Noninfectious pulmonary complications of haematopoietic stem cell transplantation

Contemporary review of critical illness following allogeneic hematopoietic stem cell transplant in adults

Significant advancements have been made in the care of the allogeneic hematopoietic stem cell (HCT) recipient. However, they remain one of the most vulnerable groups of patients who may be admitted to the ICU. On the one hand, they have been administered treatment with the goal of achieving cure for their underlying disease, yet their unique immunocompromised trajectory and treatment-associated toxicities continue to challenge the intensivist from a diagnostic and management perspective. While infectious disease, allogeneic HCT and critical care research have improved outcomes, there remain significant areas to advance critical care management to further increase the likelihood of bridging to an acceptable quality of life. This review focuses on care of the critically ill patient undergoing allogeneic HCT for hematologic malignancies, critical care conditions that may arise, contemporary practices in their management, and areas to focus future research.

Mortality is increased in those with a ≥10% reduction in spirometry following allogeneic hematopoietic stem cell transplant: a retrospective 5-year follow-up study from a single transplant service

BACKGROUND

Pulmonary graft versus host disease is a common and serious complication of haematopoietic stem cell transplant (HSCT). Early diagnosis is essential for rapid treatment before irreversible changes in lung function occur. The NIH support that a decline in forced expiratory volume in 1 second (FEV1) of ≥10% from baseline values require further investigation and close monitoring post HSCT-transplant. Previous research demonstrates that a 10-19% and ≥20% reduction in FEV1, within 6 months of transplant, is associated with higher odds of 1-mortality; however, to the authors' knowledge, there is no long-term follow-up data of FEV1 decline with an onset after the first 6-month period.

OBJECTIVES

We aimed to investigate the clinical significance of a ≥10% decrement in FEV1 measured by spirometry for predicting all-cause mortality in HSCT recipients, over a period of 5-years. A comparison was made to patients who met the NIH diagnostic criteria for lung GvHD.

STUDY DESIGN

Long-term follow-up data of patients who received an allogeneic HSCT at Westmead was retrospectively audited, using a censoring period of 5-years. A decrease in lung function was defined as a change in FEV1 by ≥10% from their best value, usually at the beginning of the transplant process. Recovery was defined as a ≥10% increase in FEV1, from the patient's maximum decline in lung function. A diagnosis of lung GvHD was made when the following criteria were met: FEV1/FVC ratio of < 0.7, and an FEV1 <75% of predicted normal with ≥10% reduction over less than two years and evidence of gas trapping.

RESULTS

Data from 364 patients who underwent an allogeneic HSCT between 2013 and 2019 were analysed; 173 patients (47.7%) experienced a ≥10% reduction in FEV1 after transplant. Ninety-five patients experienced an FEV1 decline lasting <6 months and were likely to recover over half their lost lung function (median % FEV recovered = 68.7%). Seventy-eight patients experienced an FEV1 decline lasting >6 months and were unlikely to recover any lost lung function (median % FEV recovered = 0%). There was a significant relationship between ≥10% FEV1 decline and death, X2(1, 364) = 15.67, p <0.001. All-cause mortality was doubled in those who experienced ≥10% FEV1 decline (34%), compared with those without any decline (16%). Mortality was highest in those who experienced decline without any recovery (OR = 2.98 [1.64-5.41]). However, in the group who had a decline and then later recovered mortality was still elevated (OR = 2.08 [1.17-3.69]) compared with those who did not experience any FEV1 decline ≥10%.

CONCLUSION

Mortality risk is elevated from the first ≥10% reduction in FEV1 and remains elevated even if FEV1 recovery occurs. Individuals whose FEV1 declines for longer than 6 months are unlikely to experience FEV1 recovery, despite treatment. An FEV1 decline of at least ≥10% from pre-transplant value should trigger rapid assessment to identify and treat mortality risks, and to minimise decline in overall respiratory function.

Role of Cardio-Oncology Rehabilitation in Hematopoietic Stem Cell Transplantation and Chimeric Antigen Receptor T-Cell (CAR-T) Therapy

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) and chimeric antigen receptor T-cell (CAR-T) therapy often lead to severe sarcopenia and cachexia during treatment, making it difficult to maintain exercise tolerance. Consequently, "cancer rehabilitation" programs have been implemented to sustain and improve physical activity and motor function. Hematologic malignancies often involve the use of cardiotoxic drugs. Moreover, graft-vs.-host disease associated with allo-HSCT and the cytokine release syndrome in CAR-T therapy elevate the risk of cardiovascular complications. Thus, establishing "cardio-oncology rehabilitation" (CORE) is essential to support cancer patients and survivors. CORE is expected to enhance quality of life, improve cardiopulmonary function, reduce cancer and cardiac events recurrence, and prolong survival. Our institution conducts cardiopulmonary exercise testing before HSCT and CAR-T therapy, with exercise prescriptions based on heart rate at the anaerobic threshold and guidance on resistance exercises. This report discusses current trends in CORE for patients undergoing HSCT and CAR-T therapy, along with future challenges.

