HLA-DP diversity is associated with improved response to SARS-Cov-2 vaccine in hematopoietic stem cell transplant recipients.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients show lower humoral vaccine responsiveness than immunocompetent individuals. HLA diversity, measured by the HLA evolutionary divergence (HED) metrics, reflects the diversity of the antigenic repertoire presented to T cells, and has been shown to predict response to cancer immunotherapy. We retrospectively investigated the association of HED with humoral response to SARS-CoV-2 vaccine in allo-HSCT recipients. HED was calculated as pairwise genetic distance between alleles at HLA-A, -B, -C, -DRB1, -DQB1, and -DPB1 loci in recipients and their donors. Low anti-spike IgG levels (<30 BAU/mL) were associated with short time from allo-SCT and low donor DPB1-HED, mostly related to donor DPB1 homozygosity. The diversity of donor HLA-DP molecules, assessed by heterozygosity or sequence divergence, may thus impact the efficacy of donor-derived CD4 T cells to sustain vaccine-mediated antibody response in allo-HSCT recipients.

HLA Diversity across the HLA-DP locus is associated with improved response to SARS-CoV-2 vaccine in hematopoietic stem cell transplant recipients

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients show lower humoral vaccine responsiveness than immunocompetent individuals. HLA diversity, measured by the HLA evolutionary divergence (HED) metrics, reflects the diversity of the antigenic repertoire presented to T cells, and has been shown to predict response to cancer immunotherapy. We retrospectively investigated the association of HED with humoral response to SARS-CoV-2 vaccine in allo-HSCT recipients. HED was calculated as pairwise genetic distance between alleles at HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1 loci in recipients and their donors. Low anti-spike IgG levels (< 30 BAU/mL) were associated with short time from allo-SCT and low donor DPB1-HED, mostly related to donor DPB1 homozygosity. The diversity of donor HLA-DP molecules, assessed by heterozygosity or sequence divergence, may thus impact the efficacy of donor-derived CD4 T cells to sustain vaccine-mediated antibody response in allo-HSCT recipients. Graphical

Outcome of SARS-CoV2 infection in hematopoietic stem cell transplant recipients for autoimmune diseases

Hematopoietic stem cell transplant (HSCT) recipients may be at high risk of mortality from coronavirus disease 2019 (COVID-19). However, specific data on COVID-19 after treatment with HSCT in patients affected by autoimmune diseases (ADs) are still lacking. In this multicenter observational study of the European Society for Blood and Marrow Transplantation (EBMT), clinical data on COVID-19 in 11 patients affected by severe ADs treated with HSCT (n = 3 allogeneic transplant;n = 8 autologous transplant) are reported. All patients were symptomatic during the initial phase of the SARS-CoV-2 infection. At screening, 5 patients reported upper respiratory symptoms, 3 patients had cough without oxygen requirement, and 6 patients exhibited extra-pulmonary symptoms. Four cases developed a lower respiratory tract disease (LRTD). Hospitalization was required in 6 cases, without necessity of intensive care unit (ICU) admission and/or ventilation/supplemental oxygen. Different interventions were adopted: remdesivir (n = 1), nirmatrelvir/ritonavir (n = 1), sotrovimab (n = 1), immunoglobulins (n = 1). At last follow-up, all patients solved the infection and are alive. The current analysis describing the mild-moderate course of COVID-19 in transplant recipients affected by ADs, similar to the course observed in ADs under standard treatments, provides useful information to support the delivery of HSCT programs in this field. Vaccination and new treatments available for SARS-CoV-2 infection may be useful to further minimize the infectious risks.

A 16-month-long experience of COVID-19 in allogeneic haematopoietic stem cell transplantation recipients: An SFGM-TC multicentre cohort study.

This 16-month-long multicentre retrospective study of 225 allogeneic haematopoietic stem cell transplantation (alloHSCT) recipients with COVID-19 examines risk factors for severity and mortality, describing the successive waves of infections (from March to June 2020 and from August 2020 to June 2021). We confirm the negative role of low respiratory tract disease and immunosuppressive treatment. We highlight significantly lower percentages of severe forms and COVID-19-related mortality during the second wave. Monthly comparative evolution of cases in alloHSCT recipients and in the French population shows a higher number of cases in alloHSCT recipients during the first wave and a decrease from February 2021.

Outcome of SARS-CoV2 infection in hematopoietic stem cell transplant recipients for autoimmune diseases.

Hematopoietic stem cell transplant (HSCT) recipients may be at high risk of mortality from coronavirus disease 2019 (COVID-19). However, specific data on COVID-19 after treatment with HSCT in patients affected by autoimmune diseases (ADs) are still lacking. In this multicenter observational study of the European Society for Blood and Marrow Transplantation (EBMT), clinical data on COVID-19 in 11 patients affected by severe ADs treated with HSCT (n = 3 allogeneic transplant; n = 8 autologous transplant) are reported. All patients were symptomatic during the initial phase of the SARS-CoV-2 infection. At screening, 5 patients reported upper respiratory symptoms, 3 patients had cough without oxygen requirement, and 6 patients exhibited extra-pulmonary symptoms. Four cases developed a lower respiratory tract disease (LRTD). Hospitalization was required in 6 cases, without necessity of intensive care unit (ICU) admission and/or ventilation/supplemental oxygen. Different interventions were adopted: remdesivir (n = 1), nirmatrelvir/ritonavir (n = 1), sotrovimab (n = 1), immunoglobulins (n = 1). At last follow-up, all patients are alive and had resolution of the infection. The current analysis describing the mild-moderate course of COVID-19 in transplant recipients affected by ADs, similar to the course observed in ADs under standard treatments, provides useful information to support the delivery of HSCT programs in this field. Vaccination and new treatments available for SARS-CoV-2 may be useful to further minimize the risk of infection.

