Recurrent diffuse alveolar hemorrhage and extracorporeal membrane oxygenation utilization in a hematopoietic stem cell transplant patient with Hunter's syndrome.

We describe the natural history of a three-month-old patient with Hunter Syndrome with hematopoietic stem cell transplant (HSCT) who developed recurrent diffuse alveolar hemorrhage (DAH) requiring extracorporeal membrane oxygenation (ECMO). The patient underwent HSCT with several complications, including veno-occlusive disease and DAH. He was managed with ECMO. Unfortunately, despite initial success he developed recurrent DAH and ultimately died. This is a novel report of this severe adverse event requiring ECMO following the use of HSCT in this rare patient population. We share the clinical strategies employed to address the complications associated with HSCT and the progression of his disease over his hospitalization.

Intrapulmonary administration of recombinant activated factor VII in pediatric, adolescent, and young adult oncology and hematopoietic cell transplant patients with pulmonary hemorrhage.

Introduction: Diffuse alveolar hemorrhage (DAH) is a devastating disease process with 50-100% mortality in oncology and hematopoietic cell transplant (HCT) recipients. High concentrations of tissue factors have been demonstrated in the alveolar wall in acute respiratory distress syndrome and DAH, along with elevated levels of tissue factor pathway inhibitors. Activated recombinant factor VII (rFVIIa) activates the tissue factor pathway, successfully overcoming the tissue factor pathway inhibitor (TFPI) inhibition of activation of Factor X. Intrapulmonary administration (IP) of rFVIIa in DAH is described in small case series with successful hemostasis and minimal complications. Methods: We completed a single center retrospective descriptive study of treatment with rFVIIa and outcomes in pediatric oncology and HCT patients with pulmonary hemorrhage at a quaternary hematology/oncology hospital between 2011 and 2019. We aimed to assess the safety and survival of patients with pulmonary hemorrhage who received of IP rFVIIa. Results: We identified 31 patients with pulmonary hemorrhage requiring ICU care. Thirteen patients received intrapulmonary rFVIIa, while eighteen patients did not. Overall, 13 of 31 patients (41.9%) survived ICU discharge. ICU survival (n=6) amongst those in the IP rFVIIa group was 46.2% compared to 38.9% (n=7) in those who did not receive IP therapy (p=0.69). Hospital survival was 46.2% in the IP group and 27.8% in the non-IP group (p=0.45). There were no adverse events noted from use of IP FVIIa. Conclusions: Intrapulmonary rFVIIa can be safely administered in pediatric oncology patients with pulmonary hemorrhage and should be considered a viable treatment option for these patients.

Diffuse alveolar hemorrhage after hematopoietic cell transplantation- response to treatments and risk factors for mortality.

Diffuse alveolar hemorrhage (DAH) is a life-threatening complication of hematopoietic cellular therapy (HCT). This study aimed to evaluate the effect of DAH treatments on outcomes using data from consecutive HCT patients clinically diagnosed with DAH from 3 institutions between January 2018-August 2022. Endpoints included sustained complete response (sCR) defined as bleeding cessation without recurrent bleeding, and non-relapse mortality (NRM). Forty children developed DAH at a median of 56.5 days post-HCT (range 1-760). Thirty-five (88%) had at least one concurrent endothelial disorder, including transplant-associated thrombotic microangiopathy (n=30), sinusoidal obstructive syndrome (n=19), or acute graft versus host disease (n=10). Fifty percent had a concurrent pulmonary infection at the time of DAH. Common treatments included steroids (n=17, 25% sCR), inhaled tranexamic acid (INH TXA,n=26, 48% sCR), and inhaled recombinant activated factor VII (INH fVIIa, n=10, 73% sCR). NRM was 56% 100 days after first pulmonary bleed and 70% at 1 year. Steroid treatment was associated with increased risk of NRM (HR 2.25 95% CI 1.07-4.71, p=0.03), while treatment with INH TXA (HR 0.43, 95% CI 0.19- 0.96, p=0.04) and INH fVIIa (HR 0.22, 95% CI 0.07-0.62, p=0.005) were associated with decreased risk of NRM. Prospective studies are warranted to validate these findings.

Pulmonary Manifestations and Vascular Changes in Pediatric Transplantation-Associated Thrombotic Microangiopathy.