Non-infectious pulmonary complications after haematopoietic progenitor transplantation: a diagnostic approach

Haematopoietic stem cell transplantation (HCT) is an established treatment for a wide variety of haematological diseases, both malignant and non-malignant. Infectious and non-infectious post-HCT pulmonary complications are a major cause of morbidity and mortality, with non-infectious complications becoming more prominent in recent decades as prophylaxis has led to a decrease in infectious complications. Globally, these complications can be divided into three phases (neutropenic, early and late phase) depending on their time of onset in relation to the graft. There is a growing awareness that the assessment of the patient undergoing HCT should start before the transplantation itself. It is known that total body irradiation dose, the source of HCT, myeloablative regimens or lower baseline lung function are key risk factors in the development of pulmonary complications. In general, the treatment of these entities consists of administration of corticosteroids with variable response, which highlights the need to better understand the underlying biology in order to have new drugs with more directed targets to improve the prognosis of post-HCT non-infectious pulmonary complications. In view of the limited therapeutic response mentioned above, preventive measures for patients undergoing HCT, such as conditioning of less ablative regimens or pre-selection of high-risk cases, are of paramount importance in order to mitigate the severity of these devastating pulmonary complications.

Efficacy of Ruxolitinib with corticosteroids in idiopathic pneumonia syndrome post-allogeneic hematopoietic stem cell transplantation: A single-center experience and systematic review

BACKGROUND

Idiopathic Pneumonia Syndrome (IPS) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a life-threatening complication with high morbidity and mortality. IPS is thought to arise from damage caused by various inflammatory mediators. This study assesses the effectiveness of Ruxolitinib, a Janus Kinase (JAK) 1 and 2 inhibitor that blocks cytokine production, in combination with corticosteroids (CS) for managing IPS after allo-HSCT, compared to the conventional use of CS alone in a case series and a systematic review of previously published literature.

METHODS

The study includes a retrospective case series of three patients treated for IPS with Ruxolitinib and CS from the University of Kansas Medical Center and a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement 2020 guidelines. The systematic review encompassed seven studies involving 346 cases including three cases from the case series. Statistical analyses were conducted using SPSS v.25.

RESULTS

The case series included three patients with IPS after allo-HSCT who received ruxolitinib and CS with favorable results. All patients showed substantial improvement with no IPS-associated mortality. Two of the three patients in the case series were discharged on a 2 L nasal cannula, which was later discontinued during follow-up visits, while the third was discharged on room air. There was marked improvement observed on the computed tomography (CT) following the use of ruxolitinib. Of the total 346 cases included in the systematic review, the median age was 46.6 years (Range 5-72), and 62 % were males. The primary disorders were acute leukemia (52 %), chronic myeloid leukemia (12 %), myelodysplastic syndrome (11 %), Lymphoma (10 %), and others (21 %). Stem cell sources were peripheral blood (45 %), bone marrow (49 %), and cord blood (6 %). Donor types involved match unrelated (55 %), match related (36 %), and mismatched related (4.5 %). Most patients received myeloablative conditioning (81 %). Acute GVHD was observed in 47 %, and chronic GVHD in 38 %. The primary treatment was CS (96 %), with limited use of ruxolitinib (1 %) and etanercept (9.5 %). The mortality rate was 63.3 %, whereas in our case series with the use of ruxolitinib, it was zero.

CONCLUSION

The combination of Ruxolitinib and CS for treating IPS post-allo-HSCT suggested promising results in the case series, with favorable response and improved survival by blocking the cytokine production contributing to IPS. The significant mortality difference in the systematic review supports the need for innovative treatment approaches, highlighting the potential role of Ruxolitinib in CS-refractory cases. Despite the positive outcomes in the case series, the absence of randomized controlled trials emphasizes the necessity for further research.

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.

Biomarkers to predict and diagnose pulmonary complications in children post haematopoietic stem cell transplant

OBJECTIVES

Haematopoietic cell transplant (HCT) is a cellular therapy for a group of high-risk children with cancer, immunodeficiency and metabolic disorders. Whilst curative for a child's underlying condition, HCT has significant risks associated, including lung injury. These complications are associated with increased post HCT mortality and require improved methods of risk stratification, diagnosis and treatment.

