Immunologic Profiling of Immune-Related Cutaneous Adverse Events with Checkpoint Inhibitors Reveals Polarized Actionable Pathways.

PURPOSE: Immune-related cutaneous adverse events (ircAE) occur in ≥50% of patients treated with checkpoint inhibitors, but the underlying mechanisms for ircAEs are poorly understood. EXPERIMENTAL DESIGN: Phenotyping/biomarker analyses were conducted in 200 patients on checkpoint inhibitors [139 with ircAEs and 61 without (control group)] to characterize their clinical presentation and immunologic endotypes. Cytokines were evaluated in skin biopsies, skin tape strip extracts, and plasma using real-time PCR and Meso Scale Discovery multiplex cytokine assays. RESULTS: Eight ircAE phenotypes were identified: pruritus (26%), maculopapular rash (MPR; 21%), eczema (19%), lichenoid (11%), urticaria (8%), psoriasiform (6%), vitiligo (5%), and bullous dermatitis (4%). All phenotypes showed skin lymphocyte and eosinophil infiltrates. Skin biopsy PCR revealed the highest increase in IFNγ mRNA in patients with lichenoid (P < 0.0001) and psoriasiform dermatitis (P < 0.01) as compared with patients without ircAEs, whereas the highest IL13 mRNA levels were detected in patients with eczema (P < 0.0001, compared with control). IL17A mRNA was selectively increased in psoriasiform (P < 0.001), lichenoid (P < 0.0001), bullous dermatitis (P < 0.05), and MPR (P < 0.001) compared with control. Distinct cytokine profiles were confirmed in skin tape strip and plasma. Analysis determined increased skin/plasma IL4 cytokine in pruritus, skin IL13 in eczema, plasma IL5 and IL31 in eczema and urticaria, and mixed-cytokine pathways in MPR. Broad inhibition via corticosteroids or type 2 cytokine-targeted inhibition resulted in clinical benefit in these ircAEs. In contrast, significant skin upregulation of type 1/type 17 pathways was found in psoriasiform, lichenoid, bullous dermatitis, and type 1 activation in vitiligo. CONCLUSIONS: Distinct immunologic ircAE endotypes suggest actionable targets for precision medicine-based interventions.

Longitudinal quality of life after sublobar resection and stereotactic body radiation therapy for early-stage non-small cell lung cancer.

BACKGROUND: Many patients with early-stage lung cancer are not candidates for lobectomy because of various factors, with treatment options including sublobar resection or stereotactic body radiation therapy (SBRT). Limited information exists regarding patient-centered outcomes after these treatments. METHODS: Subjects with stage I-IIA non-small cell lung cancer (NSCLC) at high risk for lobectomy who underwent treatment with sublobar resection or SBRT were recruited from five medical centers. Quality of life (QOL) was compared with the Short Form 8 (SF-8) for physical and mental health and Functional Assessment of Cancer Therapy-Lung (FACT-L) surveys at baseline (pretreatment) and 7 days, 30 days, 6 months, and 12 months after treatment. Propensity score methods were used to control for confounders. RESULTS: Of 337 subjects enrolled before treatment, 63% received SBRT. Among patients undergoing resection, 89% underwent minimally invasive video-assisted thoracic surgery or robot-assisted resection. Adjusted analyses showed that SBRT-treated patients had both higher physical health SF-8 scores (difference in differences [DID], 6.42; p = .0008) and FACT-L scores (DID, 2.47; p = .004) at 7 days posttreatment. Mental health SF-8 scores were not different at 7 days (p = .06). There were no significant differences in QOL at other time points, and all QOL scores returned to baseline by 12 months for both groups. CONCLUSIONS: SBRT is associated with better QOL immediately posttreatment compared with sublobar resection. However, both treatment groups reported similar QOL at later time points, with a return to baseline QOL. These findings suggest that sublobar resection and SBRT have a similar impact on the QOL of patients with early-stage lung cancer deemed ineligible for lobectomy.

Adverse Events Following Limited Resection versus Stereotactic Body Radiation Therapy for Early Stage Lung Cancer.

