Listeriosis in recipients of allogeneic blood and marrow transplantation: thirteen year review of disease characteristics, treatment outcomes and a new association with human cytomegalovirus infection

Listeria monocytogenes Infections in Hematopoietic Cell Transplantation Recipients: Clinical Manifestations and Risk Factors. A Multinational Retrospective Case-Control Study from the Infectious Diseases Working Party of the European Society for Blood and Marrow Transplantation

Listeriosis is rare after hematopoietic stem cell transplantation (HCT). Little is known about listeriosis in this population. In this retrospective international case-control study, we evaluated 41 listeriosis episodes occurring between 2000 and 2021 in HCT recipients (111 transplant centers in 30 countries) and assessed risk factors for listeriosis by comparisons with matched controls. The 41 listeriosis episodes (all due to Listeria monocytogenes [LM]) occurred in 30 allogeneic (allo)-HCT recipients and 11 autologous (auto)-HCT recipients at a median of 6.2 months (interquartile range [IQR], 1.6 to 19.3 months) post-HCT. The estimated incidence was 49.8/100,000 allo-HCT recipients and 13.7/100,000 auto-HCT recipients. The most common manifestations in our cohort were fever (n = 39; 95%), headache (n = 9; 22%), diarrhea, and impaired consciousness (n = 8 each; 20%). Four patients (10%) presented with septic shock, and 19 of 38 (50%) were severely lymphocytopenic. Thirty-seven patients (90%) had LM bacteremia. Eleven patients (27%) had neurolisteriosis, of whom 4 presented with nonspecific signs and 5 had normal brain imaging findings. Cerebrospinal fluid analysis revealed high protein and pleocytosis (mainly neutrophilic). Three-month mortality was 17% overall (n = 7), including 27% (n = 3 of 11) in patients with neurolisteriosis and 13% (n = 4 of 30) in those without neurolisteriosis. In the multivariate analysis comparing cases with 74 controls, non-first HCT (odds ratio [OR], 5.84; 95% confidence interval [CI], 1.10 to 30.82; P = .038); and lymphocytopenia <500 cells/mm3 (OR, 7.54; 95% CI, 1.50 to 37.83; P = .014) were significantly associated with listeriosis. There were no statistically significant differences in background characteristics, immunosuppression, and cotrimoxazole prophylaxis between cases and controls. HCT recipients are at increased risk for listeriosis compared to the general population. Listeriosis cause severe disease with septic shock and mortality. Neurolisteriosis can present with nonspecific signs and normal imaging. Lymphocytopenia and non-first HCT are associated with an increased risk of listeriosis, and cotrimoxazole was not protective.

Listeria monocytogenes: a promising vector for tumor immunotherapy

Cancer receives enduring international attention due to its extremely high morbidity and mortality. Immunotherapy, which is generally expected to overcome the limits of traditional treatments, serves as a promising direction for patients with recurrent or metastatic malignancies. Bacteria-based vectors such as Listeria monocytogenes take advantage of their unique characteristics, including preferential infection of host antigen presenting cells, intracellular growth within immune cells, and intercellular dissemination, to further improve the efficacy and minimize off-target effects of tailed immune treatments. Listeria monocytogenes can reshape the tumor microenvironment to bolster the anti-tumor effects both through the enhancement of T cells activity and a decrease in the frequency and population of immunosuppressive cells. Modified Listeria monocytogenes has been employed as a tool to elicit immune responses against different tumor cells. Currently, Listeria monocytogenes vaccine alone is insufficient to treat all patients effectively, which can be addressed if combined with other treatments, such as immune checkpoint inhibitors, reactivated adoptive cell therapy, and radiotherapy. This review summarizes the recent advances in the molecular mechanisms underlying the involvement of Listeria monocytogenes vaccine in anti-tumor immunity, and discusses the most concerned issues for future research.

