High mortality of COVID-19 early after allogeneic stem cell transplantation – a retrospective multicenter analysis on behalf of the German Cooperative Transplant Study Group

Cellular and humoral immunogenicity against SARS-CoV-2 vaccination or infection is associated with the memory phenotype of T- and B-lymphocytes in adult allogeneic hematopoietic cell transplant recipients

We conducted a cross-sectional study to evaluate cellular and humoral immunogenicity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination or infection and examine how lymphocyte subpopulations in peripheral blood correlate with cellular and humoral immunogenicity in adult allogeneic hematopoietic cell transplantation (HCT) recipients. The median period from SARS-CoV-2 vaccination or infection to sample collection was 110.5 days (range, 6-345 days). The median SARS-CoV-2 spike-specific antibody level was 1761 binding antibody units (BAU)/ml (range, 0 to > 11,360 BAU/ml). Enzyme-linked immunosorbent spot (ELISpot) assay of T cells stimulated with SARS-CoV-2 spike antigens showed that interferon-gamma (IFN-γ)-, interleukin-2 (IL-2)-, and IFN-γ + IL-2-producing T cells were present in 68.9%, 62.0%, and 56.8% of patients, respectively. The antibody level was significantly correlated with frequency of IL-2-producing T cells (P = 0.001) and IFN-γ + IL-2-producing T cells (P = 0.006) but not IFN-γ-producing T cells (P = 0.970). Absolute counts of CD8+ and CD4+ central memory T cells were higher in both IL-2- and IFN-γ + IL-2-producing cellular responders compared with non-responders. These data suggest that cellular and humoral immunogenicity against SARS-CoV-2 vaccination or infection is associated with the memory phenotype of T cells and B cells in adult allogeneic HCT recipients.

COVID-19 outcomes in haemopoietic stem cell transplant recipients in Western Australia: the value of vaccination and antiviral therapy

Coronavirus-19 (COVID-19) mortality rates among haemopoietic stem cell transplant (HSCT) patients are high, ranging between 20% and 40%. We prospectively evaluated the mortality outcomes of COVID-19 in Western Australian HSCT patients. A total of 32/492 (6.5%) HSCT recipients contracted COVID-19 during the study, of whom 30/32 (94%) developed mild or asymptomatic disease. Two allogeneic HSCT patients were hospitalised for severe COVID-19; one patient died. Stringent healthcare, social isolation practices, aggressive vaccination programmes and rapid access to COVID-19 antivirals may have promoted mild COVID-19 illness in Western Australian HSCT patients, resulting in one of the lowest COVID-19 mortality rates in HSCT recipients worldwide.

COVID-19 in hematopoietic stem cell transplant recipients during three years of the pandemic: a multicenter study in Brazil

Hematopoietic stem cell transplant (HSCT) recipients are at -increased risk for severe COVID-19. The aim of this study was to evaluate the burden of COVID-19 in a cohort of HSCT recipients. This retrospective study evaluated a cohort of adult hospitalized HSCT recipients diagnosed with COVID-19 in two large hospitals in São Paulo, Brazil post-HSCT, from January 2020 to June 2022. The primary outcome was all-cause mortality. Of 49 cases, 63.2% were male with a median age of 47 years. Allogeneic-HSCT (51.2%) and autologous-HSCT (48.9%) patients were included. The median time from HSCT to COVID-19 diagnosis was 398 days (IQR: 1211-134), with 22 (44.8%) cases occurring within 12 months of transplantation. Most cases occurred during the first year of the pandemic, in non-vaccinated patients (n=35; 71.4%). Most patients developed severe (24.4%) or critical (40.8%) disease; 67.3% received some medication for COVID-19, primarily corticosteroids (53.0%). The probable invasive aspergillosis prevalence was 10.2%. All-cause mortality was 40.8%, 51.4% in non-vaccinated patients and 14.2% in patients who received at least one dose of the vaccine. In the multiple regression analyses, the variables mechanical ventilation (OR: 101.01; 95% CI: 8.205 - 1,242.93; p = 0.003) and chest CT involvement at diagnosis ≥50% (OR: 26.61; 95% CI: 1.06 - 664.26; p = 0.04) remained associated with all-cause mortality. Thus, HSCT recipients with COVID-19 experienced high mortality, highlighting the need for full vaccination and infection prevention measures.

