Re-vaccination against SARS-COV2 in allogeneic HSCT patients: Repeated primary vaccines doses increases seroconversion rates

Patients undergoing treatment for haematological malignancies have been shown to have reduced antibody responses to vaccination against SARS-COV2. This is particularly important in patients who have undergone allogeneic haemopoietic stem cell transplantation (HSCT), in whom there is limited data about vaccine efficacy. In this retrospective single-centre analysis, we present data on serologic responses following one, two, three or four doses of either Pfizer-BioNTech (PB), AstraZeneca (AZ) or Moderna (MU) SARS-CoV- 2 vaccines from a series of 75 patients who have undergone allogeneic HSCT within 2 years from the time they were revaccinated. The seroconversion rates following post-HSCT vaccination were found to be 50.7%, 78%, 79% and 83% following the first, second, third and fourth primary post -HSCT vaccine doses, respectively. The median time from allograft to first revaccination was 145 days (range 79-700). Our findings suggest that failure to respond to the first SARS-CoV- 2 vaccine post-HSCT was associated with the presence of acute GVHD (p = 0.042) and treatment with rituximab within 12 months of vaccination (p = 0.019). A statistical trend was observed with the presence of chronic GVHD and failure to seroconvert following the second (p = 0.07) and third (p = 0.09) post-HSCT vaccine doses. Patients who had received one or more SARS-CoV- 2 vaccines prior to having an allogeneic stem cell transplant were more likely to demonstrate a positive antibody response following the first dose of revaccination against Sars-CoV- 2 (p = 0.019) and retained this seropositivity following subsequent doses. The incidence of confirmed COVID-19 diagnosis among this cohort at the time of analysis was 16%. 17% of these were hospitalised and there was one recorded death (8%) secondary to COVID-19 in a patient who was 15.7 months post allogeneic transplant. In summary, this study suggests that despite the initial low seroconversion rates observed postallogeneic transplant, increasing levels of antibody response are seen post the second primary vaccine dose. In addition, there seems to be lower risk of mortality secondary to COVID-19 in this vaccinated population, compared to what was reported in the earlier phases of the pandemic prior to use of SARS-COV2 vaccination. This adds support to the widely adopted policy of early full revaccination with repeat of primary vaccine doses and boosters post-HSCT to reduce mortality in this population. Finally, we have identified rituximab use and active GVHD as potential risk factors influencing serological responses to SARS-COV2 vaccination and further work should focus on further characterising this risk and optimum dosing schedule both pre-and post-transplant.

Case Report: Favorable outcome of allogeneic hematopoietic stem cell transplantation in SARSCoV2 positive recipient, risk-benefit balance between infection and leukemia.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) in SARS-CoV-2 positive candidates is usually delayed until the clinical resolution of the infection's symptoms and a negative nasopharyngeal molecular test. However, prolonged SARS-CoV-2 positivity has been frequently observed in haematological malignancies, thus representing a challenge for the timing of transplant procedures. Here, we report on the case of a 34-year-old patient with recent pauci-symptomatic COVID-19 undergoing transplant for high-risk acute B-lymphoblastic leukemia before achieving viral clearance. Shortly before their scheduled allogeneic HSCT from a matched unrelated donor, the patient developed mild Omicron BA.5 infection receiving nirmatrelvir/ritonavir with fever resolution within 72 hours. Twenty-three days after COVID-19 diagnosis, because of increasing minimal residual disease values in the context of high-risk refractory leukemia and clinical resolution of SARS-2-CoV infection with reduction of viral load at surveillance nasopharyngeal swabs, it was decided not to delay further allo-HSCT. During myelo-ablative conditioning, the nasopharyngeal SARS-CoV-2 viral load increased while the patient remained asymptomatic. Consequently, two days before the transplant, intra-muscular tixagevimab/cilgavimab 300/300 mg and a 3-day course of intravenous remdesivir were administered. During the pre-engraftment phase, veno-occlusive disease (VOD) occurred at day +13, requiring defibrotide treatment to obtain a slow but complete recovery. The post-engraftment phase was characterized by mild COVID-19 at day +23 (cough, rhino-conjunctivitis, fever) that spontaneously resolved, achieving viral clearance at day +28. At day +32, she experienced grade I acute graft-versus host disease (a-GVHD, skin grade II) treated with steroids and photo-apheresis, without further complications during follow-up until day +180. Addressing the issue of allo-HSCT timing in patients recovering from SARS-CoV-2 infection with high-risk malignant diseases is challenging because of 1] the high risk of COVID-19 clinical progression, 2] the impact of transplant delay on leukemia prognosis and 3] the occurrence of endothelial complications such as VOD, a-GVHD, and transplant associated thrombotic micro-angiopathy. Our report describes the favourable outcome of allo-HSCT in a recipient with active SARS-CoV2 infection and high-risk leukemia thanks to timely anti-SARS-CoV-2 preventive therapies and prompt management of transplant-related complications.