Although transplant-associated thrombotic microangiopathy (TA-TMA) commonly complicates pediatric hematopoietic cellular therapy (HCT), pulmonary manifestations and histology of TA-TMA (pTA-TMA) are rarely reported, with scant data available on timing, risk factors, pathogenesis, and outcomes. Pulmonary hypertension (PH) and diffuse alveolar hemorrhage (DAH) are recognized manifestations of pTA-TMA. The objective of this study was to characterize the pathologic findings, outcomes, and coincident diagnoses preceding biopsy-proven pTA-TMA. In Institutional Review Board- approved retrospective studies, available lung tissue was reviewed at 2 institutions between January 2016 and August 2021 to include those with pulmonary vascular pathology. Histologic features of pTA-TMA were present in 10 children with prior respiratory decline after an allogeneic HCT (allo-HCT; n = 9) or autologous HCT (n = 1). Pathologic lesions included muscular medialization, microthrombi, and red cell fragments, in addition to perivasculitis and intimal arteritis. Parenchymal findings included diffuse alveolar damage, organizing pneumonia, and plasmocytic infiltrates. Six children were clinically diagnosed with TA-TMA, and all were treated with eculizumab, at a median of 2.5 days after clinical diagnosis (range, 0 to 11 days). Four were identified postmortem. Coincident pulmonary infection was confirmed in 8 of the 10 patients. Five allo-HCT recipients (56%) experienced graft-versus-host disease (GVHD; 4 acute, 1 chronic) prior to the onset of respiratory symptoms. Two patients (20%) had clinically recognized DAH, although 9 (90%) had evidence of DAH on histology. Although all 10 patients underwent echocardiography at the time of symptom onset and 9 had serial echocardiograms, only 2 patients had PH detected. Treatments varied and included sildenafil (n = 3), steroids (n = 1), and eculizumab (n = 6). One patient was alive at the time of this report; the remaining 9 died, at a median of 52 days after onset of respiratory symptoms (range 4 to 440 days) and a median of 126 days post-HCT (range, 13 to 947 days). pTA-TMA is a heterogeneous histologic disease characterized by arteriolar inflammation, microthrombi, and often DAH. pTA-TMA presented with respiratory decline with systemic TA-TMA in all patients. Clinicians should maintain a high degree of suspicion for DAH in patients with TA-TMA and pulmonary symptoms. Coincident rates of GVHD and pulmonary infections were high, whereas the rate of PH identified by echocardiography was 20%. Outcomes were poor despite early use of eculizumab and other therapies. Our data merit consideration of pTA-TMA in patients with acute respiratory decline in the setting of systemic TA-TMA, GVHD, and infection. Investigation of additional therapies for pTA-TMA is needed as well. © 2022 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Neutrophils Contribute to ER Stress in Lung Epithelial Cells in the Pristane-Induced Diffuse Alveolar Hemorrhage Mouse Model.

Diffuse alveolar hemorrhage (DAH), although rare, is a life-threatening complication of systemic lupus erythematosus (SLE). Little is known about the pathophysiology of DAH in humans, although increasingly neutrophils, NETosis and inflammatory monocytes have been shown to play an important role in the pristane-induced model of SLE which develops lung hemorrhage and recapitulates many of the pathologic features of human DAH. Using this experimental model, we asked whether endoplasmic reticulum (ER) stress played a role in driving the pathology of pulmonary hemorrhage and what role infiltrating neutrophils had in this process. Analysis of lung tissue from pristane-treated mice showed genes associated with ER stress and NETosis were increased in a time-dependent manner and reflected the timing of CD11b+Ly6G+ neutrophil accumulation in the lung. Using precision cut lung slices from untreated mice we observed that neutrophils isolated from the peritoneal cavity of pristane-treated mice could directly induce the expression of genes associated with ER stress, namely Chop and Bip. Mice which had myeloid-specific deletion of PAD4 were generated and treated with pristane to assess the involvement of PAD4 and PAD4-dependent NET formation in pristane-induced lung inflammation. Specific deletion of PAD4 in myeloid cells resulted in decreased expression of ER stress genes in the pristane model, with accompanying reduction in IFN-driven genes and pathology. Lastly, coculture experiments of human neutrophils and human lung epithelial cell line (BEAS-2b) showed neutrophils from SLE patients induced significantly more ER stress and interferon-stimulated genes in epithelial cells compared to healthy control neutrophils. These results support a pathogenic role of neutrophils and NETs in lung injury during pristane-induced DAH through the induction of ER stress response and suggest that overactivation of neutrophils in SLE and NETosis may underlie development of DAH.

Pulmonary angiosarcoma presenting with diffuse alveolar hemorrhage: a case report.

