Similarities and differences of interstitial lung disease associated with pathogenic variants in SFTPC and ABCA3 in adults.

BACKGROUND AND OBJECTIVE: Variants in surfactant genes SFTPC or ABCA3 are responsible for interstitial lung disease (ILD) in children and adults, with few studies in adults. METHODS: We conducted a multicentre retrospective study of all consecutive adult patients diagnosed with ILD associated with variants in SFTPC or ABCA3 in the French rare pulmonary diseases network, OrphaLung. Variants and chest computed tomography (CT) features were centrally reviewed. RESULTS: We included 36 patients (median age: 34 years, 20 males), 22 in the SFTPC group and 14 in the ABCA3 group. Clinical characteristics were similar between groups. Baseline median FVC was 59% ([52-72]) and DLco was 44% ([35-50]). An unclassifiable pattern of fibrosing ILD was the most frequent on chest CT, found in 85% of patients, however with a distinct phenotype with ground-glass opacities and/or cysts. Nonspecific interstitial pneumonia and usual interstitial pneumonia were the most common histological patterns in the ABCA3 group and in the SFTPC group, respectively. Annually, FVC and DLCO declined by 1.87% and 2.43% in the SFTPC group, respectively, and by 0.72% and 0.95% in the ABCA3 group, respectively (FVC, p = 0.014 and DLCO , p = 0.004 for comparison between groups). Median time to death or lung transplantation was 10 years in the SFTPC group and was not reached at the end of follow-up in the ABCA3 group. CONCLUSION: SFTPC and ABCA3-associated ILD present with a distinct phenotype and prognosis. A radiologic pattern of fibrosing ILD with ground-glass opacities and/or cysts is frequently found in these rare conditions.

Evaluation of the Copy Number Variants and Single-Nucleotide Polymorphisms of ABCA3 in Newborns with Respiratory Distress Syndrome-A Pilot Study.

Background and Objectives: Respiratory distress syndrome (RDS) in preterm infants commonly occurs due to the immaturity-related deficiency of pulmonary surfactant. Beyond prematurity, various environmental and genetic factors can influence the onset and progression of RDS. This study aimed to analyze three single-nucleotide polymorphisms (SNPs) of the ABCA3 gene to assess the ABCA3 gene as a candidate gene for susceptibility to RDS and overall survival in newborns and to evaluate the utility of MLPA in RDS neonatal patients. Materials and Methods: Three SNPs were chosen and genotyped in a cohort of 304 newborns. Data analysis and statistical tests were employed to examine allele frequencies, haplotypes, and measures of pairwise linkage disequilibrium. Results: There was no observed haplotype association with SNPs rs13332514 (c.1059G>A) and rs170447 (c.1741+33T>C) among newborns, both with and without RDS (p > 0.05). The minor C allele frequency of the ABCA3 rs323043 (c.1755G>C) SNP showed a significant increase in preterm infants with RDS. MLPA results indicated that the predominant findings were normal, revealing no CNVs in the genes ABCA3 and SFTPC that were investigated in our patients. Conclusions: The presence of the variant C allele in the rs323043 (c.1755G>C) SNP may be a risk factor for RDS in premature newborns.

ABCA3-related interstitial lung disease beyond infancy.

