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.

ALK-positive histiocytosis is a rare subtype of histiocytic neoplasm first described in 2008 in three infants with multisystemic disease involving the liver and hematopoietic system. This entity has subsequently been documented in case reports and series to occupy a wider clinicopathologic spectrum with recurrent KIF5B-ALK fusions. The full clinicopathologic and molecular spectra of ALK-positive histiocytosis remain, however, poorly characterized. Here, we describe the largest study of ALK-positive histiocytosis to date, with detailed clinicopathologic data of 39 cases, including 37 cases with confirmed ALK rearrangements. The clinical spectrum comprised distinct clinical phenotypic groups: infants with multisystemic disease with liver and hematopoietic involvement, as originally described (Group 1A: 6/39), other patients with multisystemic disease (Group 1B: 10/39), and patients with single-system disease (Group 2: 23/39). Nineteen patients of the entire cohort (49%) had neurologic involvement (seven and twelve from Groups 1B and 2, respectively). Histology included classic xanthogranuloma features in almost one third of cases, whereas the majority displayed a more densely cellular, monomorphic appearance without lipidized histiocytes but sometimes more spindled or epithelioid morphology. Neoplastic histiocytes were positive for macrophage markers and often conferred strong expression of phosphorylated-ERK, confirming MAPK pathway activation. KIF5B-ALK fusions were detected in 27 patients, while CLTC-ALK, TPM3-ALK, TFG-ALK, EML4-ALK and DCTN1-ALK fusions were identified in single cases. Robust and durable responses were observed in 11/11 patients treated with ALK inhibition, ten with neurologic involvement. This study presents the existing clinicopathologic and molecular landscape of ALK-positive histiocytosis, and provides guidance for the clinical management of this emerging histiocytic entity.

However, it must be noted that the incidence of ITP is about 3.3 per 100 000 adults/year. 8 Therefore, it is also plausible that this patient's diagnosis was purely coincidental, given that the United States has administered over 12 million vaccines to date. 9 Additionally, 43 448 participants were included in the Pfizer-BioNTech trial, and no ITP was reported. 2 Moreover, considering the low complement C4 (10.9 mg/dL), mildly elevated SSA Ab (1.5), and 2 months prior, the platelet count (145 × 10 9 /L) was near the lower limit, it is difficult to exclude alternative causes, such as an underlying autoimmune condition with pre-existing ITP. In this scenario, the ITP became clinically apparent following the vaccine, though this patient never manifested symptoms suggestive of autoimmune disease. This case was reported to the FDA's Vaccine Adverse EventsReporting System (VAERS) and is valuable both for post-approval pharmacovigilance and as a foundation for clinicians to evaluate future patients with suspected ITP. Rare vaccination events are important, but do not diminish the enormous utility of vaccination and the well-documented safety profile 2 of the Pfizer-BioNTech BNT16B2b2 mRNA vaccine.

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