METHODS

Biomarkers measured in bronchoalveolar fluid and peripheral blood have been identified for both acute and chronic lung injury post HCT.This review evaluates the current research available investigating the use of these biomarkers to improve clinical care, with a focus on the paediatric cohort.

RESULTS

Elevated levels of cytokines such as IL-6, IL-8, G-CSF and TNF were identified as potential predictive biomarkers for the development of post HCT lung disease. The pulmonary microbiome was found to have strong potential as a biomarker pre and post HCT for the development of pulmonary complications. General limitations of the studies identified were study design, retrospective or single centre and not exclusively performed in the paediatric population.

CONCLUSION

To translate biomarker discovery into clinical implementation further research is required, utilising larger cohorts of children in prospective trials to validate these biomarkers and determine how they can be translated into better outcomes for children post HCT.

Three cases of suspected pleuroparenchymal fibroelastosis after allogeneic hematopoietic cell transplantation

This article reports the clinical course and imaging findings of three cases of suspected pleuroparenchymal fibroelastosis (PPFE) after allogeneic hematopoietic cell transplantation (HCT). All patients complained of dyspnea more than 5 years after HCT, had progressive restrictive deficits on respiratory function tests, and presented with pneumothorax, pleural thickening, or exacerbation of consolidation in the upper lobe of the lung. Though lung biopsy was not done in all three cases, the clinical findings and results of spirometry were compatible with those of PPFE. PPFE has been sporadically reported as a pulmonary complication of allogeneic HCT; however, clinical diagnostic criteria other than histological diagnosis and treatment methods have not yet been established. The accumulation of more cases is necessary to improve the prognosis of PPFE complications.

Clinical characteristics of late-onset interstitial pneumonia after allogeneic hematopoietic stem cell transplantation

Non-infectious pulmonary complications after allogeneic hematopoietic stem cell transplantation (HSCT) remain fatal. In particular, information regarding late-onset interstitial lung disease predominantly including organizing pneumonia and interstitial pneumonia (IP) is limited. A retrospective nationwide survey was conducted using data collected from the Japanese transplant outcome registry database from 2005 to 2010. This study focused on patients (n = 73) with IP diagnosed after day 90 post-HSCT. A total of 69 (94.5%) patients were treated with systemic steroids, and 34 (46.6%) experienced improvement. The presence of chronic graft-versus-host disease at the onset of IP was significantly associated with non-improvement of symptoms (odds ratio [OR] 0.35). At the time of last follow-up (median, 1471 days), 26 patients were alive. Of the 47 deaths, 32 (68%) were due to IP. The 3-year overall survival (OS) and non-relapse mortality (NRM) rates were 38.8% and 51.8%, respectively. In the multivariate analysis, the predictive factors for OS were comorbidities at IP onset (hazard ratio [HR]: 2.19) and performance status (PS) score of 2-4 (HR 2.77). Furthermore, cytomegalovirus reactivation requiring early intervention (HR 2.04), PS score of 2-4 (HR 2.63), and comorbidities at IP onset (HR 2.90) were also significantly associated with increased risk of NRM.

CRISPR Gene Therapy: A Promising One-Time Therapeutic Approach for Transfusion-Dependent β-Thalassemia—CRISPR-Cas9 Gene Editing for β-Thalassemia

β-Thalassemia is an inherited hematological disorder that results from genetic changes in the β-globin gene, leading to the reduced or absent synthesis of β-globin. For several decades, the only curative treatment option for β-thalassemia has been allogeneic hematopoietic cell transplantation (allo-HCT). Nonetheless, rapid progress in genome modification technologies holds great potential for treating this disease and will soon change the current standard of care for β-thalassemia. For instance, the emergence of the CRISPR/Cas9 genome editing platform has opened the door for precision gene editing and can serve as an effective molecular treatment for a multitude of genetic diseases. Investigational studies were carried out to treat β-thalassemia patients utilizing CRISPR-based CTX001 therapy targeting the fetal hemoglobin silencer BCL11A to restore γ-globin expression in place of deficient β-globin. The results of recently carried out clinical trials provide hope of CTX001 being a promising one-time therapeutic option to treat β-hemoglobinopathies. This review provides an insight into the key scientific steps that led to the development and application of novel CRISPR/Cas9–based gene therapies as a promising therapeutic platform for transfusion-dependent β-thalassemia (TDT). Despite the resulting ethical, moral, and social challenges, CRISPR provides an excellent treatment option against hemoglobin-associated genetic diseases.

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.

Post-Transplant and In-Hospital Risk Factors for ARDS After Hematopoietic Stem Cell Transplantation

BACKGROUND

ARDS is a serious complication of hematopoietic stem cell transplant (HSCT). Pre-transplant risk factors for developing ARDS after HSCT have been recently identified. The objective of this study was to better understand post-transplant risk factors for developing ARDS after HSCT.