Risk factors and characteristics influencing humoral response to COVID-19 vaccination in patients after allogeneic stem cell transplantation.

Introduction: Vaccination against severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is approved and recommended for immunocompromised patients such as patients after allogeneic stem cell transplantation (allo-SCT). Since infections represent a relevant cause of transplant related mortality we analyzed the advent of immunization to SARS-CoV-2 vaccination in a bicentric population of allogeneic transplanted patients. Methods: We retrospectively analyzed data of allo-SCT recipients in two German transplantation centers for safety and serologic response after two and three SARS-CoV-2 vaccinations. Patients received mRNA vaccines or vector-based vaccines. All patients were monitored for antibodies against SARS-CoV2-spike protein (anti-S-IgG) with an IgG ELISA assay or an EIA Assay after two and three doses of vaccination. Results: A total of 243 allo-SCT patients underwent SARS-CoV-2 vaccination. The median age was 59 years (range 22-81). While 85% of patients received two doses of mRNA vaccines, 10% had vector-based vaccines and 5% received a mixed vaccination. The two vaccine doses were well tolerated with only 3% patients developing a reactivation of graft versus host disease (GvHD). Overall, 72% of patients showed a humoral response after two vaccinations. In the multivariate analysis age at time of allo-SCT (p=0.0065), ongoing immunosuppressive therapy (p= 0.029) and lack of immune reconstitution (CD4-T-cell counts <200/µl, p< 0.001) were associated with no response. Sex, intensity of conditioning and the use of ATG showed no influence on seroconversion. Finally, 44 out of 69 patients that did not respond after the second dose received a booster and 57% (25/44) showed a seroconversion. Discussion: We showed in our bicentric allo-SCT patient cohort, that a humoral response could be achieve after the regular approved schedule, especially for those patients who underwent immune reconstitution and were free from immunosuppressive drugs. In over 50% of the initial non-responders after 2-dose vaccination, a seroconversion can be achieved by boostering with a third dose.

Can You Spare 100 Days? The Allogeneic Hematopoietic Cell Transplant Caregiver Requirement

Allogeneic hematopoietic cell transplantation (alloHCT) is a potentially curative treatment for patients diagnosed with blood cancers (such as acute myeloid leukemia) and blood disorders (such as sickle cell disease). It is a resource-intensive treatment that generally requires a long hospital stay and recovery period. If continuous caregiver support is not available, alloHCT likely will not be a treatment option. To learn more about caregiver requirements and perspectives on those requirements, we conducted web-based focus groups with alloHCT social workers who worked with adult patients at United States (US) transplant centers (TCs) from May-July 2022. Web-based interviews with adult alloHCT recipients,caregivers of adult alloHCT recipients, and physicians/advanced practice professionals will also be conducted. Twenty-two social workers from TCs across the US (Midwest [n=8];West [n=5];Northeast: [n=5];South, [n=4]) and with varying volumes (median: 97 alloHCTs performed/year) participated. All noted their TC required a caregiver to proceed to alloHCT. However, there was variation across TCs in the length of time a recipient was required to have a caregiver, the distance/time needed to stay near the TC post-alloHCT, and COVID-19 vaccination requirements. The majority of participants also noted variance among the transplant team in allowing exceptions for caregiver requirements. All participants noted it would be helpful to have a 'gold standard' of requirements across TCs, though there was discussion about what such a standard would include, as well as the need for flexibility to account for different patient and TC needs. Social workers were also asked to identify patient barriers to meeting the caregiver requirement;common barriers included patients feeling they did not have anyone to ask to be a caregiver, the need to relocate closer to the TC, and financial barriers. The impact of the COVID-19 pandemic was also noted (e.g., vaccination requirements, and increased telework allowing more flexibility for caregivers). In analysis of the first of four populations interviewed in this study, social workers reported variation in caregiver requirements across TCs. Finding a caregiver is one of many barriers patients face in accessing alloHCT. Though this variation may allow for some flexibility, it may also contribute to access barriers. This study focused on those who received an alloHCT, but further research is needed to learn about barriers faced by those unable to access alloHCT. Results from this and other cohorts will describe current practices related to caregiver requirements and help inform the development of new programs to reduce caregiver-related barriers to alloHCT.Copyright © 2023 American Society for Transplantation and Cellular Therapy

Can You Spare 100 Days? Allogeneic Hematopoietic Cell Transplant Caregiver Requirements from the Perspective of Recipients and Caregivers

