Predicting infections in patients with haematological malignancies treated with chimeric antigen receptor T-cell therapies: A systematic scoping review and narrative synthesis

Comparability evaluation of serum and plasma cytokine levels by multiplex bead-based flow cytometry

BACKGROUND AND AIMS

Serum and plasma are the most common matrices for cytokine assays. Nevertheless, there is a lack of comparability evaluation for cytokine levels in two matrices based on multiplex bead-based flow cytometry. The study aimed to evaluate the comparability of IL-6, IL-8, and IL-10 serum- and plasma-based measurement results using flow cytometry.

MATERIALS AND METHODS

The serum and EDTA-K2 plasma were collected from three cohorts of hematologic malignancy patients (n = 66, 75, and 37, respectively) to evaluate comparability of IL-6, IL-8, and IL-10 measurement results using QuantoBio 14-plex cytokine kit on the BeamCyte-1026 flow cytometry. The Passing-Bablok regression was performed between serum- and plasma-based levels of cytokines. Additionally, the relative deviation of cytokine measurement results from the two matrices was compared with the allowable limits from the China National External Quality Assessment cytokine program.

RESULTS

The results revealed a relatively high correlation in IL-6, IL-8, and IL-10 levels between serum and plasma, with correlation coefficients of 0.966, 0.924, and 0.985, respectively. However, the comparability in the two matrices was unsatisfactory. Compared to plasma, the relative deviation of IL-6, IL-8, and IL-10 in serum was 74.8 %, -29.3 %, and 46.5 %, respectively, and only 20 % (IL-6), 31 % (IL-8), and 38 % (IL-10) of samples met allowable limits.

CONCLUSIONS

Poor comparability was found between serum- and plasma-based measurement results. Moreover, given the great potential of cytokine profiling in diagnosing and treating diseases, there is an urgent need to develop accurate and consistent processing of samples of cytokine assays to improve the accuracy and reproducibility of results and ensure the specimen's fitness for purpose.

The impact of the bedside check of medication appropriateness (BED-CMA) at the hematology ward: a mixed-methods study

BACKGROUND

Hematology patients have complex medication regimens and rapidly changing organ function, rendering them susceptible to medication errors. Health information technology can facilitate the detection of inappropriate prescriptions and assist healthcare professionals in enhancing patient safety.

AIM

To evaluate the impact of a pharmacist-oriented clinical decision support system, called Bedside Check of Medication Appropriateness (BED-CMA), on inappropriate prescribing at the hematology ward, and to qualitatively assess its impact on the organization of bedside clinical pharmacy practice.

METHOD

A mixed-methods study was conducted at the semi-critical 15-bed hematology ward of UZ Leuven between 2020 and 2023. A pre-post study was performed to evaluate the impact of BED-CMA on residual potentially inappropriate prescriptions (PIPs), defined as those that persisted for at least 24 h after their initial identification. A time trend analysis was performed to identify any potential pre-existing patterns. The BED-CMA intervention consisted of embedding 19 clinical rules into the hospital information system. The pre-intervention cohort received usual clinical pharmacy services. Post-intervention, clinical pharmacists used BED-CMA alerts in addition to standard practices. A focus group discussion with clinical pharmacists assessed the impact on the organization of bedside clinical pharmacy practice.

RESULTS

Pre-intervention, 70% (48/69) of initial PIPs remained residual PIPs, which decreased to 20% (13/66) post-intervention (odds ratio 0.11 (95% confidence interval 0.05-0.22, P < .0.0001)). There was no evidence for a pre-existing time trend (P = .0.52). Pharmacists reported improved workflow efficiency through enhanced patient prioritization and prompt identification of PIPs.

CONCLUSION

BED-CMA significantly reduced residual PIPs by streamlining clinical pharmacy practice at a hematology ward.

Role of procalcitonin, C-reactive protein and ferritin in cytokine release syndrome after CAR T-cell therapy in children and young adults

PURPOSE

Chimeric antigen receptor (CAR) T-cell CD19 therapy has changed the treatment paradigm for patients with relapsed/refractory B-cell acute lymphoblastic leukemia. It is frequently associated with potentially severe toxicities: cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), and admission to PICU is often required. Some biomarkers seem to correlate with CRS severity. Our goal is to elucidate the role of procalcitonin (PCT), C-reactive protein (CRP) and ferritin in the context of CRS following CAR T-cell infusion to predict its severity and PICU admission.