METHODS

This was a nested case-control study. ARDS cases were matched to hospitalized non-ARDS controls by age, type of transplantation (allogeneic vs autologous), and time from transplantation. In a conditional logistic regression model, any potential risk factors were adjusted a priori for risk factors known to be associated with ARDS development.

RESULTS

One hundred and seventy ARDS cases were matched 1:1 to non-ARDS hospitalized controls. Pre-admission, cases were more likely to be on steroids (odds ratio [OR] 1.90 [1.13-3.19], P = .02). At time of admission, cases had lower platelet count (OR 0.95 [0.91-0.99], P = .02), lower bicarbonate (OR 0.94 [0.88-0.99], P = .035), and higher creatinine (OR 1.91 [1.23-2.94], P = .004). During the first 24 h after admission, cases were more likely to have received transfusion (OR 2.41 [1.48-3.94], P < .001), opioids (OR 2.94 [1.67-5.18], P < .001), and have greater fluid administration (OR 1.52 [1.30-1.78], P < .001). During the hospitalization, ARDS cases had higher temperature (OR 1.77 [1.34-2.33], P < .001) and higher breathing frequency (OR 1.52 [1.33-1.74], P < .001). ARDS cases were more likely to have had sepsis (OR 68.0 [15.2-301.7], P < .001), bloodstream infection (OR 4.59 [2.46-8.57], P < .001), and pneumonia (OR 9.76 [5.01-19.00], P < .001).

CONCLUSIONS

Several post-transplant predictors of ARDS development specific to the HSCT population were identified in the pre-hospital and early in-hospital domains. These findings can provide insights into causal mechanisms of ARDS development and be used to develop HSCT-specific risk prediction models.

Association between early corticosteroid administration and long-term survival in non-infectious pulmonary complications after allogeneic hematopoietic stem cell transplantation

Non-infectious pulmonary complications (NIPCs) after allogeneic hematopoietic stem cell transplantation (HSCT) are associated with poor outcomes. It is important to maximize the effectiveness of primary treatment because secondary treatment has not been established. We analyzed data from 393 patients who underwent allogeneic HSCT during a 10-year period. Thirty-seven were diagnosed with NIPCs, which consisted of idiopathic pneumonia syndrome, bronchiolitis obliterans, and interstitial lung disease including cryptogenic organizing pneumonia. Among these, 18 died (Dead group) while 19 remained alive (Alive group) during the study period. The median time between NIPC diagnosis and first administration of ≥ 1 mg/kg/day corticosteroids (prednisolone dose equivalent) was significantly longer in the Dead group than the Alive group, at 9 days versus 4 days (p = 0.01). We further divided these cases into those who received prednisolone within seven days and after 8 days. We found that the ≤ 7 days group were more likely to survive after their NIPC diagnosis compared to the ≥ 8 days group (p = 0.06). Our analysis showed that early initiation of corticosteroid therapy is associated with long-term survival in NIPCs.

What Is Different in Acute Hematologic Malignancy-Associated ARDS? An Overview of the Literature

Background and Objectives: Acute hematologic malignancies are a group of heterogeneous blood diseases with a high mortality rate, mostly due to acute respiratory failure (ARF). Acute respiratory distress syndrome (ARDS) is one form of ARF which represents a challenging clinical condition. The paper aims to review current knowledge regarding the variable pathogenic mechanisms, as well as therapeutic options for ARDS in acute hematologic malignancy patients. Data collection: We provide an overview of ARDS in patients with acute hematologic malignancy, from an etiologic perspective. We searched databases such as PubMed or Google Scholar, including articles published until June 2022, using the following keywords: ARDS in hematologic malignancy, pneumonia in hematologic malignancy, drug-induced ARDS, leukostasis, pulmonary leukemic infiltration, pulmonary lysis syndrome, engraftment syndrome, diffuse alveolar hemorrhage, TRALI in hematologic malignancy, hematopoietic stem cell transplant ARDS, radiation pneumonitis. We included relevant research articles, case reports, and reviews published in the last 18 years. Results: The main causes of ARDS in acute hematologic malignancy are: pneumonia-associated ARDS, leukostasis, leukemic infiltration of the lung, pulmonary lysis syndrome, drug-induced ARDS, radiotherapy-induced ARDS, diffuse alveolar hemorrhage, peri-engraftment respiratory distress syndrome, hematopoietic stem cell transplantation-related ARDS, transfusion-related acute lung injury. Conclusions: The short-term prognosis of ARDS in acute hematologic malignancy relies on prompt diagnosis and treatment. Due to its etiological heterogeneity, precision-based strategies should be used to improve overall survival. Future studies should focus on identifying the relevance of such etiologic-based diagnostic strategies in ARDS secondary to acute hematologic malignancy.