Allogeneic hematopoietic cell transplantation (alloHCT) is a potentially curative treatment for individuals diagnosed with blood cancers (e.g., acute myeloid leukemia) and blood disorders (e.g., sickle cell disease). Most transplant centers (TCs) require a caregiver to proceed with alloHCT. Caregiver requirements can be one of many barriers to alloHCT, as individuals without a caregiver can have limited or no access to this treatment. Few studies have described TC caregiver requirements, particularly from the perspective of recipients and caregivers. To learn more about alloHCT caregiver requirements and perspectives on those requirements, we conducted web-based interviews with adult alloHCT recipients and adult caregivers of adult alloHCT recipients in the United States (US) starting in May 2022. Recipients needed to be between 100 days and 1-year post-HCT and in remission;Table 1 describes participant demographics.(Table Presented)The majority of participants noted that their TC required a caregiver to proceed to alloHCT;however, there was variation in the length of time required to have a caregiver. When asked their perspective on the amount of time the TC required, the majority of participants noted that the actual length of time depended on the recipient's recovery (with some noting more time was needed and others noting less). Participants were also asked to share barriers they faced regarding the caregiver role. A common barrier included not fully understanding the specifics of the caregiver requirements, or what it would entail. Some recipients described being provided with too much information, making it difficult to sort through, while others reported feeling like they did not receive enough information. Other barriers identified by recipients included competing priorities of the caregiver (such as work/ home responsibilities and childcare), language barriers, and finances. Common barriers identified by caregivers included: feeling like they could not take time for themselves/their own health suffered and needing to be trained to perform medical tasks. Many recipients and caregivers also noted the impact of the COVID-19 pandemic (e.g., postponing alloHCT, trepidation about going to the TC, post-alloHCT housing restrictions, and increased telework for caregivers). Preliminary analysis of recipients and caregivers interviews showed variation in caregiver requirements across TCs. There is a need for clear, accessible information to help recipients and caregivers understand the caregiver role and requirements. This study included recipients and caregivers;further research is needed to identify barriers faced by individuals unable to access alloHCT. Results from this study will help facilitate the development of programs to help improve access to alloHCT.Copyright © 2023 American Society for Transplantation and Cellular Therapy

Developing Contemporary Survivorship Clinic for Recipients of Hematopoietic Cell Transplantation: A Single Center Experience

Introduction: Survival after hematopoietic cell transplantation (HCT) has improved tremendously over the last few decades. HCT survivors are at increased risk of long-term complications and secondary cancers. This poses unique challenges to the HCT-related healthcare system given the growing need for survivorship care. Developing a HCT survivorship program with a dedicated clinic to survivors ensures equitable access to care and ongoing patient education. Herein, we describe our program survivorship model and our initial experience. Method(s): The Moffitt Cancer Center (MCC) survivorship clinic (SC) planning committee was initiated in September 2019. The SC was launched in January 2021 with the mission to provide high-quality, comprehensive, and personalized survivorship care and to empower patients and community health care providers with education and a roadmap for screening for late effects. The SC initially focused on allogeneic (allo) HCT patients and later opened to autologous (auto) HCT recipients in February 2022. HCT patients are referred by primary HCT team after HCT with an emphasis on preferred timeframe of initial SC visit no earlier than 3 months but less than 12 months from HCT. SC is located at 2 physical locations: main campus and satellite, with virtual visit options to account for the distance from MCC and COVID considerations. SC applies a consultative model. SC is staffed by dedicated advanced practice professional (APP), supervised by SC faculty. The scope of SC care includes but is not limited to prevention of infections (education, vaccinations), surveillance of late effects (endocrine, pulmonary function, cardiac, bone health), and general cancer screenings (breast, colon, skin cancer). Patients' clinical data from SC inception to August 2022 were reviewed. Result(s): From January 2021 to August 2022, a total of 138 patients were seen in SC. The majority were seen in person (62% in clinic, 38% by virtual visit). Median age was 58 years (range, 19-82). Median time to first SC visit was 21 months (range, 3-1464) after HCT. Allo HCT was the most common type of HCT seen in clinic (87%, n=120). Most common diagnoses were acute myeloid leukemia (43%, n=59), myelodysplastic syndrome (17%, n=23), and acute lymphoblastic leukemia (10%, n=14). Only 17 patients (12%) were seen in 2021 but the volume increased significantly in 2022. Currently there are more than 10 patients seen in SC per month. Conclusion(s): We report successful experience in launching a contemporary HCT SC despite the challenges of an ongoing COVID pandemic. As a stand-alone cancer center, we serve a wide geographical location with subspecialty and primary care providers dispersed throughout the community. Our consultative model and experience could provide a useful guide for other programs. In 2023, we plan to expand our SC to a broader population of patients receiving other cellular immunotherapies.Copyright © 2023 American Society for Transplantation and Cellular Therapy

Cryopreservation of Unrelated Donor Stem Cell Grafts Is Associated with Lower Rates of Chronic Gvhd after Allogeneic Transplantation

