Impact of chronic lung allograft dysfunction, especially restrictive allograft syndrome, on the survival after living-donor lobar lung transplantation compared with cadaveric lung transplantation in adults: a single-center experience

Restrictive allograft dysfunction rather than bronchiolitis obliterans syndrome had a major impact on the overall survival after living-donor lobar lung transplantation

PURPOSE

Chronic lung allograft dysfunction (CLAD) is a known long-term fatal disorder after lung transplantation. In this study, we evaluated the CLAD classification of the International Society for Heart and Lung Transplantation (ISHLT) for living-donor lobar lung transplantation (LDLLT).

METHODS

We conducted a single-center retrospective review of data from 73 patients who underwent bilateral LDLLT between 1998 and 2019. Factors related to opacity on computed tomography (CT) and restriction on pulmonary function tests (PFTs) were also analyzed.

RESULTS

Overall, 26 (36%) patients were diagnosed with CLAD, including restrictive allograft syndrome (RAS), n = 10 (38.5%); bronchiolitis obliterans syndrome (BOS), n = 8 (30.8%); mixed, n = 1 (3.8%); undefined, n = 2 (7.7%); and unclassified, n = 5 (19.2%). The 5-year survival rate after the CLAD onset was 60.7%. The survival of patients with BOS was significantly better than that of patients with RAS (p = 0.012). In particular, patients with restriction on PFT had a significantly worse survival than those without restriction (p = 0.001).

CONCLUSIONS

CLAD after bilateral LDLLT does not have a major impact on the recipient survival, especially in patients with BOS. Restriction on PFT may predict a particularly poor prognosis in patients with CLAD after bilateral LDLLT.

Impact of perioperative airway pathogens on living-donor lobar lung transplantation outcomes

PURPOSE

To elucidate the clinical impact of pathogenic organism (PO) positivity early after transplantation, we evaluated the impact of perioperative airway POs on outcomes after living-donor lobar lung transplantation (LDLLT), where the graft airway is supposed to be sterile from a healthy donor.

METHOD

A retrospective review of 67 adult LDLLT procedures involving 132 living donors was performed. Presence of POs in the recipients' airways was evaluated preoperatively and postoperatively in intensive-care units.

RESULTS

POs were detected preoperatively in 13 (19.4%) recipients. No POs were isolated from the donor airways at transplantation. POs were detected in 39 (58.2%) recipients postoperatively; most were different from the POs isolated preoperatively. Postoperative PO isolation was not associated with short-term outcomes other than prolonged postoperative ventilation. The 5-year overall survival was significantly better in the PO-negative group than in the PO-positive group (89.1% vs. 63.7%, P = 0.014). In the multivariate analysis, advanced age (hazard ratio [HR]: 1.041 per 1-year increase, P = 0.033) and posttransplant PO positivity in the airway (HR: 3.684, P = 0.019) significantly affected the survival.

CONCLUSIONS

The airways of the living-donor grafts were microbiologically sterile. PO positivity in the airway early after transplantation negatively impacted long-term outcomes.

Long-term outcomes of lung transplantation requiring renal replacement therapy: A single-center experience

BACKGROUND

Life-long immunosuppressive therapy after lung transplantation (LT) may lead to end-stage renal disease (ESRD), requiring renal replacement therapy (RRT). We aimed to investigate the characteristics and long-term outcomes of patients undergoing LT and requiring RRT.

METHODS

This study was a single-center, retrospective cohort study. The patients were divided into the RRT (n = 15) and non-RRT (n = 170) groups. We summarized the clinical features of patients in the RRT group and compared patient characteristics, overall survival, and chronic lung allograft dysfunction (CLAD)-free survival between the two groups.