Noninvasive Ventilation Exposure Prior to Intubation in Pediatric Hematopoietic Cell Transplant Recipients

BACKGROUND

Noninvasive ventilation (NIV) has become more studied in immunocompromised patients. However, it has not been studied in hematopoietic cell transplantation (HCT) recipients, who have higher mortality and higher pulmonary complication rates than other immunocompromised patients. This population may be prone to negative effects from this treatment modality. The aim of this study was to determine whether NIV use is associated with worse outcomes in this vulnerable patient population.

METHODS

A secondary analysis of a retrospective multi-center database was performed. Twelve pediatric ICUs across the United States enrolled HCT subjects from 2009-2014 that were admitted to the pediatric ICU (PICU) with the diagnosis of acute respiratory failure. Subjects exposed to NIV prior to intubation were compared against those not exposed to NIV. Our primary outcome was all-cause mortality at 90 d; secondary outcomes included ventilator-free days (VFD) at 28 d and development of pediatric ARDS. Multivariable logistic and linear regression models were constructed using variables significant on univariable analysis.

RESULTS

Two-hundred eleven subjects were included. Of these, 82 (39%) received NIV prior to intubation. Those that received NIV prior to intubation were older (13 vs 6 y, P < .001) and more commonly diagnosed with respiratory distress (90% vs 74%, P = .004). On multivariable analysis, NIV use prior to intubation was associated with a higher PICU mortality (hazard ratio 1.51 [95% CI 1.18-2.28], P = .02) and fewer VFD at 28 d (β -3.50 [95% CI -6.09 to 0.91], P = .008). Those with NIV exposure prior to intubation also had higher rates of development of pediatric ARDS (95% vs 78%, P = .001).

CONCLUSIONS

In this cohort of children post-HCT, NIV use prior to intubation was associated with worse outcomes. The benefits and risks of NIV in this patient population should be carefully evaluated prior to its use, and careful patient selection is crucial for its optimal utilization.

Comparison of Pulmonary Toxicity after Total Body Irradiation- and Busulfan-Based Myeloablative Conditioning for Allogeneic Hematopoietic Stem Cell Transplantation in Pediatric Patients

Pulmonary toxicity after allogeneic hematopoietic stem cell transplantation (allo-HSCT) for childhood leukemia and myelodysplastic syndrome (MDS), along with the impact of different myeloablative conditioning regimens, remain incompletely described. Here we compared the acute and long-term incidence of pulmonary toxicity (PT) after total body irradiation (TBI)- and busulfan-based myeloablative conditioning. We conducted this retrospective cohort study of 311 consecutive pediatric patients with leukemia or MDS who underwent allo-HSCT at Dana-Farber Cancer Institute/Boston Children's Hospital between 2008 and 2018. PT was graded using Common Terminology Criteria for Adverse Events version 5.0. The primary objective was to compare the cumulative incidence of grade ≥3 and grade 5 PT after TBI-based and busulfan-based myeloablative conditioning using Gray's test. Secondary objectives were to determine factors associated with PT and overall survival (OS) using competing risk analysis and Cox regression analyses, respectively. There was no significant difference between the TBI-conditioned group (n = 227) and the busulfan-conditioned group (n = 84) in the incidence of grade ≥3 PT (29.2% versus 34.7% at 2 years; P = .26) or grade 5 pulmonary toxicity (6.2% versus 6.1% at 2 years; P = .47). Age (hazard ratio [HR], 1.70, 95% confidence interval [CI], 1.11 to 2.59; P = .01), grade ≥2 PT prior to allo-HSCT or preexisting pulmonary conditions (HR, 1.84, 95% CI, 1.24 to 2.72; P < .01), acute graft-versus-host disease (GVHD) (HR, 2.50; 95% CI, 1.51 to 4.14; P < .01), and chronic GVHD (HR, 2.61; 95% CI, 1.26 to 5.42; P = .01) were associated with grade ≥3 PT on multivariable analysis. Grade ≥3 PT was associated with worse OS (81.1% versus 61.5% at 2 years; P < .01). In pediatric allo-HSCT recipients, rates of PT were similar in recipients of TBI-based and recipients of busulfan-based myeloablative conditioning regimens. Age, the presence of PT or preexisting pulmonary conditions prior to transplantation, and the development of either acute or chronic GVHD were associated with grade ≥3 PT post-transplantation. Furthermore, the occurrence of grade 3-4 PT post-transplantation was associated with inferior OS.

