COVID-19 and HSCT (Hematopoietic stem cell transplant)

HSCT recipients are at increased risk for COVID-19-associated morbidity and mortality. Early treatment of symptomatic SARS-CoV-2 infection is an important means to decreasing risk for severe disease and death. While some HSCT recipients, particularly those who are early post-transplant and severely immunosuppressed, may have diminished response to COVID-19 vaccines, the benefits of vaccination are uncontested. Public health, healthcare facility and individual level approaches are all necessary to mitigate risk for infection in this vulnerable population.     

COVID-19 in Liver Transplant Recipients

Background and AimsCoronavirus disease 2019 (COVID-19) has infected over 93 million people worldwide as of January 14, 2021. Various studies have gathered data on liver transplant patients infected with COVID-19. Here, we discuss the presentation of COVID-19 in immunosuppressed patients with prior liver transplants. We also evaluate patient outcomes after infection.MethodsWe searched the PubMed database for all studies focused on liver transplant patients with COVID-19.ResultsWe identified eight studies that evaluated COVID-19 infection in liver transplant patients (n=494). Hypertension was the most prevalent comorbidity in our cohort. Calcineurin inhibitors were the most common immunosuppressant medications in the entire cohort. The average time from liver transplant to COVID-19 infection in our cohort was 74.1 months. Fever and cough, at 70% and 62% respectively, were the most common symptoms in our review. In total, 50% of the patients received hydroxychloroquine as treatment for COVID-19. The next most prevalent treatment was azithromycin, given to 30% of patients in our cohort. In total, 80% of the patients were admitted to a hospital and 17% required intensive care unit-level care, with 21% having required mechanical ventilation. Overall mortality was 17% in our review.ConclusionsGiven the immunocompromised status of liver transplant patients, more intensive surveillance is necessary for severe cases of COVID-19 infection. As liver transplantations have been restricted during the COVID-19 pandemic, further investigation is warranted for studying the risk of COVID-19 infection in liver transplant patients.     

Impact of Hypertension on COVID-19 Burden in Kidney Transplant Recipients: An Observational Cohort Study

Background: COVID-19 severity is determined by cardiometabolic risk factors, which can be further aggravated by chronic immunosuppression in kidney transplant recipients (KTRs). We aimed to verify the main risk factors related to hypertension (HTN) that contribute to COVID-19 progression and mortality in that population. Methods: Retrospective analysis of 300 KTRs from March 2020 to August 2020 in a single center. We compared the main outcomes between HTN (n = 225) and non-HTN (n = 75), including admission to the intensive care unit (ICU), development of acute kidney injury (AKI), need for invasive mechanical ventilation or oxygen, and mortality. Results: Of the patients in the study, 57.3% were male, 61.3% were white, the mean age was 52.5 years, and 75% had HTN. Pre-existing HTN was independently associated with higher rates of mortality (32.9%, OR = 1.96, p = 0.036), transfer to the ICU (50.7%, OR = 1.94, p = 0.017), and AKI with hemodialysis (HD) requirement (40.4%, OR = 2.15, p = 0.011). In the hypertensive group, age, diabetes mellitus, heart disease, smoking, glycemic control before admission, C-reactive protein, lactate dehydrogenase, lymphocytes, and D-dimer were significantly associated with COVID-19 progression and mortality. Both lower basal and previous estimated glomerular filtration rates posed KTRs with HTN at greater risk for HD requirement. Conclusions: Therefore, the early identification of factors that predict COVID-19 progression and mortality in KTRs affected by COVID-19 contributes to therapeutic decisions, patient flow management, and allocation of resources.     

The Yield and Safety of Thoracentesis in Hematopoietic Stem Cell Transplantation Recipients

The aim of this study was to assess the diagnostic value and safety of thoracentesis in hematopoietic stem cell transplantation (HSCT) recipients. We identified all hospitalized HSCT recipients who underwent thoracentesis from 1998 to 2006. We collected patients’ clinical characteristics, indications for thoracenstesis, the complications of the procedure, and the etiology of the pleural effusion. A total of 50 thoracentesis findings were analyzed. Twenty-six patients underwent allogeneic HSCT, while 24 patients underwent autologous HSCT. The main indications for performing thoracentesis were to rule out infection and document or diagnose malignancy. Pleural effusions were characterized as exudate in 33 patients (66%). A specific diagnosis based on the thoracentesis was made in 13 patients (26%). These were malignancy in nine patients, parapneumonic in three patients, and empyema in one patient. The only documented complication was pneumothorax in five patients. The presence of exudative effusion and underlying solid malignancy were associated with specific diagnosis by thoracentesis (p = 0.0001 and 0.013, respectively). In spite of the tendency of HSCT recipients to develop pulmonary infections, complex parapneumonic effusions are rarely diagnosed by thoracentesis. The rate of complications is comparable to other patient populations.     

