Monthly prospective analysis of hematopoietic chimerism after allogeneic hematopoietic cell transplantation

Neutrophil antigen antibodies affect engraftment and secondary graft failure in hematopoietic progenitor cell transplantation

BACKGROUND

Research is limited on the role of antibodies against human neutrophil antigen (HNA) in hematopoietic progenitor cell (HPC) transplantation outcomes.

STUDY DESIGN AND METHODS

A retrospective review was conducted on medical records of patients at the NIH Clinical Center enrolled in six research protocols. This case-control study included 21 patients tested for HNA antibodies from January 2010 to March 2022 who underwent HPC transplantation. In addition, 42 patients following the same research protocols were randomly selected as a control group.

RESULTS

The cumulative incidence of time to neutrophil engraftment was significantly impacted by the patients' anti-HNA status (p = .042), with the patients with anti-HNA experiencing delayed engraftment. Secondary graft failure occurred in 4 out of 42 patients (9.52%; 95% confidence interval [CI]: 3.7-22.1) of the control group, while 5 out of 9 patients (55.5%; 95% CI: 26.7-81.1) with anti-HNA experienced secondary graft failure (p = .005). Furthermore, patients with anti-HNA had a lower proportion (p = .008 for full and p = .002 for partial chimerism) and cumulative incidence (p = .016 for full and p = .010 for partial chimerism) of achieving donor chimerism compared to the control group.

DISCUSSION

The study reveals a potential link between anti-HNA and HPC transplantation outcomes not previously reported. Patients with anti-HNA had a lower proportion and cumulative incidence of achieving donor chimerism. Additionally, anti-HNA status affected the time for neutrophil engraftment, with a slower rate of neutrophil engraftment and increased risk of secondary failure in patients with anti-HNA.

Use of chimerism analysis after allogeneic stem cell transplantation: Belgian guidelines and review of the current literature

Background: Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative treatment option in both adult and pediatric patients with malignant and non-malignant hematological diseases.  Chimerism analysis, which determines the donor or recipient origin of hematopoietic cells in HSCT recipients, is an essential aspect of post-HSCT follow-up.Objectives: To review the current literature and develop Belgian consensus guidelines for the use of chimerism analysis in the standard of care after allogeneic HSCT.Methods: Non-systematic review of the literature in consultancy with the members of the BHS transplantation committee.Results: Clinical application with regards to prediction of graft failure or relapse as well as cell source are reviewed. A consensus guideline on the use of chimerism analysis after HSCT is presented.Conclusion: Monitoring of the dynamics or kinetics of a patient's chimerism status by serial analysis at fixed time points, as well as on suspicion of relapse or graft failure, is needed to monitor engraftment levels, as well as disease control and possible relapse.

Assessing quantitative chimerism longitudinally: technical considerations, clinical applications and routine feasibility

In this review, we describe the current laboratory approach to quantitative chimerism testing based on short tandem repeats (STRs), focusing on a longitudinal analysis. The latter is based on relative changes appearing in the course of sequential samples, and as such exploits the ultimate potential of this intrinsically semiquantitative platform. Such an analysis is more informative than single static values, less likely to be confused with platform artifacts, and is individualized to the particular patient. It is particularly useful with non-myeloablative conditioning, where mixed chimerism is common. Importantly, longitudinal monitoring is a routinely feasible laboratory option because multiplex STR-polymerase chain reaction kits are available commercially, and modern software can be used to perform computation, reliability testing and longitudinal tracking in a rapid, easy to use format. The ChimerTrack application, a shareware, user friendly program developed for this purpose, produces a report that automatically summarizes and illustrates the quantitative temporal course of the patient's chimeric status. Such a longitudinal perspective enhances the value of quantitative chimerism monitoring for decisions regarding immunomodulatory post transplant therapy. This information also provides unique insights into the biological dynamics of engraftment underlying the fluctuations in the temporal course of a patient's chimeric status.

Stable mixed chimerism after hematopoietic stem cell transplantation in Wiskott-Aldrich syndrome

Wiskott-Aldrich syndrome (WAS) is a primary immunodeficiency disease characterized by thrombocytopenia, eczema, impaired cellular and humoral immunity, and increased susceptibility to malignancy and autoimmunity. The only curative treatment for WAS is hematopoietic stem cell transplantation, especially in the presence of a matched sibling donor or matched unrelated donor. Here, we report the case of a 2.5-yr-old boy with WAS that resulted in mixed chimerism after having received bone marrow from his phenotypically identical grandfather. Although the patient has persistent thrombocytopenia (platelet counts 50-80 x 10(9)/L), he is currently alive and doing well at 36 months post-transplant and is free of any bleeding episodes.

