Late-onset noninfectious interstitial lung disease following autologous haematopoietic stem cell transplantation in paediatric patients

Pulmonary fibrosis may begin in infancy: from childhood to adult interstitial lung disease

BACKGROUND

Childhood interstitial lung disease (chILD) encompasses a group of rare heterogeneous respiratory conditions associated with significant morbidity and mortality. Reports suggest that many patients diagnosed with chILD continue to have potentially progressive or fibrosing disease into adulthood. Over the last decade, the spectrum of conditions within chILD has widened substantially, with the discovery of novel entities through advanced genetic testing. However, most evidence is often limited to small case series, with reports disseminated across an array of subspecialty, clinical and molecular journals. In particular, the frequency, management and outcome of paediatric pulmonary fibrosis is not well characterised, unlike in adults, where clear diagnosis and treatment guidelines are available.

METHODS AND RESULTS

This review assesses the current understanding of pulmonary fibrosis in chILD. Based on registry data, we have provisionally estimated the occurrence of fibrosis in various manifestations of chILD, with 47 different potentially fibrotic chILD entities identified. Published evidence for fibrosis in the spectrum of chILD entities is assessed, and current and future issues in management of pulmonary fibrosis in childhood, continuing into adulthood, are considered.

CONCLUSIONS

There is a need for improved knowledge of chILD among pulmonologists to optimise the transition of care from paediatric to adult facilities. Updated evidence-based guidelines are needed that incorporate recommendations for the diagnosis and management of immune-mediated disorders, as well as chILD in older children approaching adulthood.

Imaging of pulmonary fibrosis in children: A review, with proposed diagnostic criteria

Computed tomography (CT) imaging findings of pulmonary fibrosis are well established for adults and have been shown to correlate with prognosis and outcome. Recognition of fibrotic CT findings in children is more limited. With approved treatments for adult pulmonary fibrosis, it has become critical to define CT criteria for fibrosis in children, to identify patients in need of treatment and those eligible for clinical trials. Understanding how pediatric fibrosis compares with idiopathic pulmonary fibrosis and other causes of fibrosis in adults is increasingly important as these patients transition to adult care teams. Here, we review what is known regarding the features of pulmonary fibrosis in children compared with adults. Pulmonary fibrosis in children may be associated with genetic surfactant dysfunction disorders, autoimmune systemic disorders, and complications after radiation, chemotherapy, transplantation, and other exposures. Rather than a basal-predominant usual interstitial pneumonia pattern with honeycombing, pediatric fibrosis is primarily characterized by reticulation, traction bronchiectasis, architectural distortion, or cystic lucencies/abnormalities. Ground-glass opacities are more frequent in children with fibrotic interstitial lung disease than adults, and disease distribution appears more diffuse, without clearly defined axial or craniocaudal predominance. Following discussion and consensus amongst a panel of expert radiologists, pathologists and physicians, distinctive disease features were integrated to develop criteria for the first global Phase III trial in children with pulmonary fibrosis.

Pleuroparenchymal fibroelastosis after hematopoietic stem cell transplantation in children: a propensity score-matched analysis

OBJECTIVES

To investigate the incidence, risk factors, and clinical outcomes of pleuroparenchymal fibroelastosis (PPFE) in pediatric hematopoietic stem cell transplantation (HSCT) recipients.

METHODS

This single-center, retrospective, case-control study included 738 consecutive patients who underwent chest CT more than 3 months after HSCT. We identified patients who fulfilled the diagnostic criteria for PPFE and assessed their clinical characteristics and radiologic findings. Propensity score-matched analysis was performed using four covariates (age, sex, HSCT type, and primary disease). The risk factors and clinical outcomes of PPFE were analyzed using the Fine and Gray regression model and stratified log-rank test in the matched groups.

RESULTS

PPFE was identified in 4% (31/738, 8.3 ± 3.1 years, 15 males) of the pediatric HSCT recipients with a median time of 2.7 years after HSCT, and it occurred following allogeneic (5%, 15/317), autologous (4%, 15/379), or both (2%, 1/42). Matching yielded 30 and 130 cases in the PPFE and control groups, respectively. The PPFE group showed more frequent late-onset noninfectious pulmonary complications (LONIPCs) and pneumonia more than 3 months after HSCT (p < 0.05). Multivariable analysis showed a significantly higher risk of PPFE in HSCT recipients who had pneumonia more than 3 months after HSCT (hazard ratio = 10.78 [95% confidence interval: 4.29, 27.13], p < 0.001). The PPFE group showed higher mortality (73%, 22/30) and poorer median overall survival (6.8 years [95% confidence interval: 4.1, 9.5]) than the control group (p < 0.001).

CONCLUSIONS

PPFE represents a severe type of LONIPC after HSCT. HSCT recipients with pneumonia after HSCT may have an increased risk of PPFE.

KEY POINTS

• The incidence of pleuroparenchymal fibroelastosis is not negligible (4%), and it can occur after either allogeneic or autologous hematopoietic stem cell transplantation. • Pleuroparenchymal fibroelastosis after hematopoietic stem cell transplantation showed poor outcome with a high mortality rate of 73% and median overall survival of 6.8 years. • After hematopoietic stem cell transplantation, pneumonia may increase the risk of pleuroparenchymal fibroelastosis development in children. • Lung biopsy should not be indicated in patients with pleuroparenchymal fibroelastosis findings on chest CT as it can cause refractory pneumothorax without helping the diagnosis.

