S.S. Weigt

Chronic lung allograft rejection: mechanisms and therapy.

Lung transplantation is a therapeutic option for patients with end-stage pulmonary disorders. Unfortunately, due to post-lung transplant complications, both infectious and noninfectious, it is only a treatment and not a cure. Importantly, despite induction combined with triple or quadruple maintenance immunosuppressive therapy, chronic lung rejection, in the form of obliterative bronchiolitis or its clinical correlate bronchiolitis obliterans syndrome (BOS), continues to be highly prevalent and is the major limitation to long-term survival. In this review we evaluate the presentation, diagnosis, histopathology, pathologic mechanisms, risk factors, and prevention/treatment options for BOS. A better understanding of the risk factors and how it relates to the pathologic mechanisms of chronic lung allograft rejection should lead to better pharmacologic targets to prevent/treat this syndrome without increasing the recipients risk for infections.

Aspergillus Colonization of the Lung Allograft Is a Risk Factor for Bronchiolitis Obliterans Syndrome

Multiple infections have been linked with the development of bronchiolitis obliterans syndrome (BOS) post‐lung transplantation. Lung allograft airway colonization by Aspergillus species is common among lung transplant recipients. We hypothesized that Aspergillus colonization may promote the development of BOS and may decrease survival post‐lung transplantation. We reviewed all lung transplant recipients transplanted in our center between January 2000 and June 2006. Bronchoscopy was performed according to a surveillance protocol and when clinically indicated. Aspergillus colonization was defined as a positive culture from bronchoalveolar lavage or two sputum cultures positive for the same Aspergillus species, in the absence of invasive pulmonary Aspergillosis. We found that Aspergillus colonization was strongly associated with BOS and BOS related mortality in Cox regression analyses. Aspergillus colonization typically preceded the development of BOS by a median of 261 days (95% CI 87–520). Furthermore, in a multivariate Cox regression model, Aspergillus colonization was a distinct risk factor for BOS, independent of acute rejection. These data suggest a potential causative role for Aspergillus colonization in the development of BOS post‐lung transplantation and raise the possibility that strategies aimed to prevent Aspergillus colonization may help delay or reduce the incidence of BOS.

Systemic sclerosis and bilateral lung transplantation: a single centre experience

Lung involvement is the leading cause of death in systemic sclerosis (SSc), but lung transplantation (LT) for systemic disease remains controversial. Our objective was to comprehensively evaluate post-LT outcomes for SSc compared to idiopathic pulmonary fibrosis (IPF). We retrospectively evaluated bilateral LT recipients (LTRs) with SSc or IPF at our centre between January 1, 2003 and December 31, 2007. The primary end-point was all-cause mortality at 1 yr post-LT. Secondary end-points included assessments of acute rejection (AR), pulmonary function, infection and chronic rejection. 14 patients with SSc and 38 patients with IPF underwent LT. Apart from a younger SSc cohort (53.2 versus 58.8 yrs; p = 0.02), the two groups were well matched. 1-yr all-cause mortality was no different between SSc (6.6%) and IPF (13.1%) groups, after adjusting for age (p = 0.62). Rates of (AR) ≥2 were significantly increased for the SSc compared with the IPF group (hazard ratio (HR) 2.91; p = 0.007). Other end-points, including chronic rejection, infection and pulmonary function, showed no differences. SSc LTRs experience similar survival 1 yr post-LT when compared to IPF. AR rates may be significantly higher in the SSc group. Longer follow-up is necessary to determine the effects of gastrointestinal dysfunction and AR on late allograft function in SSc LTR.

