The Rome Transplant Network model compared to the Italian Bone Marrow Donor Registry activity for unrelated donor search process and transplant efficiency for hematologic malignancy

Availability of HLA-allele-matched unrelated donors and registry size: Estimation from haplotype frequency in the Italian population

In Italy, an HLA-matched unrelated donor is currently the primary donor when a HLA matched sibling is not found for allogeneic haematopoietic stem cell transplantation (HSCT). Better outcomes for transplantation require optimal matching between donor and recipient at least at the HLA-A, -B, -C, and -DRB1 loci; therefore, the availability of HLA-matched unrelated donors is important. The enormous HLA polymorphism has always necessitated registries with a large number of individuals in order to be able to provide well-matched donors to a substantial percentage of patients. In order to increase the efficiency of the Italian Bone Marrow Donor Registry (IBMDR) in providing Italian patients with a suitable donor, the probability of finding an HLA-A, -B, -C, and -DRB1 allele-matched (8/8) or a single mismatch unrelated donor (7/8) was estimated in this study according to IBMDR size. Using a biostatistical approach based on HLA haplotype frequencies of more than 100,000 Italian donors enrolled in the IBMDR and HLA-typed at high-resolution level, the probability of finding an 8/8 HLA-matched donor was 23.8%; 33.4%; and 41.4% in simulated registry sizes of 200,000; 500,000; and 1,000,000 donors; respectively. More than 2 million recruited donors are needed to increase the likelihood of identifying an HLA 8/8 matched donor for 50% of Italian patients. If one single mismatch at HLA I class loci was accepted, the probability of finding a 7/8 HLA-matched donor was 62.8%; 73.7%; and 80.3% in 200,000 donors; 500,000; and 1,000,000 donors; respectively. Using the regional haplotype frequencies of IBMDR donors, the probability of recruiting a donor with a new HLA phenotype, in the different Italian regions, was also calculated. Our findings are highly relevant in estimating the optimal size of the national registry, in planning a cost-effective strategy for donor recruitment in Italy, and determining the regional priority setting of recruitment activity in order to increase the phenotypic variability of IBMDR as well as its efficiency.

Allelic HLA Matching and Pair Origin Are Favorable Prognostic Factors for Unrelated Hematopoietic Stem Cell Transplantation in Neoplastic Hematologic Diseases: An Italian Analysis by the Gruppo Italiano Trapianto di Cellule Staminali e Terapie Cellulari, Italian Bone Marrow Donor Registry, and Associazione Italiana di Immunogenetica e Biologia dei Trapianti

HLA molecules are important for immunoreactivity in allogeneic hematopoietic stem cell transplantation (HSCT). The Gruppo Italiano Trapianto di Cellule Staminali e Terapie Cellulari, Italian Bone Marrow Donor Registry, and Associazione Italiana di Immunogenetica e Biologia dei Trapianti promoted a retrospective observational study to evaluate HLA matching and the impact of allelic HLA mismatching and non-HLA factors on unrelated Italian HSCT outcomes. From 2012 to 2015, 1788 patients were enrolled in the study. The average donor age was 29 years and the average recipient age was 49 years. As a conditioning regimen, 71% of the patients received myeloablative conditioning. For GVHD prophylaxis, 76% received either antithymocyte or anti-T lymphocyte globulin, cyclosporine A, and methotrexate. Peripheral blood was the stem cell source in 80%. The median duration of follow-up was 53 months. Regarding HLA matching, 50% of donor-recipient pairs were 10/10 matched, 38% had 1 mismatch, and 12% had 2 or more mismatches. A total of 302 pairs shared Italian origin. Four-year overall survival (OS), progression-free survival, GVHD-free relapse-free survival, and relapse rates were 49%, 40%, 22%, and 34%, respectively. The 4-year NRM was 27%, and the 100-day cumulative incidence of grade ≥II acute GVHD (aGVHD) was 26%. In multivariate analysis, 9/10 and ≤8/10 HLA allele-matched pairs were associated with worse OS (P = .04 and .007, respectively), NRM (P = .007 and P < .0001, respectively), and grade III-IV aGVHD (P = .0001 and .01, respectively). Moreover, the incidences of grade II-IV aGVHD (P = .001) and chronic GVHD (P = .002) were significantly lower in Italian pairs. In conclusion, 10/10 HLA matching is a favorable prognostic factor for unrelated HSCT outcome in the Italian population. Moreover, the presence of 2 HLA-mismatched loci was associated with a higher NRM (P < .0001) and grade II-IV aGVHD (P = .006) and a poorer OS (P = .001) compared with 1 HLA-mismatched locus in early or intermediate disease phases. Finally, we found that Italian donor and recipient origin is a favorable prognostic factor for GVHD occurrence.