Disparities in COVID-19 mortality amongst the immunosuppressed: A systematic review and meta-analysis for enhanced disease surveillance

BACKGROUND

Effective disease surveillance, including that for COVID-19, is compromised without a standardised method for categorising the immunosuppressed as a clinical risk group.

METHODS

We conducted a systematic review and meta-analysis to evaluate whether excess COVID-associated mortality compared to the immunocompetent could meaningfully subdivide the immunosuppressed. Our study adhered to UK Immunisation against infectious disease (Green Book) criteria for defining and categorising immunosuppression. Using OVID (EMBASE, MEDLINE, Transplant Library, and Global Health), PubMed, and Google Scholar, we examined relevant literature between the entirety of 2020 and 2022. We selected for cohort studies that provided mortality data for immunosuppressed subgroups and immunocompetent comparators. Meta-analyses, grey literature and any original works that failed to provide comparator data or reported all-cause or paediatric outcomes were excluded. Odds Ratios (OR) and 95% confidence intervals (CI) of COVID-19 mortality were meta-analysed by immunosuppressed category and subcategory. Subgroup analyses differentiated estimates by effect measure, country income, study setting, level of adjustment, use of matching and publication year. Study screening, extraction and bias assessment were performed blinded and independently by two researchers; conflicts were resolved with the oversight of a third researcher. PROSPERO registration number is CRD42022360755.

FINDINGS

We identified 99 unique studies, incorporating data from 1,542,097 and 56,248,181 unique immunosuppressed and immunocompetent patients with COVID-19 infection, respectively. Compared to immunocompetent people (pooled OR, 95%CI), solid organ transplants (2.12, 1.50-2.99) and malignancy (2.02, 1.69-2.42) patients had a very high risk of COVID-19 mortality. Patients with rheumatological conditions (1.28, 1.13-1.45) and HIV (1.20, 1.05-1.36) had just slightly higher risks than the immunocompetent baseline. Case type, setting income and mortality data matching and adjustment were significant modifiers of excess immunosuppressed mortality for some immunosuppressed subgroups.

INTERPRETATION

Excess COVID-associated mortality among the immunosuppressed compared to the immunocompetent was seen to vary significantly across subgroups. This novel means of subdivision has prospective benefit for targeting patient triage, shielding and vaccination policies during periods of high disease transmission.

COVID-19 in hematopoietic stem-cell transplant recipients: A systematic review and meta-analysis of clinical characteristics and outcomes

Patients who undergo hematopoietic stem-cell transplantation (HSCT) are more susceptible to developing severe forms of COVID-19 with an increased risk of mortality. The aim of this study was to analyze, by performing a systematic review and meta-analysis, all studies that evaluated COVID-19 in HSCT adult recipients and present clinical characteristics and outcomes. Studies were eligible for inclusion if they: (I) described the clinical characteristics of COVID-19 in adult (aged 18 years old or above) HSCT recipients; (II) described outcomes of COVID-19 in this population, mainly lethality; (III) were full-text articles. We searched MedLine, Embase, SCOPUS, LILACS and Web of Science for full-text studies that evaluated COVID-19 in adult HSCT patients until 26 Apr 2023. Two independent reviewers screened the articles and extracted the data. The Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Studies Reporting Prevalence Data was used to assess quality of the included studies. Meta-analysis was performed and the pooled prevalence of severe/critical disease and of death with a 95% CI was calculated with the random-effects model. Sixteen studies were included; seven (43.7%) were multicenter. Most of the studies were from Europe (37.5%). All of them had a low risk of bias using the JBI Checklist. A total of 1186 patients were included. Allogeneic HSCT patients were the majority in most studies, with a total of 861 patients (72.5%). The symptomatic rate was 79.4%. The pooled prevalence of severe/critical COVID-19 was 24.0% (95% CI 0.13-0.36; I2  = 94%; n = 334/990). The pooled prevalence of death for the entire population was 17% (95% CI 0.13-0.22; I2  = 76%; n = 221/1117), 17% (95% CI 0.12-0.23; I2  = 67%; n = 152/822) for allogeneic-HSCT and 14% (95% CI 0.08-0.22; I4  = 65%; n = 48/293) for autologous-HSCT. In conclusion, frequently the infection of SARS-CoV-2 in HSCT was symptomatic and lethality is higher than in general population. Thus, it is essential to focus on the implementation of measures to mitigate the risk of SARS-CoV-2 infection in this population, as well as to carefully assess HSCT recipients who develop COVID-19.

