Pre-and Post-Transplant Serum Lactate Dehydrogenase Levels as a Predictive Marker for Patient Survival and Engraftment in Allogeneic Hematopoietic Stem Cell Transplant Recipients

The Relationship Between Serum Lactate Dehydrogenase Enzyme Levels and Myeloid Engraftment in Hematopoietic Stem Cell Transplantation

BACKGROUND

The early detection of myeloid engraftment after hematopoietic stem cell transplantation (HSCT) is of clinical importance for clinicians. In this study, we evaluated whether serum lactic dehydrogenase enzyme levels are significant predictors in the early detection of successful myeloid engraftment after HSCT.

METHODS

The study included 74 patients, all of whom underwent HSCT between February 2014 and June 2020. Serum lactic dehydrogenase (LDH) enzyme and complete blood parameters were evaluated at the start of the preparation regimen, on the day of product infusion, 5 days before myeloid engraftment, on the day of myeloid engraftment, and 5 days after engraftment.

RESULTS

LDH enzyme levels increased statistically significantly 5 days before myeloid engraftment (P = .005), and this increase was observed to continue on the day of engraftment, and 5 days after engraftment, but the differences between the measurements 5 days before engraftment and those on the day of engraftment, and 5 days after engraftment were statistically insignificant (P > .05). There was no significant difference in LDH enzyme levels between the measurements made at the beginning of the preparation regimen and those made on the infusion day (P > .05).

CONCLUSIONS

Increased LDH enzyme levels after HSCT are associated with increased myelopoiesis in the bone marrow. The monitoring of serum LDH levels and the detection of the onset of increase in enzyme levels in patients undergoing HSCT may be predictors of engraftment.

Endothelial Activation and Stress Index in adults undergoing allogeneic hematopoietic cell transplantation with post-transplant cyclophosphamide-based prophylaxis

BACKGROUND AIMS

Post-transplant cyclophosphamide (PTCY)-based prophylaxis is becoming widespread for allogeneic hematopoietic cell transplantation (allo-HCT) performed independently of the selected donor source. In parallel, use of the Endothelial Activation and Stress Index (EASIX)-considered a surrogate parameter of endothelial activation-for predicting patient outcomes and clinical complications is gaining popularity in the allo-HCT setting.

METHODS

We first investigated whether the dynamics of EASIX after allo-HCT differ between patients receiving PTCY and patients receiving other prophylaxis. We then investigated whether the predictive capacity of EASIX persists in PTCY-based allo-HCT. A total of 328 patients transplanted between 2014 and 2020 were included, and 201 (61.2%) received PTCY.

RESULTS

EASIX trends differed significantly between the groups. Compared with patients receiving other prophylaxis, patients receiving PTCY had lower EASIX on day 0 and higher values between day 7 and day 100. In patients receiving PTCY, higher EASIX correlated significantly with higher non-relapse mortality (NRM) and lower overall survival (OS) when measured before and during the first 180 days after allo-HCT. In addition, higher EASIX scores measured at specific time points were predictors of veno-occlusive disease (VOD), transplant-associated thrombotic microangiopathy (TA-TMA) and grade 2-4 acute graft-versus-host disease (aGVHD) risk.

CONCLUSIONS

This study demonstrates how EASIX trends vary during the first 180 days after allo-HCT in patients receiving PTCY and those not receiving PTCY and validates the utility of this index for predicting NRM, OS and risk of VOD, TA-TMA and grade 2-4 aGVHD in patients receiving PTCY.

Lactylation: a Passing Fad or the Future of Posttranslational Modification

Lactate is a glycolytic product and a significant energy source. Moreover, it regulates gene transcription via lactylation of histones and non-histone proteins, i.e., a novel posttranslational modification. This review summarizes recent advances related to lactylation in lactate metabolism and diseases. Notably, lactylation plays a vital role in cancer, inflammation, and regeneration; however, the specific mechanism remains unclear. Histone lactylation regulates oncogenic processes by targeting gene transcription and inflammation via macrophage activation. Eventually, we identified research gaps and recommended several primary directions for further studies.