Early predictors of mortality in children with pulmonary complications after haematopoietic stem cell transplantation

PC are a main cause of death following HSCT in children. We aimed to evaluate early predictors of mortality in paediatric recipients with PCs. A retrospective observational study of 35 patients with 49 episodes of PI on chest radiography (of 124 patients) who had undergone HSCT at a tertiary university hospital between January 2011 and December 2012 was performed. During follow-up (median 26.1 months), 15 episodes led to death (30.6%). An aetiologic diagnosis was made by non-invasive tests in 24 episodes (49.0%) and by adding bronchoalveolar lavage and/or lung biopsy in 7 episodes with diagnostic yield (77.8%, P = .001). Thus, a specific diagnosis was obtained in 63.3% of the episodes. Aetiology identification and treatment modification after diagnosis did not decrease mortality (P = .057, P = .481). However, the number of organ dysfunctions at the beginning of PI was higher in the mortality group, compared to the survivor group (1.7 ± 1.2 vs 0.32 ± 0.59; P = .001). Hepatic dysfunction (OR, 11.145; 95% CI, 1.23 to 101.29; P = .032) and neutropaenia (OR, 10.558; 95% CI, 1.07 to 104.65; P = .044) were independently associated with risk of mortality. Therefore, hepatic dysfunction and neutropaenia are independent early predictors of mortality in HSCT recipients with PCs.

Incidence, clinical characteristics, and outcome of interstitial pneumonia in patients with lymphoma

Interstitial pneumonia (IP) is a lethal complication in lymphoma patients undergoing chemotherapy. A total of 2212 consecutive patients diagnosed with lymphoma between 2009 and 2014 were enrolled in the present study. IP was defined as diffuse pulmonary interstitial infiltrate found on computed tomography scans. IP was observed in 106 patients. Of these, 23 patients were excluded from the study. Finally, 83 patients with IP were included in this study. The incidence of IP was 3.9% (7/287) in Hodgkin lymphoma and 2.4% (76/1925) in non-Hodgkin lymphoma (P = 0.210). The median number of chemotherapy cycles before IP was 3. The median time from the cessation of chemotherapy to IP was 17 days. Eighty-two (98.8%) patients recovered after the treatment with glucocorticoids. Sixty-six (79.5%) patients had a delay in chemotherapy, and 14 (16.9%) patients had premature termination of chemotherapy. Sixty-nine patients were re-treated with chemotherapy after remission from IP, of which 22 (31.9%) experienced IP recurrence. The incidence of IP recurrence was significantly higher in patients re-treated with a similar regimen than in those re-treated with an alternative regimen (65.4 vs. 11.6%, P < 0.001). In a multivariate Cox regression analysis, B symptoms and a history of drug allergies were identified as risk factors for IP. In conclusion, IP is a life-threatening complication in lymphoma patients. Glucocorticoid therapy with continuous monitoring of chest radiographic changes may be a favourable strategy for treating IP. However, IP may recur, especially in patients re-treated with a similar chemotherapy regimen.

Late-onset noninfectious interstitial lung disease following autologous haematopoietic stem cell transplantation in paediatric patients

Background and objective

High‐dose chemotherapy (HDCT) followed by autologous haematopoietic stem cell transplantation (HSCT) is widely used in paediatric cancer patients, but few data about noninfectious interstitial lung disease (ILD) following this treatment are available. Therefore, we aimed to evaluate the incidence, clinical features and risk factors of noninfectious ILD after HDCT in paediatric patients.

Methods

This was a retrospective cohort study of paediatric solid tumour patients who underwent HDCT and autologous HSCT between 1997 and 2012. ILD was diagnosed using clinical symptoms and radiography after excluding cardiac, renal and infectious causes. Risk factors were analysed using a Cox proportional hazard regression model.

Results

Three hundred and forty patients were enrolled, and the median age was 3 years (interquartile range 1–7). Eight patients (2.4%) were diagnosed with noninfectious ILD. The median duration of symptom onset was 30 months (range 7–74). Six (75%) of eight ILD patients died during the study period, even though steroids were administered for treatment. High‐dose cyclophosphamide use (hazard ratio = 11.37, 95% confidence interval = 1.38–93.32, P = 0.023) and sex (hazard ratio = 0.10, 95% confidence interval = 0.01–0.84, P = 0.034) were associated with late‐onset, noninfectious ILD upon multivariate analysis.

Conclusion

The incidence of noninfectious ILD after HDCT and autologous HSCT was not negligible, and the clinical features of ILD showed late onset and a poor prognosis. Female gender and high‐dose cyclophosphamide treatment may be risk factors for noninfectious ILD, but further studies with a larger number of ILD patients are suggested.

We investigated noninfectious interstitial lung disease after autologous transplantation in 340 paediatric patients. The incidence was 2.4%. The symptom onset was late and the prognosis was poor. High‐dose cyclophosphamide and female gender were risk factors of interstitial lung disease.