Rationale: Approximately a quarter of patients with early stage lung cancer are not medically fit for lobectomy. Limited resection and stereotactic body radiation therapy (SBRT) have emerged as alternatives for these patients. Given the equipoise on the effectiveness of the two treatments, treatment-related adverse events (AEs) could have a significant impact on patients' decision-making and treatment outcomes. Objectives: To compare the AE profile between SBRT versus limited resection. Methods: Data were derived from a prospective cohort of patients with stage I-IIA non-small cell lung cancer who were deemed as high-risk for lobectomy recruited from five centers across the United States. Propensity scores and inverse probability weighting were used to compare the rates of 30- and 90-day AEs among patients treated with limited resection versus SBRT. Results: Overall, 65% of 252 patients underwent SBRT. After adjusting for propensity scores, there was no significant difference in developing at least one AE comparing SBRT to limited resection (odds ratio [OR]: 1.00; 95% confidence interval [CI]: 0.65-1.55 and OR: 1.27; 95% CI: 0.84-1.91 at 30 and 90 days, respectively). SBRT was associated with lower risk of infectious AEs than limited resection at 30 days (OR: 0.05; 95% CI: 0.01-0.39) and 90 days posttreatment (OR: 0.41; 95% CI: 0.17-0.98). Additionally, SBRT was associated with persistently elevated risk of fatigue (OR: 2.47; 95% CI: 1.34-4.54 at 30 days and OR: 2.69; 95% CI: 1.52-4.77 at 90 days, respectively), but significantly lower risks of respiratory AEs (OR: 0.36; 95% CI: 0.20-0.65 and OR: 0.51; 95% CI: 0.31-0.86 at 30 and 90 days, respectively). Conclusions: Though equivalent in developing at least one AE, we found that SBRT is associated with less toxicity than limited resection in terms of infectious and respiratory AEs but higher rates of fatigue that persisted up to 3 months posttreatment. This information, combined with data about oncologic effectiveness, can help patients' decision-making regarding these alternative therapies.

Beyond Steroids: Immunosuppressants in Steroid-Refractory or Resistant Immune-Related Adverse Events.

INTRODUCTION: The optimal management for immune-related adverse events (irAEs) in patients who do not respond or become intolerant to steroids is unclear. Guidelines suggest additional immunosuppressants on the basis of case reports and expert opinion. METHODS: We evaluated patients with lung cancers at Memorial Sloan Kettering Cancer Center treated with immune checkpoint blockade from 2011 to 2020. Pharmacy records were queried to identify patients who received systemic steroids and an additional immunosuppressant (e.g., tumor necrosis factor-α inhibitor, mycophenolate mofetil). Patient records were manually reviewed to evaluate baseline characteristics, management, and outcomes. RESULTS: Among 2750 patients with lung cancers treated with immune checkpoint blockade, 51 (2%) received both steroids and an additional immunosuppressant for a severe irAE (tumor necrosis factor-α inhibitor (73%), mycophenolate mofetil (20%)). The most common events were colitis (53%), pneumonitis (20%), hepatitis (12%), and neuromuscular (10%). At 90 days after the start of an additional immunosuppressant, 57% were improved from their irAE, 18% were unchanged, and 25% were deceased. Improvement was more common in hepatitis (five of six) and colitis (18 of 27) but less common in neuromuscular (one of five) and pneumonitis (3 of 10). Of the patients who died, 8 of 13 were attributable directly to the irAE and 4 of 13 were related to toxicity from immunosuppression (three infection-related deaths, one drug-induced liver injury leading to acute liver failure). CONCLUSIONS: Steroid-refractory or resistant irAEs events are rare. Although existing treatments help patients with hepatitis and colitis, many patients with other irAEs remain refractory or experience toxicities from immunosuppression. A more precise understanding of the pathophysiology of specific irAEs is needed to guide biologically-informed treatments for severe irAEs.

Our current understanding of checkpoint inhibitor therapy in cancer immunotherapy.

OBJECTIVE: Treatments with Food and Drug Administration-approved blocking antibodies targeting inhibitory cytotoxic T lymphocyte antigen 4 (CTLA4), programmed cell death protein 1 (PD-1) receptor, or programmed cell death ligand 1 (PD-L1), collectively named checkpoint inhibitors (CPIs), have been successful in producing long-lasting remissions, even in patients with advanced-stage cancers. However, these treatments are often accompanied by undesirable autoimmune and inflammatory side effects, sometimes bringing severe consequences for the patient. Rapid expansion of clinical applications necessitates a more nuanced understanding of CPI function in health and disease to develop new strategies for minimizing the negative side effects, while preserving the immunotherapeutic benefit. DATA SOURCES: This review summarizes a new paradigm-shifting approach to cancer immunotherapy with the focus on the mechanism of action of immune checkpoints (CTLA4, PD-1, and its ligands). STUDY SELECTIONS: We performed a literature search and identified relevant recent clinical reports, experimental research, and review articles. RESULTS: This review highlights our understanding of the CPI mechanism of action on cellular and molecular levels. The authors also discuss how reactivation of T cell responses through the inhibition of CTLA4, PD-1, and PD-L1 is used for tumor inhibition in cancer immunotherapy. CONCLUSION: Mechanisms of PD-1 and CTLA4 blockade and normal biological functions of these molecules are highly complex and require additional studies that will be critical for developing new approaches to dissociate the benefits of checkpoint blockade from off-target effects of the immune reactivation that leads to immune-related adverse events.

