Pulmonary infectious complications after hematopoietic stem cell transplantation: a practical guide to clinicians

Pulmonary complications of bone marrow transplantation

Bone marrow transplantation, now often known as haematopoietic stem cell transplantation (HSCT), is a complex choreographed procedure used to treat both acquired and inherited disorders of the bone marrow. It has proven invaluable as therapy for haematological and immunological disorders, and more recently in the treatment of metabolic and enzyme disorders. As the number of performed transplants grows annually, and with patients enjoying improved survival, a knowledge of both early and late complications of HSCT is essential for respiratory trainees and physicians in practice. This article highlights the spectrum of respiratory complications, both infectious and non-infectious, the timeline of their likely occurrence, and the approaches used for diagnosis and treatment, keeping in mind that more than one entity may occur simultaneously. As respiratory issues are often a leading cause of short- and long-term morbidity, consideration of a combined haematology/respiratory clinic may prove useful in this patient population.

High-Dose Busulfan-Fludarabine Conditioning and Low Alveolar Volume as Predictors of Pulmonary Complications after Allogeneic Peripheral Blood Stem Cell Transplantation in Children

This study was conducted to investigate risk factors and predictors of infectious and noninfectious pulmonary complications (PCs) after allogeneic hematopoietic stem cell transplantation in children. We conducted a retrospective analysis of the post-transplantation PCs of 240 patients who underwent allogeneic peripheral blood stem cell transplantation (allo-PBSCT) between 2009 and 2018. Transplantation-related variables, pretransplantation baseline spirometry, body plethysmography, and CO diffusing capacity were analyzed for association with the development of infectious PCs (IPCs) and noninfectious PCs (NIPCs). Compared with the control group, the PC group had statistically significantly lower overall survival (50.6% versus 77.8%; P < .001), higher disease-related mortality (26.6% versus 54.4%; P < .001), and higher nonrelapse mortality (31.6% versus 5.9%; P < .001). A greater number of patients received pretransplantation conditioning with high-dose busulfan (520 mg/m²; Bu 520) and fludarabine (160 mg/m²; Flu 160) in both the IPC and NIPC groups. In the multivariate Cox hazard regression analysis, Bu 520 significantly increased the risk of NIPCs (hazard ratio [HR], 1.99; 95% confidence interval [CI], 1.13 to 3.49; P = .016), and Flu 160 was a predictor of IPCs (HR, 1.99; 95% CI, 1.13 to 3.49; P = .016). The Bu 520 + Flu 160 regimen was associated with a statistically significant increase in the risk of NIPC (HR, 1.92; 95% CI, 1.09 to 3.37; P = .023). In a multivariate analysis using pretransplantation baseline lung function, alveolar volume (VA) grades 3 and 4 and lung function score (LFS) VA categories III and IV were associated with increased risk for both IPCs and NIPCs. Our data identify receipt of the high-dose Bu-Flu conditioning regimen as an independent risk factor for NIPCs after allo-PBSCT. Impaired CO diffusing capacity before transplantation, especially VA reduction, contributes to the risk of post-transplantation pulmonary complications, and pretransplantation risk can be estimated by grading the degree of insufficiency of VA and LFS VA.

Pulmonary Complications in Hematopoietic Stem Cell Transplant Recipients-A Clinician Primer

Hematopoietic stem cell transplants (HSCT) are becoming more widespread as a result of optimization of conditioning regimens and prevention of short-term complications with prophylactic antibiotics and antifungals. However, pulmonary complications post-HSCT remain a leading cause of morbidity and mortality and are a challenge to clinicians in both diagnosis and treatment. This comprehensive review provides a primer for non-pulmonary healthcare providers, synthesizing the current evidence behind common infectious and non-infectious post-transplant pulmonary complications based on time (peri-engraftment, early post-transplantation, and late post-transplantation). Utilizing the combination of timing of presentation, clinical symptoms, histopathology, and radiographic findings should increase rates of early diagnosis, treatment, and prognostication of these severe illness states.