Australia and New Zealand Transplant and Cellular Therapies (ANZTCT) position statement: COVID-19 management in patients with haemopoietic stem cell transplant and chimeric antigen receptor T cell

Patients with post-haemopoietic stem cell transplant or chimeric antigen receptor T -cell (CAR-T) therapy face a significant risk of morbidity and mortality from coronavirus disease 2019 because of their immunosuppressed state. As case numbers in Australia and New Zealand continue to rise, guidance on management in this high-risk population is needed. Whilst we have learned much from international colleagues who faced high infection rates early in the pandemic, guidance relevant to local health system structures, medication availability and emerging therapies is essential to equip physicians to manage our patients optimally.     

Human Herpesvirus 6 Meningoencephalitis in Allogeneic Hematopoietic Stem Cell Transplant Recipients

We retrospectively investigated the clinical characteristics of human herpesvirus 6 (HHV-6) meningoencephalitis within 100 days after allogeneic hematopoietic stem cell transplantation (HSCT). Of 1148 patients who received transplants between January 1999 and December 2003, 11 patients (0.96%) with HHV-6 meningoencephalitis were identified. Ten of 11 recipients received hematopoietic stem cells from donors other than HLA-identical siblings. Confusion was the most frequent central nervous system (CNS) symptom, and a skin rash with high-grade fever preceded the CNS symptoms in 9 patients. Magnetic resonance imaging of the brain showed an abnormal increased T2 signal in the hypothalamus of 5 patients. Eight patients were treated with ganciclovir, and an improvement of CNS symptoms was obtained in 3 patients; 3 patients treated with acyclovir showed no improvement. Improvement in the meningoencephalitis seemed less frequent in patients with abnormal findings in the hypothalamus than in those without such findings. Because the symptoms of HHV-6 meningoencephalitis mimicked those of cyclosporine- or tacrolimus-induced encephalopathy, the drugs were withdrawn at the onset of CNS symptoms in 10 patients, resulting in the development of grade IV graft-versus-host disease (GVHD) in 5 patients. Three patients died of HHV-6 meningoencephalitis, and 6 died of other causes, including GVHD. In conclusion, HHV-6 meningoencephalitis is a rare but potentially life-threatening complication in patients who undergo allogeneic HSCT. Careful assessment of the clinical findings and the brain may allow early and precise diagnosis of HHV-6 meningoencephalitis and contribute to improving its prognosis.     

COVID-19 in Liver Transplant Recipients - A Series with Successful Recovery

The severe acute respiratory syndrome corona virus-2 (referred to as SARS CoV2) pandemic had a great impact on public life in general as well as on populations with pre-existing disease and co-morbidities. Liver transplant and immunosuppressant medication predisposes to more severe disease and is often associated with poor outcome. The clinical features, disease course, treatment and process of modulating the immunosuppression is challenging. Here, we describe the clinical presentation, treatment and outcomes in six liver transplant recipients. Out of those six patients, three had mild, one had moderate and one had severe COVID-19, and one was asymptomatic. The immunosuppression minimization or withdrawal was done based upon the clinical severity. Consideration of tocilizumab and/o convalescent plasma as well as antivirals i.e. remdesvir done in severe cases. The routine practice of prophylactic anticoagulation, consideration of repurposed drugs (i.e. teicoplanin and doxycycline), and watchful monitoring of asymptomatic recipients helped to achieve an uneventful recovery.     

Mesenchymal Stem Cells in Stem Cell Transplant Recipients Are Damaged and Remain of Host Origin

The aim of this study was to investigate the expansion capacity and origin of bone marrow-derived mesenchymal stem cells (MSCs) in 34 patients who received a sex-mismatched stem cell transplant (SCT). Polymerase chain reaction (PCR) analysis of the amelogenin gene (AMEL) was used to detect donor-derived MSCs. Cultured MSCs were hybridized with fluorescence in situ hybridization (FISH) probes for chromosomes X and Y to distinguish cells of donor origin from those of host origin. The MSCs of 31 of the 34 patients showed confluent stroma, and the MSCs from 24 of these 31 patients were successfully passaged more than 5 times and were able to be used for PCR and FISH analyses.The colony-forming unit-fibroblast, confluence time, and passage numbers of the MSCs and the colony-forming capacity of the hematopoietic progenitor cells of the patients were significantly different from those of 30 healthy control subjects. Flow cytometry results showed that the proportion of CD14(+)CD45(+) cells, which are regarded as monocytes/macrophages, in cultured MSCs (fifth passage) was less than 0.04%. PCR and FISH analyses revealed that the MSC-derived cells in all 24 patients were from the host. In conclusion, the expansion capacity of MSCs in patients who receive an SCT is damaged, and the MSCs originate from the host.     