Allogeneic hematopoietic stem cell transplantation (allo- HSCT) has traditionally involves administering fresh peripheral blood or bone marrow stem cells. At onset of the COVID-19 pandemic in March 2020, the National Marrow Donor Program (NDMP) mandated cryopreservation of all unrelated peripheral blood stem cell (PBSC) products to prevent interruptions in transplant plans by donor COVID-19 infection after recipient's start of conditioning chemotherapy. Since the lifting of this mandate, many centers have continued to cryopreserve grafts prior to initiation of conditioning, but the longer-term clinical outcomes of this practice including chronic graft versus host disease (cGVHD) rates of patients receiving cryopreserved stem cells have not been previously well described. Prior work has raised concern for a deleterious effect of cryopreservation on overall survival and non-relapse mortality (PMID: 33865804). However, heterogeneity in the patient population and reason for cryopreservation suggest that further study is needed to assess these outcomes. Here we report our single-institution experience of clinical outcomes using cryopreserved versus fresh URD PBSCs for allo-HSCT. We examined long-term outcomes in 387 patients who received unrelated donor (URD) PBSCs (136 cryopreserved, 251 fresh) between January 1, 2019 and July 31, 2021. The cohorts had similar baseline characteristics including donor/recipient age/sex, disease, conditioning regimen/intensity, and GVHD prophylaxis regimens. Two-year OS, PFS, relapse, NRM, and acute GVHD rates were not different between recipients of fresh versus cryopreserved PBSCs. Strikingly, 2-year incidence of cGVHD (28% vs 52%, p=0.00001) and moderate/severe cGVHD (9% vs 24%, p=0.00016) was substantially lower in recipients of cryopreserved PBSCs compared to fresh, respectively (Figure 1). This difference was only noted in patients receiving a GVHD prophylaxis regimen without post-transplantation cyclophosphamide (PTCY) (no PTCY 2-year cGVHD incidence cryopreserved vs fresh: 29% vs 57%, p=0.000016), moderate/severe cGVHD 16% vs 34%, p=0.0006) (Figure 2). For patients receiving a PTCY-containing GVHD prophylaxis regimen, there was no difference in cGVHD incidence (cGVHD cryopreserved vs fresh: 24% vs 27%, p=0.56, moderate/severe cGVHD 7% vs 9.3%, p=0.3, Figure 3). (Figure Presented) (Figure Presented) (Figure Presented) While survival and relapse rates are not different, cryopreservation is associated with a marked reduction in cGVHD rates in the setting of non-PTCy based GVHD prophylaxis. Larger multicenter or registry analyses are needed to confirm these observations and may prompt a re-assessment of the role of cryopreservation of stem cell products in clinical practice. If confirmed, it will be critical to understand the immunologic consequences of cryopreservation and how they might influence the clinical impact on chronic GVHDCopyright © 2023 American Society for Transplantation and Cellular Therapy

Why Are Patients Not Getting a Graft? An Intent-to-Transplant Analysis in the Times of Universal Coverage and Haploidentical Donors

Introduction: Allogeneic hematopoietic stem cell transplantation (alloHSCT) is a potentially curative option for patients with hematologic diseases. When considered candidates, patients face barriers to receive a transplant. Therefore, we aimed to analyze factors that limit or favor access to an alloHSCT in a population that has been HLA typed and therefore with a potential intent-to-transplant. Method(s): We retrospectively reviewed records from 2015 until the start of the COVID19 pandemic in two Mexican government- funded transplant centers and one private that have in-house HLA typing;in two of them, an outpatient transplant strategy is followed for most patients. HLA-typed patients who were potentially eligible for transplantation were included and their outcomes were assessed in an intent-to-transplant basis. We compared the outcomes of patients who underwent transplantation to those who did not and evaluated contributing barriers to access alloHSCT with multivariate logistic regression. Result(s): A total of n=374 patients were analyzed. The median age at HLA-typing was 35 years (IQR 23-47);59.3% had acute(Table Presented) leukemia, 17.4% bone marrow failure or myelodysplastic neoplasms, 13.1% lymphoma, 8% myeloproliferative neoplasms, 1.1% chronic lymphocytic leukemia and 1.1% multiple myeloma. Most patients (55.9%) had government insurance coverage. Median time from diagnosis to HLA-typing was 8 months (IQR 3-19). The majority had a potential donor (94.4%): 56.4% haploidentical, 37.4% a matched sibling donor and 0.5% an unrelated donor. Almost half of them received a transplant (n=185, 49.5%), the median time from HLA-typing to alloHSCT was 2 months (IQR 1-5.5). Disease activity or progression was the biggest barrier for transplantation;Table 1. Donor availability limited transplant access for 12.1% of patients. Access to transplantation was favored by private/out-of-pocket payment (OR 2.1 95% CI 1.3-3.4), and receiving care in the outpatient center (OR 6.4 95% CI 4-10.0), while HLA matching was not (OR 1.2 95% CI 0.8-1.8). Non-relapse mortality in alloHSCT was 21%. Median overall survival (OS) from the intent-to-transplant cohort was 16 months (CI 95% 12.4-19.6). An OS landmark analysis for patients alive at or beyond 2 months (the median time from HLA-typing to alloHSCT) showed prolonged survival in alloHSCT (30 vs 12 months, p <.001), Figure 1. By the time of the analysis 159 patients (42.5%) were still alive and 115 (30.7%) were event-free.(Figure Presented)Conclusion: The most frequent barrier to transplantation was the disease itself, followed by the transplant waitlist and comorbidities. Access to resources and an outpatient strategy or "center effect" favored alloHSCT. In the era of haploidentical transplantation, donor availability was a smaller issue. Efforts to improve timely referrals and access to effective pre-transplant therapies should be undertaken.Copyright © 2023 American Society for Transplantation and Cellular Therapy

