Procalcitonin as a biomarker for predicting bacterial infection in chimeric antigen receptor T‐cell therapy recipients

Abstract Background It is unknown whether serum procalcitonin (PCT) concentration monitoring can differentiate between bacterial infection or cytokine release syndrome (CRS) when chimeric antigen receptor T‐cell (CAR‐T) recipients present with a constellation of signs and symptoms that may represent both complications. Objective The objective of the study was to assess the utility of serum PCT concentrations as a biomarker of bacterial infection in CAR‐T recipients. Study design This single‐center, retrospective, medical record review evaluated patients prescribed CAR‐T therapy until death or 30 days after infusion. Logistic regression modeling determined the association between elevated serum PCT concentrations within 48 h of fever onset and microbiologically confirmed infection. Secondary outcomes included clinically suspected infection, CAR‐T toxicity rates, and broad‐spectrum antibiotic usage. Predictive performance of PCT was assessed by area under the receiver operating characteristic curve (AUC). Results The 98 included patients were a median age of 63 (IQR: 55–69) years old, 47 (48%) were male, and 87 (89%) were Caucasian. Baseline demographics and clinical characteristics were similar between patients with and without a bacterial infection. Serum PCT >0.4 ng/mL within 48 h of fever was significantly associated with a microbiologically confirmed bacterial infection (OR: 2.75 [95% CI: 1.02–7.39], p = 0.045). Median PCT values in patients with and without confirmed infections were 0.40 ng/mL (IQR: 0.26, 0.74) and 0.26 ng/mL (IQR: 0.13, 0.47), respectively. The AUC for PCT to predict bacterial infection was 0.62 (95% CI 0.48–0.76). All patients experienced CRS of some grade, with no difference in CRS severity based on elevated PCT. Broad‐spectrum antibiotics were used for a median of 45% and 23% of days in those with and without confirmed infection, respectively (p = 0.075). Conclusion Elevated serum PCT concentrations above 0.4 ng/mL at time of first fever after CAR‐T infusion was significantly associated with confirmed bacterial infection. Furthermore, rigorous, prospective studies should validate our findings and evaluate serial PCT measurements to optimize antimicrobial use after CAR‐T therapy

International Assessment of Event-Free Survival at 24 Months and Subsequent Survival in Peripheral T-Cell Lymphoma

Purpose Peripheral T-cell lymphomas (PTCLs) have aggressive clinical behavior. We have previously shown that event-free survival (EFS) at 24 months (EFS24) is a clinically useful end point in diffuse large B-cell lymphoma. Here, we assess EFS24 and subsequent overall survival (OS) in large, multinational PTCL cohorts. Patients and Methods Patients with systemic PTCL newly diagnosed from 2000 to 2012 and treated with curative intent were included from the United States and Sweden (initial cohorts) and from Canada (replication cohort). EFS was defined as time from date of diagnosis to progression after primary treatment, retreatment, or death. Subsequent OS was measured after achieving EFS24 or from the time of progression if it occurred within 24 months. OS rates were compared with the age-, sex-, and country-matched general population. Results Seven hundred seventy-five patients were included in the study (the median age at diagnosis was 64 years; 63% were men). Results were similar in the initial and replication cohorts, and a combined analysis was undertaken. Sixty-four percent of patients progressed within the first 24 months and had a median OS of only 4.9 months (5-year OS, 11%). In contrast, median OS after achieving EFS24 was not reached (5-year OS, 78%), although relapses within 5 years of achieving EFS24 occurred in 23% of patients. Superior outcomes after achieving EFS24 were observed in younger patients (≤ 60 years of age: 5-year OS, 91%). Conclusion EFS24 stratifies subsequent outcome in PTCL. Patients with PTCL with primary refractory disease or early relapse have extremely poor survival. However, more than one third of patients with PTCL remain in remission 2 years after diagnosis with encouraging subsequent OS, especially in younger patients. These marked differences in outcome suggest that EFS24 has utility for patient counseling, study design, and risk stratification in PTCL

Metabolic PET/CT analysis of aggressive Non-Hodgkin lymphoma prior to Axicabtagene Ciloleucel CAR-T infusion: predictors of progressive disease, survival, and toxicity

Abstract PET/CT is used to evaluate relapsed/refractory non-Hodgkin lymphoma (NHL) prior to chimeric antigen receptor T-cell (CAR-T) infusion at two time points: pre-leukapheresis (pre-leuk) and pre-lymphodepletion chemotherapy (pre-LD). We hypothesized that changes in PET/CT between these time points predict outcomes after CAR-T. Metabolic tumor volume (MTV), total lesion glycolysis (TLG), and other metrics were calculated from pre-leuk and pre-LD PET/CT scans in patients with NHL who received axicabtagene ciloleucel, and assessed for association with outcomes. Sixty-nine patients were analyzed. While single time point PET/CT characteristics were not associated with risk of PD or death, increases from pre-leuk to pre-LD in parenchymal MTV, nodal MTV, TLG of the largest lesion, and total number of lesions were associated with increased risk of death (p < 0.05 for all). LASSO analysis identified increasing extranodal MTV and increasing TLG of the largest lesion as strong predictors of death (AUC 0.74). Greater pre-LD total MTV was associated with higher risk of grade 3+ immune effector cell-associated neurotoxicity syndrome (ICANS) (p = 0.042). Increasing metabolic disease burden during CAR-T manufacturing is associated with increased risk of progression and death. A two variable risk score stratifies prognosis prior to CAR-T infusion and may inform risk-adapted strategies

Clinicopathologic Characteristics, Treatment, and Outcomes of Post-transplant Lymphoproliferative Disorders: A Single-institution Experience Using 2017 WHO Diagnostic Criteria

The World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues (WHO 2017) included updated criteria for diagnosis and classification of post-transplant lymphoproliferative disorders (PTLDs). This study evaluated the clinicopathologic spectrum using WHO 2017 criteria and adult PTLD patients’ outcomes over 30 years between 1987 and 2017 at Mayo Clinic (Rochester, MN). Patients were retrospectively reviewed for clinical features, outcomes, and diagnostic pathology material and classified based on WHO 2017 criteria. A total of 227 patients were diagnosed with PTLD, with a median time from transplant to PTLD of 45 months. PTLD occurred >1 year after transplant in 149 (66%) patients. Monomorphic PTLD was the most common subtype (173, 76%), with diffuse large B cell lymphoma as the commonest morphology (n = 137). Epstein-Barr virus was positive in 61% of total cases and 90% of PTLD that developed within 1 year from transplant. The median event-free survival (EFS) and overall survival for the entire cohort were 21 months (95% confidence interval [CI]: 9–35) and 82 months (95% CI: 39–115), respectively. The EFS or overall survival was not impacted by Epstein-Barr virus status but differed based on WHO subtypes and year of diagnosis. Management changed over time with increased use of rituximab or chemotherapy + immunosuppression reduction as initial therapy. When compared to the matched general population and de novo diffuse large B cell lymphoma, patients not achieving EFS 24 status (no progression/treatment or death within 24 mo of diagnosis) had a worse standardized mortality ratio 16.75 (95% CI: 13.91–20) versus SMR 1.72 (95% CI: 1.26–2.28) in those who achieved EFS24. Cause of death was mostly attributed to non-lymphoma–related causes in those achieving EFS 24