Analysis of donor-type chimerism in lineage-specific cell populations after allogeneic myeloablative and nonmyeloablative stem cell transplantation

We analyzed donor-type chimerism in CD3+, CD14.15+ and CD56+ cells from 36 patients who had undergone conventional-intensity allogeneic stem cell transplantation (CST) and 34 patients who had undergone non-myeloablative allogeneic stem cell transplantation (NST) for hematological malignancies. On day 28 after transplantation, all fractions in NST patients and CD3+ cells in CST patients who received a non-total body irradiation (TBI) regimen showed more frequent mixed chimerism (<90% donor cells) than those in patients who had received TBI. NST patients with acute graft-versus-host disease (grade II-IV) frequently showed more than 50% donor-type chimerism in CD3+ cells on day 14 (P=0.029). NST patients with <50% donor-type chimerism on day 14 and with <90% donor-type chimerism on day 28 in CD56+ cells had significantly poor 1-year overall survival (0 vs 91%, P<0.001 and 20 vs 74%, P=0.002, respectively). Both NST and CST patients with <90% donor-type chimerism in CD14.15+ cells on day 28 had significantly poor 1-year overall survival (14 vs 70%, P=0.005 and 0 vs 66%, P=0.002, respectively). Our data show that the extent of donor-type chimerism in lineage-specific cells appears to have an impact on outcome after allogeneic stem cell transplantation.

Treatment of relapsed acute lymphoblastic leukemia after allogeneic bone marrow transplantation with chemotherapy followed by G-CSF-primed donor leukocyte infusion: a prospective study

Donor leukocyte infusion (DLI) alone has very limited efficacy for patients with acute lymphoblastic leukemia (ALL) who have relapsed after allogeneic bone marrow transplantation (BMT). We, therefore, prospectively tested the efficacy of cytoreductive chemotherapy (intermediate-dose cytarabine+idarubicin+etoposide) followed immediately by G-CSF-primed DLI (Chemo-DLI) in 10 relapsed ALL patients after allogeneic BMT. Seven achieved complete remission (CR) at a median of 25 days (19-73 days) after DLI. Of these seven CR patients, only one remains alive in CR 907 days after DLI. Two CR patients died in CR of graft-versus-host disease. The remaining four CR patients relapsed at a median of 153 days (120-991 days) after DLI. One is alive with leukemia at post-DLI day 1217. The median survival duration after DLI was 175 days (15-1217 days). In summary, although Chemo-DLI for relapsed ALL after allogeneic BMT induced a relatively high CR rate, durable remissions were rare. Although our data should be interpreted cautiously considering the small number of patients, these results suggest that poor outcome of DLI in relapsed ALL may be primarily due to intrinsic resistance to graft-versus-leukemia effect rather than to the rapid pace of the disease.

Cyclosporine alone vs cyclosporine plus methotrexate for post-transplant immunosuppression after HLA-identical sibling bone marrow transplantation: a randomized prospective study

The role of methotrexate (MTX), given with cyclosporine (CS), after HLA-identical sibling bone marrow transplantation needs to be defined. In all, 80 patients with hematologic malignancies were enrolled in a prospective randomized trial. All were given BuCy conditioning. The 40 patients in the CS arm received CS 3 mg/kg/day intravenously, with subsequent oral dosing. Patients in the CS + MTX arm received, in addition to CS, MTX intravenously, 15 mg/m2 on day 1, and 10 mg/m2 on days 3, 6, and 11. Transplantation-related mortality was low in both groups of patients (13 vs 11% for CS vs CS + MTX groups, P = 0.94). The CS group had a significantly higher frequency of chronic graft-versus-host disease (56 vs 32%, P = 0.05). After a median follow-up of 22.1 months (5.1-47.8 months), three of 30 vs 10 of 28 patients with acute leukemia/myelodysplastic syndrome (MDS) in CS group vs CS + MTX group relapsed (P = 0.01) yielding better overall survival for patients with acute leukemia/MDS treated with CS (P = 0.02). After HLA-identical sibling bone marrow transplantation, immunosuppression with CS, with or without MTX, resulted in similarly low transplantation-related mortality. In acute leukemia/MDS, decreased relapse with patient survival prolongation was observed in the CS group.

Failure of trilineage blood cell reconstitution after initial neutrophil engraftment in patients undergoing allogeneic hematopoietic cell transplantation – frequency and outcomes

The outcomes of patients who experience the failure to reconstitute a trilineage of blood cells after initial neutrophil engraftment were evaluated in 178 patients with hematologic disorders, who underwent allogeneic HCT. Of 165 qualified patients (five with primary engraftment failure; eight deaths before day 60 of HCT), 43 (26%) satisfied the criteria for the initial (n=22; failure of platelet >20 000/microl or red blood cell transfusion independence/reticulocyte count >/=1.0% by day 60) or subsequent (n=21, ANC <500/microl for >/=3 days, platelet <20 000/microl for >/=7 days, or red blood cells transfusion/reticulocyte <1.0% after initial trilineage reconstitution) failure. GVHD was the most common clinical condition associated with cytopenia (n=24). In all, 20 patients (47%) recovered at least partially with a median of 52 days (range 8-323) later, with 12 of those 20 patients recovering completely. The eventual reconstitution failure rate was 14% (23/163 patients). The number of cell lineages involved in the cytopenia was the only independent variable that predicted partial recovery (1 lineage vs 2-3 lineages with odds ratio of 8.69 (95% CI 1.96-38.60), P=0.004). Five/20 patients with vs 20/23 patients without partial recovery died. Trilineage reconstitution failures after allogeneic HCT need systematic analysis in the future studies.