Development and current use of in hematopoietic stem cell transplantation in children and adolescents in Poland: Report of the Polish pediatric study group for hematopoietic stem cell transplantation of the Polish society for pediatric oncology and hematology

The impact of NKG2A and NKG2D receptors and HLA-E and MICA ligands polymorphisms on post-transplant complications after paediatric allogeneic HSCT: a single-centre experience

Introduction: Natural Killer cells are the first subpopulation of lymphocytes that reconstitute after allogeneic haematopoietic stem cell transplantation (HSCT). Their activity is regulated by various receptor-ligand interactions, including stimulation of the activating NKG2D receptor by the MICA molecule, and inhibitory NKG2A receptor interacting with the HLA-E. In this study the research effort focused on the effect of selected NKG2A and NKG2D receptors and their ligands (HLA-E and MICA molecules) polymorphisms that may affect the pathomechanisms of post-transplant complications after HSCT in children. Methods: One hundred donor-recipient pairs from a single paediatric transplantation centre were investigated. Altogether six single nucleotide substitutions (NKG2A rs7301582; NKG2D rs1049174, rs1154831; HLA-E rs1264457; MICA rs1051792, rs1063635) were genotyped, and the influence of polymorphisms was analysed on acute and chronic graft-versus-host disease (GvHD), cytomegalovirus (CMV) infection incidence, disease relapse and survival. Results: The distribution of the evaluated polymorphisms did not differ between patients and their donors. The results showed a significant influence of HLA-E rs1264457 polymorphism in patients' HLA-E*01:01 allele, which was associated with increased risk of CMV infection (p = 0.050), especially in children positive for CMV IgG before transplantation (p = 0.001). Furthermore, the effect of HLA-E*01:01 allele on CMV infections was more evident in children above the age of 7 years (p = 0.031). Strong tendencies (0.05 < p < 0.10) towards association with the risk of acute GvHD were also observed for the NKG2A or MICA polymorphisms of the recipients. In addition, NKG2D rs1154831 AA and MICA rs1063635 GG might play a protective role as they were not present in any recipient who died after transplantation. Conclusion: In summary, there is emerging evidence that genotyping results of NKG2 receptors and their ligands, may have prognostic value for the outcome of paediatric allogeneic HSCT, but more extensive studies performed on larger groups of donors and transplant recipients are required to confirm these observations.

Impact of early chimerism status on clinical outcome in children with acute lymphoblastic leukaemia after haematopoietic stem cell transplantation

Background

The significance of very early chimerism assessment before day + 28, which is considered the moment of engraftment, is still unclear. In this retrospective study, we evaluated the clinical impact of very early chimerism on the clinical outcome after allogeneic haematopoietic stem cell transplantation (allo-HSCT) in children with acute lymphoblastic leukaemia (ALL).

Methods

The study group included 38 boys and 18 girls. Very early chimerism was evaluated on days + 7, + 14, + 21 and + 28 after the transplant. Short tandem repeat polymerase chain reaction (STR PCR) was used to analyse chimerism.

Results

Overall survival (OS) and event-free survival (EFS) were 84 and 80%, respectively. The OS in the group of 24 patients with complete donor chimerism on day + 14 was 83%, and it did not differ statistically compared to the 32 patients with mixed chimerism on day + 14 (OS was 84%). In our cohort of patients, the matched unrelated donor, male gender of donor, number of transplanted cells above 4.47 × 10⁶ kg and no serotherapy with anti-thymocyte globulin (ATG) were statistically related to a higher level of donor chimerism. The immunophenotypes of disease, age of patient at time HSCT, recipient sex, stem cell source (peripheral blood/bone marrow) and conditioning regimen had no impact on early chimerism. Acute graft versus host disease grades II-IV was diagnosed in 23 patients who presented with donor chimerism levels above 60% on day 7.

Conclusions

The data presented in this study provide valuable insight into the analysis of very early chimerism in children with ALL treated with HSCT.