RESULTS

The cumulative incidences of ESRD requiring RRT after LT at 5, 10, and 15 years were 0.8 %, 7.6 %, and 25.2 %, respectively. In the RRT group, all 15 patients underwent hemodialysis but not peritoneal dialysis, and two patients underwent living-donor kidney transplantation. The median follow-up period was longer in the RRT group than in the non-RRT group (P < 0.001). The CLAD-free survival and overall survival did not differ between the two groups. The 5-year survival rate even after the initiation of hemodialysis was 53.3 %, and the leading cause of death in the RRT group was infection.

CONCLUSIONS

Favorable long-term outcomes can be achieved by RRT for ESRD after LT.

Plasma concentrations of histidine-rich glycoprotein in primary graft dysfunction after lung transplantation

OBJECTIVES

Histidine-rich glycoprotein has been reported as an anti-inflammatory glycoprotein that inhibits acute lung injury in mice with sepsis and as a prognostic biomarker in patients with sepsis. We investigated the relationship between plasma concentrations of histidine-rich glycoprotein and the risk of occurrence of primary graft dysfunction.

METHODS

According to the primary graft dysfunction grade at post-transplant 72 h, patients who underwent lung transplantation were divided into three groups: non-primary graft dysfunction group (grade 0-1), moderate primary graft dysfunction group (grade 2), and severe primary graft dysfunction group (grade 3). The plasma concentrations of histidine-rich glycoprotein measured daily during the first post-transplant 7 days were compared among the three groups. Appropriate cutoff values of the concentrations were set for survival analyses after lung transplantation.

RESULTS

A total of 68 patients were included. The plasma histidine-rich glycoprotein concentration at post-transplant 72 h was significantly lower in the severe primary graft dysfunction group (n = 7) than in the other two groups [non-primary graft dysfunction group (n = 43), P = 0.042; moderate primary graft dysfunction group (n = 18), P = 0.040]. Patients with plasma histidine-rich glycoprotein concentration ≥34.4 µg/ml at post-transplant 72 h had significantly better chronic lung allograft dysfunction-free survival (P = 0.012) and overall survival (P = 0.037) than those with the concentration <34.4 µg/ml.

CONCLUSIONS

Plasma histidine-rich glycoprotein concentrations at post-transplant 72 h might be associated with the risk of development of primary graft dysfunction.

Living-donor lobar lung transplantation

Living-donor lobar lung transplantation (LDLLT) is indicated for critically ill patients who would not survive the waiting period in the case of severe brain-dead donor shortage. It is essential to confirm that potential donors are willing to donate without applying psychological pressure from others. In standard LDLLT, the right and left lower lobes donated by 2 healthy donors are implanted into the recipient under cardiopulmonary support. LDLLT can be applied to various lung diseases including restrictive, obstructive, infectious, and vascular lung diseases in both adult and pediatric patients if size matching is acceptable. Functional size matching by measuring donor pulmonary function and anatomical size matching by 3-dimensional computed tomography volumetry are very useful. When 2 donors with ideal size matching are not available, various transplant procedures, such as single lobe, segmental, recipient lobe-sparing, and inverted lobar transplants are valuable options. There seems to be immunological advantages in LDLLT as compared to cadaveric lung transplantation (CLT). Unilateral chronic allograft dysfunction is a unique manifestation after bilateral LDLLT, which may contribute to better prognosis. The growth of adult lung graft implanted into growing pediatric recipients is suggested by radiologic evaluation. Although only 2 lobes are implanted, postoperative pulmonary function is equivalent between LDLLT and CLT. The long-term outcome after LDLLT is similar to or better than that after CLT. The author has performed 164 LDLLTs resulting in 71.6% survival rate at 10 years. All living-donors returned to their previous life styles. Because of possible serious morbidity in donors, LDLLT should be applied only for critically ill patients.

Percentage of low attenuation area on computed tomography detects chronic lung allograft dysfunction, especially bronchiolitis obliterans syndrome, after bilateral lung transplantation

INTRODUCTION

The percentage of low attenuation area (%LAA) on computed tomography (CT) is useful for evaluating lung emphysema, and higher %LAA was observed in patients with chronic lung allograft dysfunction (CLAD). This study investigated the relationship between the %LAA and the development of CLAD after bilateral lung transplantation (LT).