BACKGROUND: The majority of patients with childhood interstitial lung disease (chILD) caused by pathogenic variants in ATP binding cassette subfamily A member 3 (ABCA3) develop severe respiratory insufficiency within their first year of life and succumb to disease if not lung transplanted. This register-based cohort study reviews patients with ABCA3 lung disease who survived beyond the age of 1 year. METHOD: Over a 21-year period, patients diagnosed as chILD due to ABCA3 deficiency were identified from the Kids Lung Register database. 44 patients survived beyond the first year of life and their long-term clinical course, oxygen supplementation and pulmonary function were reviewed. Chest CT and histopathology were scored blindly. RESULTS: At the end of the observation period, median age was 6.3 years (IQR: 2.8-11.7) and 36/44 (82%) were still alive without transplantation. Patients who had never received supplemental oxygen therapy survived longer than those persistently required oxygen supplementation (9.7 (95% CI 6.7 to 27.7) vs 3.0 years (95% CI 1.5 to 5.0), p=0.0126). Interstitial lung disease was clearly progressive over time based on lung function (forced vital capacity % predicted absolute loss -1.1% /year) and on chest CT (increasing cystic lesions in those with repetitive imaging). Lung histology pattern were variable (chronic pneumonitis of infancy, non-specific interstitial pneumonia, and desquamative interstitial pneumonia). In 37/44 subjects, the ABCA3 sequence variants were missense variants, small insertions or deletions with in-silico tools predicting some residual ABCA3 transporter function. CONCLUSION: The natural history of ABCA3-related interstitial lung disease progresses during childhood and adolescence. Disease-modifying treatments are desirable to delay such disease course.

Learning from cystic fibrosis: How can we start to personalise treatment of Children's Interstitial Lung Disease (chILD)?

Cystic fibrosis (CF) is a monogenic disorder cause by mutations in the CF Transmembrane Regulator (CFTR) gene. The prognosis of cystic fibrosis has been transformed by the discovery of highly effective modulator therapies (HEMT). Treatment has changed from reactive therapy dealing with complications of the disease to pro-active correction of the underlying molecular functional abnormality. This has come about by discovering the detailed biology of the different CF molecular sub-endotypes; the development of biomarkers to assess response even in mild disease or young children; the performance of definitive large randomised controlled trials in patients with a common mutation and the development of in vitro testing systems to test efficacy in those patients with rare CFTR mutations. As a result, CF is now an umbrella term, rather than a specific diagnostic label; we have moved from clinical phenotypes to molecular subendotypes. Children's Interstitial Lung Diseases (chILDs) comprise more than 200 entities, and are a diverse group of diseases, for an increasing number of which an underlying gene mutation has been discovered. Many of these entities are umbrella terms, such as pulmonary alveolar proteinosis or hypersensitivity pneumonitis, for each of which there are multiple and very different endotypes. Even those chILDs for which a specific gene mutation has been discovered comprise, as with CF, different molecular subendotypes likely mandating different therapies. For most chILDs, current treatment is non-specific (corticosteroids, azithromycin, hydroxychloroquine). The variability of the different entities means that there is little evidence for the efficacy of any treatment. This review considers how some of the lessons of the success story of CF are being applied to chILD, thus opening the opportunities for truly personalised medicine in these conditions. Advances in knowledge in the molecular biology of surfactant protein C and Adenosine triphosphate binding cassette subfamily A member 3 (ABCA3), and the possibilities of discovering novel therapies by in vitro studies will especially be highlighted.

Quantifying Functional Impairment of ABCA3 Variants Associated with Interstitial Lung Disease.

ATP-binding cassette subfamily A member 3 (ABCA3) is a lipid transporter within alveolar type II cells. Patients with bi-allelic variants in ABCA3 may suffer from a variable severity of interstitial lung disease. We characterized and quantified ABCA3 variants' overall lipid transport function by assessing the in vitro impairment of its intracellular trafficking and pumping activity. We expressed the results relative to the wild type, integrated the quantitative readouts from eight different assays and used newly generated data combined with previous results to correlate the variants' function and clinical phenotype. We differentiated normal (within 1 normalized standard deviation (nSD) of the wild-type mean), impaired (within 1 to 3 nSD) and defective (beyond 3 nSD) variants. The transport of phosphatidylcholine from the recycling pathway into ABCA3+ vesicles proved sensitive to the variants' dysfunction. The sum of the quantitated trafficking and pumping predicted a clinical outcome. More than an approximately 50% loss of function was associated with considerable morbidity and mortality. The in vitro quantification of ABCA3 function enables detailed variant characterization, substantially improves the phenotype prediction of genetic variants and possibly supports future treatment decisions.

ABCA3 Deficiency-Variant-Specific Response to Hydroxychloroquine.