Matched-Pair Analysis of Transplant from Haploidentical, Unmanipulated Bone Marrow Donor versus HLA Identical Sibling for Patients with Hematologic Malignancies

A matched-pair analysis of transplant-related outcomes was carried out in 116 of 255 consecutive patients who received transplants from an HLA identical sibling (n = 58) or haploidentical related donor (n = 58). The 2 patient series were matched with 9 variables: period of transplant, patient and donor age, sex, diagnosis, disease phase, conditioning regimen, donor-recipient sex, and cytomegalovirus (CMV) status combinations. As graft-versus-host disease (GVHD) prophylaxis, all patients received the standard cyclosporine and methotrexate association with the addition of anti-thymocyte globulins, mycophenolate mofetil, and basiliximab in haploidentical, unmanipulated bone marrow recipients. Anti-infectious management, transfusion policy, and supportive care were identical for all patients. By comparing the 2 patient series, no statistically significant difference was observed for the cumulative incidence of advanced acute and extensive chronic GVHD, transplant-related mortality, and relapse. With a median follow-up of 3.5 years, the 5-year disease-free survival was 37% ± 6% and 36% ± 6% for HLA identical sibling and haploidentical recipients, respectively. The results of transplant from HLA identical siblings and haploidentical donors are comparable. Regardless of the HLA matching, other factors known to affect the transplant outcomes, such as donor-recipient age, sex, and CMV status combinations, might drive the search for the best donor.

Cerebellar Neurocysticercosis as Long-Term Complication of Allogeneic Haematopoietic Stem Cell Transplantation from Haploidentical Donor

Neurocysticercosis, an infection of the central nervous system with the larval stage of the cestode Taenia solium, is uncommon in developed countries. We report a case of allogeneic haematopoietic stem cell transplantation from a haploidentical donor complicated, in the long term, by T. solium infection of the central nervous system and successfully treated with empiric antiparasitic therapy with albendazole plus dexamethasone. Revised diagnostic criteria proposed by Del Brutto et al. were used for the definitive diagnosis of cerebellar neurocysticercosis.

ASSESSMENT OF HLA-COMPATIBILITY AND REQUIREMENTS FOR HLA-TYPING OF PATIENT AND DONOR IN ALLOGENEIC HEMATOPOIETIC STEM CELL TRANSPLANTATION

Introduction.Unification of guidelines and standards concerning requirements for HLA typing and assessment of the degree of HLA match between the recipient and the donor for different types of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is of a great importance.

Aim.To present contemporary requirements for the HLA typing of a recipient and a donor for allo-HSCT, to generalize recom mendations for assessing a required match degree of a recipient and a donor and to provide data on additional immunogenetic factors capable of improving the results of allogeneic hematopoietic stem cell transplantation.

General findings.Allo-HSCT appears to be an effective, and, in some cases, non-alternative treatment for many diseases of the blood system. The number of allo-HSCT types is constantly growing globally. Currently, an allogeneic hematopoietic stem cell donor can be selected for almost every recipient having indication for this type of therapy. Such a transplantation can be performed from an HLA-identical sibling, an HLA-match unrelated donor, a partially HLA-match unrelated donor, a relative haploidentical donor or cord blood. HLA match between the recipient and the donor present itself as an important factor affecting the results of allo-HSCT. The choice of a donor should involve a correct assessment the HLA match degree between the recipient and the donor, as well as consideration of additional factors that may affect the results of allo-HSCT.