Updated COVID-19 clearance time among patients with cancer in the Delta and Omicron waves

BACKGROUND

COVID-19 infection delays therapy and in-person evaluation for oncology patients, but clinic clearance criteria are not clearly defined.

METHODS

We conducted a retrospective review of oncology patients with COVID-19 at a tertiary care center during the Delta and Omicron waves and compared clearance strategies.

RESULTS

Median clearance by two consecutive negative tests was 32.0 days (Interquartile Range [IQR] 22.0-42.5, n = 153) and was prolonged in hematologic malignancy versus solid tumors (35.0 days for hematologic malignancy, 27.5 days for solid tumors, p = 0.01) and in patients receiving B-cell depletion versus other therapies. Median clearance by single negative test was reduced to 23.0 days (IQR 16.0-33.0), with recurrent positive rate 25.4% in hematologic malignancy versus 10.6% in solid tumors (p = 0.02). Clearance by a predefined waiting period required 41 days until an 80% negative rate.

CONCLUSIONS

COVID-19 clearance remains prolonged in oncology patients. Single-negative test clearance can balance delays in care with risk of infection in patients with solid tumors.

Lung Transplant Recipients and COVID-19: Report of Two Cases

Although the WHO has declared the end of the pandemic emergency, COVID-19 still poses a threat to immunocompromised patients. The COVID-19 pandemic has spread throughout the world over the last two years, causing a significant number of deaths. After three years, SARS-CoV-2 has lost its initial lethality but has shown a significantly worse prognosis for immunocompromised patients, especially those who have undergone lung transplantation, compared with the general population. This paper presents two compelling case studies that highlight the complex challenges of COVID-19 infection in lung transplant recipients. The first case involves a patient who received a bilateral lung transplant for pulmonary artery hypertension in 2009, followed by a kidney transplant in 2022. Surprisingly, despite an initially favorable clinical course after contracting COVID-19, the patient deteriorated rapidly and died within a few days due to extensive lung involvement. This case highlights the unpredictable nature of COVID-19 and its potentially devastating impact on lung transplant recipients. The second case involves a patient who underwent bilateral lung transplantation five years earlier for chronic obstructive pulmonary disease (COPD). This individual also contracted COVID-19 and had pre-existing complications, including chronic lung allograft rejection (CLAD) and diffuse bronchial stenosis. Following viral infection, the patient's clinical condition deteriorated rapidly, with worsening bronchial stenosis. This case highlights the ability of COVID-19 to exacerbate pre-existing pulmonary complications in transplant recipients. These cases highlight the urgent need for increased vigilance and tailored management strategies when dealing with COVID-19 in lung transplant recipients. The unpredictable and detrimental course of the disease observed in these patients highlights the importance of implementing stringent preventive measures, such as vaccination and strict adherence to infection control protocols, in this vulnerable population. Further research is essential to gain a full understanding of the unique dynamics of COVID-19 in lung transplant recipients and to develop targeted interventions to improve their outcomes.

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.

Allogeneic hematopoietic stem cell transplantation in the COVID-19 era

Allogeneic hematopoietic stem-cell transplantation (allo-HSCT) recipients are especially vulnerable to coronavirus disease 19 (COVID-19), because of their profound immunodeficiency. Indeed, the first pandemic wave was marked by a high mortality rate in this population. Factors increasing immunodepression such as older age, immunosuppressive treatments or a short delay between transplant and infection appear to worsen the prognosis. Many changes in clinical practice had to be implemented in order to limit this risk, including postponing of transplant for non-malignant diseases, preference for local rather than international donations and for peripheral blood as stem cell source, and the widespread use of cryopreservation. The great revolution in the COVID-19 pandemic came from the development of mRNA vaccines that have shown to be able to prevent severe forms of the disease. More than 75% of allo-HSCT recipients develop seroconversion after 2 doses of vaccine. Multiple studies have identified lymphopenia, exposure to immunosuppressive or anti-CD20 therapies, and a short post-transplant period as factors associated with a poor response to vaccination. The use of repeated injections of the vaccine, including a third dose, not only improves the seroconversion rate but also intensifies the immune response, both in B cells and T cells. Vaccines are an effective and well-tolerated method in this high-risk population. Some studies investigated the possibility of immune protection being transferred from a vaccinated donor to a recipient, with encouraging initial results. However, dynamic mutations and immune escape of the virus can lead to breakthrough infections with new variants in vaccinated individuals and still represent a threat of severe disease in allo-HSCT recipients. New challenges include the need to adapt vaccine protection to emerging variants.