Biallelic variants in ABCA3, the gene encoding the lipid transporter ATP-binding cassette subfamily A member 3 (ABCA3) that is predominantly expressed in alveolar type II cells, may cause interstitial lung diseases in children (chILD) and adults. Currently, there is no proven therapy, but, frequently, hydroxychloroquine (HCQ) is used empirically. We hypothesized that the in vitro responsiveness to HCQ might correlate to patients' clinical outcomes from receiving HCQ therapy. The clinical data of the subjects with chILD due to ABCA3 deficiency and treated with HCQ were retrieved from the literature and the Kids Lung Register data base. The in vitro experiments were conducted on wild type (WT) and 16 mutant ABCA3-HA-transfected A549 cells. The responses of the functional read out were assessed as the extent of deviation from the untreated WT. With HCQ treatment, 19 patients had improved or unchanged respiratory conditions, and 20 had respiratory deteriorations, 5 of whom transiently improved then deteriorated. The in vitro ABCA3 functional assays identified two variants with complete response, five with partial response, and nine with no response to HCQ. The variant-specific HCQ effects in vivo closely correlated to the in vitro data. An ABCA3+ vesicle volume above 60% of the WT volume was linked to responsiveness to HCQ; the HCQ treatment response was concentration dependent and differed for variants in vitro. We generated evidence for an ABCA3 variant-dependent impact of the HCQ in vitro. This may also apply for HCQ treatment in vivo, as supported by the retrospective and uncontrolled data from the treatment of chILD due to ABCA3 deficiency.

[Congenital pulmonary alveolar proteinosis in a neonate]. / æ–°ç”Ÿå„¿å ˆå¤©æ€§è‚ºæ³¡è›‹ç™½æ²‰ç§¯ç—‡1例.

The male patient was referred to the hospital at 44 days old due to dyspnea after birth and inability to wean off oxygen. His brother died three days after birth due to respiratory failure. The main symptoms observed were respiratory failure, dyspnea, and hypoxemia. A chest CT scan revealed characteristic reduced opacity in both lungs with a "crazy-paving" appearance. The bronchoalveolar lavage fluid (BALF) showed periodic acid-Schiff positive proteinaceous deposits. Genetic testing indicated a compound heterozygous mutation in the ABCA3 gene. The diagnosis for the infant was congenital pulmonary alveolar proteinosis (PAP). Congenital PAP is a significant cause of challenging-to-treat respiratory failure in full-term infants. Therefore, congenital PAP should be considered in infants experiencing persistently difficult-to-treat dyspnea shortly after birth. Early utilization of chest CT scans, BALF pathological examination, and genetic testing may aid in early diagnosis.

Rare surfactant-related variants in familial and sporadic pulmonary fibrosis.

The role of constitutional genetic defects in idiopathic pulmonary fibrosis (IPF) is increasingly appreciated. Monogenic disorders associated with IPF affect two pathways: telomere maintenance, accounting for approximately 10% of all patients with IPF, and surfactant biology, responsible for 1%-3% of cases and often co-occurring with lung cancer. We examined the prevalence of rare variants in five surfactant-related genes, SFTPA1, SFPTA2, SFTPC, ABCA3, and NKX2-1, that were previously linked to lung disease in whole genome sequencing data from 431 patients with IPF. We identified functionally deleterious rare variants in SFTPA2 with a prevalence of 1.3% in individuals with and without a family history of IPF. All individuals had no personal history of lung cancer, but substantial bronchiolar metaplasia was noted on lung explants and biopsies. Five patients had novel missense variants in NKX2-1, but the contribution to disease is unclear. In general, patients were younger and had longer telomeres compared with the majority of patients with IPF suggesting that these features may be useful for identifying this subset of patients in the clinic. These data suggest that SFTPA2 variants may be more common in unselected IPF cohorts and may manifest in the absence of personal/family history of lung cancer or IPF.

High-Content Screening Identifies Cyclosporin A as a Novel ABCA3-Specific Molecular Corrector.