METHODS

Prospective observational study (2016-2022) in children and young adult who received CAR T-cell therapy (Tisagenlecleucel/ARI-0001). We collected epidemiologic data, specific CAR T-cell toxicities, PICU admission, biomarker results (PCT, CRP and ferritin), length of stay and mortality. Biomarkers were analyzed considering two values: the highest value during ward admission, and the highest overall value including PICU admission.

RESULTS

Seventy-seven patients were included. Median age at infusion was 9.1 years (IQR 6-13), 49.4% were females. Before CAR T-cell infusion, the median bone marrow blast was 9% (IQR 0-59). The most frequent toxicity was CRS in 62 patients (80.5%), it was severe in 18 cases (23.4%). Fourteen patients (18.1%) had ICANS. Thirty-one patients (40.3%) required admission to the PICU. PCT and ferritin were higher in patients admitted to PICU (PCT 0.8 ng/mL vs 0.15 ng/mL, p < 0.001, ferritin 5490 vs. 2900 µg/L, p < 0.019). The proposed cut-off for PCT to predict admission to PICU is 0.55 ng/mL, presenting a sensitivity of 67.7% and a specificity of 86.7%. The maximum value of three biomarkers was higher in those who presented any primary outcome: development of severe CRS, the need for admission to PICU, and in-hospital mortality. Biomarkers were higher in those who needed inotropic or respiratory support.

CONCLUSIONS

PCT levels increase after CAR-T cell therapy in the setting of systemic inflammation and could be a predictor of PICU admission and evolution to death. Further research studying its role in the context of CRS and the differential diagnosis between infection and CRS is needed to better understand the biology of this biomarker and to define its value in clinical practice.

Invasive Fungal Disease After Chimeric Antigen Receptor-T Immunotherapy in Adult and Pediatric Patients

Invasive fungal diseases (IFDs) have been documented among the causes of post-chimeric antigen receptor-T (CAR-T) cell immunotherapy complications, with the incidence of IFDs in CAR-T cell therapy recipients being measured between 0% and 10%, globally. IFDs are notorious for their potentially life-threatening nature and challenging diagnosis and treatment. In this review, we searched the recent literature aiming to examine the risk factors and epidemiology of IFDs post-CAR-T infusion. Moreover, the role of antifungal prophylaxis is investigated. CAR-T cell therapy recipients are especially vulnerable to IFDs due to several risk factors that contribute to the patient's immunosuppression. Those include the underlying hematological malignancies, the lymphodepleting chemotherapy administered before the treatment, existing leukopenia and hypogammaglobinemia, and the use of high-dose corticosteroids and interleukin-6 blockers as countermeasures for immune effector cell-associated neurotoxicity syndrome and cytokine release syndrome, respectively. IFDs mostly occur within the first 60 days following the infusion of the T cells, but cases even a year after the infusion have been described. Aspergillus spp., Candida spp., and Pneumocystis jirovecii are the main cause of these infections following CAR-T cell therapy. More real-world data regarding the epidemiology of IFDs and the role of antifungal prophylaxis in this population are essential.

[Hematological toxicities post-CAR-T cells: Recommendations of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]

Chimeric antigen receptor T cell (CAR-T cell) therapy has become a standard-of-care for several hematological and a promising treatment for solid malignancies or for selected non-malignant autoimmune disorders. Hematological complications following this treatment are very common with the majority of patients experiencing at least one cytopenia after CAR-T cell injections. The management of these adverse events is not standardized and represents an area of active research and unmet clinical needs. This harmonization workshop, gathering a group of experts who analyzed this topic, has been conceived for the optimization of the management of patients presenting with post-CAR-T cell hematological toxicities. Based on the data present in the literature, these practical recommendations were made to harmonize the practices of Francophone centers involved in the management of these patients.

Chimeric antigen receptor-T-cell therapies going viral: latent and incidental viral infections

PURPOSE OF REVIEW

Infections are the leading cause of non-relapse mortality following chimeric antigen receptor (CAR)-T-cell therapy, with viral infections being frequent both in the early and late phases post-infusion. We review the epidemiology of viral infections and discuss critical approaches to prevention and management strategies in this setting.

