Updated prevalence, predictors and treatment outcomes for bronchiolitis obliterans syndrome after allogeneic stem cell transplantation

A Nasal Inflammatory Cytokine Signature Is Associated with Early Graft-versus-Host Disease of the Lung after Allogeneic Hematopoietic Cell Transplantation: Proof of Concept

Respiratory inflammation in bronchiolitis obliterans syndrome (BOS) after hematopoietic cell transplantation (HCT) is poorly understood. Clinical criteria for early-stage BOS (stage 0p) often capture HCT recipients without BOS. Measuring respiratory tract inflammation may help identify BOS, particularly early BOS. We conducted a prospective observational study in HCT recipients with new-onset BOS (n = 14), BOS stage 0p (n = 10), and recipients without lung impairment with (n = 3) or without (n = 8) chronic graft-versus-host disease and measured nasal inflammation using nasosorption at enrollment and then every 3 mo for 1 y. We divided BOS stage 0p into impairment that did not return to baseline values (preBOS, n = 6), or transient impairment (n = 4). We tested eluted nasal mucosal lining fluid from nasosorption matrices for inflammatory chemokines and cytokines using multiplex magnetic bead immunoassays. We analyzed between-group differences using the Kruskal-Wallis method, adjusting for multiple comparisons. We found increased nasal inflammation in preBOS and therefore directly compared patients with preBOS to those with transient impairment, as this would be of greatest diagnostic relevance. After adjusting for multiple corrections, we found significant increases in growth factors (FGF2, TGF-α, GM-CSF, VEGF), macrophage activation (CCL4, TNF-α, IL-6), neutrophil activation (CXCL2, IL-8), T cell activation (CD40 ligand, IL-2, IL-12p70, IL-15), type 2 inflammation (eotaxin, IL-4, IL-13), type 17 inflammation (IL-17A), dendritic maturation (FLT3 ligand, IL-7), and counterregulatory molecules (PD-L1, IL-1 receptor antagonist, IL-10) in preBOS patients compared to transient impairment. These differences waned over time. In conclusion, a transient multifaceted nasal inflammatory response is associated with preBOS. Our findings require validation in larger longitudinal cohorts.

The predictive value of pulmonary function test before transplantation for chronic pulmonary graft-versus-host-disease after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Pulmonary chronic graft-versus-host disease (cGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a devastating complication and often diagnosed at a late stage when lung dysfunction is irreversible. Identifying patients before transplant who are at risk may offer improved strategies to decrease the mortality. Bronchiolitis obliterans syndrome (BOS) is the typical manifestation of pulmonary cGVHD, which is clinically diagnosed by pulmonary function test (PFT). This study aimed to evaluate the predictive value of PFT pre-HSCT for BOS.

METHODS

A single center cohort of 923 allo-HSCT recipients was analyzed, including 15 patients who developed pulmonary cGVHD. Kaplan-Meier method was used to analyze the 3 year progression free survival and 3 year overall survival (OS). A Cox regression model was applied for univariate and multivariate models.

RESULTS

The 3 year cumulative incidence of pulmonary cGVHD was 2.04% (95% CI 1.00-3.08%). According to the cut-off values determined by receiver operator characteristic curve, higher ratio of forced expiratory volume during one second to forced vital capacity (FEV1/FVC) pre-HSCT was correlated to a lower incidence of pulmonary cGVHD [0.91% (95% CI 0.01-1.81%) vs. 3.61% (95% CI 1.30-5.92%), P < 0.01], and so as peak expiratory flow to predictive value (PEF/pred) [0.72% (95% CI 0-1.54%) vs. 3.74% (95% CI 1.47-6.01%), P < 0.01]. Multivariate analysis showed that FEV1/FVC (HR = 3.383, P = 0.047) and PEF/pred (HR = 4.426, P = 0.027) were independent risk factors for onset of BOS. Higher FEV1/FVC and PEF/pred level were related to a significantly decreased 3 year non-relapse mortality. The 3 year OS was superior in patients with higher PEF/pred [78.17% (95% CI 74.50-81.84%) vs. 71.14% (95% CI 66.08-76.20%), P = 0.01], while FEV1/FVC did not show significance difference.

CONCLUSION

Our results suggested that PFT parameters such as PEF/pred and FEV1/FVC could be predictors for pulmonary cGVHD and even transplant outcomes before HSCT.

Bronchiolitis obliterans syndrome after lung or haematopoietic stem cell transplantation: current management and future directions

Bronchiolitis obliterans syndrome (BOS) may develop after either lung or haematopoietic stem cell transplantation (HSCT), with similarities in histopathological features and clinical manifestations. However, there are differences in the contributory factors and clinical trajectories between the two conditions. BOS after HSCT occurs due to systemic graft-versus-host-disease (GVHD), whereas BOS after lung transplantation is limited to the lung allograft. BOS diagnosis after HSCT is more challenging, as the lung function decline may occur due to extrapulmonary GVHD, causing sclerosis or inflammation in the fascia or muscles of the respiratory girdle. Treatment is generally empirical with no established effective therapies. This review provides rare insights and commonalities of both conditions, that are not well elaborated elsewhere in contemporary literature, and highlights the importance of cross disciplinary learning from experts in other transplant modalities. Treatment algorithms for each condition are presented, based on the published literature and consensus clinical opinion. Immunosuppression should be optimised, and other conditions or contributory factors treated where possible. When initial treatment fails, the ultimate therapeutic option is lung transplantation (or re-transplantation in the case of BOS after lung transplantation) in carefully selected candidates. Novel therapies under investigation include aerosolised liposomal cyclosporine, Janus kinase inhibitors, antifibrotic therapies, and (in patients with BOS after lung transplantation) B-cell–directed therapies. Effective novel treatments that have a tangible impact on survival and thereby avoid the need for lung transplantation or re-transplantation are urgently required.

Long-Term Health Effects of Curative Therapies on Heart, Lungs, and Kidneys for Individuals with Sickle Cell Disease Compared to Those with Hematologic Malignancies

The goal of curing children and adults with sickle cell disease (SCD) is to maximize benefits and minimize intermediate and long-term adverse outcomes so that individuals can live an average life span with a high quality of life. While greater than 2000 individuals with SCD have been treated with curative therapy, systematic studies have not been performed to evaluate the long-term health effects of hematopoietic stem cell transplant (HSCT) in this population. Individuals with SCD suffer progressive heart, lung, and kidney disease prior to curative therapy. In adults, these sequalae are associated with earlier death. In comparison, individuals who undergo HSCT for cancer are heavily pretreated with chemotherapy, resulting in potential acute and chronic heart, lung, and kidney disease. The long-term health effects on the heart, lung, and kidney for children and adults undergoing HSCT for cancer have been extensively investigated. These studies provide the best available data to extrapolate the possible late health effects after curative therapy for SCD. Future research is needed to evaluate whether HSCT abates, stabilizes, or exacerbates heart, lung, kidney, and other diseases in children and adults with SCD receiving myeloablative and non-myeloablative conditioning regimens for curative therapy.