Long-Term Recipient Health-Related Quality of Life and Donor-Recipient Relationship following Sibling Pediatric Hematopoietic Stem Cell Transplantation

Despite the fact that the choice of donors and the number of sources of hematopoietic stem cells have increased, a sibling remains a preferred donor for allogeneic hematopoietic stem cell transplantation (HSCT). Transplant donation between siblings is a unique life experience that may have an impact on their future relationship. The aim of the study was to quantitatively measure the quality of life (QoL) in patients who underwent transplant and to describe the relationship between a recipient and a sibling donor after HSCT. We identified and invited 82 adults aged 18.0 to 38.7 years (median, 23.6) who underwent HSCT in our center and their sibling donors to participate in this survey. Forty-five patients (54.9%) and their siblings consented to take part in the study. The studied group consisted of 45 matched siblings donor (MSD)-HSCT recipients (19 women and 26 men) aged 18.0 to 36.2 (median, 28.5) years, who underwent MSD-HSCT at the age of 5.8 to 16.3 (median, 11.9) years, and their sibling donors aged 21.0 to 36.0 (median, 31.0) years, who were aged 11.2 to 20.2 (median, 15.5) years at bone marrow harvesting. For QoL and sibling relationship assessment, we used the Functional Assessment of Cancer Therapy-Bone Marrow Transplantation (FACT-BMT) and the Adult Sibling Relationship Questionnaire (ASQR). Higher scores indicate better quality of life in each scale of the FACT-BMT and the more significant is the factor in a sibling relationship measured by the ASQR. The questionnaires were given to both subgroups, HSCT recipients and donors, and the results were compared with each other. The overall result of the FACT-BMT questionnaire was 117 ± 35.0. The highest QoL was found in the functional (25.0 ± 3.5) and social well-being (25.0 ± 3.5) subscales, whereas the worst was in the emotional well-being (18.0 ± 9.5) subscale. Statistically, the QoL score was not influenced by current age (P = .378), age at the moment of HSCT (P = .256), and sex (P = .117). Being a recipient or a donor of HSCT was not a significant factor associated with warmth (2.6 ± 0.5 versus 3.1 ± 0.5; P = .830) and conflict (2.0 ± 0.7 versus 2.1 ± 1.2; P = .886) within the sibling relationship, whereas recipients scored significantly lower in rivalry within the sibling relationship compared with HSCT donors (0.8 ± 0.3 versus 1.2 ± 0.2; P = .012). The FACT Treatment Outcome Index remained the only significant predictor of warmth in the sibling relationship between HSCT recipient and donor. QoL in adult patients after HSCT in childhood was good. Sibling donor-recipient relationship is unbalanced, with a higher level of rivalry presented among donors. Further multicenter studies based on a larger cohort of patients are necessary to assess all aspects of the sibling relationship after transplantation experience.

Primary immunodeficiency and autoimmunity: A comprehensive review

The primary immunodeficiency diseases (PIDs) include many genetic disorders that affect different components of the innate and adaptive responses. The number of distinct genetic PIDs has increased exponentially with improved methods of detection and advanced laboratory methodology. Patients with PIDs have an increased susceptibility to infectious diseases and non-infectious complications including allergies, malignancies and autoimmune diseases (ADs), the latter being the first manifestation of PIDs in several cases. There are two types of PIDS. Monogenic immunodeficiencies due to mutations in genes involved in immunological tolerance that increase the predisposition to develop autoimmunity including polyautoimmunity, and polygenic immunodeficiencies characterized by a heterogeneous clinical presentation that can be explained by a complex pathophysiology and which may have a multifactorial etiology. The high prevalence of ADs in PIDs demonstrates the intricate relationships between the mechanisms of these two conditions. Defects in central and peripheral tolerance, including mutations in AIRE and T regulatory cells respectively, are thought to be crucial in the development of ADs in these patients. In fact, pathology that leads to PID often also impacts the Treg/Th17 balance that may ease the appearance of a proinflammatory environment, increasing the odds for the development of autoimmunity. Furthermore, the influence of chronic and recurrent infections through molecular mimicry, bystander activation and super antigens activation are supposed to be pivotal for the development of autoimmunity. These multiple mechanisms are associated with diverse clinical subphenotypes that hinders an accurate diagnosis in clinical settings, and in some cases, may delay the selection of suitable pharmacological therapies. Herein, a comprehensively appraisal of the common mechanisms among these conditions, together with clinical pearls for treatment and diagnosis is presented.