METHODS

We conducted a single-center retrospective study of 75 recipients who underwent bilateral LT; the recipients were divided into a CLAD group (n = 30) and a non-CLAD group (n = 45). The %LAA was calculated using CT and compared between the two groups from 4 years before to 4 years after the diagnosis of CLAD. The relationships between the %LAA and the percent baseline values of the pulmonary function test parameters were also calculated.

RESULTS

The %LAA was significantly higher in the CLAD group than in the non-CLAD group from 2 years before to 2 years after the diagnosis of CLAD (P < .05). In particular, patients with bronchiolitis obliterans syndrome (BOS) exhibited significant differences even from 4 years before to 4 years after diagnosis (P < .05). Significant negative correlations between the %LAA and the percent baseline values of the forced expiratory volume in 1 s (r = -.36, P = .0031), the forced vital capacity (r = -.27, P = .027), and the total lung capacity (r = -.40, P < .001) were seen at the time of CLAD diagnosis.

CONCLUSION

The %LAA on CT was associated with the development of CLAD and appears to have the potential to predict CLAD, especially BOS, after bilateral LT.

Identification of genetic loci associated with renal dysfunction after lung transplantation using an ethnic-specific single-nucleotide polymorphism array

Renal dysfunction is a long-term complication associated with an increased mortality after lung transplantation (LT). We investigated the association of single-nucleotide polymorphisms (SNPs) with the development of renal dysfunction after LT using a Japanese-specific SNP array. First, eligible samples of 34 LT recipients were genotyped using the SNP array and divided into two groups, according to the presence of homozygous and heterozygous combinations of mutant alleles of the 162 renal-related SNPs. To identify candidate SNPs, the renal function tests were compared between the two groups for each SNP. Next, we investigated the association between the candidate SNPs and the time course of changes of the estimated glomerular filtration rate (eGFR) in the 99 recipients until 10 years after the LT. ΔeGFR was defined as the difference between the postoperative and preoperative eGFR values. Eight SNPs were identified as the candidate SNPs in the 34 recipients. Validation analysis of these 8 candidate SNPs in all the 99 recipients showed that three SNPs, namely, rs10277115, rs4690095, and rs792064, were associated with significant changes of the ΔeGFR. Pre-transplant identification of high-risk patients for the development of renal dysfunction after LT based on the presence of these SNPs might contribute to providing personalized medicine.

Diagnostic value of circulating microRNA-21 in chronic lung allograft dysfunction after bilateral cadaveric and living-donor lobar lung transplantation

Background

MicroRNAs (miRNAs) involved in the pathogenesis of pulmonary fibrosis have been shown to be associated with the development of chronic lung allograft dysfunction (CLAD) after lung transplantation (LT). We investigated the role of circulating miRNAs in the diagnosis of CLAD after bilateral LT, including cadaveric LT (CLT) and living-donor lobar LT (LDLLT).

Methods

The subjects of this retrospective study were 37 recipients of bilateral CLT (n = 23) and LDLLT (n = 14), and they were divided into a non-CLAD group (n = 24) and a CLAD group (n = 13). The plasma miRNA levels of the two groups were compared, and correlations between their miRNAs levels and percent baseline forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and total lung capacity (TLC) values were calculated from one year before to one year after the diagnosis of CLAD.

Results

The plasma levels of both miR-21 and miR-155 at the time of the diagnosis of CLAD were significantly higher in the CLAD group than in the non-CLAD group (miR-21, P = 0.0013; miR-155, P = 0.042). The miR-21 levels were significantly correlated with the percent baseline FEV1, FVC, and TLC value of one year before and at the time of diagnosis of CLAD (P < 0.05). A receiver operating characteristic curve analysis of the performance of miR-21 levels in the diagnosis of CLAD yielded an area under the curve of 0.89.