Cytomegalovirus Exposure and the Risk of Overall Infection After Kidney Transplantation: A Cohort Study on the Indirect Effects Attributable to Viral Replication

Previous reports hypothesized that cytomegalovirus (CMV) may predispose to non-CMV infection after kidney transplantation (KT). We analysed the incidence of non-CMV infection (overall, bacterial and opportunistic) in 291 KT recipients according to the previous development of any level or high-level (≥1,000 IU/ml) CMV viremia. Exposure to CMV replication was assessed throughout fixed intervals covering first the 30, 90, 180 and 360 post-transplant days (cumulative exposure) and non-overlapping preceding periods (recent exposure). Adjusted Cox models were constructed for each landmark analysis. Overall, 67.7 and 50.5% patients experienced non-CMV and CMV infection, respectively. Patients with cumulative CMV exposure had higher incidence of non-CMV infection beyond days 30 (p-value = 0.002) and 90 (p-value = 0.068), although these associations did not remain after multivariable adjustment. No significant associations were observed for the remaining landmark models (including those based on high-level viremia or recent CMV exposure), or when bacterial and opportunistic infection were separately analysed. There were no differences in viral kinetics (peak CMV viremia and area under curve of CMV viral load) either. Our findings do not support the existence of an independent association between previous CMV exposure and the overall risk of post-transplant infection, although results might be affected by power limitations.

Human Cytomegalovirus Host Interactions: EGFR and Host Cell Signaling Is a Point of Convergence Between Viral Infection and Functional Changes in Infected Cells

Viruses have evolved diverse strategies to manipulate cellular signaling pathways in order to promote infection and/or persistence. Human cytomegalovirus (HCMV) possesses a number of unique properties that allow the virus to alter cellular events required for infection of a diverse array of host cell types and long-term persistence. Of specific importance is infection of bone marrow derived and myeloid lineage cells, such as peripheral blood monocytes and CD34⁺ hematopoietic progenitor cells (HPCs) because of their essential role in dissemination of the virus and for the establishment of latency. Viral induced signaling through the Epidermal Growth Factor Receptor (EGFR) and other receptors such as integrins are key control points for viral-induced cellular changes and productive and latent infection in host organ systems. This review will explore the current understanding of HCMV strategies utilized to hijack cellular signaling pathways, such as EGFR, to promote the wide-spread dissemination and the classic life-long herpesvirus persistence.

Neurological complications of hematopoietic cell transplantation in children and adults

Hematopoietic cell transplantation (HCT) is widely performed for neoplastic and non-neoplastic diseases. HCT involves intravenous infusion of hematopoietic progenitor cells from human leukocyte antigen (HLA)-matched donor (allogeneic) or from the patient (autologous). Before HCT, the patient is prepared with high dose chemotherapy and/or radiotherapy to destroy residual malignant cells and to reduce immunologic resistance. After HCT, chemotherapy is used to prevent graft rejection and graft versus host disease (GvHD). Neurological complications are related to the type of HCT, underlying disease, toxicity of the conditioning regimens, immunosuppression caused by conditioning regimens, vascular complications generated by thrombocytopenia and/or coagulopathy, GvHD and inappropriate immune response. In this review, neurological complications are presented according to time of onset after HCT: (1) early complications (in the first month) - related to harvesting of stem cells, during conditioning (drug toxicity, posterior reversible encephalopathy syndrome), related to pancytopenia, (2) intermediate phase complications (second to sixth month) - central nervous system infections caused by prolonged neutropenia and progressive multifocal leukoencephalopathy due to JC virus, (3) late phase complications (after sixth month) - neurological complications of GvHD, second neoplasms and relapses of the original disease.

Central nervous system infections in cancer patients and hematopoietic stem cell transplant recipients

Central nervous system (CNS) infections in cancer patients present a diagnostic and therapeutic challenge for clinicians. While CNS infections are not frequent complications of cancer, its therapies, or hematopoietic stem cell transplantation, the importance of CNS infections lies in their propensity to result in profound morbidity and substantial mortality in this vulnerable patient population. With an expanding population of patients with malignant disease undergoing more potent and aggressive therapies and with the advent of newer immunomodulatory agents, the incidence of CNS infectious complications is likely to rise. This chapter will summarize the clinical and diagnostic evaluation of potential infections of the CNS in these patients and will discuss particular pathogens of interest with regard to this at-risk patient population.