Immune-related cutaneous adverse events due to checkpoint inhibitors.

OBJECTIVE: To familiarize the reader with the most common cutaneous adverse events with immune checkpoint inhibitors (CPIs) and their grading and treatment. DATA SOURCES: Recent research articles, relevant review articles, and case series/reports in English from the PubMed database mostly, from 2010 onward. STUDY SELECTIONS: Most data are from retrospective studies and case series. Older studies regarding the mechanism were included if they were of particular importance. RESULTS: An understanding of this review should enable the reader to identify specific skin disorders in patients receiving immune CPIs, grade the adverse event, and be able to treat or refer the patient as needed. CONCLUSION: Allergists/immunologists need to be familiar with these immune-related cutaneous adverse events because their incidence will increase with the ever-expanding use of CPIs and, in particular, because patients will certainly continue to be referred suspecting drug allergies.

Role of mTOR As an Essential Kinase in SCLC.

OBJECTIVES: SCLC represents 15% of all lung cancer diagnoses in the United States and has a particularly poor prognosis. We hypothesized that kinases regulating SCLC survival pathways represent therapeutically targetable vulnerabilities whose inhibition may improve SCLC outcome. METHODS: A short-hairpin RNA (shRNA) library targeting all human kinases was introduced in seven chemonaive patient-derived xenografts (PDX) and the cells were cultured in vitro and in vivo. On harvest, lost or depleted shRNAs were considered as regulating-cell survival pathways and deemed essential kinases. RESULTS: Unsupervised hierarchical cluster analysis of recovered shRNAs separated the PDXs into two clusters, suggesting kinase-based heterogeneity among the SCLC PDXs. A total of 23 kinases were identified as essential in two or more PDXs, with mechanistic Target of Rapamycin (mTOR) a candidate essential kinase in four. mTOR phosphorylation status correlated with PDX sensitivity to mTOR kinase inhibition, and mTOR inhibition sensitized the PDX to cisplatin and etoposide. In the PDX in which mTOR was defined as essential, mTOR inhibition caused a 43% decrease in tumor volume at 21 days (p < 0.01). Combining mTOR inhibition with cisplatin and etoposide decreased PDX tumor volume 96% compared with cisplatin and etoposide alone at 70 days (p < 0.002). Chemoresistance did not develop with the combination of mTOR inhibition and cisplatin and etoposide in mTOR-essential PDX over 105 days. The prevalence of phospho-mTOR-Ser-2448 in a tissue microarray of chemonaive SCLC was 27%, thus, identifying an important SCLC subtype that might benefit from the addition of mTOR inhibition to standard chemotherapy. CONCLUSIONS: These studies reveal that kinases can define SCLC subgroups, can identify therapeutic vulnerabilities, and can potentially be used to optimize therapeutic approaches. Significance We used functional genomics to identify kinases regulating SCLC survival. mTOR was identified as essential in a subset of PDXs. mTOR inhibition decreased PDX growth, sensitized PDX to cisplatin and etoposide, and prevented chemoresistance.

Immune checkpoint inhibitor-related dermatologic adverse events.

Immune checkpoint inhibitors have emerged as a pillar in the management of advanced malignancies. However, nonspecific immune activation may lead to immune-related adverse events, wherein the skin and its appendages are the most frequent targets. Cutaneous immune-related adverse events include a diverse group of inflammatory reactions, with maculopapular rash, pruritus, psoriasiform and lichenoid eruptions being the most prevalent subtypes. Cutaneous immune-related adverse events occur early, with maculopapular rash presenting within the first 6 weeks after the initial immune checkpoint inhibitor dose. Management involves the use of topical corticosteroids for mild to moderate (grades 1-2) rash, addition of systemic corticosteroids for severe (grade 3) rash, and discontinuation of immunotherapy with grade 4 rash. Bullous pemphigoid eruptions, vitiligo-like skin hypopigmentation/depigmentation, and psoriasiform rash are more often attributed to programmed cell death-1/programmed cell death ligand-1 inhibitors. The treatment of bullous pemphigoid eruptions is similar to the treatment of maculopapular rash and lichenoid eruptions, with the addition of rituximab in grade 3-4 rash. Skin hypopigmentation/depigmentation does not require specific dermatologic treatment aside from photoprotective measures. In addition to topical corticosteroids, psoriasiform rash may be managed with vitamin D3 analogues, narrowband ultraviolet B light phototherapy, retinoids, or immunomodulatory biologic agents. Stevens-Johnson syndrome and other severe cutaneous immune-related adverse events, although rare, have also been associated with checkpoint blockade and require inpatient care as well as urgent dermatology consultation.