ABCA3 (ATP-binding cassette subfamily A member 3) is a lipid transporter expressed in alveolar type II cells and localized in the limiting membrane of lamellar bodies. It is crucial for pulmonary surfactant storage and homeostasis. Mutations in the ABCA3 gene are the most common genetic cause of respiratory distress syndrome in mature newborns and of interstitial lung disease in children. Apart from lung transplant, there is no cure available. To address the lack of causal therapeutic options for ABCA3 deficiency, a rapid and reliable approach is needed to investigate variant-specific molecular mechanisms and to identify pharmacologic modulators for monotherapies or combination therapies. To this end, we developed a phenotypic cell-based assay to autonomously identify ABCA3 wild-type-like or mutant-like cells by using machine learning algorithms aimed at identifying morphologic differences in wild-type and mutant cells. The assay was subsequently used to identify new drug candidates for ABCA3-specific molecular correction by using high-content screening of 1,280 Food and Drug Administration-approved small molecules. Cyclosporin A was identified as a potent corrector, specific for some but not all ABCA3 variants. Results were validated by using our previously established functional small-format assays. Hence, cyclosporin A may be selected for orphan drug evaluation in controlled repurposing trials in patients.

Cigarette smoke extract combined with LPS reduces ABCA3 expression in chronic pulmonary inflammation may be related to PPARγ/ P38 MAPK signaling pathway.

ABCA3 (ATP-binding cassette class A3) is a transmembrane transporter that plays a positive role in chronic pulmonary inflammation by regulating lipid metabolism. However, it is not completely clear whether ABCA3 and its signaling factors are involved in chronic pulmonary inflammation induced by the combination of CSE (cigarette smoke extract) and LPS (lipopolysaccharide). In this study, we used the method of combining CSE and LPS which was widely used to study lung inflammation-related diseases and has been proven effective in our group's studies to create in vivo and in vitro pulmonary inflammation models. The result showed that, after CSE in combination with LPS treatment, ABCA3 expression was downregulated in rat lung in vivo and in a human alveolar cell line in vitro. ABCA3 expression was upregulated, and related inflammatory factors were downregulated in the state of overexpression of PPARγ or inhibition of the p38 MAPK pathway, while PPARγ deletion or MAPK14 overexpression showed the opposite results. The level of PPARγ remained unchanged, and the expression of ABCA3 was upregulated in the state of the p38 MAPK pathway was inhibited under overexpression of PPARγ. These results indicate that CSE combined with LPS can result in downregulation of ABCA3 under conditions of inflammation, and that the p38 MAPK signaling pathway mediated by PPARγ can regulate the expression changes of ABCA3, thus providing new targets for treating chronic pulmonary inflammation.

The common ABCA3E292V variant disrupts AT2 cell quality control and increases susceptibility to lung injury and aberrant remodeling.

ATP-binding cassette class A3 (ABCA3) is a lipid transporter that plays a critical role in pulmonary surfactant function. The substitution of valine for glutamic acid at codon 292 (E292V) produces a hypomorphic variant that accounts for a significant portion of ABCA3 mutations associated with lung disorders spanning from neonatal respiratory distress syndrome and childhood interstitial lung disease to diffuse parenchymal lung disease (DPLD) in adults including pulmonary fibrosis. The mechanisms by which this and similar ABCA3 mutations disrupt alveolar type 2 (AT2) cell homeostasis and cause DPLD are largely unclear. The present study, informed by a patient homozygous for the E292V variant, used an in vitro and a preclinical murine model to evaluate the mechanisms by which E292V expression promotes aberrant lung injury and parenchymal remodeling. Cell lines stably expressing enhanced green fluorescent protein (EGFP)-tagged ABCA3 isoforms show a functional deficiency of the ABCA3E292V variant as a lipid transporter. AT2 cells isolated from mice constitutively homozygous for ABCA3E292V demonstrate the presence of small electron-dense lamellar bodies, time-dependent alterations in macroautophagy, and induction of apoptosis. These changes in AT2 cell homeostasis are accompanied by a spontaneous lung phenotype consisting of both age-dependent inflammation and fibrillary collagen deposition in alveolar septa. Older ABCA3E292V mice exhibit increased vulnerability to exogenous lung injury by bleomycin. Collectively, these findings support the hypothesis that the ABCA3E292V variant is a susceptibility factor for lung injury through effects on surfactant deficiency and impaired AT2 cell autophagy.