Haploidentical Transplantation with Post-Transplant Cyclophosphamide versus Unrelated Donor Hematopoietic Stem Cell Transplantation: A Systematic Review and Meta-Analysis

Hematopoietic stem cell transplantation (HSCT) is the standard treatment for patients with high-risk hematologic malignancies. Only approximately 25% of siblings are HLA-matched, and thus alternative donors-unrelated or haploidentical-are usually the only options available. This meta-analysis aimed to compare haploidentical HSCT with post-transplantation cyclophosphamide and unrelated donor (URD) HSCT. We searched the PubMed and Cochrane databases for pertinent studies indexed between 2008 and 2018. Twenty observational studies (with a total of 1783 haploidentical HSCT recipients and 6077 URD HSCT recipients) were included. Results for overall survival, graft-versus-host disease (GVHD), nonrelapse mortality (NRM), and relapse incidence were pooled. Measures of association used were hazard ratios and risk differences. The median age was 51 years for haploidentical transplant recipients and 52 years for URD transplant recipients. Peripheral blood stem cell (PBSC) grafts were more frequent in the URD transplant recipients (85%) than in the haploidentical transplant recipients (31%). Overall survival was not different between the 2 groups. NRM was lower for haploidentical transplantation. All forms of GVHD (acute grades II-IV and III-IV and moderate, severe, and extensive chronic) were lower with haploidentical donor HSCT. The risk of chronic GVHD was fairly proportional to the differential use of PBSC grafts across studies, however. All included studies were retrospective, representing the major limitation of this meta-analysis. In conclusion, haploidentical HSCT for hematologic malignancies achieved the same overall survival as URD HSCT, with a lower incidence of GVHD and NRM. The increased frequency of PBSC use in the unrelated donor group could partially explain the higher cGVHD rate. Haploidentical transplantation with post-transplantation cyclophosphamide should strongly be considered as the first option for adult patients with hematologic malignancies who do not have matched sibling donors in experienced centers. This systematic review has been registered at PROSPERO (65790).

High-resolution analysis of the HLA-A, -B, -C and -DRB1 alleles and national and regional haplotype frequencies based on 120 926 volunteers from the Italian Bone Marrow Donor Registry

HLA genes are highly polymorphic and structurally complex. They are located in the major histocompatibility complex (MHC) on chromosome 6, and the frequency of alleles and haplotypes varies widely among human populations. In this paper, we calculated the allele and haplotype frequencies using the HLA data of more than 120 000 Italian unrelated bone marrow donors enrolled in the national registry (IBMDR) and typed them with a high-resolution (HR) method for the HLA-A, -B, -C and -DRB1 alleles. The allele frequency data were obtained by manual counting; haplotype frequencies were calculated using the expectation maximisation (EM) algorithm. The total numbers of observed alleles were 226 for HLA-A, 343 for HLA-B, 201 for HLA-C and 210 for HLA-DRB1, which account for 5.4%, 6.7%, 5.2% and 8.5%, respectively, of each locus allele (IPD-IMGT/HLA Database Release 3.32, April 2018). The three most frequent Italian haplotypes were HLA-A*01:01~B*08:01~C*07:01~DRB1*03:01 (2.5%), A*02:01~B*18:01~C*07:01~DRB1*11:04 (1.1%) and A*30:01~B*13:02~C*06:02~DRB1*07:01 (1.1%). Moreover, for a relevant subset of the examined population (>100 000 individuals), the birthplace was available, and thus, we grouped the frequency data based on the corresponding Italian geographic areas, describing the HLA specificity of the Italian regional populations. The haplotype frequencies were also compared between national and regional data, and we observed remarkable differences in the regional haplotype frequencies, particularly in Sardinia. This study represents a valid tool to identify a more efficient haematopoietic stem cell unrelated donor recruitment and selection strategy, as well as for population genetic and HLA-disease association fields.