This study aimed to analyze the diagnosis and treatment of one case of pulmonary angiosarcoma (PPA) retrospectively. The main manifestation of this female patient was cough, hemoptysis and dyspnea. Computed tomography (CT) of the chest revealed multiple small nodules and ground-glass patches in both lungs suggesting of diffuse alveolar hemorrhage (DAH). Laboratory examination revealed decreased hemoglobin and platelet counting, normal coagulation function. Results of rheumatic markers testing including antinuclear antibody (ANA), anti-extractable nuclear antigen antibody (ENA), vasculitis marker, and antiphospholipid antibody were negative. Tumor markers were negative. Sputum smear, sputum culture, and alveolar lavage fluid culture showed negative results. The bone marrow smear was essentially normal. The patient received methylprednisolone pulse therapy (250 mg daily × 5 days) and immunoglobin (20 d daily × 7 days) treatment, but her hemoptysis persisted. Bilateral pleural effusion drainage found a large amount of bloody effusion, but cytology of the pleural fluid showed negative results. The clinical symptoms, laboratory results, imaging findings, and pathological features of the patient were summarized, and problems in diagnosis and treatment were discussed. A thoracoscopic lung biopsy was performed and the diagnosis of PPA was confirmed by pathology and immunohistochemistry (IHC) staining. This case suggested that the possibility of PPA should be considered in patients with DAH, but with negative findings in routine examinations, lung biopsy is usually required.

Preclinical Testing of Viral Therapeutic Efficacy in Pristane-Induced Lupus Nephritis and Diffuse Alveolar Hemorrhage Mouse Models.

Systemic lupus erythematosus (SLE) is a multifactorial and heterogeneous autoimmune disease involving multiple organ systems and tissues. Lupus nephritis occurs in approximately 60% of patients with SLE and is the leading cause of morbidity. Diffuse alveolar hemorrhage (DAH) is a rare but very serious complication of SLE with a greater than 50% associated mortality. The etiology of SLE is unclear but has proposed genetic, hormonal, and environmental aspects. Pristane is a saturated terpenoid alkane and has become the most popular laboratory model for inducing lupus in mice. The pristane model of SLE has the capacity to reproduce many components of the human presentation of the disease. Previous studies have demonstrated that virus-derived immune-modulating proteins have the potential to control inflammatory and autoimmune disorders. Serp-1, a 55 kDa secreted and highly glycosylated immune modulator derived from myxoma virus (MYXV), has potent immunomodulatory activity in models of vasculitis, viral sepsis, collagen-induced arthritis, and transplant rejection. This chapter describes the mouse preclinical pristane lupus model as a method to examine virus-derived protein efficacy for treating autoimmune diseases and specifically lupus nephritis and DAH.

Case Report: Management Approach and Use of Extracorporeal Membrane Oxygenation for Diffuse Alveolar Hemorrhage After Pediatric Hematopoietic Cell Transplant.

Introduction: Diffuse alveolar hemorrhage (DAH) is an early pulmonary complication of hematopoietic cell transplantation (HCT) associated with severe hypoxemic respiratory failure and mortality. Extracorporeal membrane oxygenation (ECMO) support is often used for respiratory failure refractory to conventional interventions; however, its use has been limited in HCT patients with DAH due to potential for worsening alveolar hemorrhage and reported high mortality. Case Presentation: We report two cases of DAH following HCT who developed refractory hypoxemic respiratory failure despite cessation of bleeding and were successfully supported with ECMO. Conclusion: DAH after HCT should not automatically preclude ECMO support; rather, these patients must be evaluated individually for ECMO within the context of their overall clinical picture.

Noninfectious Acute Lung Injury Syndromes Early After Hematopoietic Stem Cell Transplantation.

Noninfectious acute lung injury syndromes are major causes of respiratory failure and early mortality after hematopoietic stem cell transplantation (HSCT). Pulmonary edema and transfusion-related acute lung injuries are important respiratory complications seen after HSCT and in the nontransplant setting. Early transplant-specific causes of lung injury, such as idiopathic pneumonia syndrome, are reviewed. Several complications, such as drug-induced pneumonitis and cryptogenic organizing pneumonia, that occur in both the early and later time periods after HSCT are also briefly discussed. The important role of pretransplant pulmonary function testing measurements in predicting posttransplant respiratory failure is highlighted.

Looking beyond the obvious: an unusual cause of iron deficiency anaemia.

Iron deficiency anaemia (IDA) is the most common haematological disorder seen in childhood. While poor intake of iron is the most common cause of IDA, a diligent search must be made to exclude other causes. We present a 5 year old girl who had recurrent hospital admissions for chest infection, radiographic evidence of bilateral pulmonary infiltrates and severe IDA. When she failed to respond to repeated courses of antibiotics, anti tubercular and parenteral and oral iron therapy, a lung biopsy was done which revealed blood and hemosiderophages within the alveoli. Further investigations were suggestive of SLE (dsDNA positivity). A diagnosis of SLE induced alveolar haemorrhage was made and therapy with glucocorticoids was initiated. She has responded well to therapy.