Post-Transplantation Cyclophosphamide for the Prevention of Graft-Versus-Host Disease Should Not Limit Transplantation for Acute Lymphoblastic Leukemia in People with Trisomy 21

Introduction: Use of hematopoietic cell transplantation (HCT) in patients with trisomy 21 (+21) is infrequent given concerns about increased toxicity with cytotoxic chemotherapy.1 Due to increasing evidence of benefit from post-HCT cyclophosphamide (PTCy) for graft-vs.-host disease (GVHD) prophylaxis and lack of prior descriptions in patients with +21,2-4 we report on 2 patients with +21 and acute lymphoblastic leukemia (ALL) who underwent HCT with PTCy. Method(s): Retrospective data were collected from 2 patients with ALL and +21 who underwent allogeneic HCT with PTCybased GVHD prophylaxis from 2019 to 2021. Data collected included age, disease risk, HCT-CI, GVHD incidence, and survival. Result(s): Patient 1 is a 22-year-old male and patient 2 a 25-year-old female. Both had Ph-negative, B-cell ALL. Patient 1 had ETV6/RUNX1 rearrangement, del 12p, gain of X, and he had recurrence of measurable residual disease (MRD) after initial MRD-negative CR with two lines of therapy pre-HCT. Patient 2 had normal cytogenetics and relapsed disease with 4 prior lines of therapy. Both achieved MRD-negativity pre-HCT. Both received fludarabine and melphalan conditioning, and patient 1 also received thiotepa 2.5 mg/kg. PTCy was given on days +3 and 4 at 50 mg/kg with sirolimus and tacrolimus for GVHD prophylaxis. Patient 1 had a haploidentical donor and received one dose of rabbit ATG (1 mg/kg) on day +5. Patient 2 had a matched unrelated donor. There was no significant delay in engraftment of ANC (day 16-19) or platelets (day 15-16). Patient 2 developed acute GVHD at day 30 (stage I skin, stage II GI) that resolved with steroids which were tapered off by day 96 without recurrence. Sirolimus stopped at day 79 (pt 1) and 103 (pt 2) and tacrolimus was stopped at day 274 (pt 1) and 469 (pt 2). Patient 1 developed a sirolimus-induced pericardial effusion at day 84 which did not recur after sirolimus discontinuation. Patient 2 developed moyamoya 8 months post-HCT during tacrolimus taper without other GVHD symptoms. Response to steroids was noted, so tacrolimus was restarted for residual neurological deficit. Neither patient developed chronic GVHD or left ventricular ejection fraction decline, and neither patient had disease relapse at follow-up of 30 and 16 months respectively. Patient 2 developed COVID pneumonia 16 months post-HCT and died while in CR. Patient 1 remains alive, in CR, and off immunosuppression nearly 3 years post HCT. Conclusion(s): Allogeneic HCT with PTCy at standard doses did not appear prohibitively toxic in patients with +21 when administered after reduced-intensity conditioning. In this case series, GVHD rates seemed consistent with larger series in patients without +21. Moyamoya development is associated with autoimmunity in patients with +21 and hence may have been GVHD-related5. Trisomy 21 should not be a barrier to patients otherwise eligible for HCT, even with PTCy prophylaxis.Copyright © 2023 American Society for Transplantation and Cellular Therapy

Case report: mRNA-1273 COVID-19 vaccine-associated myopericarditis: Successful treatment and re-exposure with colchicine.

