limited settings. Here we describe the addition of KSHV proteins LANA and K8.1 to a previously evaluated HIV/co-infection multiplexed fluorescence immunoassay system. This study demonstrates assay performance by measuring antibody reactivity for KSHV and HIV-1 in a collection of clinical specimens from patients with biopsy-proven KS and sourced negative controls. The KSHV assay correctly identified 155 of 164 plasma samples from patients with biopsy-proven KS and 85 of 93 KSHV antibody (Ab)-negative samples for a sensitivity of 95.1% and specificity of 91.4%. Assay performance for HIV-1 detection was also assessed with 100% agreement with independently verified HIV-1 Ab-positive and Ab-negative samples. These results demonstrate good sensitivity and specificity for detection of antibody to KSHV antigens, and demonstrate the potential for multiplexed co-infection testing in resource-limited settings to identify those at increased risk for HIV-1-related complications.

Performance evaluation of the MBio Diagnostics point-of-care CD4 counter.

The measurement of the absolute CD4 T-cell count is critical in the initial evaluation and staging of HIV-infected persons, yet access to this technology remains limited in many low resource settings where disease burden is highest. Here we evaluate the performance of a prototype point-of-care device (POC) to quantify CD4 T cells from MBio Diagnostics, Inc. Whole blood samples, both venous and capillary (finger stick), were collected from known HIV-infected participants at the University of California, San Diego Antiviral Research Center, and tested using the MBio system and conventional flow cytometry. A total of 94 venipuncture and 52 capillary samples were processed and statistical analyses included comparison to flow cytometry results. For the venipuncture samples, Bland-Altman analysis resulted in a mean bias of -10 cells/µL (-23 to +3 cells/µL, 95% CI), and limits of agreement (LOA) of -132 and +112 cells/µL. For the capillary samples, Bland-Altman resulted in a mean bias of -4 cells/µL (-31 to +23 cells/µL, 95% CL), and LOA of -195 and +186 cells/µL. For the San Diego study cohort, the prototype MBio system showed negligible quantitative bias relative to flow cytometry. Higher variability was observed in the capillary samples relative to venipuncture, but system precision for both capillary and venipuncture samples was good. There was also close agreement between results from the same participant when tested with two different systems, different operators and different locations. This preliminary evaluation suggests that the MBio CD4 device holds promise as a POC system for quantitation of CD4 T cells in limited-resource settings.