Three Infants with Pathogenic Variants in the ABCA3 Gene: Presentation, Treatment, and Clinical Course.

ABCA3 deficiency is a rare cause of neonatal respiratory failure. Biallelic complete loss of function variants lead to neonatal demise without lung transplantation, but children with partial function variants have variable outcomes. The favorable clinical course of 3 such infants presenting with respiratory distress at birth is described.

Surfactant protein disorders in childhood interstitial lung disease.

Surfactant, which was first identified in the 1920s, is pivotal to lower the surface tension in alveoli of the lungs and helps to lower the work of breathing and prevents atelectasis. Surfactant proteins, such as surfactant protein B and surfactant protein C, contribute to function and stability of surfactant film. Additionally, adenosine triphosphate binding cassette 3 and thyroid transcription factor-1 are also integral for the normal structure and functioning of pulmonary surfactant. Through the study and improved understanding of surfactant over the decades, there is increasing interest into the study of childhood interstitial lung diseases (chILD) in the context of surfactant protein disorders. Surfactant protein deficiency syndrome (SPDS) is a group of rare diseases within the chILD group that is caused by genetic mutations of SFTPB, SFTPC, ABCA3 and TTF1 genes.Conclusion: This review article seeks to provide an overview of surfactant protein disorders in the context of chILD. What is Known: • Surfactant protein disorders are an extremely rare group of disorders caused by genetic mutations of SFTPB, SPTPC, ABCA3 and TTF1 genes. • Given its rarity, research is only beginning to unmask the pathophysiology, inheritance, spectrum of disease and its manifestations. What is New: • Diagnostic and treatment options continue to be explored and evolve in these conditions. • It is, therefore, imperative that we as paediatricians are abreast with current development in this field.

Structure-Based Understanding of ABCA3 Variants.

ABCA3 is a crucial protein of pulmonary surfactant biosynthesis, associated with recessive pulmonary disorders such as neonatal respiratory distress and interstitial lung disease. Mutations are mostly private, and accurate interpretation of variants is mandatory for genetic counseling and patient care. We used 3D structure information to complete the set of available bioinformatics tools dedicated to medical decision. Using the experimental structure of human ABCA4, we modeled at atomic resolution the human ABCA3 3D structure including transmembrane domains (TMDs), nucleotide-binding domains (NBDs), and regulatory domains (RDs) in an ATP-bound conformation. We focused and mapped known pathogenic missense variants on this model. We pinpointed amino-acids within the NBDs, the RDs and within the interfaces between the NBDs and TMDs intracellular helices (IHs), which are predicted to play key roles in the structure and/or the function of the ABCA3 transporter. This theoretical study also highlighted the possible impact of ABCA3 variants in the cytosolic part of the protein, such as the well-known p.Glu292Val and p.Arg288Lys variants.

Functional characterization of four ATP-binding cassette transporter A3 gene (ABCA3) variants.