Periostitis Secondary to Prolonged Voriconazole Therapy in Lung Transplant Recipients

We report five cases of possible drug‐induced periostitis associated with long‐term use of voriconazole therapy after lung transplantation (LT). The diagnosis of periostitis was made by the documentation of bone pain, elevation of serum alkaline phosphatase and characteristic findings on radionuclide bone imaging in the absence of any identifiable rheumatologic disease. This periostitis appears similar to hypertrophic osteoarthopathy (HOA) but does not meet all criteria for HOA. In all patients, the symptoms resolved rapidly after discontinuation of voriconazole therapy. Awareness of this potential syndrome, which manifests as bone pain, elevated serum alkaline phosphatase and a bone scan suggestive of periostitis, is necessary in LT recipients on long‐term voriconazole.

Colonization with Small Conidia Aspergillus Species is associated with Bronchiolitis Obliterans Syndrome: A Two-Center Validation Study

Aspergillus colonization after lung transplantation may increase the risk for bronchiolitis obliterans syndrome (BOS), a disease of small airways. We hypothesized that colonization with small conidia Aspergillus species would be associated with a greater risk of BOS, based upon an increased likelihood of deposition in small airways. We studied adult primary lung recipients from two large centers; 298 recipients at University of California, Los Angeles and 482 recipients at Duke University Medical Center. We grouped Aspergillus species by conidia diameter ≤3.5 μm. We assessed the relationship of colonization with outcomes in Cox models. Pre‐BOS colonization with small conidia Aspergillus species, but not large, was a risk factor for BOS (p = 0.002, HR 1.44, 95% CI 1.14–1.82), along with acute rejection, single lung and Pseudomonas. Colonization with small conidia species also associated with risk of death (p = 0.03, HR 1.30, 95% CI 1.03–1.64). Although other virulence traits besides conidia size may be important, we have demonstrated in two large independent cohorts that colonization with small conidia Aspergillus species increases the risk of BOS and death. Prospective evaluation of strategies to prevent Aspergillus colonization of small airways is warranted, with the goal of preserving lung allograft function as long as possible.

Altered Levels of CC Chemokines During Pulmonary CMV Predict BOS and Mortality Post-Lung Transplantation

Pulmonary CMV infection (CMVI) and disease (CMVD) is associated with reduced long‐term survival post‐lung transplantation, however, the specific biologic mechanisms remain unclear. We have demonstrated a role of CC chemokines during lung allograft dysfunction. Based on these findings, we hypothesized that pulmonary CMV upregulates the expression of multiple CC chemokines that leads to allograft dysfunction and decreased long‐term survival.

The 2015 International Society for Heart and Lung Transplantation Guidelines for the management of fungal infections in mechanical circulatory support and cardiothoracic organ transplant recipients: Executive summary.

Shahid Husain, MD, MS, Amparo Sole, MD, PhD, Barbara D. Alexander, MD, MHS, Saima Aslam, MD, MS, Robin Avery, MD, Christian Benden, MD, Eliane M. Billaud, PharmD, PhD, Daniel Chambers, MBBS, MD, Lara Danziger-Isakov, MD, Savitri Fedson, MD, Kate Gould, MD, Aric Gregson, MD, Paolo Grossi, MD, PhD, Denis Hadjiliadis, MD, Peter Hopkins, MD, Me-Linh Luong, MD, Debbie J.E. Marriott, MD, Victor Monforte, MD, Patricia Munoz, MD, PhD, Alessandro C. Pasqualotto, MD, PhD, Antonio Roman, MD, Fernanda P. Silveira, MD, Jeffrey Teuteberg, MD, MS, Stephen Weigt, MD, Aimee K. Zaas, MD, MHS, Andreas Zuckerman, MD, and Orla Morrissey, MD, PhD

CXCR3 chemokine ligands during respiratory viral infections predict lung allograft dysfunction.

