Lung transplantation in autoimmune diseases

Causal links between 13 autoimmune diseases and graft dysfunction: A Mendelian randomization study

Previous studies have suggested a possible link between autoimmune diseases and graft dysfunction; however, a causal link remains unclear. Exposure factors were set as 13 autoimmune diseases, and outcomes were set as graft dysfunction. Mendelian randomization was used to analyze the causal link between exposure and outcome. Alopecia areata and asthma were linked to graft dysfunction (odds ratio 0.828; 95% confidence interval 0.699-0.980; P = .029; odds ratio 1.79; 95% confidence interval 1.069-2.996; P = .027). At the same time, primary sclerosing cholangitis was found to be heterogeneous as an exposure factor (P = .009), but no heterogeneity or pleiotropy was found in other exposure factors. Our preliminary findings show 2 autoimmune diseases as risk factors for graft dysfunction, 1 autoimmune disease as a protective factor for graft dysfunction and the mechanisms remain to be understood.

Post-lung transplant outcomes of connective tissue disease-related interstitial lung diseases compared with idiopathic interstitial pneumonia: a single-center experience in Japan

OBJECTIVES

The aim of this study was to investigate the outcomes of lung transplantation for connective tissue disease-related interstitial lung disease (CTD-ILD) conducted at our institution, compared with those for idiopathic interstitial pneumonias (IIPs).

METHODS

We retrospectively reviewed patients with CTD-ILD and IIPs who underwent lung transplantation at our hospital from July 2015 to October 2023. We compared patients' backgrounds, early complications within 28 days post-transplant (CTCAE grade 3 or higher), postoperative courses, and prognoses between the two groups.

RESULTS

The CTD-ILD group (n = 19) and the IIPs group (n = 56) were compared. The CTD-ILD group had significantly higher preoperative use of corticosteroids and antifibrotic agents, mean pulmonary arterial pressure, anti-human leukocyte antigen antibody positivity, and donor age (p < 0.05). In addition, the CTD-ILD group had significantly longer operation times (579.0 vs 442.5 min), longer stays in the intensive care unit (17.0 vs 9.0 days) and hospital (58.0 vs 44.0 days); required more tracheostomies (57.9 vs 25.0%); and experienced more respiratory (52.6 vs 25.0%) and gastrointestinal (42.1 vs 8.9%) complications (p < 0.05). However, there were no significant differences in overall survival, nor chronic lung allograft dysfunction (CLAD)-free survival between the two groups.

CONCLUSION

Perioperative complications, notably respiratory and gastrointestinal complications, were prevalent after lung transplantation among CTD-ILD patients. Despite this, long-term survival rates were comparable to those observed in IIP cases.

Lung Transplantation: A Viable Option for Connective Tissue Disease?

Interstitial lung disease (ILD) and pulmonary hypertension (PH) caused by connective tissue disease (CTD) are one of the main causes of morbidity and death in patients. Although the International Society for Heart & Lung Transplant suggested that ILD and PH related to CTD are rare indications for lung transplantation in 2006, many lung transplantation centers are concerned that the multisystem involvement of CTD will affect survival outcomes after lung transplantation, and CTD is regarded as a relative contraindication for lung transplantation. However, long-term and short-term survival after lung transplantation in CTD patients is similar compared with survival in common indications for lung transplantation such as idiopathic pulmonary fibrosis (IPF), and no higher incidence of complications after transplantation in many lung transplant centers. This suggests that lung transplantation may be beneficial in CTD patients with disease that progresses to end-stage lung disease, and CTD should not be considered a contraindication for lung transplantation. In the future, more prospective studies are needed to analyze the risk factors of lung transplantation in CTD patients to improve survival rates and reduce the risk of complications. This narrative review summarizes the selection and evaluation of candidates for CTD before lung transplantation and describes the clinical outcomes in CTD after lung transplantation in large-capacity lung transplantation center. The purpose of this review is to help rheumatologists decide when to refer patients with CTD-related lung involvement to a lung transplantation center and the conditions to consider before transplantation and to provide confidence to lung transplant experts.

Prognosis of patients with systemic sclerosis-related interstitial lung disease on the lung transplant waiting list: a retrospective study

Advanced systemic sclerosis-associated interstitial lung disease (SSc-ILD) can be treated with lung transplantation. There is limited data on lung transplantation outcomes in patients with SSc-ILD, in non-Western populations.We assessed survival data of patients with SSc-ILD, on the lung transplant (LT) waiting list, and evaluated post-transplant outcomes in patients from an Asian LT center. In this single-center retrospective study, 29 patients with SSc-ILD, registered for deceased LT at Kyoto University Hospital, between 2010 and 2022, were identified. We investigated post-transplant outcomes in recipients who underwent LT for SSc-ILD, between February 2002 and April 2022. Ten patients received deceased-donor LT (34%), two received living-donor LT (7%), seven died waiting for LT (24%), and ten survived on the waiting list (34%). Median duration from registration to deceased-donor LT was 28.9 months and that from registration to living-donor LT or death was 6.5 months. Analysis of 15 recipients showed improved forced vital capacity with a median of 55.1% at baseline, 65.8% at 6 months, and 80.3% at 12 months post-transplant. The 5-year survival rate for post-transplant patients with SSc-ILD was 86.2%. The higher post-transplant survival rate at our institute than previously reported suggests that lung transplantation is acceptable in Asian patients with SSc-ILD.