Introduction: Vaccine-induced myocarditis is a rare complication of messenger RNA (mRNA) COVID-19 vaccines. Case presentation: We report a case of acute myopericarditis in a recipient of allogeneic hematopoietic cells following the first dose of the mRNA-1273 vaccine and the successful administration of a second and third dose while on prophylactic treatment with colchicine to successfully complete the vaccination. Conclusion: Treatment and prevention of mRNA-vaccine-induced myopericarditis represent a clinical challenge. The use of colchicine is feasible and safe to potentially reduce the risk of this rare but severe complication and allows re-exposure to an mRNA vaccine.

Specific immune response to mRNA vaccines against COVID-19 in patients receiving allogeneic stem cell transplantation for myeloid malignancy was altered by immunosuppressive therapy.

BACKGROUND: Allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients are at high risk of complications associated with COVID-19 infection due to dysfunction of their immune system. Vaccination can protect from the adverse consequences of COVID-19. However, studies on the efficacy of COVID-19 vaccines in HSCT recipients with insufficient post-HSCT immune reconstitution are still scarce. In our study, we determined how immunosuppressive medication and the reconstitution of the cellular immune system influenced T cell responses specific for the surface glycoprotein of SARS-CoV-2 virus (S antigen) after two doses of mRNA vaccine against COVID-19 in patients with myeloid malignancies treated with HSCT. METHODS: Vaccination outcomes were followed in 18 (allo-HSCT) recipients and 8 healthy volunteers. The IgG antibodies against SARS-CoV-2 spike (S) and nucleocapsid (NCP) protein were determined in ELISA and S-specific T cells were detected using a sensitive ELISPOT-IFNγ based on in vitro expansion and restimulation of T cells in pre- and post-vaccination blood samples. Multiparametric flow cytometry analysis of peripheral blood leukocyte differentiation markers was employed for determination of reconstitution of the main subpopulations of T cells and NK cells at month 6 after HSCT. RESULTS: S- specific IgG antibody response detected in 72% of the patients was lower than in healthy vaccinees (100%). Vaccine-induced T-cell responses to S1 or S2 antigen were significantly reduced in HSCT recipients, which were treated with corticosteroids in dose 5 mg of prednisone- equivalents or higher during the vaccination period or in preceeding 100 days in comparison with recipients un-affected with corticosteroids. A significant positive correlation was found between the level of anti-SARS-Cov-2 spike protein IgG antibodies and the number of functional S antigen-specific T cells. Further analysis also showed that the specific response to vaccination was significantly influenced by the interval between administration of vaccine and transplantation. Vaccination outcomes were not related to age, sex, type of mRNA vaccine used, basic diagnosis, HLA match between HSC donor and recipient, and blood counts of lymphocytes, neutrophils, and monocytes at the time of vaccination. Multiparametric flow cytometry analysis of peripheral blood leukocyte differentiation markers showed that good humoral and cellular S-specific immune responses induced by vaccination were associated with well-reconstituted CD4+ T cells, mainly CD4+ effector memory subpopulation at six months after HSCT. CONCLUSIONS: The results showed that both humoral and cellular adaptive immune responses of HSCT recipients to the SARS-CoV-2 vaccine were significantly suppressed by corticosteroid therapy. Specific response to the vaccine was significantly affected by the length of the interval between HSCT and vaccination. Vaccination as early as 5 months after HSCT can lead to a good response. Immune response to the vaccine is not related to age, gender, HLA match between HSC donor and recipient, or type of myeloid malignancy. Vaccine efficacy was dependent on well-reconstituted CD4+ T cells, at six months after HSCT.

4 - Bayesian Statistical Methods in Stem Cell Transplantation and Cellular Therapy

A brief overview of Bayesian statistics is given, followed by illustrative applications of Bayesian methods in allogeneic hematopoietic cell transplantation (allo-HCT) and cellular therapy. Three clinical trial designs are described, including a study to evaluate safety and efficacy of cytotoxic T-lymphocytes for posttransplant viral infections, a trial to optimize chimeric antigen receptor T-cell dose for hematologic malignancies based on efficacy-toxicity trade-offs, and a randomized study of cord blood derived regulatory T-cells for COVID-19 induced acute respiratory distress syndrome. Three data analyses are described, including a sensitivity analysis of preparative regimen effects for allo-HCT that are confounded with institutional effects, regression-based estimation of the effects on survival of antigens in convalescent plasma therapy for COVID-19, and precision pharmacokinetic-guided dosing of intravenous busulfan in allo-HCT.

COVID-19 infection in hematopoietic stem cell transplant recipients.

