Cytokine profiling during conditioning in haploidentical stem cell transplantation and its prognostic impact on early transplant outcomes

Pre-transplant inflammation and its associations with acute GvHD and mortality in pediatric allogeneic hematopoietic stem cell transplantation patients

In this explorative study we aimed to identify inflammatory serum proteins measured before allogeneic hematopoietic stem cell transplantation (HSCT) that are associated with acute Graft-versus-Host Disease (aGvHD) and mortality in pediatric HSCT recipients. We measured 28 inflammatory serum proteins in 384 pediatric patients (2010-2022) with malignant (30%) and non-malignant (70%) indications for allogeneic HSCT. A sample before the start of the conditioning (T1) was included, as well as a sample on the day of HSCT (T2). For patients who developed aGvHD we also included a sample at the time of diagnosis, before initiation of systemic treatment (TP-GvHD). Associations with aGvHD, steroid-refractory aGvHD, non-relapse mortality (NRM) and overall survival (OS) were analyzed using robust (cause-specific) Cox models. At T1, TNFR1, sIL-2Rα and TNFR2 were among the most strongly associated proteins for the development of aGvHD. Multiple inflammatory proteins, such as CXCL16, TNFR1 and SCF at T1 were highly associated with NRM and OS. At TP-GvHD, ST2 levels were significantly associated with the development of steroid-refractory aGvHD and NRM. This study shows that inflammatory serum protein levels before HSCT are associated with aGvHD and mortality and lays the groundwork for further validation and use in risk-adapted therapy for pediatric HSCT recipients.

Serum of interleukin-6 and procalcitonin as early diagnostic markers for the identification of poor hematopoietic reconstitution following allogeneic hematopoietic stem cell transplantation

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains a potential curative option for the treatment of various hematologic diseases. Poor hematopoietic reconstitution (PHR) is a common and serious complicating disease after allo-HSCT. The authors conducted a case-control study to determine the potential value of serum interleukin (IL)-6 and procalcitonin (PCT) levels during the peritransplantation period in predicting PHR after allo-HSCT.

METHODS

The concentrations of IL-6 and PCT were compared, and a receiver operating characteristic (ROC) curve was constructed to determine the optimal cutoff values. Sensitivity and specificity were subsequently calculated.

RESULTS

In our study, the levels of IL-6 and PCT were significantly elevated in patients with PHR compared to those in good hematopoietic restitution (GHR). The logistic regression analysis revealed that IL-6 and PCT posttransplantation were significant predictors of PHR after allo-HSCT. The calculation of the area under the curve (AUC) of IL-6 and PCT in predicting PHR was 0.805 and 0.724, respectively. The optimal cutoff values for PHR were 41.8 pg/mL and 0.404 ng/mL, with a sensitivity of 73.7% and 52.6% and a specificity of 81% and 85.7%, respectively. The AUC-ROC of IL-6 combined with PCT for predicting the PHR was 0.801, with a sensitivity of 75.4% and a specificity of 77.8%.

CONCLUSION

IL-6 and PCT can serve as potential biomarkers to predict PHR after allo-HSCT.

Batch-to-Batch Variation and Patient Heterogeneity in Thymoglobulin Binding and Specificity: One Size Does Not Fit All

Background: Thymoglobulin is used to prevent allograft rejection and is being explored at low doses as intervention immunotherapy in type 1 diabetes. Thymoglobulin consists of a diverse pool of rabbit antibodies directed against many different targets on human thymocytes that can also be expressed by other leukocytes. Since Thymoglobulin is generated by injecting rabbits with human thymocytes, this conceivably leads to differences between Thymoglobulin batches. Methods: We compared different batches for antibody composition and variation between individuals in binding to PBMC and T cell subsets, and induction of cytokines. Four different batches of Thymoglobulin were directly conjugated with Alexa-Fluor 647. Blood was collected from five healthy donors, and PBMCs were isolated and stained with Thymoglobulin followed or preceded by a panel of fluorescent antibodies to identify PBMC and T cell subsets. In addition, whole blood was incubated with unlabeled Thymoglobulin to measure cytokine induction. Results: Cluster analysis of flow cytometry data shows that Thymoglobulin bound to all PBMC subpopulations including regulatory T cells. However, Thymoglobulin binding was highly variable between donors and to a lesser extent between batches. Cytokines related to cytokine release syndrome were highly, but variably, increased by all Thymoglobulin batches, with strong differences between donors and moderate differences between batches. Discussion: The variation in Thymoglobulin binding and action between donors regarding PBMC recognition and cytokine response may underlie the different clinical responses to Thymoglobulin therapy and require personalized dose adjustment to maximize efficacy and minimize adverse side effects.

Allogeneic hematopoietic stem cell transplantation: A single-center experience, 2017 to 2021

INTRODUCTION

Hematopoietic stem cell transplantation (HSCT) remains a critical treatment for advanced or high-risk hematological malignancies, posing challenges such as finding suitable donors and managing of graft-versus-host disease (GvHD). This study estimates 3-year overall survival in patients who underwent HSCT at our referral service in the state of Minas Gerais, Brazil.

MATERIAL AND METHODS

This retrospective observational cohort study involved 41 patients who received HSCT between 2017 and 2021 at the Felício Rocho Hospital. Recipients received HSCT from either haploidentical donor (Haplo), matched unrelated donor (MUD), or HLA-matched sibling donor (MSD). The study evaluated parameters that included 3-year overall survival (OS), treatment-related mortality (TRM), GvHD incidence, post-transplant relapse rate, and engraftment. ANOVA, Kruskal-Wallis, and chi-square tests were used for statistical analysis. Survival curves were calculated using the Kaplan-Meier method and the Log-rank test compared the curves.

RESULTS

Our study found that the engraftment time differed among groups: Haplo recipients engrafted earlier within a median of 16 days (ranging between 10 and 20 days) than MSD recipients with 18 days (ranging between 11 and 28 days), and MUD recipients with 19 days (ranging between 11 and 24 days; p = 0.019). Mild acute GvHD (grade I-II) was observed in 13 patients, progressing to chronic GvHD in 5 patients. Three-year OS rates were as follows: MSD group - 67.7%, Haplo group - 42.2%, and MUD group - 44.4% (MSD vs Haplo, p = 0.039). Three-year cumulative treatment-related mortality (TRM) rates were 17.8% for MSD group, 22.9% for Haplo group, and 22.1% for MUD group (pairwise comparisons p > 0.05). Infection-related mortality was reported in eight patients, while relapse rates at 3 years were similar across MSD, Haplo, and MUD groups (p = 0.891). Donor age influenced OS rates, showing better outcomes with donors under 45 years old, and significant differences were found in pairwise comparisons (p = 0.015).

CONCLUSION

Donor type and donor age significantly impacted HSCT outcomes in our analysis, thus emphasizing the importance of rigorous donor selection in risk stratification and suggesting potential benefits for younger donors.