Acute hemolytic anemia after hematopoietic stem cell transplantation: An unusual invader.

69-year-old man with a history of diffuse large B-cell lymphoma (DLBCL) presented with severe acute hemolytic anemia 27 months after an autologous hematopoietic stem cell transplantation. Bone marrow aspirate revealed intracellular micro-organisms (arrows) located within the cytoplasm of red blood cells confirming the diagnosis of severe babesiosis.

Angioimmunoblastic T-cell lymphoma presenting with severe plasmacytosis mimicking plasma cell leukemia.

Peripheral blood smear (A) demonstrates increased numbers of plasma cells (representative cells indicated by arrows), (B) demonstrates polytypic nature of plasma cells.

Efficacy and Toxicity of CD19 Chimeric Antigen Receptor T Cell Therapy for Lymphoma in Solid Organ Transplant Recipients: A Systematic Review and Meta-Analysis.

The safety and efficacy of chimeric antigen receptor (CAR) T cell therapy in solid organ transplant recipients is poorly understood, given the paucity of available data in this patient population. There is a theoretical risk of compromising transplanted organ function with CAR T cell therapy; conversely, organ transplantation-related immunosuppression can alter the function of CAR T cells. Given the prevalence of post-transplantation lymphoproliferative disease, which often can be difficult to treat with conventional chemoimmunotherapy, understanding the risks and benefits of delivering lymphoma-directed CAR T cell therapy in solid organ transplant recipients is of utmost importance. We sought to determine the efficacy of CAR T cell therapy in solid organ transplant recipients as well as the associated adverse effects, including cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and compromised solid organ transplant function. We conducted a systematic review and meta-analysis of adult recipients of solid organ transplant who received CAR T cell therapy for non-Hodgkin lymphoma. Primary outcomes included efficacy, defined as overall response (OR), complete response (CR), progression-free survival, and overall survival, as well as rates of CRS and ICANS. Secondary outcomes included rates of transplanted organ loss, compromised organ function, and alterations to immunosuppressant regimens. After a systematic literature review and 2-reviewer screening process, we identified 10 studies suitable for descriptive analysis and 4 studies suitable for meta-analysis. Among all patients, 69% (24 of 35) achieved a response to CAR T cell therapy, and 52% (18 of 35) achieved a CR. CRS of any grade occurred in 83% (29 of 35), and CRS grade ≥3 occurred in 9% (3 of 35). Sixty percent of the patients (21 of 35) developed ICANS, and 34% (12 of 35) developed ICANS grade ≥3. The incidence of any grade 5 toxicity among all patients was 11% (4 of 35). Fourteen percent of the patients (5 of 35) experienced loss of the transplanted organ. Immunosuppressant therapy was held in 22 patients but eventually restarted in 68% of them (15 of 22). Among the studies included in the meta-analysis, the pooled OR rate was 70% (95% confidence interval [CI], 29.2% to 100%; I2 = 71%) and the pooled CR rate was 46% (95% CI, 25.4% to 67.8%; I2 = 29%). The rates of any grade CRS and grade ≥3 CRS were 88% (95% CI, 69% to 99%; I2 = 0%) and 5% (95% CI, 0% to 21%; I2 = 0%), respectively. The rates of any grade ICANS and ICANS grade ≥3 were 54% (95% CI, 9% to 96%; I2 = 68%) and 40% (95% CI, 3% to 85%; I2 = 63%), respectively. The efficacy of CAR T cell therapy in solid organ transplant recipients is comparable to that in the general population as reported in prior investigational studies, with an acceptable toxicity profile in terms of CRS, ICANS, and transplanted organ compromise. Further studies are needed to determine long-term effects on organ function, sustained response rates, and best practices peri-CAR T infusion period in this patient population.

Safety and Toxicity Profiles of CAR T Cell Therapy in Non-Hodgkin Lymphoma: A Systematic Review and Meta-Analysis.