Bacterial pathogens

Bacterial infections are frequent complications among patients treated for cancer. The type, severity, and treatment of bacterial infections vary and depend upon the specific malignancy, associated chemotherapies, and transplantation. This chapter discusses commonly encountered bacterial pathogens as well as Nocardia and mycobacteria in patients with cancer and addresses the clinical syndromes and management. Drug-resistant bacteria are becoming an increasingly recognized problem in patients with cancer. Antimicrobial resistance in select gram-positive and gram-negative bacteria are discussed along with the mechanisms of resistance and recommended therapies.

Opportunistic infections of the central nervous system in the transplant patient

Therapeutic advances in transplantation medicine have resulted in ever expanding patient populations that receive organ or stem cell transplantation. Modern potent immunomodulatory therapies have resulted in improvements in allograft and patient survival, but, consequently, as a result of the immunosuppressive state, transplant recipients are highly vulnerable to infection, including those that affect the central nervous system (CNS). CNS infections present a diagnostic and therapeutic challenge for clinicians involved in the care of the transplant patient, with a propensity to result in profound morbidity and often high mortality in this patient population. Here, we review major opportunistic pathogens of the CNS seen in transplant patients, highlighting distinguishing epidemiologic and clinical features.

Neurological complications of transplantation: part I: hematopoietic cell transplantation

Hematopoietic cell transplantation (HCT) is the preferred treatment for an expanding range of neoplastic and nonmalignant conditions. Increasing numbers of solid organ transplantations (SOTs) add an additional population of immunosuppressed patients with multiple potential neurological problems. While the spectrum of neurological complications varies with conditioning procedure and hematopoietic cell or solid organ source, major neurological complications occur with all transplantation procedures. This 2 part review emphasizes a practical consultative approach to central and peripheral nervous system problems related to HCT or SOT with clinical and neuroimaging examples from the authors' institutional experience with the following conditions: the diversity of manifestations of common infections such as varicella zoster virus, Aspergillus, and progressive multifocal leukoencephalopathy (PML), drug therapy-related complications, stroke mechanisms, the spectrum of graft versus host disease (GVHD), and neurologically important syndromes of immune reconstitution inflammatory syndrome (IRIS), posterior reversible encephalopathy syndrome (PRES), and posttransplantation lymphoproliferative disorder (PTLD). These complications preferentially occur at specific intervals after HCT and SOT, and neurological consultants must recognize an extensive spectrum of syndromes in order to effect timely diagnosis and expedite appropriate treatment.

The occurrence and prevention of foodborne disease in vulnerable people

In developed countries, such as the United Kingdom and the United States, between 15% and 20% of the population show greater susceptibility than the general population to foodborne disease. This proportion includes people with primary immunodeficiency, patients treated with radiation or with immunosuppressive drugs for cancer and diseases of the immune system, those with acquired immune-deficiency syndrome and diabetics, people suffering from liver or kidney disease or with excessive iron in the blood, pregnant women, infants, and the elderly. Malnutrition and use of antacids, particularly proton-pump inhibitors, also increase susceptibility. We review the occurrence of infection by foodborne pathogens in these groups of people and measures to prevent infection. The nature and use of low microbial diets to reduce the risk of foodborne disease in immunocompromised patients are very variable. Diets for vulnerable people in care should exclude higher-risk foods, and vulnerable people in the community should receive clear advice about food safety, in particular avoidance of higher-risk foods and substitution of safer, nutritious foods.

Qualitative studies of the food safety knowledge and perceptions of transplant patients

Organ and stem cell transplant patients are at risk for foodborne illness due to disease and medically induced immunosuppression. The food safety knowledge and informational needs of these groups have not been documented in the literature. The objectives of this study were to assess transplant patients' food safety knowledge and perceptions, to probe the likelihood of practicing safe food handling behavior, and to test an educational strategy for future food safety interventions aimed at transplant patients. Subjects were organ or stem cell transplant patients, or their family care providers. Research was conducted in inpatient or outpatient facilities at a large, Midwestern United States comprehensive cancer and transplant center. Differences in survey data between the organ and stem cell transplant groups were determined by Student's t tests. Ethnographic methods were used to analyze qualitative focus groups and interview data for themes. Organ transplant patients had less motivation to follow food safety recommendations than did stem cell transplant patients, and they were more likely to consume risky foods. Stem cell transplant patients overall had a better understanding of their susceptibility to foodborne illness and had better prepared themselves with the knowledge and behavior changes needed to protect their health. Educational materials aimed at communicating food safety information for transplant patients were evaluated by patients and judged acceptable. This study found that organ transplant and stem cell transplant patients are distinct patient populations, with differing perceptions regarding the seriousness of foodborne illness and willingness to adopt preventative food handling practices. Population differences should be accounted for in food safety educational strategies.