Incidence and predictors of idiopathic pneumonia syndrome in hematopoietic stem cell transplant patients: a nationwide registry study

Idiopathic pneumonia syndrome (IPS) is a rare but deadly complication of hematopoietic stem cell transplantation (HSCT). This study characterized the incidence and risk factors for IPS after HSCT in Taiwan. Data from January 2009 to February 2019 was collected from the Taiwan Society of BMT national registry. Forty-three (1.1%) of 3924 HSCT patients who developed IPS were identified. Incidence of IPS was lower in patients who received autologous HSCT than patients who received allogeneic HSCT (0.68% vs 1.44%, P = 0.022). Multivariate analysis showed that use of TBI and intravenous busulfan in the conditioning regimen were each independent predictor of IPS after HSCT. In addition, development of IPS was significantly associated with increased risk of death in the first 120 days post-HSCT (HR, 2.09; 95% CI, 1.08 to 4.05, P = 0.029) and 2 years post-HSCT (HR, 1.65; 95% CI, 1.07 to 2.542, P = 0.023), but not beyond 2 years post-HSCT. However, survival outcomes did not differ significantly between patients with IPS who received autologous versus allogeneic HSCT (P = 0.52). In conclusion, despite the relatively low incidence of post-HSCT IPS in Taiwan, mortality remains high. The results of this study will help to identify high-risk patients for early intervention and guide future therapeutic research.

Fibrotic Cystic Lung Disease Post Hematopoietic Stem Cell Transplant: Who is the Culprit?

Pulmonary complications post hematopoietic stem cell transplant (HSCT) are associated with poor outcomes and require extensive management depending on the etiology. They usually present in the form of bronchiolitis obliterans syndrome, interstitial pneumonitis, or drug toxicity that can lead to fibrosis. Scant data exists regarding diffuse cystic lung disease following HSCT, and the existing literature only mentions mild cystic changes. We present the case of a 25-year-old man with stage IVB Hodgkin's lymphoma post allogeneic HSCT, who developed progressive traction bronchiectasis, with the appearance of extensive pulmonary cysts that followed significant fibrotic changes and discuss the possible etiologies behind it.

A Systematic Review on Pulmonary Complications Secondary to Hematopoietic Stem Cell Transplantation

The main purpose of this systematic review was to identify and synthesize evidence about pulmonary complications following stem cell transplantation to raise awareness among physicians since it is a lesser-known topic. Studies that included targeted pulmonary complications that occurred after stem cell transplantation; in humans; and were randomized controlled trials, cohort studies, and case studies between January 2011 and 2021. Fifteen intervention features were identified and analyzed in terms of their association with successful or unsuccessful interventions. Fifteen of 15 studies that met inclusion criteria had positive results. Features that appeared to have the most consistent positive effects included relevant information consisting of clinical presentations and management of complications. 

Hematopoietic stem cell transplantation is a therapeutic method that has been introduced for various hematological diseases. Its main objective is to restore the hematopoietic function that has been eradicated or affected. The stem cell transplantation requires a period of administration of chemotherapeutic agents that may lead to infectious and/or non-infectious pulmonary complications that require follow-up.

Noninfectious pulmonary complications include bronchiolitis obliterans, alveolar hemorrhage, fibroelastosis, pulmonary hypertension, and infections. Bronchiolitis obliterans syndrome is an obstructive lung disease that affects the small airways, reducing lung function, and it’s the most frequent late-onset complication. Furthermore, diffuse pulmonary hemorrhage is a fatal adverse effect and the most common noninfectious pulmonary complication of acute leukemia, observed within the first weeks after the procedure. Pulmonary hypertension has multiple etiologies, mainly related to the pulmonary veno-occlusive disease. It carries a poor prognosis, with a 55% mortality rate. The area of hematology is very wide and prone to new development of treatments and procedures that could be available for new emerging diseases and improving survival rates. 

Demystifying idiopathic interstitial pneumonia: time for more etiology-focused nomenclature in interstitial lung disease

INTRODUCTION

A major focus of interstitial lung disease (ILD) has centered on disorders termed idiopathic interstitial pneumonias (IIPs) which include, among others, idiopathic pulmonary fibrosis, idiopathic nonspecific interstitial pneumonia, cryptogenic organizing pneumonia, and respiratory bronchiolitis-interstitial lung disease.

AREAS COVERED

We review the radiologic and histologic patterns for the nine disorders classified by multidisciplinary approach as IIP, and describe the remarkable amount of published epidemiologic, translational, and molecular studies demonstrating their associations with numerous yet definitive environmental exposures, occupational exposures, pulmonary diseases, systemic diseases, medication toxicities, and genetic variants.