Listing Dilemmas: Age, Frailty, Weight, Preexisting Cancers, and Systemic Diseases

Selection of lung transplant candidates is an evolving field that pushes the boundaries of what is considered the norm. Given the continually changing demographics of the typical lung transplant recipient as well as the growing list of risk factors that predispose patients to poor posttransplant outcomes, we explore the dilemmas in lung transplant candidate selections pertaining to older age, frailty, low and high body mass index, preexisting cancers, and systemic autoimmune rheumatic diseases.

Risk of primary graft dysfunction following lung transplantation in selected adults with connective tissue disease-associated interstitial lung disease

BACKGROUND

Previous studies have reported similarities in long-term outcomes following lung transplantation for connective tissue disease-associated interstitial lung disease (CTD-ILD) and idiopathic pulmonary fibrosis (IPF). However, it is unknown whether CTD-ILD patients are at increased risk of primary graft dysfunction (PGD), delays in extubation, or longer index hospitalizations following transplant compared to IPF patients.

METHODS

We performed a multicenter retrospective cohort study of CTD-ILD and IPF patients enrolled in the Lung Transplant Outcomes Group registry who underwent lung transplantation between 2012 and 2018. We utilized mixed effects logistic regression and stratified Cox proportional hazards regression to determine whether CTD-ILD was independently associated with increased risk for grade 3 PGD or delays in post-transplant extubation and hospital discharge compared to IPF.

RESULTS

A total of 32.7% (33/101) of patients with CTD-ILD and 28.9% (145/501) of patients with IPF developed grade 3 PGD 48-72 hours after transplant. There were no significant differences in odds of grade 3 PGD among patients with CTD-ILD compared to those with IPF (adjusted OR 1.12, 95% CI 0.64-1.97, p = 0.69), nor was CTD-ILD independently associated with a longer post-transplant time to extubation (adjusted HR for first extubation 0.87, 95% CI 0.66-1.13, p = 0.30). However, CTD-ILD was independently associated with a longer post-transplant hospital length of stay (median 23 days [IQR 14-35 days] vs17 days [IQR 12-28 days], adjusted HR for hospital discharge 0.68, 95% CI 0.51-0.90, p = 0.008).

CONCLUSION

Patients with CTD-ILD experienced significantly longer postoperative hospitalizations compared to IPF patients without an increased risk of grade 3 PGD.

Comparison of short-term outcomes for connective tissue disease-related interstitial lung disease and idiopathic pulmonary fibrosis after lung transplantation

Background

Pulmonary involvement is common in connective tissue disease (CTD), and respiratory failure is a major cause of morbidity and mortality in CTD-related interstitial lung disease (CTD-ILD). Lung transplantation is thus important for these patients. However, survival, outcomes, and management of these patients after transplantation have been debated. The aim of this study was to evaluate the outcomes for CTD-ILD compared to those for idiopathic pulmonary fibrosis (IPF) after lung transplantation.

Methods

We performed a single-centre retrospective study of 62 patients with CTD-ILD or IPF who underwent lung transplantation at a tertiary hospital in South Korea between October 2012 and October 2016.

Results

Patients with CTD-ILD (n=15) were younger (46 vs. 60 years, P=0.001) and were less likely to be male (33.3% vs. 76.6%, P=0.004) than were patients with IPF (n=47). The 1-year cumulative survival rate was 80.0% for CTD-ILD and 59.6% for IPF (log-rank P=0.394). There was no difference in the cumulative survival rate (log-rank P=0.613) of age- and sex-matched patients with CTD-ILD (n=15) and IPF (n=15). The incidence of primary graft dysfunction was similar (P=0.154), and 2 (18.2%) patients developed possible CTD flare.

Conclusions

Patients with CTD-ILD and those with IPF who underwent lung transplantation had similar survival rates.