BACKGROUND: The application of CD19-directed chimeric antigen receptor T (CAR T) cell therapy has improved outcomes for thousands of patients with non-Hodgkin B cell lymphoma (NHL). The toxicities associated with various CAR T cell products, however, can be severe and difficult to anticipate. METHODS: In this systematic review and meta-analysis, we set out to determine whether there are measurable differences in common toxicities, including cytokine release syndrome (CRS), immune effector cell associated neurotoxicity syndrome (ICANS), cytopenias, and infections, between CAR T products that are commercially available for the treatment of NHL. RESULTS: After a stringent study selection process, we used a cohort of 1364 patients enrolled in 15 prospective clinical trials investigating the use of axicabtagene ciloleucel (axi-cel), lisocabtagene maraleucel (liso-cel), and tisagenlecleucel (tisa-cel). We found that the rates of CRS and ICANS were significantly higher with axi-cel as compared to both liso-cel and tisa-cel. Conversely, we demonstrated that rates of all-grade and severe neutropenia were significantly greater with liso-cel. Febrile neutropenia and all-grade infection rates did not differ significantly between products though rates of severe infection were increased with axi-cel. CONCLUSIONS: Overall, this study serves as the first to delineate toxicity profiles associated with various available CAR T products. By better understanding associated toxicities, it may become possible to tailor therapies towards individual patients and anticipate the development of toxicities at earlier stages.

Second Primary Malignancies after CAR T-Cell Therapy: A Systematic Review and Meta-analysis of 5,517 Lymphoma and Myeloma Patients.

PURPOSE: Chimeric antigen receptor (CAR) T-cell therapy is a potent immunotherapy for hematologic malignancies, but patients can develop long-term adverse events, including second primary malignancies (SPM) that impact morbidity and mortality. To delineate the frequency and subtypes of SPMs following CAR-T in lymphoma and myeloma, we performed a systematic review and meta-analysis. EXPERIMENTAL DESIGN: A literature search was conducted in the MEDLINE, Embase, and Cochrane CENTRAL databases. Following the extraction of SPM cases and assignment of malignant origin, we analyzed SPM point estimates using random effects models. RESULTS: We identified 326 SPMs across 5,517 patients from 18 clinical trials and 7 real-world studies. With a median follow-up of 21.7 months, the overall SPM point estimate was 6.0% (95% confidence interval, 4.8%-7.4%). SPM estimates were associated with treatment setting (clinical trials > real-world studies), duration of follow-up, and number of prior treatment lines, which were each confirmed as independent study-level risk factors of SPM in a meta-regression model. A subgroup meta-analysis of the four trials that randomized CAR-T versus standard-of-care revealed a similar risk of SPM with either treatment strategy (P = 0.92). In a distribution analysis of SPM subtypes, hematologic malignancies were the most common entity (37%), followed by solid tumors (27%) and non-melanoma skin cancers (16%). T-cell malignancies represented a small minority of events (1.5%). We noted disease- and product-specific variations in SPM distribution. CONCLUSIONS: These data raise awareness of SPM as a clinically relevant long-term adverse event in patients receiving CAR T-cell therapy. However, our findings do not indicate that SPM frequency is higher with CAR-T versus previous standard-of-care strategies.

Screening Chest CT Prior to Allogenic Hematopoietic Stem Cell Transplantation.

Pulmonary complications constitute a major cause of morbidity and mortality in the post-allogenic hematopoietic stem cell transplantation (alloHSCT) period. Although chest X-ray (CXR) is customarily used for screening, we have used chest computed tomography (CT) scans. To characterize the prevalence of abnormalities and explore their impact on alloHSCT eligibility and outcomes post-transplantation, we conducted a retrospective analysis using real-world data collected at our center for adult patients who were evaluated for alloHSCT between January 2013 and December 2020 and identified 511 eligible patients. The most common primary disease was acute myeloid leukemia, in 49% of patients, followed by myelodysplastic syndrome (23%), lymphoma (11%), and acute lymphocytic leukemia (10%). Abnormal screening chest CT results were found in 199 patients (39%). The most frequent detected abnormality was pulmonary nodule, in 78 patients (35%), followed by consolidation in 42 (19%), ground-glass opacification in 33 (15%), bronchitis and bronchiolitis in 25 (11%), pleural effusions in 14 (6%), and new primary cancer in 7 (2%). CXR detected abnormalities in only approximately one-half of the patients (48%) with an abnormal chest CT scan. Among the 199 patients with an abnormal chest CT scan, 98 (49%) underwent further assessment and/or intervention before transplantation. The most common workup was pulmonary consultation in 32%, followed by infectious diseases consultation in 24%. Lung biopsy was obtained in 20%, and antimicrobial therapy was initiated after confirming an infection diagnosis in 20%. Patients with an abnormal chest CT scan demonstrated worse overall survival (P = .032), nonrelapse mortality (P = .015), and pulmonary-related mortality (P < .001) compared to those with a normal chest CT scan. Our study suggests that pretransplantation screening chest CT is beneficial in uncovering invasive infections and underlying malignancies and allows for appropriate interventions before alloHSCT to prevent potentially serious post-transplantation complications without causing a delay in alloHSCT. Nevertheless, abnormal CT findings prior to transplantation may be associated with overall worse prognosis.