Objective. To assess the course and outcomes of COVID-19 in recipients of allogeneic and autologous hematopoietic stem cell transplant (HSCT). Materials and methods. The retrospective study included 44 adult recipients (allogeneic - 33 [75%] and autologous - 11 [25%] of HSCT who diagnosed with COVID-19 after transplantation. Group mostly represented by acute leukemia - 18 (41%) and lymphoma - 10 (22.7%). The median follow-up time since the development of COVID-19 was 231 days (1-818 days), after HSCT - 507.5 days (14-3723 days). Overall and progression-free survival was assessed using the Kaplan-Meier and Log-Rank method. We also evaluated the characteristics of the course of a new coronavirus infection. Results. Median time for the development of COVID-19 from the moment of HSCT was 122.5 days (-1-3490 days). Twelve patients (27.2%) were in grade 3-4 neutropenia at the time of COVID-19 diagnosis, 16 (36.4%) patients were in grade 1-2 neutropenia. Sixteen (48.4%) allo-HSCT recipients had active graft-versus-host disease (GVHD) at the time of COVID-19 development. Disease severity was mild in 19 (43.2%) and moderate in 13 (29.5%) patients. Overall, 200-day survival from the onset of COVID-19 was 78.8% (95% CI [63.1-88.4]). Anemia (p = 0.02) and thrombocytopenia (p = 0.01) significantly decrease OS in patients with COVID-19 after HSCT. Patients with GVHD at the time of COVID-19 onset had a better survival rate (p = 0.02). The timing of COVID-19 development after HSCT did not affect outcomes. Conclusions. The key points of the course of COVID-19 in HSCT recipients are the presence of cytopenia and graft-versus-host disease. Overall survival was 78.8%.Copyright © 2022, Interregional Association for Clinical Microbiology and Antimicrobial Chemotherapy. All rights reserved.

Vaccines for the prevention of infections in adults with haematological malignancies

Objectives: This is a protocol for a Cochrane Review (intervention). The objectives are as follows:. To assess the benefits and adverse effects of vaccines for the prevention of infections in adults with haematological malignancies.Copyright © 2023 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.

The impact of SARS-CoV2 vaccines on the incidence of graft versus host disease in allogeneic hematopoietic stem cell transplant recipients: a single-center retrospective study.

This study reports the incidence of chronic graft versus host disease (GvHD) in allogeneic hematopoietic stem cell transplant (alloHCT) recipients who received SARS-CoV2 vaccination. The overall rates of new and worsening chronic GvHD combined were 14%, with median time from vaccination to GVHD being approximately three to four weeks. A majority of the cases were of mild to moderate severity and primarily localized to either the skin, mouth, or joints. Prior chronic GVHD and recent transplant were associated with higher GVHD rates following COVID-19 vaccination. More prospective studies are needed to provide a definitive mechanism for the impact of SARS-CoV2 vaccination on alloHCT patients.

Persistent Immunity against SARS-CoV-2 in Individuals with Oncohematological Diseases Who Underwent Autologous or Allogeneic Stem Cell Transplantation after Vaccination.

The high morbimortality due to SARS-CoV-2 infection in oncohematological diseases (OHD) and hematopoietic stem cell transplant (HSCT) recipients in the pre-vaccine era has made vaccination a priority in this group. After HSCT, the immune responses against common vaccines such as tetanus, varicella, rubella, and polio may be lost. However, the loss of immunity developed by COVID-19 vaccination after HSCT has not been completely defined. In this study, both humoral and cellular immunity against SARS-CoV-2 were analyzed in 29 individuals with OHD who were vaccinated before receiving allogeneic (n = 11) or autologous (n = 18) HSCT. All participants had low but protective levels of neutralizing IgGs against SARS-CoV-2 after HSCT despite B-cell lymphopenia and immaturity. Although antibody-dependent cellular cytotoxicity was impaired, direct cellular cytotoxicity was similar to healthy donors in participants with autologous-HSCT, in contrast to individuals with allogeneic-HSCT, which severely deteriorated. No significant changes were observed in the immune response before and after HSCT. During follow-up, all reported post-HSCT SARS-CoV-2 infections were mild. This data emphasizes that COVID-19 vaccination is effective, necessary, and safe for individuals with OHD and also supports the persistence of some degree of immune protection after HSCT, at least in the short term, when patients cannot yet be revaccinated.

Third BNT162b2 mRNA SARS-CoV-2 Vaccine Dose Significantly Enhances Immunogenicity in Recipients of Allogeneic Hematopoietic Stem Cell Transplantation.

COVID-19-related mortality among hematopoietic stem cell transplantation (HSCT) recipients in the pre-vaccine era ranged between 22 and 33%. The Pfizer/BioNTech BNT162b2 vaccine demonstrated significant immunogenicity and efficacy in the healthy population; however, its long-term effects on allogeneic HSCT recipients remained unclear. Our study longitudinally evaluated humoral and cellular responses to the BNT162b2 vaccine in adult allogeneic HSCT patients. A positive response was defined as antibody titers ≥ 150 AU/mL post-second vaccination. Among 77 included patients, 51 (66.2%) responded to vaccination. Response-associated factors were female gender, recent anti-CD20 therapy, and a longer interval between transplant and vaccination. Response rates reached 83.7% in patients vaccinated >12 months post-transplant. At 6 months post-second vaccination, antibody titers dropped, but were significantly increased with the booster dose. Moreover, 43% (6/14) of non-responders to the second vaccination acquired sufficient antibody titers after booster administration, resulting in an overall response rate of 79.5% for the entire cohort. The BNT162b2 vaccine was effective in allogeneic transplant recipients. Although antibody titers decreased with time, the third vaccination led to their significant elevation, with 93% of third-dose responders maintaining titers above 150 AU/mL at 3 months post-administration.