Central nervous system infections in immunocompromised patients: update on diagnostics and therapy

Infections of the central nervous system (CNS) are increasingly reported in patients with malignancies. Heavily immunocompromised patients like those after allogeneic stem cell transplantation (SCT) or previous T cell depleting treatment regimens (e.g. with fludarabine or alemtuzumab) are at highest risk for cerebral infections. The spectrum of causative organisms may vary greatly, depending on the underlying malignancy, its treatment and various other factors. Toxoplasma gondii and fungi are the leading causative organisms in patients after allogeneic SCT, but also viruses such as herpes simplex virus or JC virus may be detected in these patients. Definitive diagnosis of cerebral infection still remains a high challenge, although diagnostics have improved by the wide availability of imaging techniques and polymerase chain reaction in recent years. Novel therapeutic options are arising, particularly for fungal CNS infections. Here, we summarise aspects on epidemiology, clinical symptoms and prognosis of CNS infections in patients with malignancies. Additionally, we give an overview on the diagnostics and management of cerebral infections in these patients including evidence evaluation of efficacy of treatment.

Zoonoses in Solid-Organ and Hematopoietic Stem Cell Transplant Recipients

Numerous reports exist of the transmission of zoonoses to humans during and after solid-organ and hematopoietic stem cell transplantation. Donor-derived infections of numerous etiologies, including West Nile virus infection, Chagas disease, toxoplasmosis, rabies, lymphocytic choriomeningitis virus infection, and infection due to Brucella species have been reported. Most zoonoses occur as a primary infection after transplantation, and immunocompromised patients are more likely to experience significant morbidity and mortality from these infections. Risks of zoonotic infection in the posttransplantation period could be reduced by patient education. Increased recognition of the risks of zoonoses, as well as the advent of molecular biology-based testing, will potentially augment diagnostic aptitude. Documented zoonotic infection as it affects transplantation will be the primary focus of this review.

Strategies to enhance immune function in hematopoietic transplantation recipients who have fungal infections

The challenges in the treatment of systemic fungal infections after HSCT include: (1) changing epidemiology as less drug-susceptible saprophytic fungi are increasingly associated with human disease; (2) the difficulty of early and correct diagnosis, even with the new generation of enzymatic immunoassays; (3) the inability to reduce or eliminate predisposing factors, especially severe immune suppression in most transplant patients with these infections and (4) the uncertain role of antifungal drug combinations and risk of drug antagonism complicating effective empiric-pre-emptive therapy. Current, developing and future immune enhancement strategies including recombinant granulocyte- and granulocyte macrophage-colony stimulating factor (GM-CSF), interferon-gamma (IFN-gamma), adjuvant pro-inflammatory cytokine therapy during mobilized donor granulocyte transfusions, therapeutic potential of pentraxin, adaptive immune transfer and dendritic cell fungal vaccines. Improved understanding of the molecular pathogenesis of fungal infections and of the complexity of host antifungal immune responses has provided the critical information to readdress existing treatment paradigms and further evaluate the role of GM-CSF and IFN-gamma early in the course of therapy against life-threatening fungal infections in high-risk patients following stem cell transplantation.

