Patterns of leukocyte recovery predict infectious complications after CD19 CAR-T cell therapy in a real-world setting.

BACKGROUND: Adoptive immunotherapy using CD19-targeted Chimeric antigen receptor T cells (CAR-T) has revolutionized the treatment of relapsed/refractory diffuse large B-cell lymphoma (DLBCL). Data is limited on the propensity of infections and lymphohematopoietic reconstitution after Day 30 (D30) following CAR-T cell therapy. In this study, we evaluated the prevalence and nature of infectious complications in an expanded cohort of DLBCL patients treated with CD19 CAR-T therapy and its association with the dynamics of leukocyte subpopulation reconstitution post-CAR-T cell therapy. METHODS: We conducted a retrospective study including 19 patients who received axicabtagene ciloleucel and investigated associations between cytopenia and infectious complications after D30. RESULTS: Nineteen patients were included, consisting of 42% Hispanic, 32% Caucasian, 21% African-American, and 5% Asian subjects. Post-D30 of CAR-T infusion, 47% patients (n=9) developed an infection and 53% (n=10) remained infection-free. The most common infection type observed was viral (7 patients) followed by bacterial (5 patients) and fungal (3 patients). Of 25 total infectious events, 56% were grade 1 or 2 and 44% were grade 3 with 10 being viral in etiology. To determine the kinetics of lymphohematopoietic reconstitution and its association with infection risk, we evaluated the relationship between cytopenias and rates of infection after D30. Notably, compared to non-infection group, infection group had a higher median absolute lymphocyte count (ALC) (1,000/µL vs. 600/µL, P<0.05), a lower median absolute neutrophil count (ANC)/ALC ratio (1.6 vs. 3.1, P<0.05) and a lower median AMC/ALC at D30 (0.37 vs. 1.67, P<0.05). In addition, we observed that only 22% of patients had recovered ANC >1,500/µL in the infection group as opposed to 70% in the non-infection group at D90 (P<0.05). Fifty-eight percent of the patients (11/19) with relapsed refractory DLBCL achieved a complete response with a median follow-up of 233 days (7.7 months). CONCLUSIONS: Although CAR-T cell therapy is highly effective, infectious complications remain an important cause of morbidity and mortality. Low ANC/ALC and AMC/ALC ratios at D30 are potential novel predictors of infection and can be considered in future prophylactic strategies.

Group O plasma as a media supplement for CAR-T cells and other adoptive T-cell therapies.

BACKGROUND: Most chimeric antigen receptor T (CAR-T) cells and other adoptive T-cell therapies (ACTs) are currently manufactured by ex vivo expansion of patient lymphocytes in culture media supplemented with human plasma from group AB donors. As lymphocytes do not express A or B antigens, the isoagglutinins of non-AB plasmas are unlikely to cause deleterious effects on lymphocytes in culture. STUDY DESIGN AND METHODS: Seeding cultures with peripheral blood mononuclear cell (PBMNC) concentrates from group A1 donors and using a CAR-T culture protocol, parallel cultures were performed, each with unique donor plasmas as media supplements (including group O plasmas with high-titer anti-A and group AB plasmas as control). An additional variable, a 3% group A1 red blood cell (RBC) spike, was added to simulate a RBC-contaminated PBMNC collection. Cultures were monitored by cell count, viability, flow cytometric phenotype, gene expression analysis, and supernatant chemokine analysis. RESULTS: There was no difference in lymphocyte expansion or phenotype when cultured with AB plasma or O plasma with high-titer anti-A. Compared to controls, the presence of contaminating RBCs in lymphocyte culture led to poor lymphocyte expansion and a less desirable phenotype-irrespective of the isoagglutinin titer of the plasma supplement used. CONCLUSIONS: This study suggests that ABO incompatible plasma may be used as a media supplement when culturing cell types that do not express ABO antigens-such as lymphocytes for CAR-T or other ACT. The presence of contaminating RBCs in culture was disadvantageous independent of isoagglutinin titer.

Axicabtagene ciloleucel CD19 CAR-T cell therapy results in high rates of systemic and neurologic remissions in ten patients with refractory large B cell lymphoma including two with HIV and viral hepatitis.