Interleukin-6 is required for Neuregulin-1 induced HER2 signaling in lung epithelium.

A clear understanding of the mechanisms that regulate the alveolar epithelium's barrier is critical to develop new therapeutic strategies to mitigate lung injury. The HER2/HER3 receptor tyrosine kinase complex plays a central role in maintaining the alveolar-capillary barrier. This receptor complex is activated by its ligand, neuregulin-1 (NRG-1). Interleukin-6 (IL-6) is also known to induce HER2 signaling through HER2 transphosphorylation by the IL-6 receptor (IL-6R) complex (1). Due to this interaction, we hypothesized that NRG-1 and IL-6 cooperatively interacted to activate the HER2/HER3 complex. Studies were performed in cultured pulmonary epithelial cells measuring the HER2/IL-6/IL-6R/GP130 interaction and receptor activation by western blotting and confocal microscopy, IL-6 production by ELISA, and IL-6 inhibition using specific antibodies, small molecule inhibitors and shRNA. We found that IL-6 was required for NRG-1 induced activation of HER2 in pulmonary epithelial cells. IL-6 inhibition led to a decrease in NRG-1 induced HER2 activation. The IL-6R and GP130, a subunit of the IL-6R complex, were physically associated with HER2 and were required for NRG-1 induced HER2 activation. Inhibition of GP130, the ß-subunit of the IL-6 receptor decreased NRG-1 induced HER2 activation lower than control by 38% Finally, HER2 activation increased IL-6 secretion more than two-fold over resting cells (526 ± 131 vs 231 ± 39.7 pg/ml), and inhibition of HER2 gene expression decreased basal IL-6 secretion over 80% (89 + 4.6 vs 1.3 + 0.8 pg/ml). These findings identify a requirement for IL-6 and the IL-6R complex to allow NRG-1 mediated HER2 activation, and a HER2 driven IL-6 production feedback loop.

The Kinome of Human Alveolar Type II and Basal Cells, and Its Reprogramming in Lung Cancer.

The discovery of mutant tyrosine kinases as oncogenic drivers of lung adenocarcinomas has changed the basic understanding of lung cancer development and therapy. Yet, expressed kinases (kinome) in lung cancer progenitor cells, as well as whether kinase expression and the overall kinome changes or is reprogrammed upon transformation, is incompletely understood. We hypothesized that the kinome differs between lung cancer progenitor cells, alveolar type II cells (ATII), and basal cells (BC) and that their respective kinomes undergo distinct lineage-specific reprogramming to adenocarcinomas and squamous cell carcinomas upon transformation. We performed RNA sequencing on freshly isolated human ATII, BC, and lung cancer cell lines to define the kinome in nontransformed cells and transformed cells. Our studies identified a unique kinome for ATII and BC and changes in their kinome upon transformation to their respective carcinomas.

Antigen-Presenting Intratumoral B Cells Affect CD4+ TIL Phenotypes in Non-Small Cell Lung Cancer Patients.

Effective immunotherapy options for patients with non-small cell lung cancer (NSCLC) are becoming increasingly available. The immunotherapy focus has been on tumor-infiltrating T cells (TILs); however, tumor-infiltrating B cells (TIL-Bs) have also been reported to correlate with NSCLC patient survival. The function of TIL-Bs in human cancer has been understudied, with little focus on their role as antigen-presenting cells and their influence on CD4+ TILs. Compared with other immune subsets detected in freshly isolated primary tumors from NSCLC patients, we observed increased numbers of intratumoral B cells relative to B cells from tumor-adjacent tissues. Furthermore, we demonstrated that TIL-Bs can efficiently present antigen to CD4+ TILs and alter the CD4+ TIL phenotype using an in vitro antigen-presentation assay. Specifically, we identified three CD4+ TIL responses to TIL-Bs, which we categorized as activated, antigen-associated, and nonresponsive. Within the activated and antigen-associated CD4+ TIL population, activated TIL-Bs (CD19+CD20+CD69+CD27+CD21+) were associated with an effector T-cell response (IFNγ+ CD4+ TILs). Alternatively, exhausted TIL-Bs (CD19+CD20+CD69+CD27-CD21-) were associated with a regulatory T-cell phenotype (FoxP3+ CD4+ TILs). Our results demonstrate a new role for TIL-Bs in NSCLC tumors in their interplay with CD4+ TILs in the tumor microenvironment, establishing them as a potential therapeutic target in NSCLC immunotherapy. Cancer Immunol Res; 5(10); 898-907. ©2017 AACR.

Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia and Neuroendocrine Hyperplasia of Infancy.

Although incidental reactive pulmonary neuroendocrine cell hyperplasia (PNECH) is seen on biopsy specimens in adults with chronic lung disease, disorders characterized by marked PNECH are rare. Primary hyperplasia of neuroendocrine cells in the lung and obstructive lung disease related to remodeling or physiologic constriction of small airways define diffuse idiopathic neuroendocrine cell hyperplasia (DIPNECH) in the adult and neuroendocrine cell hyperplasia of infancy (NEHI) in children. DIPENCH and NEHI share a similar physiology, typical imaging appearance, and increased neuroendocrine cells on biopsy. However, there are important differences related to the underlying disease mechanisms leading to disparate outcomes.

Development of a Cancer Care Summary Through the Electronic Health Record.

INTRODUCTION: Our objective was to improve communication concerning lung cancer patients by developing and distributing a Cancer Care Summary that would provide clinically useful information about the patient's diagnosis and care to providers in diverse settings. METHODS: We designed structured, electronic forms for the electronic health record (EHR), detailing tumor staging, classification, and treatment. To ensure completeness and accuracy of the information, we implemented a data quality cycle, composed of reports that are reviewed by oncology clinicians. The data from the EHR forms are extracted into a structured query language database system on a daily basis, from which the Summaries are derived. We conducted focus groups regarding the utility, format, and content of the Summary. Cancer Care Summaries are automatically generated 4 months after a patient's date of diagnosis, then every 6 months for those receiving treatment, and on an as-needed basis for urgent care or hospital admission. RESULTS: The product of our improvement project is the Cancer Care Summary. To date, 102 individual patient Summaries have been generated. These documents are automatically entered into the National Jewish Health (NJH) EHR, attached to correspondence to primary care providers, available to patients as electronic documents on the NJH patient portal, and faxed to emergency departments and admitting physicians on patient evaluation. CONCLUSION: We developed a sustainable tool to improve cancer care communication. The Cancer Care Summary integrates information from the EHR in a timely manner and distributes the information through multiple avenues.

The clinical course of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia.

BACKGROUND: Current understanding of the clinical course of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is poor and based predominantly on small case series. In our clinical experience, we have found that the diagnosis of DIPNECH is frequently delayed because respiratory symptoms are ascribed to other lung conditions. The objectives of this study were to collect and analyze longitudinal clinical data on pulmonary physiology, chest high-resolution CT (HRCT) imaging, and therapies to better delineate the course of disease. METHODS: We established a cohort of patients (N = 30) with DIPNECH seen at our institution. We used descriptive statistics to summarize cohort characteristics and longitudinal analytic techniques to model FEV1 % predicted (FEV1%) over time. RESULTS: All subjects were women who presented with long-standing cough and dyspnea. The majority had an FEV1% < 50% at the time of diagnosis. Forty percent were given a diagnosis of asthma as the cause for physiologic obstruction. The mean FEV1% for the entire cohort showed no statistically significant decline over time, but 26% of the subjects experienced a 10% decline in FEV1 within 2 years. Among the pathology samples available for review, 28% (five of 18) had typical carcinoids and 44% had associated constrictive bronchiolitis. We propose clinical diagnostic criteria for DIPNECH that incorporate demographic, pulmonary physiology, HRCT imaging, and transbronchial and surgical lung biopsy data. CONCLUSIONS: DIPNECH is a female-predominant lung disease manifested by dyspnea and cough, physiologic obstruction, and nodules on HRCT imaging. Additional research is needed to understand the natural history of this disease and validate the proposed diagnostic criteria.

HER2 activation results in ß-catenin-dependent changes in pulmonary epithelial permeability.

