Early lymphocyte recovery after allogeneic hematopoietic SCT is associated with significant GVL effect in pediatric ALL but not acute myelogenous leukemia—Update study

Prognostic Role of Cell Blood Count in Chronic Myeloid Neoplasm and Acute Myeloid Leukemia and Its Possible Implications in Hematopoietic Stem Cell Transplantation

Numerous prognostic indexes have been developed in hematological diseases based on patient characteristics and genetic or molecular assessment. However, less attention was paid to more accessible parameters, such as neutrophils, lymphocytes, monocytes, and platelet counts. Although many studies have defined the role of neutrophil-to-lymphocyte or platelet-to-lymphocyte in lymphoid malignancies, few applications exist for myeloid neoplasm or hematopoietic stem cell transplantation procedures. In this review, we synthesized literature data on the prognostic value of count blood cells in myeloid malignancies and hematopoietic stem cell transplantation in the context of classical prognostic factors and clinical outcomes.

Early reconstitution of lymphocytes after allogenic hematopoietic stem cell transplantation affects chronic graft-versus-host disease

BACKGROUND

Lymphocyte reconstitution after hematopoietic stem cell transplantation (HSCT) is important for the prevention of infections, as well as for the reduction of recurrence, by its graft versus tumor effect. However, these lymphocytes may also play a role in the development of graft-versus-host disease (GVHD). Few studies have investigated the association between lymphocyte reconstitution and clinical outcomes after HSCT.

METHODS

This issue was investigated by retrospectively analyzing pediatric patients who received their first allogeneic-HSCT using a newly developed parameter, the LD-index, which evaluates both the intensity and duration of lymphopenia. A total of 101 patients underwent allo-HSCT from April 2007 to August 2019 in our hospital. Excluding patients who died before lymphocyte recovery or underwent multiple HSCT, 78 patients were analyzed for associations between the LD-index with various factors relating to HSCT.

RESULTS

A significantly high association was observed between a low LD-index and the incidence of chronic GVHD (P = 0.0019). Analysis of predictive factors for chronic GVHD was carried out using univariate analysis. Lower LD-index, donor source and duration of lymphopenia were found to be significant factors associated with chronic GVHD. Multivariate analysis, however, only identified an association between a lower LD-index and an increased incidence of chronic GVHD (P = 0.00081).

CONCLUSIONS

Early reconstitution of lymphocytes after allo-HSCT is associated with a higher incidence of chronic GVHD.

Allogeneic hematopoietic cell transplantation for lymphoma: baseline and posttransplant prognostic factors

The present study aimed to investigate baseline and posttransplant prognostic factors for allogeneic hematopoietic cell transplantation (HCT) in 61 lymphoma patients. The 5-year probabilities of overall survival (OS), non-relapse mortality (NRM), progression-free survival (PFS), and event-free survival (EFS) were 31.1%, 28.8%, 38.8%, and 23.2%, respectively. Multivariate analysis demonstrated that the International Prognostic Index risk at HCT was a significantly independent prognostic factor for OS, NRM, PFS, and EFS, and chemosensitivity was a prognostic factor for OS, NRM, and EFS. The occurrence of chronic graft-versus-host disease (GVHD) was significantly associated with higher OS, but it was not with PFS or EFS. Various parameters of immune reconstitution at 1 month after transplantation were associated with clinical outcomes in different ways. Our study results might be helpful in selecting appropriate patients or adopting effective posttransplant treatment strategies, eventually leading to an improvement in outcomes after allogeneic HCT for lymphoma.

Optimal Threshold and Time of Absolute Lymphocyte Count Assessment for Outcome Prediction after Bone Marrow Transplantation

The recovery pace of absolute lymphocyte count (ALC) is prognostic after hematopoietic stem cell transplantation. Previous studies have evaluated a wide range of ALC cutoffs and time points for predicting outcomes. We aimed to determine the optimal ALC value for outcome prediction after bone marrow transplantation (BMT). A total of 518 patients who underwent BMT for acute leukemia or myelodysplastic syndrome between 1999 and 2010 were divided into a training set and a test set to assess the prognostic value of ALC on days 30, 60, 90, 120, 180, as well as the first post-transplantation day of an ALC of 100, 200, 300, 400, 500, and 1000/μL. In the training set, the best predictor of overall survival (OS), relapse-free survival (RFS), and nonrelapse mortality (NRM) was ALC on day 60. In the entire patient cohort, multivariable analyses demonstrated significantly better OS, RFS, and NRM and lower incidence of graft-versus-host disease (GVHD) in patients with an ALC >300/μL on day 60 post-BMT, both including and excluding patients who developed GVHD before day 60. Among the patient-, disease-, and transplant-related factors assessed, only busulfan-based conditioning was significantly associated with higher ALC values on day 60 in both cohorts. The optimal ALC cutoff for predicting outcomes after BMT is 300/μL on day 60 post-transplantation.

Importance of early absolute lymphocyte count after allogeneic stem cell transplantation: a retrospective study

INTRODUCTION

Early lymphocyte recovery after allogeneic hematopoietic stem cell transplantation (HSCT) is related to the prevention of serious infections and the clearing of residual tumor cells.