RECENT FINDINGS

Herpesviruses dominate the early period. herpes simplex virus and varicella zoster virus infections are rare due to widespread antiviral prophylaxis, but cytomegalovirus (CMV) reactivation is increasingly observed, particularly in high-risk groups including B cell maturation antigen (BCMA)-CAR-T-cell therapy recipients and patients receiving corticosteroids. While CMV end-organ disease is rare, CMV is associated with increased mortality, emphasizing the need to evaluate the broader impact of CMV on long-term hematological, infection, and survival outcomes. Human herpesvirus-6 (HHV-6) has also emerged as a concern, with its diagnosis complicated by overlapping symptoms with neurotoxicity, underscoring the importance of considering viral encephalitis in differential diagnoses. Respiratory viruses are the most common late infections with a higher incidence after BCMA CAR-T-cell therapy. Vaccination remains a critical preventive measure against respiratory viruses but may be less immunogenic following CAR-T-cell therapy. The optimal timing, type of vaccine, and dosing schedule require further investigation.

SUMMARY

A better understanding of viral epidemiology and preventive trials are needed to improve infection prevention practices and outcomes following CAR-T-cell therapies.

Optimizing the post-CAR T monitoring period in recipients of axicabtagene ciloleucel, tisagenlecleucel, and lisocabtagene maraleucel

ABSTRACT

CD19-directed chimeric antigen receptor T-cell (CAR T) therapies, including axicabtagene ciloleucel (axi-cel), tisagenlecleucel (tisa-cel), and lisocabtagene maraleucel (liso-cel), have transformed the treatment landscape for B-cell non-Hodgkin lymphoma, showcasing significant efficacy but also highlighting toxicity risks such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). The US Food and Drug Administration has mandated patients remain close to the treatment center for 4 weeks as part of a Risk Evaluation and Mitigation Strategy to monitor and manage these toxicities, which, although cautious, may add to cost of care, be burdensome for patients and their families, and present challenges related to patient access and socioeconomic disparities. This retrospective study across 9 centers involving 475 patients infused with axi-cel, tisa-cel, and liso-cel from 2018 to 2023 aimed to assess CRS and ICANS onset and duration, as well as causes of nonrelapse mortality (NRM) in real-world CAR T recipients. Although differences were noted in the incidence and duration of CRS and ICANS between CAR T products, new-onset CRS and ICANS are exceedingly rare after 2 weeks after infusion (0% and 0.7% of patients, respectively). No new cases of CRS occurred after 2 weeks and a single case of new-onset ICANS occurred in the third week after infusion. NRM is driven by ICANS in the early follow-up period (1.1% until day 28) and then by infection through 3 months after infusion (1.2%). This study provides valuable insights into optimizing CAR T therapy monitoring, and our findings may provide a framework to reduce physical and financial constraints for patients.

Best Practice Considerations by The American Society of Transplant and Cellular Therapy: Infection Prevention and Management After Chimeric Antigen Receptor T Cell Therapy for Hematological Malignancies

Chimeric antigen receptor (CAR) T-cell therapy is rapidly advancing, offering promising treatments for patients with hematological malignancy. However, associated infectious complications remain a significant concern because of their contribution to patient morbidity and non-relapse mortality. Recent epidemiological insights shed light on risk factors for infections after CAR T-cell therapy. However, the available evidence is predominantly retrospective, highlighting a need for further prospective studies. Institutions are challenged with managing infections after CAR T-cell therapy but variations in the approaches taken underscore the importance of standardizing infection prevention and management protocols across different healthcare settings. Therefore, the Infectious Diseases Special Interest Group of the American Society of Transplantation and Cellular Therapy assembled an expert panel to develop best practice considerations. The aim was to guide healthcare professionals in optimizing infection prevention and management for CAR T-cell therapy recipients and advocates for early consultation of Infectious Diseases during treatment planning phases given the complexities involved. By synthesizing current evidence and expert opinion these best practice considerations provide the basis for understanding infection risk after CAR T-cell therapies and propose risk-mitigating strategies in children, adolescents, and adults. Continued research and collaboration will be essential to refining and effectively implementing these recommendations.

Rapid identification of early infections in febrile patients after CD19 target CAR-T cell therapy for B-cell malignancies

BACKGROUND

CD19-targeted chimeric antigen receptor T (CAR-T) cell therapy stands out as a revolutionary intervention, exhibiting remarkable remission rates in patients with refractory/relapsed (R/R) B-cell malignancies. However, the potential side effects of therapy, particularly cytokine release syndrome (CRS) and infections, pose significant challenges due to their overlapping clinical features. Promptly distinguishing between CRS and infection post CD19 target CAR-T cell infusion (CTI) remains a clinical dilemma. Our study aimed to analyze the incidence of infections and identify key indicators for early infection detection in febrile patients within 30 days post-CTI for B-cell malignancies.