Neurologic complications of bone marrow, stem cell, and organ transplantation in patients with cancer

Bone marrow and peripheral blood stem cell transplantation are part of the standard of care for a variety of oncologic and non-oncologic disorders and are associated with a large spectrum of neurologic complications. These complications may arise at any time during and after the transplantation process, especially in subjects requiring chronic immunosuppression, and are most frequently related to infections, cerebrovascular or metabolic events, and toxicity from radiation or chemotherapy. Due to the unique circumstances and treatments surrounding each step in the transplantation process, there is a higher incidence of some neurologic complications during discrete time periods. Being aware of the temporal relationship of the neurologic disorder within the transplantation process can therefore facilitate diagnosis and institution of appropriate therapy. Neurologic complications after solid organ transplantation are often due to similar mechanisms as in patients after bone marrow and stem cell transplantation although there are several complications unique to these patients such as transmission of infectious agents by the donated organ. For these patients, the clinician needs to have a high index of suspicion that the neurologic problem is related to the transplant.

Achieving continuous improvement in reductions in foodborne listeriosis--a risk-based approach

Listeria monocytogenes is a foodborne pathogen that can cause listeriosis, a severe disease that can lead to septicemia, meningitis, and spontaneous abortion. Ongoing efforts are needed to further reduce the incidence of listeriosis, due to its high mortality rate. The focus of this report is the use of a risk-based approach to identify strategies that will have the greatest impact on reducing foodborne listeriosis. A continuum of risk for listeriosis is observed in the human population, ranging from exquisitely sensitive groups, who are highly immunocompromised and at very high risk of listeriosis, through the normal healthy population younger than 65 years of age, who appear to have a minimal risk for listeriosis. In addition, unique subpopulations may exist; for example, pregnant Latina women appear to have a higher risk of listeriosis than pregnant women of other ethnic groups, most likely due to consumption of contaminated soft cheeses such as queso fresco and queso blanco. The International Life Sciences Institute Risk Science Institute Expert Panel concluded that certain foods pose a high risk for causing listeriosis. High-risk foods have all of the following properties: (1) have the potential for contamination with L. monocytogenes; (2) support the growth of L. monocytogenes to high numbers; (3) are ready to eat; (4) require refrigeration; and (5) are stored for an extended period of time. Control strategies are needed in the food chain from preharvest through consumption to minimize the likelihood that food will become contaminated by L. monocytogenes and to prevent the growth of the organism to high numbers. The Expert Panel identified three main strategies for ensuring continuous improvement in reducing foodborne listeriosis: (1) preventing contamination of foods with L. monocytogenes; (2) preventing growth of L. monocytogenes to high numbers in foods; and (3) science-based education messages targeted to susceptible populations and their caregivers. Of these strategies, the Expert Panel concluded that preventing growth of L. monocytogenes to high numbers would have the greatest impact in reducing cases of listeriosis. Dose-response models predict that the risk of listeriosis increases as the number of organisms in a food increases and can be used as a scientific basis for a target level below which the organism should be reduced to minimize the likelihood of listeriosis in high-risk populations. This requires implementation of effective food safety control measures and ensuring that these control strategies are consistently met. Most effective strategies to control L. monocytogenes in high-risk foods include (1) good manufacturing practices, sanitation standard operating procedures, and hazard analysis critical control point programs to minimize environmental L. monocytogenes contamination and to prevent cross-contamination in processing plants and at retail; (2) an intensive environmental sampling program in plants processing high-risk foods and an effective corrective action plan to reduce the likelihood of contamination of high-risk foods; (3) time and temperature controls throughout the entire distribution and storage period, including establishing acceptable storage times of foods that support growth of L. monocytogenes to high numbers; (4) reformulating foods to prevent or retard the growth of L. monocytogenes; and (5) using postpackaging treatments to destroy L. monocytogenes on products. Science-based education and risk communication strategies aimed at susceptible populations and focused on high-risk foods should be delivered through health care providers or other credible sources of information. Exquisitely sensitive consumers may become ill when exposed to low numbers of L. monocytogenes or other opportunistic pathogens, so reducing the risk to this population could be achieved by maintaining them on restricted low-microbe diets during those periods when they are most severely immunocompromised. High-risk individuals (i.e., the elderly, pregnant women, and most immunocompromised individuals) should be provided with guidance on healthy eating, including specific information on high-risk foods that they should avoid, and strategies to reduce their risk, such as thorough cooking, avoidance of cross-contamination, and short-term refrigerated storage of cooked perishable foods. Those at low risk for listeriosis should receive information on safe food handling practices, preferably starting at a preschool age.