METHODS

We analyzed the absolute lymphocyte count at 20 (D+20) and 30 (D+30) days after HSCT in 100 patients with malignant hematologic diseases and correlated with the risk of transplant-related mortality, overall survival (OS), disease-free survival (DFS), nonrelapsed mortality (NRM), and risk of infection.

RESULTS

Patients presenting with lymphocyte counts of <300 × 103/μL on D+30 have a 3.76 times greater risk of death in <100 days. Over a medium follow-up of 20 months OS, DFS, and NRM were similar between the groups.

CONCLUSION

In our group of patients delayed lymphocyte recovery after HSCT was a predictor of early death post-HSCT.

Impact of very early CD4(+) /CD8(+) T cell counts on the occurrence of acute graft-versus-host disease and NK cell counts on outcome after pediatric allogeneic hematopoietic stem cell transplantation

BACKGROUND

Increasing evidence suggests that early and rapid lymphocyte recovery following allogeneic hematopoietic stem cell transplantation (HSCT) is associated with better survival.

PROCEDURE

We retrospectively analyzed very early lymphocyte subset counts following transplantation from our 5-year pediatric allogeneic HSCT material to find clinically relevant associations with post transplant outcome, and the major complication of HSCT, acute graft-versus-host disease (aGVHD). We analyzed HSCTs performed due to acute leukemias and lymphomas from matched unrelated donors (MUD, n = 33), unrelated cord blood (UCB, n = 9) and matched sibling donors (MSD, n = 17).

RESULTS

Patients with grafts from MUDs and grade II-IV aGVHD) had higher (median 2.1 compared to 0.3, P<0.0001) and earlier (at day +18 post transplant vs. day +25, P = 0.004) first measurable CD4(+) /CD8(+) T cell ratio, compared to patients with no or grade I aGVHD, respectively. At day +32 after HSCT patients with MUDs and significant aGVHD had higher levels of both CD4(+) and CD8(+) T cell subsets. Low (below median 120/µL) versus high natural killer (NK) cell counts at day +32 were associated with 3-year event-free survival of 27.4 +/- 9.0% versus 82.4 +/- 6.4% (P < 0.0001), cumulative transplant-related mortality of 44.7 +/- 12.2% versus 3.0 +/- 3.0% (P < 0.001) and cumulative relapse incidence of 50.4 +/- 12.2% versus 15.0 +/- 6.2% (P = 0.019), respectively.

CONCLUSIONS

We conclude that early lymphocyte subset counts following allogeneic HSCT have an association with aGVHD and post transplant outcome.

The impact of HLA-E polymorphisms on relapse following allogeneic hematopoietic stem cell transplantation

Since relapse following allogeneic hematopoietic stem cell transplantation (HSCT) can be due to the escape of the residual malignant cells from the graft-versus-leukemia (GvL) effect and given the role of NK cells in GvL and the importance of HLA-E in the modulation of NK cell function, we investigated whether polymorphisms of HLA-E molecule could impact on the incidence of relapse and the improvement of Disease-free Survival (DFS) after allogeneic HSCT. The study group included 56 pairs of donors and patients with malignant hematological disorders undergoing HLA-E matched allogeneic HSCT. The median follow-up was 43.6 (range 20.5-113.1) months. They were genotyped for HLA-E locus using a sequence-specific primer (SSP)-PCR. We found a lower incidence of relapse (p=0.02) in the patients with HLA-E*0103/0103 genotype compared to those with other genotypes of HLA-E. We also showed an association between HLA-E*0103/0103 genotype and a better DFS (p=0.001). Our results suggest a protective role for HLA-E*0103/0103 genotype against relapse and an association between this genotype and an improved DFS following HLA-E matched allogeneic HSCT.

Post-transplant immune reconstitution after unrelated allogeneic stem cell transplant in patients with acute myeloid leukemia

We evaluated immune recovery in 67 patients with acute myeloid leukemia (AML) with a median age of 40 years (4-69) following allo-SCT after reduced (n = 35) or myeloablative (n = 32) conditioning. The following lymphocyte populations were determined on days +30, +90, +180, +270, and +365 by flow associated cell sorting: CD3+, CD3+CD4+, CD3+CD8+, CD3+CD4+/CD3+CD8+ ratio, CD3-CD56+, and CD19+ cells. Peripheral blast count >5% was related to lower number of CD3+CD4+ (day +30) and NK cells (day +180; p = 0.02). Intensity of conditioning did not have any significant impact on the kinetics of immune recovery. Patients with normal CD3+CD4+/CD3+CD8+ ratio (day +30) and NK cell count (day +90; p <0.05) experienced better survival than those with decreased parameters. Post-transplant sepsis/severe infections impaired CD3+CD8+ (day +90; p = 0.015) and CD19+ (day +90; p = 0.02) recovery. Relapse in patients following allo-SCT showed an association with decreased numbers of CD19+ (day +270) and NK cells (day +365). Acute GvHD (II-IV) was accompanied by reduced CD19+ and CD3+CD4+ cells. Thus, the evaluation of post-transplant immune reconstitution in patients with AML might improve risk stratification concerning either relapse or TRM and remains to be further explored.