ABCA3 transports phospholipids across lamellar body membranes in pulmonary alveolar type II cells and is required for surfactant assembly. Rare, biallelic, pathogenic ABCA3 variants result in lethal neonatal respiratory distress syndrome and childhood interstitial lung disease. Qualitative functional characterization of ABCA3 missense variants suggests two pathogenic classes: disrupted intracellular trafficking (type I mutant) or impaired ATPase-mediated phospholipid transport into the lamellar bodies (type II mutant). We qualitatively compared wild-type (WT-ABCA3) with four uncharacterized ABCA3 variants (c.418A>C;p.Asn140His, c.3609_3611delCTT;p.Phe1203del, c.3784A>G;p.Ser1262Gly, and c.4195G>A;p.Val1399Met) in A549 cells using protein processing, colocalization with intracellular organelles, lamellar body ultrastructure, and ATPase activity. We quantitatively measured lamellar body-like vesicle diameter and intracellular ABCA3 trafficking using fluorescence-based colocalization. Three ABCA3 variants (p.Asn140His, p.Ser1262Gly, and p.Val1399Met) were processed and trafficked normally and demonstrated well-organized lamellar body-like vesicles, but had reduced ATPase activity consistent with type II mutants. P.Phe1203del was processed normally, had reduced ATPase activity, and well-organized lamellar body-like vesicles, but quantitatively colocalized with both endoplasmic reticulum and lysosomal markers, an intermediate phenotype suggesting disruption of both intracellular trafficking and phospholipid transport. All ABCA3 mutants demonstrated mean vesicle diameters smaller than WT-ABCA3. Qualitative and quantitative functional characterization of ABCA3 variants informs mechanisms of pathogenicity.

Functional Genomics of ABCA3 Variants.

Rare or private, biallelic variants in the ABCA3 (ATP-binding cassette transporter A3) gene are the most common monogenic cause of lethal neonatal respiratory failure and childhood interstitial lung disease. Functional characterization of fewer than 10% of over 200 disease-associated ABCA3 variants (majority missense) suggests either disruption of ABCA3 protein trafficking (type I) or of ATPase-mediated phospholipid transport (type II). Therapies remain limited and nonspecific. A scalable platform is required for functional characterization of ABCA3 variants and discovery of pharmacologic correctors. To address this need, we first silenced the endogenous ABCA3 locus in A549 cells with CRISPR/Cas9 genome editing. Next, to generate a parent cell line (A549/ABCA3-/-) with a single recombination target site for genomic integration and stable expression of individual ABCA3 missense variant cDNAs, we used lentiviral-mediated integration of a LoxFAS cassette, FACS, and dilutional cloning. To assess the fidelity of this cell-based model, we compared functional characterization (ABCA3 protein processing, ABCA3 immunofluorescence colocalization with intracellular markers, ultrastructural vesicle phenotype) of two individual ABCA3 mutants (type I mutant, p.L101P; type II mutant, p.E292V) in A549/ABCA3-/- cells and in both A549 cells and primary, human alveolar type II cells that transiently express each cDNA after adenoviral-mediated transduction. We also confirmed pharmacologic rescue of ABCA3 variant-encoded mistrafficking and vesicle diameter in A549/ABCA3-/- cells that express p.G1421R (type I mutant). A549/ABCA3-/- cells provide a scalable, genetically versatile, physiologically relevant functional genomics platform for discovery of variant-specific mechanisms that disrupt ABCA3 function and for screening of potential ABCA3 pharmacologic correctors.

Potentiation of ABCA3 lipid transport function by ivacaftor and genistein.

ABCA3 is a phospholipid transporter implicated in pulmonary surfactant homoeostasis and localized at the limiting membrane of lamellar bodies, the storage compartment for surfactant in alveolar type II cells. Mutations in ABCA3 display a common genetic cause for diseases caused by surfactant deficiency like respiratory distress in neonates and interstitial lung disease in children and adults, for which currently no causal therapy exists. In this study, we investigated the effects of ivacaftor and genistein, two potentiators of the cystic fibrosis transmembrane conductance regulator (CFTR), on ABCA3-specific lipid transport function. Wild-type (WT) and functional ABCA3 mutations N568D, F629L, G667R, T1114M and L1580P were stably expressed in A549 cells. Three-dimensional modelling predicted functional impairment for all five mutants that was confirmed by in vitro experiments (all <14% of WT functional activity). Treatment with potentiators rescued the mutants N568D (up to 114% of WT), F629L (up to 47% of WT), and G667R (up to 60% of WT), the latter variation needing higher concentrations of genistein, showing reduced affinity of the potentiator to the mutant protein. Our results present a first proof that functional ABCA3 mutations are rescued by CFTR potentiators, making them a potential therapeutical option for patients suffering from surfactant deficiency due to ABCA3 mutations.