Conclusion

Circulating miR-21 appears to be of potential value in diagnosing CLAD after bilateral LT.

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.

Perioperative diabetes mellitus affects the outcomes of lung transplant recipients

OBJECTIVE

Identifying the risks for chronic lung allograft dysfunction (CLAD) after lung transplantation (LTx) is beneficial to the patient. We hypothesized that diabetes mellitus (DM) is relevant to CLAD development. Our study aimed to clarify if DM is a risk for poor post-LTx outcomes.

METHODS

The records of patients first undergoing LTx in our institution between 2010 and 2018 were reviewed retrospectively. Patient characteristics and postoperative outcomes were analyzed. We established 6 months post-LTx as the landmark point for predicting overall survival (OS) and CLAD development. To identify perioperative DM, we evaluated the patient for DM at 6 months post-LTx.

RESULTS

A total of 172 patients were investigated. DM and CLAD occurred in 76 and 39 patients, respectively, and 40 died. At 6 months post-LTx, the unadjusted and adjusted hazard ratios (HRs) of DM for OS were 3.36 (95% confidence interval [CI95%] = [1.67-6.73]) and 2.78 (CI95% = [1.35-5.75]), respectively. The unadjusted and adjusted HRs of DM for CLAD-free survival were 2.20 (CI95% = [1.27-3.80]) and 2.15 (CI95% = [1.24-3.74]). The patients with DM were older and had a higher body mass index and more incidents of post-LTx malignant disease than the non-DM patients. The five-year OS and CLAD-free survival rates of the patients with or without DM were 57.2% vs 86.5% and 50.1% vs 72.9%, respectively.

CONCLUSIONS

Perioperative DM was identified as an independent adverse factor for OS and CLAD-free survival. Perioperative management of DM should be emphasized in the clinical setting of lung transplantation.

Long-term outcomes of living-donor lobar lung transplantation

OBJECTIVE

Although living-donor lobar lung transplantation (LDLLT) enables an intermediate survival similar to cadaveric lung transplantation, the long-term outcome remains unknown. We examined the long-term outcomes of 30 patients who received LDLLT more than 16 years previously.

METHODS

We retrospectively reviewed the clinical data of 30 patients who underwent LDLLT (bilateral LDLLT, 29 patients; single LDLLT, 1 pediatric patient) between October 1998 and April 2004.

RESULTS

LDLLT was performed for 25 female and 5 male patients ranging in age from 8 to 55 years. The diagnoses included pulmonary hypertension (n = 11), pulmonary fibrosis (n = 7), bronchiolitis obliterans (n = 5), and others (n = 7). At a median follow-up of 205 months, 22 patients were alive and 8 were dead. The causes of death were infection (n = 3), malignancy (n = 2), acute rejection (n = 2), and chronic lung allograft dysfunction (CLAD; n = 1). Unilateral CLAD occurred in 17 patients (56.7%), but only 1 of these patients subsequently developed bilateral CLAD. Two patients underwent bilateral cadaveric lung retransplantations. The 5-, 10-, and 15-year CLAD-free survival rates were 80.0%, 62.8%, and 44.3%, respectively. Malignancy occurred in 7 patients. Two of 5 patients with chronic kidney disease requiring hemodialysis underwent living-donor kidney transplantation. The 5-, 10-, and 15-year overall survival rates were 96.7%, 86.7%, and 73.3%, respectively.

CONCLUSIONS

Although only 2 lobes are implanted, LDLLT provides encouraging long-term outcomes. In patients with unilateral CLAD, the functioning contralateral graft might contribute to a favorable long-term outcome.

Emphysematous changes and lower levels of plasma irisin are associated with bronchiolitis obliterans syndrome after bilateral living-donor lobar lung transplantation

PURPOSE

Decreased irisin levels may be associated with the development of emphysema. Similarly, emphysematous changes may develop in patients with chronic lung allograft dysfunction (CLAD) after living-donor lobar lung transplantation (LDLLT). We investigated the severity of emphysematous changes and the relationship between irisin levels and CLAD after bilateral LDLLT and cadaveric lung transplantation (CLT).