Radiation therapy improves CAR T cell activity in acute lymphoblastic leukemia.

Autologous T cells engineered to express a chimeric antigen receptor (CAR) specific for CD19 are approved for the treatment of various CD19+ hematological malignancies. While CAR T cells induce objective responses in a majority of patients, relapse frequently occurs upon loss of CD19 expression by neoplastic cells. Radiation therapy (RT) has been successfully employed to circumvent the loss of CAR targets in preclinical models of pancreatic cancer. At least in part, this reflects the ability of RT to elicit death receptor (DR) expression by malignant cells, enabling at least some degree of CAR-independent tumor killing. In a human model of CD19+ acute lymphoblastic leukemia (ALL), we also observed DR upregulation by RT, both in vitro and in vivo. Moreover, low-dose total body irradiation (LD-TBI) delivered to ALL-bearing mice prior to CAR T cell infusion considerably extended the overall survival benefit afforded by CAR T cells alone. Such an improved therapeutic activity was accompanied by a superior expansion of CAR T cells in vivo. These data encourage the initiation of clinical trials combining LD-TBI with CAR T cells in patients with hematological malignancies.

Methods to monitor in vivo expansion and efficacy of CAR-T cells in preclinical models.

The landscape of CAR-T detection and monitoring techniques in preclinical models is rapidly evolving. In this chapter, we will discuss the most widely used methods. The chapter begins with elaborating on the rational of establishing and optimizing protocols for CAR-T monitoring and explaining why this is a crucial step in CAR-T early development. This conceptual basis will be followed by detailed protocols: polymerase chain reaction (PCR), flow cytometry and bioluminescence imaging (BLI). These in vivo methods can be implemented in labs with interest in CAR-T pre-clinical research. It will provide important tools in the process of CAR-T development and offer better understanding of their efficacy, cytotoxicity and survival.

COVID-19 infection triggering Thrombotic Thrombocytopenic Purpura.

We present a 62-year-old gentleman with history of Crohn's disease, G6PD deficiency, who presented with immune-mediated thrombotic thrombocytopenia purpura (iTTP) one week after the diagnosis of COVID-19 infection. He was admitted with worsening dyspnea, acute renal failure, and profound thrombocytopenia with marked schistocytosis on peripheral smear. ADAMTS13 level was severely deficient. He was treated with oral prednisone, plasma exchange and rituximab with complete clinical resolution. Given the temporal association of this recurrent episode of iTTP with COVID-19 infection and no other discernible cause, COVID-19 infection was the most likely trigger.

High-dose interleukin-2 therapy related adverse events and implications on imaging.

High-dose interleukin-2 (HDIL-2) therapy was initially approved by the U.S. Food and Drug Administration for metastatic renal cell carcinoma (mRCC) and metastatic melanoma. IL-2 is able to promote CD8+ T cell and natural killer (NK) cell cytotoxicity to increase tumoricidal activity of the innate immune system. HDIL-2 therapy is associated with a wide spectrum of immune-related adverse events (irAEs) that can be radiologically identified. HDIL-2 toxicity can manifest in multiple organ systems, most significantly leading to cardiovascular, abdominal, endocrine, and neurological adverse events. The collective impact of the irAEs and the rise of immune checkpoint inhibitors (ICIs) and tyrosine kinase inhibitors led to the demise of HDIL-2 as a primary therapy for mRCC and metastatic melanoma. However, with innovation in ICIs and the creation of mutant IL-2 conjugates, there has been a drive for combination therapy. Knowledge of the HDIL-2 therapy and HDIL-2 related adverse events with radiology relevance is critical in diagnostic image interpretation.