Severe epidermolysis bullosa acquisita in a patient with graft-versus-host disease: causal or coincidental?

Graft-versus-host disease (GvHD) is common after haematopoietic cell transplantation (HCT). Mucocutaneous manifestations are variable and may simulate autoimmune bullous dermatoses. However, the association of GvHD with autoimmune disorders, including bullous dermatoses, is also well recognized. We describe a patient with GvHD in whom severe and relapsing epidermolysis bullosa acquisita (EBA) was diagnosed 3 years after transplant and propose a causal association with GvHD. A 66-year-old woman developed GvHD following allogeneic HCT for acute myeloid leukaemia in 2016. This affected her gastrointestinal tract and skin but improved with oral corticosteroids and ciclosporin. In 2019 she presented with a widespread rash consisting of large, tense, haemorrhagic blisters. Histological features were in keeping with EBA. Direct immunofluorescence was also consistent with EBA, demonstrating linear positivity for IgG and C3 confined to the blister base, as was detection of collagen VII antibodies on indirect immunofluorescence. She was admitted and treated with high-dose oral steroids, ciclosporin and intravenous immunoglobulin (IVIg) with eventual resolution of blistering. Although further IVIg administration was planned as an outpatient, this coincided with the start of the COVID-19 pandemic and she elected not to attend and also stopped all medication. Despite this, her EBA remained quiescent until September 2021 when she was readmitted with a severe deterioration in blistering and significant dysphagia due to an oesophageal stricture, with a weight of 31.7 kg. Once again, she responded rapidly to oral prednisolone and IVIg. Dapsone was considered but precluded by G6PD deficiency and there were clinical and adherence concerns about using mycophenolate mofetil. Upon discharge she was again nonadherent to medication and failed to attend for planned IVIg. She flared and was admitted for a third time in December 2021, requiring gastrostomy for nutritional support;her weight at this time was 26.4 kg. Her EBA is currently well controlled on prednisolone and IVIg. EBA is a rare, acquired blistering disorder secondary to autoantibodies targeting type VII collagen. Previous studies have found circulating basement membrane zone (BMZ) antibodies in 24% of chronic GvHD patients, possibly generated in response to chronic BMZ damage (Hofmann SC, Kopp G, Gall C et al. Basement membrane antibodies in sera of haematopoietic cell recipients are associated with graft-versushost disease. J Eur Acad Dermatol Venereol 2010;24: 587-94). Corresponding clinical manifestations are rare, with bullous pemphigoid the most frequently reported. EBA is much less common with four previously reported cases [Brassat S, Fleury J, Camus M, et al. (Epidermolysa bullosa acquisita and graftversus- host disease). Ann Dermatol Venereol 2014;141: 369-73 (in French)]. As a fifth case of EBA, our patient provides further evidence of a likely pathophysiological relationship between GvHD and autoimmune subepidermal bullous dermatoses, and highlights the significant challenges of managing these vulnerable patient groups during the COVID-19 pandemic.

Optimal approach to T-cell ALL

T-lineage acute lymphoblastic leukemia (T-ALL) is curable for most children and adolescent and young adult patients with contemporary frontline chemotherapy regimens. During the past decade, improved survival rates have resulted from the optimization of frontline chemotherapy regimens, the use of minimal residual disease (MRD) assessment for evaluating a patient's risk for relapse, and the intensification of treatment based on the persistence of MRD. Optimization of initial therapy is critical because relapsed T-ALL after initial intensive chemotherapy is incurable for most adult patients. Current T-ALL salvage chemotherapy regimens are minimally effective, and unlike in B-cell ALL, there are no approved antibody therapies or chimeric antigen receptor T-cell therapies for relapsed disease. Immunotherapy and small-molecule inhibitors are beginning to be tested in relapsed T-ALL and have the potential to advance the treatment. Until effective salvage strategies are discovered, however, intensive frontline therapy is required for cure. In this article I review the current frontline chemotherapy regimens for adult patients with T-ALL, summarize the novel targeted and immune therapeutics currently in early-phase clinical trials, and outline how these therapies are helping to define an optimal approach for T-ALL.Copyright © 2022 by The American Society of Hematology.