Improved outcomes over time and higher mortality in CMV seropositive allogeneic stem cell transplantation patients with COVID-19; An infectious disease working party study from the European Society for Blood and Marrow Transplantation registry.

Introduction: COVID-19 has been associated with high morbidity and mortality in allogeneic hematopoietic stem cell transplant (allo-HCT) recipients. Methods: This study reports on 986 patients reported to the EBMT registry during the first 29 months of the pandemic. Results: The median age was 50.3 years (min - max; 1.0 - 80.7). The median time from most recent HCT to diagnosis of COVID-19 was 20 months (min - max; 0.0 - 383.9). The median time was 19.3 (0.0 - 287.6) months during 2020, 21.2 (0.1 - 324.5) months during 2021, and 19.7 (0.1 - 383.9) months during 2022 (p = NS). 145/986 (14.7%) patients died; 124 (12.6%) due to COVID-19 and 21 of other causes. Only 2/204 (1%) fully vaccinated patients died from COVID-19. There was a successive improvement in overall survival over time. In multivariate analysis, increasing age (p<.0001), worse performance status (p<.0001), contracting COVID-19 within the first 30 days (p<.0001) or 30 - 100 days after HCT (p=.003), ongoing immunosuppression (p=.004), pre-existing lung disease (p=.003), and recipient CMV seropositivity (p=.004) had negative impact on overall survival while patients contracting COVID-19 in 2020 (p<.0001) or 2021 (p=.027) had worse overall survival than patients with COVID-19 diagnosed in 2022. Discussion: Although the outcome of COVID-19 has improved, patients having risk factors were still at risk for severe COVID-19 including death.

Humoral and cellular responses to SARS-CoV-2 BNT162b2 vaccination in allogeneic hematopoietic stem cell transplantation recipients.

Previous studies reporting the response to SARS-CoV-2 mRNA vaccination in alloHSCT recipients used serological and/or cellular assays, but no study has evaluated vaccine-induced neutralizing antibodies. We prospectively studied 28 alloHSCT recipients who received two BNT162b2 doses. Two patients groups were defined according to time from alloHSCT and immunosuppressive treatment, and had different baseline immunologic status. Study end-point was the evaluation of humoral and cellular responses one month after the second vaccine. All patients seroconverted. Anti-S IgG levels and neutralizing antibodies percentages were not significantly different between both groups. Using IFNγ ELISpot assay, five patients showed a strong increase, without correlation with the humoral response. Using flow cytometry lymphocyte proliferation assay, 14 patients exhibited responding T cells, without difference between both groups or correlation with anti-S IgG levels. A few low serological responders had a detectable CD4 + T cell proliferative response. This finding should be confirmed in a larger cohort.

COVID-19 and stem cell transplantation; results from an EBMT and GETH multicenter prospective survey.

This study reports on 382 COVID-19 patients having undergone allogeneic (n = 236) or autologous (n = 146) hematopoietic cell transplantation (HCT) reported to the European Society for Blood and Marrow Transplantation (EBMT) or to the Spanish Group of Hematopoietic Stem Cell Transplantation (GETH). The median age was 54.1 years (1.0-80.3) for allogeneic, and 60.6 years (7.7-81.6) for autologous HCT patients. The median time from HCT to COVID-19 was 15.8 months (0.2-292.7) in allogeneic and 24.6 months (-0.9 to 350.3) in autologous recipients. 83.5% developed lower respiratory tract disease and 22.5% were admitted to an ICU. Overall survival at 6 weeks from diagnosis was 77.9% and 72.1% in allogeneic and autologous recipients, respectively. Children had a survival of 93.4%. In multivariate analysis, older age (p = 0.02), need for ICU (p < 0.0001) and moderate/high immunodeficiency index (p = 0.04) increased the risk while better performance status (p = 0.001) decreased the risk for mortality. Other factors such as underlying diagnosis, time from HCT, GVHD, or ongoing immunosuppression did not significantly impact overall survival. We conclude that HCT patients are at high risk of developing LRTD, require admission to ICU, and have increased mortality in COVID-19.

Seasonal Human Coronavirus Respiratory Tract Infection in Recipients of Allogeneic Hematopoietic Stem Cell Transplantation.

BACKGROUND: Little is known about characteristics of seasonal human coronaviruses (HCoVs) (NL63, 229E, OC43, and HKU1) after allogeneic stem cell transplantation (allo-HSCT). METHODS: This was a collaborative Spanish and European bone marrow transplantation retrospective multicenter study, which included allo-HSCT recipients (adults and children) with upper respiratory tract disease (URTD) and/or lower respiratory tract disease (LRTD) caused by seasonal HCoV diagnosed through multiplex polymerase chain reaction assays from January 2012 to January 2019. RESULTS: We included 402 allo-HSCT recipients who developed 449 HCoV URTD/LRTD episodes. Median age of recipients was 46 years (range, 0.3-73.8 years). HCoV episodes were diagnosed at a median of 222 days after transplantation. The most common HCoV subtype was OC43 (n = 170 [38%]). LRTD involvement occurred in 121 episodes (27%). HCoV infection frequently required hospitalization (18%), oxygen administration (13%), and intensive care unit (ICU) admission (3%). Three-month overall mortality after HCoV detection was 7% in the whole cohort and 16% in those with LRTD. We identified 3 conditions associated with higher mortality in recipients with LRTD: absolute lymphocyte count <0.1 × 109/mL, corticosteroid use, and ICU admission (hazard ratios: 10.8, 4.68, and 8.22, respectively; P < .01). CONCLUSIONS: Seasonal HCoV after allo-HSCT may involve LRTD in many instances, leading to a significant morbidity.