The receptor tyrosine kinase human epidermal growth factor receptor-2 (HER2) is known to regulate pulmonary epithelial barrier function; however, the mechanisms behind this effect remain unidentified. We hypothesized that HER2 signaling alters the epithelial barrier through an interaction with the adherens junction (AJ) protein ß-catenin, leading to dissolution of the AJ. In quiescent pulmonary epithelial cells, HER2 and ß-catenin colocalized along the lateral intercellular junction. HER2 activation by the ligand neuregulin-1 was associated with tyrosine phosphorylation of ß-catenin, dissociation of ß-catenin from E-cadherin, and decreased E-cadherin-mediated cell adhesion. All effects were blocked with the HER2 inhibitor lapatinib. ß-Catenin knockdown using shRNA significantly attenuated neuregulin-1-induced decreases in pulmonary epithelial resistance in vitro. Our data indicate that HER2 interacts with ß-catenin, leading to dissolution of the AJ, decreased cell-cell adhesion, and disruption of the pulmonary epithelial barrier.

Bioinformatics-driven discovery of rational combination for overcoming EGFR-mutant lung cancer resistance to EGFR therapy.

MOTIVATION: Non-small-cell lung cancer (NSCLC) is the leading cause of cancer death in the United States. Targeted tyrosine kinase inhibitors (TKIs) directed against the epidermal growth factor receptor (EGFR) have been widely and successfully used in treating NSCLC patients with activating EGFR mutations. Unfortunately, the duration of response is short-lived, and all patients eventually relapse by acquiring resistance mechanisms. RESULT: We performed an integrative systems biology approach to determine essential kinases that drive EGFR-TKI resistance in cancer cell lines. We used a series of bioinformatics methods to analyze and integrate the functional genetics screen and RNA-seq data to identify a set of kinases that are critical in survival and proliferation in these TKI-resistant lines. By connecting the essential kinases to compounds using a novel kinase connectivity map (K-Map), we identified and validated bosutinib as an effective compound that could inhibit proliferation and induce apoptosis in TKI-resistant lines. A rational combination of bosutinib and gefitinib showed additive and synergistic effects in cancer cell lines resistant to EGFR TKI alone. CONCLUSIONS: We have demonstrated a bioinformatics-driven discovery roadmap for drug repurposing and development in overcoming resistance in EGFR-mutant NSCLC, which could be generalized to other cancer types in the era of personalized medicine. AVAILABILITY AND IMPLEMENTATION: K-Map can be accessible at: http://tanlab.ucdenver.edu/kMap. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Lung cancer screening: past, present and future.

Lung cancer is the leading cause of cancer death for men and women. Most lung cancer cases are diagnosed at an advanced stage, when cure is no longer an option; this heavily influences mortality. Historically, attempts at lung cancer screening using chest x-rays and sputum cytology have failed to influence lung cancer mortality. However, the recent National Lung Screening Trial demonstrated that low-dose computed tomography screening for lung cancer decreases mortality. This article outlines the history of lung cancer screening, the current state of screening and possible future adjuncts to screening.

Bronchoalveolar lavage neuregulin-1 is elevated in acute lung injury and correlates with inflammation.

Shedding of neuregulin (NRG)-1 from the pulmonary epithelium leads to activation of the epithelial human epidermal growth factor receptor (HER)2 receptor, increased pulmonary epithelial permeability and acute lung injury (ALI). We sought to determine whether NRG-1 was detectable and elevated in bronchoalveolar lavage (BAL) and plasma from patients with ALI compared with controls and to determine whether a correlation exists between NRG-1 and inflammation and outcome in ALI. Matched BAL and plasma samples were obtained from 23 ALI patients requiring intubation and mechanical ventilation. Control patients (n=5) included healthy volunteers. NRG-1 and indices of inflammation were measured in BAL and plasma via ELISA. The mean±sd BAL NRG-1 concentration in ALI patients was 187.0±21.35 pg·mL(-1) compared with 85.50±9.2 pg·mL(-1) in controls (p=0.001). Increased BAL NRG-1 was associated with markers of inflammation, and inversely correlated with ventilator-free days (VFDs; r= -0.51, p=0.015). Plasma NRG-1 was elevated in ALI patients compared with controls (611.7±354.2 versus 25.17±19.33 pg·mL(-1), p<0.001) and inversely correlated with VFDs (r= -0.51, p=0.04). These results confirm shedding of NRG-1 in ALI and suggest that the NRG-1-HER2 pathway is active in patients with ALI.