METHODS

The subjects of this retrospective study were 59 recipients of bilateral LDLLT (n = 31) or CLT (n = 28), divided into a non-CLAD group (n = 41), a LDLLT-CLAD group (n = 11), and a CLT-CLAD group (n = 7). We compared the severity of emphysematous changes, the skeletal muscle mass, and the plasma irisin levels among the groups.

RESULTS

The emphysematous changes were significantly more severe in the LDLLT-CLAD and CLT-CLAD groups (p = 0.046 and 0.036), especially in patients with bronchiolitis obliterans syndrome (BOS), than in the non-CLAD group. Although the skeletal muscle mass was similar in all the groups, the plasma irisin levels were significantly lower in the LDLLT-CLAD group (p = 0.022), especially in the patients with BOS after LDLLT, than in the non-CLAD group.

CONCLUSION

Emphysematous changes and lower levels of plasma irisin were associated with CLAD, especially in patients with BOS, after bilateral LDLLT.

The prognostic nutritional index is correlated negatively with the lung allocation score and predicts survival after both cadaveric and living-donor lobar lung transplantation

PURPOSE

The prognostic nutritional index (PNI), calculated based on the serum albumin levels and the total lymphocyte count, has been identified as a predictor of clinical outcomes in various fields of surgery. In this study, we investigated the relationship between the PNI and the lung allocation score (LAS) as well as the impact of the PNI on the outcomes of both cadaveric lung transplantation (CLT) and living-donor lobar lung transplantation (LDLLT).

METHODS

We reviewed retrospective data for 127 recipients of lung transplantation (LT), including 71 recipients of CLT and 56 recipients of LDLLT.

RESULTS

The PNI was correlated significantly and negatively with the LAS (r = - 0.40, P = 0.0000037). Multivariate analysis revealed that age (P = 0.00093), BMI (P = 0.00087), and PNI (P = 0.0046) were independent prognostic factors of a worse outcome after LT. In a subgroup analysis, survival after both CLT (P = 0.015) and LDLLT (P = 0.041) was significantly worse in the low PNI group than in the high PNI group.

CONCLUSION

Preoperative nutritional evaluations using the PNI can assist with the assessment of disease severity in LT recipients and may predict survival after both CLT and LDLLT.

Lung perfusion scintigraphy to detect chronic lung allograft dysfunction after living-donor lobar lung transplantation

Because chronic lung allograft dysfunction (CLAD) develops predominantly on one side after bilateral living-donor lobar lung transplantation (LDLLT), lung perfusion scintigraphy (Q-scinti) was expected to show a perfusion shift to the contralateral unaffected lung with the development of CLAD. Our study examined the potential usefulness of Q-scinti in the diagnosis of CLAD after bilateral LDLLT. We conducted a single-center retrospective cohort study of 58 recipients of bilateral LDLLT. The unilateral shift values on Q-scinti were calculated and compared between the CLAD group (N = 27) and the non-CLAD group (N = 31) from 5 years before to 5 years after the diagnosis of CLAD. The unilateral shift values in Q-scinti were significantly higher in the CLAD group than in the non-CLAD group from 5 years before the diagnosis of CLAD to 5 years after the diagnosis (P < 0.05). The unilateral shift values in Q-scinti were significantly correlated with the percent baseline values of the forced expiratory volume in 1 s (P = 0.0037), the total lung capacity (P = 0.0028), and the forced vital capacity (P = 0.00024) at the diagnosis of CLAD. In patients developing unilateral CLAD after bilateral LDLLT, Q-scinti showed a unilateral perfusion shift to the contralateral unaffected lung. Thus, Q-scinti appears to have the potential to predict unilateral CLAD after bilateral LDLLT.