EXPERT OPINION

In the 21st century, these disorders termed IIPs are rarely idiopathic, but rather are well-described radiologic and histologic patterns of lung injury that are associated with a wide array of diverse etiologies. Accordingly, the idiopathic nomenclature is misleading and confusing, and may also promote a lack of inquisitiveness, suggesting the end rather than the beginning of a thorough diagnostic process to identify ILD etiology and initiate patient-centered management. A shift toward more etiology-focused nomenclature will be beneficial to all, including patients hoping for better life quality and disease outcome, general medicine and pulmonary physicians furthering their ILD knowledge, and expert ILD clinicians and researchers who are advancing the ILD field.

Late-Onset, Noninfectious Pulmonary Complications following Allogeneic Hematopoietic Stem Cell Transplantation: A Nationwide Cohort Study of Long-Term Survivors

BACKGROUND

Survivors of allogeneic hematopoietic stem cell transplantation (allo-HSCT) are at risk for pulmonary adverse events. Data on late-onset noninfectious pulmonary complications in long-term adult survivors of allo-HSCT are limited and incomplete.

OBJECTIVES

This study aimed (1) to determine occurrence and degree of pulmonary sequelae in adult survivors of allo-HSCT and (2) to identify associations between pulmonary function, high-resolution CT (HRCT), and clinical characteristics.

METHOD

In a nationwide, single-center cross-sectional study, 103 survivors (aged median [range] 35 [17-58] years, 53% females) were examined 17 (6-32) years after allo-HSCT and compared with healthy controls (n = 105). Methods included pulmonary function tests and HRCT.

RESULTS

Chronic graft-versus-host disease was diagnosed in 33% of survivors, including 12% with bronchiolitis obliterans syndrome (BOS). Mean lung volumes (TLC, FVC, and FEV1) and gas diffusing capacity were >80% of predicted for the survivors as a group, but significantly lower than in healthy controls. Pathological HRCT findings were detected in 48% of the survivors (71% airways disease, 35% interstitial lung disease, and 24% apical subpleural interstitial thickening). Air trapping (%) on HRCT correlated with % predicted FEV1, p < 0.001. In a multiple logistic regression model, both BOS and pathological findings on HRCT were associated with chemotherapy prior to allo-HSCT, p < 0.05.

CONCLUSIONS

Long-term allo-HSCT survivors had significantly lower pulmonary function than age- and gender-matched healthy controls and nearly half had pathological findings on HRCT. Longitudinal data will determine if pulmonary sequelae will remain stable or progress. We recommend lifelong monitoring of pulmonary function in allo-HSCT survivors. HRCT provides additional information, but is not suited for surveillance.

Noninfectious complications of hematopoietic cell transplantation

Noninfectious lung diseases contribute to nonrelapse mortality. They constitute a spectrum of diseases that can affect the parenchyma, airways, or vascular pulmonary components and specifically exclude cardiac and renal causes. The differential diagnoses of these entities differ as a function of time after hematopoietic cell transplantation. Specific diagnosis, prognosis, and optimal treatment remain challenging, although progress has been made in recent decades.

Successful ruxolitinib administration for a patient with steroid-refractory idiopathic pneumonia syndrome following hematopoietic stem cell transplantation: A case report and literature review

Idiopathic pneumonia syndrome (IPS) is an acute lung complication observed after the early posthematopoietic stem cell transplantation (HSCT) period. Ruxolitinib was effective for a patient with myelodysplastic syndrome who developed severe IPS after second HSCT. No severe adverse effects were observed. Ruxolitinib may be an alternative choice for HSCT-related IPS.

Non-neoplastic respiratory fluid cytology including cell differential counts for interstitial lung disease

Bronchioloalveolar lavage (BAL) is a non-invasive and well-tolerated procedure that plays a key role in the diagnosis of a variety of non-neoplastic pulmonary diseases, including acute respiratory failure, infection, diffuse parenchymal lung disease (DLPD), paediatric and occupational lung disease, and in the evaluation of the lung allograft. A variety of analytic techniques are commonly performed on BAL fluid, including cytology, cell differential count, microbiology and virology, as well as a number of additional techniques in specific circumstances.

Diffuse alveolar hemorrhage in a healthy stem cell donor following administration of granulocyte colony - stimulating factor

BACKGROUND

Granulocyte colony - stimulating factor (G-CSF) is frequently used in healthy adults prior to stem cell donation in order to mobilize stem cells to peripheral blood. Adverse events of G-CSF occur in about 30% and mainly include bone pain, fatigue, and headache. Pulmonary adverse events are rare.

CASE PRESENTATION

Here, we describe a case of a healthy donor who developed diffuse alveolar hemorrhage after G-CSF administration. We suggest the underlying mechanism of this injury.

CONCLUSION

Diffuse alveolar hemorrhage can occur following G-CSF administration. Treating physicians should be aware of this infrequent but often life-threatening pulmonary side effect of G-CSF.