Impairments in dyspnea, exercise capacity, physical activity and quality of life of allogeneic hematopoietic stem cell transplantation survivors compared with healthy individuals: a cross sectional study

Background: A limited number of studies have reported impairments in physical activity, exercise capacity and quality of life (QOL) in allogeneic hematopoietic stem cell transplantation (allogeneic-HSCT) recipients. We aimed to compare dyspnea, exercise capacity, physical activity and QOL in allogeneic-HSCT recipients with age-gender matched healthy individuals, since this has not been investigated hitherto. Methods: A total of 80 allogeneic-HSCT recipients (>100 days status post-transplantation) (38.88 ± 13.25 years) and 60 healthy individuals (35.92 ± 10.83 years) were compared. Exercise capacity [6-minute walk test (6-MWT)], physical activity level (total and active energy expenditure, moderate and severe physical activity duration, number of steps, average metabolic equivalent, lying down and sleeping duration) [metabolic holter], QOL [European Organization for Research and Treatment of Cancer QOL Questionnaire (EORTCQOL)], dyspnea [Modified Medical Research Council Dyspnea scale] and pulmonary functions [spirometry] were evaluated. Clinical trials #NCT03606005. Results: Six-MWT distance, energy expenditure, physical activity duration, number of steps, average metabolic equivalent, global health status, functional and social function subscales of EORTCQOL were significantly lower in recipients compared with controls; dyspnea score, lying down, sleep durations, symptom and fatigue subscales of EORTCQOL were significantly higher in recipients compared with controls (p < 0.05). Conclusion: Dyspnea during daily living activities, exercise capacity, physical activity level and QOL are considerably impaired in allogeneic-HSCT recipients during post-engraftment period. To improve impaired outcomes, allogeneic-HSCT recipients should be oriented to cardiopulmonary rehabilitation programs.

Bronchoalveolar lavage with pediatric flexible fibreoptic bronchoscope in pediatric haematopoietic stem cell transplant patients: Nursing considerations for operative complications

PURPOSE

Bronchoalveolar lavage (BAL) with pediatric flexible fibreoptic bronchoscopy (FB) is used for diagnostic and therapeutic purposes in pediatric haematopoietic stem cell transplant (HSCT) patients with pulmonary complications. The aim of our study was to evaluate complications in pediatric HSCT patients undergoing BAL/FB and to explore the nursing emphases on complications.

DESIGN AND METHODS

We performed a retrospective, case-controlled study to evaluate perioperative complications of HSCT children. BAL/FB was conducted for 42 children with HSCT who experienced pulmonary complications between January 2017 and January 2018 within a tertiary hospital. Forty patients diagnosed with general pneumonia were randomly selected during the same period and served as the control group. We analyzed the signs and symptoms of all patients and compared the operative complications between the two groups. Furthermore, we presented the methods used to manage complications.

RESULTS

The presence of cough, lung rales, and imaging findings in the HSCT patients was significantly different from that of the control group (p < 0.0001). The complication rate was 66.67% (28/42) in the HSCT group and 22.5% (9/40) in the control group, and the difference was significant (p < 0.0001). Twelve out of 42 HSCT patients experienced airway mucosal bleeding (28.57%), and six had transient fever (14.29%). The topical use of epinephrine diluted saline (1:10,000) was highly effective for controlling airway mucosal bleeding without causing fluctuations in blood pressure.

PRACTICE IMPLICATIONS

There were more perioperative complications in the HSCT patients than in the general pneumonia patients who underwent BAL/FB. Airway mucosal bleeding was a key focus of perioperative nursing in HSCT patients undergoing bronchoscopy as main complication. BAL with the use of epinephrine diluted saline (1:10,000) effectively decreased airway mucosal bleeding.

Restoring antiviral immunity with adoptive transfer of ex-vivo generated T cells

PURPOSE OF REVIEW

Latent viruses such as cytomegalovirus (CMV), Epstein-Barr virus (EBV) and adenovirus (ADV) often reactivate in immunocompromised patients, contributing to poor clinical outcomes. A rapid reconstitution of antiviral responses via adoptive transfer of virus-specific T cells (VSTs) can prevent or eradicate even refractory infections. Here, we evaluate this strategy and the associated methodological, manufacturing and clinical advances.

RECENT FINDINGS

From the early pioneering but cumbersome efforts to isolate CMV-specific T cell clones, new approaches and techniques have been developed to provide quicker, safer and broader-aimed ex-vivo antigen-specific cells. New manufacturing strategies, such as the use of G-Rex flasks or 'priming' with a library of overlapping viral peptides, allow for culturing greater numbers of cells that could be patient-specific or stored in cell banks for off-the-shelf applications. Rapid isolation of T cells using major histocompatibility complex tetramer or cytokine capture approaches, or genetic reprogramming of cells to target viral antigens can accelerate the generation of potent cellular products.

SUMMARY

Advances in the ex-vivo generation of VSTs in academic medical centres and as off-the-shelf blood bank-based or commercially produced reagents are likely to result in broader accessibility and possible manufacturing cost reduction of these cell products, and will open new therapeutic prospects for vulnerable and critically ill immunocompromised patients.