Hematopoietic Stem Cell Transplantation: The Vancouver Experience

Hematopoietic stem cell transplantation has been available as a therapeutic modality for selected adult patients in Vancouver, British Columbia since 1981. We report on the history, progress, and future prospects of the Leukemia/Bone Marrow Transplantation Program of British Columbia. The basic mechanisms and indications for hematopoietic stem cell transplantation are outlined. Limitations of this procedure are also examined, particularly that of associated toxicities such as graft-versus-host-disease.     

Myeloablative Versus Reduced Intensity Conditioning Regimens for Allogeneic Hematopoietic Stem Cell Transplant for Acute Myeloid Leukemia and Myelodysplastic Syndrome: A Retrospective Analysis

The conditioning regimens used for the allo-HSCT include either myeloablative conditioning (MAC) or reduced intensity conditioning (RIC) regimens based on the age, performance status and co-morbidities. Studies comparing the survival outcomes of RIC and MAC allo-HSCT in AML and MDS patients have reported contradictory results. We therefore retrospectively analyzed our data of AML and MDS patients who received MAC and RIC allo-HSCT at our center and compared the long term outcome of the two conditioning regimens. One hundred twenty six consecutive patients were evaluated, 32 (25.4%) underwent MAC allo-HSCT and 94 (74.6%) underwent RIC allo-HSCT. The most common MAC regimen used was busulfan plus cyclophosphamide and the most common RIC regimen used was fludarabine plus melphalan. The median age was higher in RIC group (44 years, range 4–75 years) compared to MAC group (31 yrs, range 6–51 yrs, p = 0.001). There was no significant difference in terms of overall survival (p = 0.498), relapse-free survival (p = 0.791) and non-relapse mortality (p = 0.366) between the two groups. In multivariate analysis, only chronic graft-versus-host disease resulted in decreased risk of relapse and improved overall survival irrespective of the conditioning regimens used.     

Urinary Elafin and Kidney Injury in Hematopoietic Cell Transplant Recipients

Background and objectives

Graft-versus-host disease (GVHD) is associated with kidney injury after hematopoietic cell transplantation (HCT). Because plasma elafin levels correlate with skin GVHD, this study examined urinary elafin as a potential marker of renal inflammation and injury.

Design, setting, participants, & measurements

Urine was collected prospectively on 205 patients undergoing their first HCT from 2003 to 2010. Collections were done at baseline, weekly through day 100, and monthly through year 1 to measure elafin and urine albumin-to-creatinine ratio (ACR). Associations between urinary elafin levels and microalbuminuria, macroalbuminuria, AKI and CKD, and mortality were examined using Cox proportional hazards or linear regression models. Available kidney biopsy specimens were processed for immunohistochemistry.

Results

Mean urinary elafin levels to day 100 were higher in patients with micro- or macroalbuminuria (adjusted mean difference, 529 pg/ml; P=0.03) at day 100 than in those with a normal ACR (adjusted mean difference, 1295 pg/ml; P<0.001). Mean urinary elafin levels were higher in patients with AKI compared with patients without AKI (adjusted mean difference, 558 pg/ml; P<0.01). The average urinary elafin levels within the first 100 days after HCT were higher in patients who developed CKD at 1 year than in patients without CKD (adjusted mean difference, 894 pg/ml; P=0.002). Among allogeneic recipients, a higher proportion of patients with micro- or macroalbuminuria at day 100 also had grade II-IV acute GVHD (80% and 86%, respectively) compared with patients with a normal ACR (58%; global P<0.01). Each increase in elafin of 500 pg/ml resulted in a 10% increase in risk of persistent macroalbuminuria (hazard ratio, 1.10; 95% confidence interval [95% CI], 1.06 to 1.13; P<0.001) and a 7% increase in the risk of overall mortality (95% CI, 1.02 to 1.13, P<0.01). Renal biopsy specimens from a separate cohort of HCT survivors demonstrated elafin staining in distal and collecting duct tubules.

Conclusion

Higher urinary elafin levels are associated with an increased risk of micro- and macroalbuminuria, AKI and CKD, and death after HCT.