Autologous stem-cell transplantation in systemic sclerosis-associated interstitial lung disease: early action in selected patients rather than escalation therapy for all

Systemic sclerosis (SSc) is a rare rheumatic disease characterised by inflammation, vasculopathy and fibrosis of skin and internal organs. A common complication and a leading cause of death in SSc is interstitial lung disease (ILD). The current armamentarium of treatments in SSc-ILD mainly includes immunosuppressive therapies and has recently been expanded with anti-fibrotic agent nintedanib. Autologous stem cell transplantation (SCT) is increasingly used in progressive diffuse cutaneous SSc. This intensive treatment has been studied in three randomised trials and demonstrated to improve survival and quality of life. In the subsets of patients with SSc-ILD, SCT resulted in stabilisation and modest improvement of lung volumes and disease extent on high resolution computed tomography, but less impact was seen on diffusion capacity. Comparison of SCT outcomes with results from SSc-ILD trials is difficult though, as lung involvement per se was not an inclusion criterion in all SCT trials. Also, baseline characteristics differed between studies. The risk of severe treatment-related complications from SCT is still considerable and patients with extensive lung disease are particularly at risk of complications during transplantation. Therefore SCT should only be provided by experienced multidisciplinary teams in carefully selected patients. Future research needs to include comprehensive pulmonary evaluation and establish whether SCT early in the disease might prevent irreversible pulmonary damage and reduce treatment-related complications. Also, more insight in mechanisms of action of SCT in the lung and predictors for response will improve the use of this treatment in SSc-ILD. In this review the role of SCT in the treatment of SSc-ILD is summarised.

Pleural Effusion Secondary to Dasatinib Following Allogenic Hematopoietic Stem Cell Transplantation

Patient: Male, 72-year-old

Final Diagnosis: Dasatinib induced pleural effusion

Symptoms: Cough • shortness of breath

Medication: —

Clinical Procedure: Chest computed tomography • chest xray • thoracentesis

Specialty: Hematology • General and Internal Medicine • Oncology • Pulmonology

Major pulmonary complications following Hematopoietic stem cell transplantation: What the pulmonologist needs to know

Hematopoietic stem cell transplantation (HSCT) is used for treatment of a myriad of both malignant and non-malignant disorders. However, despite many advances over the years which have resulted in improved patient mortality, this subset of patients remains at risk for a variety of post-transplant complications. Pulmonary complications of HSCT are categorized into infectious and non-infectious and occur in up to one-third of patients undergoing HSCT. Infectious etiologies include bacterial, viral and fungal infections, each of which can have significant mortality if not identified and treated early in the course of infection. Advances in the diagnosis and management of infectious complications highlight the importance of non-infectious pulmonary complications related to chemoradiation toxicities, immunosuppressive drugs toxicities, and graft-versus-host disease. This report aims to serve as a guide and clinical update of pulmonary complications following HSCT for the general pulmonologist who may be involved in the care of these patients.

A bi-centric experience of extracorporeal carbon dioxide removal (ECCO2 R) for acute hypercapnic respiratory failure following allogeneic hematopoietic stem cell transplantation

Acute respiratory failure (ARF) is the main reason for ICU admission following allogeneic hematopoietic stem cell transplantation (HSCT). Extracorporeal CO₂ removal (ECCO₂R) can be used as an adjunct to mechanical ventilation in patients with severe hypercapnia but has not been assessed in HSCT recipients. Retrospective analysis of all allogeneic HSCT recipients ≥18 years treated with ECCO₂R at two HSCT centers. 11 patients (m:f = 4:7, median age: 45 [IQR: 32‐58] years) were analyzed. Acute leukemia was the underlying hematologic malignancy in all patients. The time from HSCT to ICU admission was 37 [8‐79] months, and 9/11 (82%) suffered from chronic graft‐versus‐host disease (GVHD) with lung involvement. Pneumonia was the most frequent reason for ventilatory decompensation (n = 9). ECCO₂R was initiated for severe hypercapnia (P_aCO₂: 96 [84‐115] mm Hg; pH: 7.13 [7.09‐7.27]) despite aggressive mechanical ventilation (invasive, n = 9; non‐invasive, n = 2). ECCO₂R effectively resolved blood gas disturbances in all patients, but only 2/11 (18%) could be weaned off ventilatory support, and one (9%) patient survived hospital discharge. Progressive respiratory and multiorgan dysfunction were the main reasons for treatment failure. ECCO₂R was technically feasible but resulted in a low survival rate in our cohort. A better understanding of the prognosis of ARF in patients with chronic GVHD and lung involvement is necessary before its use can be reconsidered in this setting.