Listeria monocytogenes skin infection with cerebritis and haemophagocytosis syndrome in a bone marrow transplant recipient

In this report, we describe unusual and unreported manifestations of Listeria monocytogenes infection in a bone marrow transplant recipient, including cutaneous infection with an hamophagocytosis syndrome and cerebritis. L. monocytogenes occurred despite a broad spectrum antibiotherapy. L. monocytogenes was isolated from a skin biopsy. Outcome was favorable with amoxicillin and gentamicin therapy. L. monocytogenes infection should be suspected in patients with cerebritis despite large spectrum antibiotherapy and this report underscores the usefulness of skin biopsies in febrile immunocompromised patients.

Listeria monocytogenes infection in patients with cancer

Listeriosis (LT) is an important infection in immunocompromised patients, but no large series of LT in cancer patients have been recently described. We reviewed the records of 34 cancer patients with LT at our institution (1990-2001). Twenty patients (59%) had an underlying hematologic malignancy. In 11 patients, LT complicated bone marrow transplantation. Lymphocytopenia was observed in 62% of the patients. Twenty-six patients (76%) received prior corticosteroids. Bacteremia was the most common presentation of LT (74%) followed by meningoencephalitis (21%). The most common treatment of LT was ampicillin with or without gentamicin (68%). The median duration of treatment was 26 days (range, 8-74 days). The rate of response to antimicrobial therapy was 79%. No relapses were identified. LT contributed to death in 9 (75%) of the 12 patients who died. Meningoencephalitis had the worst prognosis (3 of 6 cases were fatal). Treatment of central nervous system LT continues to have a high failure rate.

Listeriosis in patients at a comprehensive cancer center, 1955-1997

Listeria monocytogenes infection occurred in 94 patients during 1955-1997 at Memorial Sloan-Kettering Cancer Center. The incidence was 0.5 (1955-1966), 0.96 (1970-1979), and 0.14 (1985-1997) cases per 1000 new admissions. Eighty-five patients (90%) were bacteremic, and 34 (36%) had evidence of intracranial infection. In 91 patients with cancer, 70 (77%) received chemotherapy for advanced or relapsed malignancy (n=51; 56%); 64 (68%) received corticosteroids. Breast cancer was the most common solid-organ cancer (n=14; 45%), and 34 (36%) had preexisting advanced liver disease. In 14 (39%) of 37 patients who died of listeriosis, death occurred within 48 h of L. monocytogenes isolation. Four (80%) of 5 patients with extracranial foci of infection died of their infection, compared with 33 (37%) of 89 patients with isolated bacteremia and/or intracranial infection (odds ratio, 2.34; P=.05). Most infections (60%) were due to L. monocytogenes serotype 1/2, and the remainder (40%) were due to serovar 4b. Listeriosis in these patients with cancer occurred most often in individuals receiving antineoplastic therapy for advanced or relapsed malignancy and systemic corticosteroids. The presence of advanced liver disease may have increased the risk of systemic listeriosis in susceptible patients with underlying cancer.

Antimicrobial activities against 84 Listeria monocytogenes isolates from patients with systemic listeriosis at a comprehensive cancer center (1955-1997)

Listeriosis is a serious complication in patients undergoing treatment for cancer. We present antimicrobial susceptibility profiles of 84 clinical Listeria monocytogenes isolates. During 1955 to 1997, in vitro susceptibility for penicillin (97.6%), ampicillin (90.7%), erythromycin (98.8%), tetracycline (96.9%), and gentamicin (98.0%) remained unchanged. All isolates were susceptible to amikacin, ciprofloxacin, imipenem, rifampin, trimethoprim-sulfamethoxazole (TMP-SMX), and vancomycin. High prevalence of clindamycin resistance (96.2%) was unexpected. Ampicillin plus gentamicin is standard therapy for systemic listerosis, and TMP-SMX may be used for patients with beta-lactam intolerance. In vitro susceptibility profiles for carbapenem and fluoronated quinolone are promising, although clinical validation is critically needed before routine use is advocated, especially for listeric patients with severe cellular immune defects.