Neonatal Lung Disease Associated with TBX4 Mutations.

Variable lung disease was documented in 2 infants with heterozygous TBX4 mutations; their clinical presentations, pathology, and outcomes were distinct. These findings demonstrate that TBX4 gene mutations are associated with neonatal respiratory failure and highlight the wide spectrum of clinicopathological outcomes that have implications for patient diagnosis and management.

Lung disease in STAT3 hyper-IgE syndrome requires intense therapy.

BACKGROUND: Pulmonary complications are responsible for high morbidity and mortality rates in patients with the rare immunodeficiency disorder STAT3 hyper-IgE syndrome (STAT3-HIES). The aim of this study was to expand knowledge about lung disease in STAT3-HIES. METHODS: The course of pulmonary disease, radiological and histopathological interrelations, therapeutic management, and the outcome of 14 STAT3-HIES patients were assessed. RESULTS: The patients' quality of life was compromised most by pulmonary disease. All 14 patients showed first signs of lung disease at a median onset of 1.5 years of age. Lung function revealed a mixed obstructive-restrictive impairment with reduced FEV1 and FVC in 75% of the patients. The severity of lung function impairment was associated with Aspergillus fumigatus infection and prior lung surgery. Severe lung tissue damage, with reduced numbers of ATP-binding cassette sub-family A member 3 (ABCA3) positive type II pneumocytes, was observed in the histological assessment of two deceased patients. Imaging studies of all patients above 6 years of age showed severe airway and parenchyma destruction. Lung surgeries frequently led to complications, including fistula formation. Long-term antifungal and antibacterial treatment proved to be beneficial, as were inhalation therapy, chest physiotherapy, and exercise. Regular immunoglobulin replacement therapy tended to stabilize lung function. CONCLUSIONS: Due to its severity, pulmonary disease in STAT3-HIES patients requires strict monitoring and intensive therapy.

Array comparative genomic hybridization analysis discloses chromosome copy number alterations as indicators of patient outcome in lymph node-negative breast cancer.

BACKGROUND: Patients with lymph node metastasis-negative (pN0) invasive breast cancer have favorable outcomes following initial treatment. However, false negatives which occur during routine histologic examination of lymph nodes are reported to underestimate the clinical stage of disease. To identify a high-risk group in pN0 invasive breast cancer, we examined copy number alterations (CNAs) of 800 cancer-related genes. METHODS: Using array-based comparative genomic hybridization (CGH) in 51 pN0 cases (19 relapsed and 32 non-relapsed cases), the positivities of specific gene CNAs in the relapsed and non-relapsed groups were compared. An unsupervised hierarchical cluster analysis was then performed to identify case groups that were correlated with patient outcomes. RESULTS: The cluster analysis identified three distinct clusters of cases: groups 1, 2, and 3. The major component was triple-negative cases (69%, 9 of 13) in group 1, luminal B-like (57%, 13 of 23) and HER2-overexpressing (26%, 6 of 23) subtypes in group 2, and luminal A-like subtype (60%, 9 of 15) in group 3. Among all 51 cases, those in group 1 showed significantly worse overall survival (OS) than group 2 (p = 0.014), and 5q15 loss was correlated with worse OS (p = 0.017). Among 19 relapsed cases, both OS and relapse-free survival (RFS) rates were significantly lower in group 1 than in group 2 (p = 0.0083 and 0.0018, respectively), and 5q15 loss, 12p13.31 gain, and absence of 16p13.3 gain were significantly correlated with worse OS and RFS (p = 0.019 and 0.0027, respectively). CONCLUSIONS: As the target genes in these loci, NR2F1 (5q15), TNFRSF1A (12p13.31), and ABCA3 (16p13.3) were examined. 5q15 loss, 12p13.31 gain, and absence of 16q13.3 gain were potential indicators of high-risk recurrence and aggressive clinical behavior of pN0 invasive breast cancers.