Therapeutic efficiency of platelet gel for the treatment of oral ulcers related to chronic graft versus host disease after allogeneic haematopoietic stem cell transplantation

BACKGROUND

Platelet (PLT) gel has been successfully used in tissue regeneration of diabetic and surgical wounds through the releasing of growth factors such as basic fibroblast and PLT-derived growth factors. Based on this background, our previous clinical trial have assessed the feasibility and efficacy of PLT gel for the treatment of muco-cutaneous lesions related to graft versus host disease (GvHD) after allogeneic haematopoietic stem cell transplantion (HSCT). The promising results reported in a small series of 6 patients, of whom 1 with oral ulcers, represent the rationale of the present study.

MATERIALS AND METHODS

The aim of this study was to verify the efficacy and safety of PLT gel for treating oral ulcers due to chronic GvHD. Allogeneic hemocomponents were used to obtain PLT gel with an automated system for the on-site preparation and application of patient (autologous) or healthy blood donor (allogeneic)-derived fibrin sealant or PLT-rich fibrin (Vivostat system, Vivostat A/S). Ten patients with multiple oral lesions related to chronic GvHD underwent allogeneic PLT gel as local therapy alone or in combination with systemic therapy in half of the cases.

RESULTS

After the second PLT gel application, all patients resumed the feeding and a significant improvement of the oral pain was observed. After a median of five PLT gel applications (range, 2-15), 7 out of 10 patients showed a complete response. No side effects were documented.

CONCLUSION

These data confirm that the PLT gel may be used as a safe and effective tool, alone or in combination with systemic therapy, for the treatment of mucosal lesions of mouth related to cGvHD.

Identification of oral risk factors for chronic graft versus host disease in haematological patients who underwent allogeneic haematopoietic stem cell transplantation

OBJECTIVE

The aim of this prospective observational study was to identify local risk factors for the development of clinical manifestations of oral chronic Graft versus Host Disease (cGvHD) in a cohort of patients affected by haematological malignant diseases who underwent allogeneic haematopoietic stem cell transplantation (HSCT).

MATERIALS AND METHODS

In the context of an active collaboration between the Rome Transplant Network of the Hematology and the Oral Pathology Division at "Policlinico Tor Vergata", in Rome, 47 haematological patients were included in this trial based on a systematic dental screening and follow-up protocol. The dental checks were planned 1 month before the transplant procedure while the subsequent follow ups were scheduled on day +100, +180, +365 and + 730 after the transplant. The tool used for the dental checks was a detailed report including all the potential oral features responsible of mechanical, chemical or infective injuries, except for the drugs.

RESULTS

Overall, 64% of patients (N=30) did not perform dental hygiene during the screening pre-transplant and 53% (25/47) developed cGvHD with oral involvement. The most part of patients (84%) who experienced oral manifestations of cGvHD during the follow-up period after HSCT did not perform dental hygiene before the transplant procedure. Moreover, the comparison between the "presence" or "absence" of dental hygiene before the allogeneic HSCT showed a statistical significant increasing during the follow-up period in the occurrence of oral lesions due to the cGvHD for patients who lack pre-transplant dental care (p=0.029).On the contrary, the frequency of the other factors such as malocclusions, fractured teeth, incongruous prosthesis, food, smoke, alcol and bad habits, resulted similar between the group with or without typical oral lesions of cGvHD.

CONCLUSIONS

The prevention of oral infectious complications provided by primary and secondary dental cares can result in a great benefit for haematological patients who underwent allogeneic HSCT. The combined hematological and dental management represents a clinical need before and after allogeneic HSCT for the removal of inconvenient issues with impact on the short and long-term outcome. Poor dental hygiene seems to be a local risk factor for the development of oral lesions due to cGvHD. However, a larger cohort of patients is necessary to confirm these preliminary data and to evaluate the best preventive and therapeutic oral hygiene protocol in this specific setting.