Community‐acquired respiratory viruses (CARV) can accelerate the development of lung allograft dysfunction, but the immunologic mechanisms are poorly understood. The chemokine receptor CXCR3 and its chemokine ligands, CXCL9, CXCL10 and CXCL11 have roles in the immune response to viruses and in the pathogenesis of bronchiolitis obliterans syndrome, the predominant manifestation of chronic lung allograft rejection. We explored the impact of CARV infection on CXCR3/ligand biology and explored the use of CXCR3 chemokines as biomarkers for subsequent lung allograft dysfunction. Seventeen lung transplant recipients with CARV infection had bronchoalveolar lavage fluid (BALF) available for analysis. For comparison, we included 34 BALF specimens (2 for each CARV case) that were negative for infection and collected at a duration posttransplant similar to a CARV case. The concentration of each CXCR3 chemokine was increased during CARV infection. Among CARV infected patients, a high BALF concentration of either CXCL10 or CXCL11 was predictive of a greater decline in forced expiratory volume in 1 s, 6 months later. CXCR3 chemokine concentrations provide prognostic information and this may have important implications for the development of novel treatment strategies to modify outcomes after CARV infection.

CXCR3 ligands are augmented during the pathogenesis of pulmonary sarcoidosis

We and other investigators have hypothesised that the CXC chemokine receptor (CXCR)3/CXCR3 ligand biological axis is involved in the formation of sarcoid lung granulomas; however, significant discrepancies in the current literature remain. In an effort to clarify previous conflicting findings, we performed the largest observational study to date of interferon-inducible ELR- (lacking the sequence glutamic acid–leucine–arginine) CXC chemokines in sarcoid bronchoalveolar fluid (BALF). BALF chemokine levels from sarcoid patients (n = 72) and healthy controls (n = 8) were measured with the ELISA method. Immunohistochemical staining was performed for CXCR3 and its ligands. BALF CXC chemokine ligand (CXCL)10 levels from sarcoid patients were not significantly increased compared with controls. BALF CXCL11 levels from sarcoid patients demonstrated a trend towards elevation; subgroup analysis by stage showed significant BALF CXCL11 elevation in stage I sarcoid patients compared with controls. BALF CXCL9 levels were elevated from sarcoid patients compared with controls. CXC11, CXCL9 and CXCR3 were expressed from epithelioid histiocytes, multinucleated giant cells and other inflammatory cells forming sarcoid lung granulomas. Our data suggest that CXCL9 and CXCL11 are important mediators in recruiting CXCR3-expressing cells. Importantly, we have made the novel observation that both lymphocytes and cells of monocyte linage express CXCR3 and are involved in the formation of sarcoid lung granulomas.

Immune response CC chemokines CCL2 and CCL5 are associated with pulmonary sarcoidosis

BackgroundPulmonary sarcoidosis involves an intense leukocyte infiltration of the lung with the formation of non-necrotizing granulomas. CC chemokines (chemokine (C-C motif) ligand 2 (CCL2)-CCL5) are chemoattractants of mononuclear cells and act through seven transmembrane G-coupled receptors. Previous studies have demonstrated conflicting results with regard to the associations of these chemokines with sarcoidosis. In an effort to clarify previous discrepancies, we performed the largest observational study to date of CC chemokines in bronchoalveolar lavage fluid (BALF) from patients with pulmonary sarcoidosis.ResultsBALF chemokine levels from 72 patients affected by pulmonary sarcoidosis were analyzed by enzyme-linked immunosorbent assay (ELISA) and compared to 8 healthy volunteers. BALF CCL3 and CCL4 levels from pulmonary sarcoidosis patients were not increased compared to controls. However, CCL2 and CCL5 levels were elevated, and subgroup analysis showed higher levels of both chemokines in all stages of pulmonary sarcoidosis. CCL2, CCL5, CC chemokine receptor type 1 (CCR1), CCR2 and CCR3 were expressed from mononuclear cells forming the lung granulomas, while CCR5 was only found on mast cells.ConclusionsThese data suggest that CCL2 and CCL5 are important mediators in recruiting CCR1, CCR2, and CCR3 expressing mononuclear cells as well as CCR5-expressing mast cells during all stages of pulmonary sarcoidosis.