Cellular and Humoral SARS-CoV-2 Vaccination Responses in 192 Adult Recipients of Allogeneic Hematopoietic Cell Transplantation

To determine factors influencing the vaccination response against SARS-CoV-2 is of importance in recipients of allogeneic hematopoietic cell transplantation (allo-HCT) as they display an increased mortality after SARS-CoV-2 infection, an increased risk of extended viral persistence and reduced vaccination response. Real-life data on anti-SARS-CoV-2-S1-IgG titers (n = 192) and IFN-γ release (n = 110) of allo-HCT recipients were obtained using commercially available, validated assays after vaccination with either mRNA (Comirnaty™, Pfizer-BioNTech™, NY, US and Mainz, Germany or Spikevax™, Moderna™, Cambridge, Massachusetts, US) or vector-based vaccines (Vaxzevria™,AstraZeneca™, Cambridge, UK or Janssen COVID-19 vaccine™Johnson/Johnson, New Brunswick, New Jersey, US), or after a heterologous protocol (vector/mRNA). Humoral response (78% response rate) was influenced by age, time after transplantation, the usage of antithymocyte globulin (ATG) and ongoing immunosuppression, specifically corticosteroids. High counts of B cells during the vaccination period correlated with a humoral response. Only half (55%) of participants showed a cellular vaccination response. It depended on age, time after transplantation, ongoing immunosuppression with ciclosporin A, chronic graft-versus-host disease (cGvHD) and vaccination type, with vector-based protocols favoring a response. Cellular response failure correlated with a higher CD8+ count and activated/HLA-DR+ T cells one year after transplantation. Our data provide the basis to assess both humoral and cellular responses after SARS-CoV2 vaccination in daily practice, thereby opening up the possibility to identify patients at risk.

Zelltherapie in den Zeiten von SARS-CoV-2

Ein breites Spektrum von Disruptionen, aber auch blitzschnelle Innovationen, hat die SARS-CoV-2 Pandemie gebracht. Dieser Übersichtsartikel betrachtet die Pandemie aus der Warte der Zelltherapie; konkret werden vier Aspekte untersucht: Wie unterscheiden sich die Risiken von Zelltherapie-Patienten mit SARS-CoV-2 Infektion und COVID von denen der Allgemeinbevölkerung? Sind Empfänger von Zelltherapien, hier speziell autologe und allogene Stammzelltransplantationsempfänger sowie Empfänger von CAR-T-Zell-Präparaten, klinisch relevant durch SARS-CoV-2 Vakzine immunisierbar? Welche Auswirkungen hat die Pandemie mit Spenderausfallrisiko und Zusammenbruch von Supply Chains auf die Versorgung mit Zelltherapeutika? Gibt es Zelltherapeutika, die bei schwerem COVID therapeutisch nutzbringend eingesetzt werden können? In aller Kürze, das erwartete massiv erhöhte Risiko von Zelltherapie-Patienten, im Infektionsfall einen schweren Verlauf zu erleiden oder zu sterben, wurde bestätigt. Die Vakzine induziert jedoch bei vielen dieser Patienten humorale und zelluläre Immunität, wenn auch weniger zuverlässig als bei Gesunden. Dank kreativer Lösungen gelang es, die Versorgung mit Zelltherapeutika im Wesentlichen uneingeschränkt aufrecht zu erhalten. SARS-CoV-2-spezifische T-Zell-Präparate für den adoptiven Immuntransfer wurden entwickelt, eine therapeutische Konstellation diese anzuwenden ergab sich jedoch nicht. Therapiestudien mit mesenchymalen Stromazellen beim schweren COVID laufen weltweit; die Frage der Wirksamkeit bleibt zurzeit offen, bei jedoch substanziellem Optimismus in der Szene. Einige der Erkenntnisse und Innovationen aus der SARS-CoV-2-Pandemie können möglicherweise verallgemeinert werden und so auf die Zeit nach ihrem Ende langfristig nachwirken.