Axicabtagene ciloleucel (Axi-cel) is a CD-19 Chimeric Antigen Receptor T cell therapy approved for the treatment of relapsed/refractory diffuse large B cell lymphoma. We treated ten patients with DLBCL post-FDA approval in an inner-city tertiary center in the Bronx. Eight patients (80%) had received ≥ 3 lines of therapy, six patients had received prior radiation, and seven had recurrent disease after prior autologous hematopoietic stem cell transplant (AHCT). Our cohort included one patient with HIV, two patients with hepatitis B, and two patients with CNS involvement of lymphoma. Axi-cel treatment led to significant responses with 8/10 patients achieving a complete remission at 3 months, including both patients with prior CNS involvement. The treatment was generally well tolerated with 20% of patients experiencing grade ≥ 2 CRS. One patient each with HIV and hepatitis B responded without significant toxicities. In conclusion, Axi-cel led to significant efficacy with manageable toxicity in DLBCL in a real-world setting.

How we evaluate red blood cell compatibility and transfusion support for patients with sickle cell disease undergoing hematopoietic progenitor cell transplantation.

Multiple hematopoietic progenitor cell (HPC) transplantation options for patients with sickle cell disease (SCD) are currently under investigation. Patients with SCD have a high rate of alloimmunization to red blood cell antigens, often complicating transfusion support. Transfusion reactions, including acute and delayed hemolytic reactions, have been observed despite immunosuppressive regimens. Allogeneic donor transplants have been shown to carry a risk of prolonged reticulocytopenia and acute hemolysis with severe anemia in nonmyeloablative regimens. We discuss our experience providing transfusion support to patients with SCD undergoing HPC transplantation, propose an outline for a complete pretransplantation evaluation, and discuss donor/recipient compatibility issues and their implications.

Chagas heart disease: report on recent developments.

Chagas disease, caused by the parasite Trypanosoma cruzi, is an important cause of cardiac disease in endemic areas of Latin America. It is now being diagnosed in nonendemic areas because of immigration. Typical cardiac manifestations of Chagas disease include dilated cardiomyopathy, congestive heart failure, arrhythmias, cardioembolism, and stroke. Clinical and laboratory-based research to define the pathology resulting from T. cruzi infection has shed light on many of the cellular and molecular mechanisms leading to these manifestations. Antiparasitic treatment may not be appropriate for patients with advanced cardiac disease. Clinical management of Chagas heart disease is similar to that used for cardiomyopathies caused by other processes. Cardiac transplantation has been successfully performed in a small number of patients with Chagas heart disease.

Confirmation of Choclo virus as the cause of hantavirus cardiopulmonary syndrome and high serum antibody prevalence in Panama.

Choclo virus (CHOV) was described in sigmodontine rodents, Oligoryzomys fulvescens, and humans during an outbreak of hantavirus cardiopulmonary syndrome (HCPS) in 1999-2000 in western Panama. Although HCPS is rare, hantavirus-specific serum antibody prevalence among the general population is high suggesting that CHOV may cause many mild or asymptomatic infections. The goals of this study were to confirm the role of CHOV in HCPS and in the frequently detected serum antibody and to establish the phylogenetic relationship with other New World hantaviruses. CHOV was cultured to facilitate the sequencing of the small (S) and medium (M) segments and to perform CHOV-specific serum neutralization antibody assays. Sequences of the S and M segments found a close relationship to other Oligoryzomys-borne hantaviruses in the Americas, highly conserved terminal nucleotides, and no evidence for recombination events. The maximum likelihood and maximum parsimony analyses of complete M segment nucleotide sequences indicate a close relationship to Maporal and Laguna Negra viruses, found at the base of the South American clade. In a focus neutralization assay acute and convalescent sera from six Panamanian HCPS patients neutralized CHOV in dilutions from 1:200 to 1:6,400. In a sample of antibody-positive adults without a history of HCPS, 9 of 10 sera neutralized CHOV in dilutions ranging from 1:100 to 1:6,400. Although cross-neutralization with other sympatric hantaviruses not yet associated with human disease is possible, CHOV appears to be the causal agent for most of the mild or asymptomatic hantavirus infections, as well as HCPS, in Panama.