Survival and outcomes after lung transplantation for non-scleroderma connective tissue-related interstitial lung disease

BACKGROUND

Patients with non-scleroderma connective tissue-related lung disease (NS-CTLD), including rheumatoid arthritis, idiopathic inflammatory myopathies, Sjögren syndrome, mixed connective tissue disease, and systemic lupus erythematosus, may be at risk for worse outcomes after lung transplantation because of immune dysregulation or extrapulmonary manifestations of their underlying disease. We compared survival, acute and chronic rejection, and extrapulmonary organ dysfunction after transplantation in patients with NS-CTLD and idiopathic pulmonary fibrosis (IPF).

METHODS

This was a retrospective cohort study of patients with NS-CTLD and IPF who were listed in the Scientific Registry of Transplant Recipients and underwent lung transplantation from May 5, 2005, to March 1, 2016.

RESULTS

Patients with NS-CTLD (n = 275) were younger, a higher percentage female and non-white than patients with IPF (n = 6,346). NS-CTLD patients did not have worse adjusted survival (hazard ratio, 1.14, 95% confidence interval [CI], 0.92-1.42; p = 0.24). They were not more likely to have an episode of acute cellular rejection (odds ratio, 0.96; 95% CI, 0.72-1.28; p = 0.77) or to develop bronchiolitis obliterans syndrome (odds ratio, 0.82; 95% CI, 0.60-1.12; p = 0.21). Patients with NS-CTLD were not more likely to require plasmapheresis or dialysis or to develop a lymphoproliferative malignancy or liver disease after transplantation.

CONCLUSIONS

We found no significant differences in survival, acute or chronic rejection, or extrapulmonary organ dysfunction in patients who underwent lung transplantation for NS-CTLD compared with IPF. In appropriately selected candidates, NS-CTLD should not be considered a contraindication to lung transplantation.

Hypoxia-Induced Epithelial-Mesenchymal Transition Is Involved in Bleomycin-Induced Lung Fibrosis

Pulmonary fibrosis is a severe disease that contributes to the morbidity and mortality of a number of lung diseases. However, the molecular and cellular mechanisms leading to lung fibrosis are poorly understood. This study investigated the roles of epithelial-mesenchymal transition (EMT) and the associated molecular mechanisms in bleomycin-induced lung fibrosis. The bleomycin-induced fibrosis animal model was established by intratracheal injection of a single dose of bleomycin. Protein expression was measured by Western blot, immunohistochemistry, and immunofluorescence. Typical lesions of lung fibrosis were observed 1 week after bleomycin injection. A progressive increase in MMP-2, S100A4, α-SMA, HIF-1α, ZEB1, CD44, phospho-p44/42 (p-p44/42), and phospho-p38 MAPK (p-p38) protein levels as well as activation of EMT was observed in the lung tissues of bleomycin mice. Hypoxia increased HIF-1α and ZEB1 expression and activated EMT in H358 cells. Also, continuous incubation of cells under mild hypoxic conditions increased CD44, p-p44/42, and p-p38 protein levels in H358 cells, which correlated with the increase in S100A4 expression. In conclusion, bleomycin induces progressive lung fibrosis, which may be associated with activation of EMT. The fibrosis-induced hypoxia may further activate EMT in distal alveoli through a hypoxia-HIF-1α-ZEB1 pathway and promote the differentiation of lung epithelial cells into fibroblasts through phosphorylation of p38 MAPK and Erk1/2 proteins.

Survival and extrapulmonary course of connective tissue disease after lung transplantation

BACKGROUND

Connective tissue disease (CTD)-related lung dysfunction is a common cause of morbidity and mortality; however, few lung transplantations (LTs) are performed in this population secondary to uncertainty regarding the posttransplant survival, outcome, and management.

OBJECTIVES

The objectives were to evaluate the survival and the pulmonary and extrapulmonary courses of CTD after LT.

METHODS

Survival outcomes of patients documented within the Organ Procurement and Transplantation Network who had undergone a LT for CTD were compared with those who underwent LT for chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF). In addition, the pulmonary and extrapulmonary courses of the CTD were evaluated after LT.

RESULTS

From 1991 to 2009, there were 284 documented LT in patients with CTD. Post-LT cumulative survival of patients with CTD was less than that for COPD through 5 years, with a difference that peaked at 1 year (72.7% vs. 83.1%, P < 0.001). When patients with CTD were compared with those with IPF, a difference was only noted at 1 year (72.7% vs. 77.7%, P = 0.049). There were no documented post-LT pulmonary recurrences of the CTD, and extrapulmonary flares of the CTD were rare (1 possible flare per 20.3 patient-years and 1 probable flare per 81.0 patient-years).

CONCLUSIONS

Cumulative survival of patients with CTD who underwent LT is similar to those with IPF and slightly less than those with COPD, with an increased risk of mortality that was most prominent at 6 months after transplant followed by subsequent narrowing of the survival differences over time. Lung transplantation may be a viable therapeutic option for patients with end-stage lung dysfunction resulting from a CTD.