METHODS

In this retrospective cohort study, a cohort of 104 consecutive patients with R/R B-cell malignancies who underwent CAR-T therapy was reviewed. Clinical data including age, gender, CRS, ICANS, treatment history, infection incidence, and treatment responses were collected. Serum biomarkers procalcitonin (PCT), interleukin-6 (IL-6), and C-reactive protein (CRP) levels were analyzed using chemiluminescent assays. Statistical analyses employed Pearson's Chi-square test, t-test, Mann-Whitney U-test, Kaplan-Meier survival analysis, Cox proportional hazards regression model, Spearman rank correlation, and receiver operating characteristic (ROC) curve analysis to evaluate diagnostic accuracy and develop predictive models through multivariate logistic regression.

RESULTS

In this study, 38 patients (36.5%) experienced infections (30 bacterial, 5 fungal, and 3 viral) within the first 30 days of CAR T-cell infusion. In general, bacterial, fungal, and viral infections were detected at a median of 7, 8, and 9 days, respectively, after CAR T-cell infusion. Prior allogeneic hematopoietic cell transplantation (HCT) was an independent risk factor for infection (Hazard Ratio [HR]: 4.432 [1.262-15.565], P = 0.020). Furthermore, CRS was an independent risk factor for both infection ((HR: 2.903 [1.577-5.345], P < 0.001) and severe infection (9.040 [2.256-36.232], P < 0.001). Serum PCT, IL-6, and CRP were valuable in early infection prediction post-CAR-T therapy, particularly PCT with the highest area under the ROC curve (AUC) of 0.897. A diagnostic model incorporating PCT and CRP demonstrated an AUC of 0.903 with sensitivity and specificity above 83%. For severe infections, a model including CRS severity and PCT showed an exceptional AUC of 0.991 with perfect sensitivity and high specificity. Based on the aforementioned analysis, we proposed a workflow for the rapid identification of early infection during CAR-T cell therapy.

CONCLUSIONS

CRS and prior allogeneic HCT are independent infection risk factors post-CTI in febrile B-cell malignancy patients. Our identification of novel models using PCT and CRP for predicting infection, and PCT and CRS for predicting severe infection, offers potential to guide therapeutic decisions and enhance the efficacy of CAR-T cell therapy in the future.

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.

Managing Infection Complications in the Setting of Chimeric Antigen Receptor T cell (CAR-T) Therapy

Chimeric antigen receptor T-cell (CAR T-cell) therapy has changed the paradigm of management of non-Hodgkin's lymphoma (NHL) and Multiple Myeloma. Infection complications have emerged as a concern that can arise in the setting of therapy and lead to morbidity and mortality. In this review, we classified infection complications into three categories, pre-infusion phase from the time pre- lymphodepletion (LD) up to day zero, early phase from day of infusion to day 30 post-infusion, and late phase after day 30 onwards. Infections arising in the pre-infusion phase are closely related to previous chemotherapy and bridging therapy. Infections arising in the early phase are more likely related to LD chemo and the expected brief period of grade 3-4 neutropenia. Infections arising in the late phase are particularly worrisome because they are associated with adverse risk features including prolonged neutropenia, dysregulation of humoral and adaptive immunity with lymphopenia, hypogammaglobinemia, and B cell aplasia. Bacterial, respiratory and other viral infections, protozoal and fungal infections can occur during this time . We recommend enhanced supportive care including prompt recognition and treatment of neutropenia with growth factor support, surveillance testing for specific viruses in the appropriate instance, management of hypogammaglobulinemia with repletion as appropriate and extended antimicrobial prophylaxis in those at higher risk (e.g. high dose steroid use and prolonged cytopenia). Finally, we recommend re-immunizing patients post CAR-T based on CDC and transplant guidelines.

Consensus position statement on advancing the standardised reporting of infection events in immunocompromised patients

Patients can be immunocompromised from a diverse range of disease and treatment factors, including malignancies, autoimmune disorders and their treatments, and organ and stem-cell transplantation. Infections are a leading cause of morbidity and mortality in immunocompromised patients, and the disease treatment landscape is continually evolving. Despite being a critical but preventable and curable adverse event, the reporting of infection events in randomised trials lacks sufficient detail while inconsistency of categorisation and definition of infections in observational and registry studies limits comparability and future pooling of data. A core reporting dataset consisting of category, site, severity, organism, and endpoints was developed as a minimum standard for reporting of infection events in immunocompromised patients across study types. Further additional information is recommended depending on study type. The standardised reporting of infectious events and attributable complications in immunocompromised patients will improve diagnostic, treatment, and prevention approaches and facilitate future research in this patient group.

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.