Serum pro-surfactant protein B is correlated with clinical properties in osteosarcoma patients.

It is critical to find efficient non-invasive prognostic factor for osteosarcoma. In this study, we demonstrated that serum protein of pro-surfactant protein B (pro-SFTPB) may be a potential diagnostic indicator in osteosarcoma. We found that serum pro-SFTPB was highly expressed in osteosarcoma patients and presented good diagnostic value to discern osteosarcoma patients from non-osteosarcoma control subjects. Serum pro-SFTPB was also significantly correlated with advanced clinical stage, distant metastasis, and shorter overall survival. In addition, serum pro-SFTPB was demonstrated to be an independent prognostic factor for osteosarcoma. Overall, our study demonstrated that serum pro-SFTPB may be a useful diagnostic factor for osteosarcoma.

Pulmonary surfactant protein B carried by HDL predicts incident CVD in patients with type 1 diabetes.

Atherosclerotic CVD is the major cause of death in patients with type 1 diabetes mellitus (T1DM). Alterations in the HDL proteome have been shown to associate with prevalent CVD in T1DM. We therefore sought to determine which proteins carried by HDL might predict incident CVD in patients with T1DM. Using targeted MS/MS, we quantified 50 proteins in HDL from 181 T1DM subjects enrolled in the prospective Coronary Artery Calcification in Type 1 Diabetes study. We used Cox proportional regression analysis and a case-cohort design to test associations of HDL proteins with incident CVD (myocardial infarction, coronary artery bypass grafting, angioplasty, or death from coronary heart disease). We found that only one HDL protein-SFTPB (pulmonary surfactant protein B)-predicted incident CVD in all the models tested. In a fully adjusted model that controlled for lipids and other risk factors, the hazard ratio was 2.17 per SD increase of SFTPB (95% confidence interval, 1.12-4.21, P = 0.022). In addition, plasma fractionation demonstrated that SFTPB is nearly entirely bound to HDL. Although previous studies have shown that high plasma levels of SFTPB associate with prevalent atherosclerosis only in smokers, we found that SFTPB predicted incident CVD in T1DM independently of smoking status and a wide range of confounding factors, including HDL-C, LDL-C, and triglyceride levels. Because SFTPB is almost entirely bound to plasma HDL, our observations support the proposal that SFTPB carried by HDL is a marker-and perhaps mediator-of CVD risk in patients with T1DM.

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.

Prediction of lung cancer risk using circulating pro-surfactant protein B and high-sensitivity C-reactive protein among Egyptian workers in the rubber industry.

OBJECTIVE: For several decades, there has been increasing evidence for excess incidence of lung cancer among workers in the rubber industry. The purpose of this study was to assess the risk of lung cancer occurrence among Egyptian workers involved in the rubber industry using two circulating protein biomarkers. METHODS: This study was performed in a rubber manufacturing factory in Shubra El-Kheima region in Greater Cairo, Egypt. Environmental assessment for the suspended particulate matter of size 10 µm (PM10) concentrations was done. Levels of plasma pro-surfactant protein B (pro-SFTPB) and serum high-sensitivity C-reactive protein (HsCRP) were measured among the studied population (n = 155) who were divided into two groups. The first group included 75 workers exposed to rubber manufacturing process while the control group involved 80 administrative subjects. RESULTS: The levels of PM10 neither exceeded the Egyptian nor the international permissible limits where the highest levels were observed in the mixing department. However, through medical history and clinical examination, it was observed that some general and respiratory manifestations were more prevalent among the exposed group when compared with their controls. Laboratory investigations revealed that the mean values of pro-SFTPB and HsCRP levels among exposed workers were significantly higher than those of the control group. These increased circulating proteins levels were strongly and positively correlated with each other and with the duration of employment of exposed workers. CONCLUSION: The study results support the conclusion that prolonged occupational exposure to rubber manufacturing process is associated with an elevated risk of lung cancer.

Gene polymorphisms of SFTPB rs7316, rs9752 and PAOX rs1046175 affect the diagnostic value of plasma Pro-SFTPB and DAS in Chinese Han non-small-cell lung cancer patients.

Plasma pro-surfactant protein B (pro-SFTPB) and N1,N12-diacetylspermine (DAS) can be used as markers for the diagnosis of non-small-cell lung carcinoma (NSCLC). Whether the genetic diversity affects the application value of Pro-SFTPB and DAS as a diagnostic marker for NSCLC is still unknown. This study aims to explore the relationship between SFTPB rs7316, rs9752 and PAOX rs1046175 gene polymorphisms and the diagnostic value of plasma Pro-SFTPB and DAS in patients with Chinese Han lung cancer. SFTPB rs7316, rs9752 and PAOX rs1046175 genotypes were analyzed by direct sequencing in 425 patients with NSCLC and 425 controls, and the levels of Pro-SFTPB and DAS in plasma were determined by enzyme-linked immunosorbent assay (ELISA). The area under the curve (AUC) of the SFTPB rs7316 locus TT genotype for the diagnosis of NSCLC was 0.758, and the AUC of the TC/CC genotype for the diagnosis of NSCLC was 0.872. The AUC of the SFTPB rs9752 locus GG genotype for the diagnosis of NSCLC was 0.935, and the AUC of the GC/CC genotype for the diagnosis of NSCLC was 0.648. The AUC of the PAOX rs1046175 locus GG for the diagnosis of NSCLC was 0.669, and the AUC of the GC/CC genotype for the diagnosis of NSCLC was 0.749. In conclusion, SFTPB rs7316, rs9752, and PAOX rs1046175 gene polymorphisms affect the diagnostic value of plasma Pro-SFTPB and DAS in patients with Chinese Han NSCLC.

Delayed Presentation and Prolonged Survival of a Child with Surfactant Protein B Deficiency.

Surfactant protein B encoding gene mutations have been related to early onset fatal respiratory distress in full-term neonates. We report a school-aged male child homozygous for a surfactant protein B encoding gene missense mutation who presented after the neonatal period. His respiratory insufficiency responded to high dose intravenous methylprednisolone and hydroxychloroquine.

Outcomes of Lung Transplantation for Infants and Children with Genetic Disorders of Surfactant Metabolism.

OBJECTIVE: To compare outcomes of infants and children who underwent lung transplantation for genetic disorders of surfactant metabolism (SFTPB, SFTPC, ABCA3, and NKX2-1) over 2 epochs (1993-2003 and 2004-2015) at St Louis Children's Hospital. STUDY DESIGN: We retrospectively reviewed clinical characteristics, mortality, and short- and long-term morbidities of infants (transplanted at <1 year; n = 28) and children (transplanted >1 year; n = 16) and compared outcomes by age at transplantation (infants vs children) and by epoch of transplantation. RESULTS: Infants underwent transplantation more frequently for surfactant protein-B deficiency, whereas children underwent transplantation more frequently for SFTPC mutations. Both infants and children underwent transplantation for ABCA3 deficiency. Compared with children, infants experienced shorter times from listing to transplantation (P = .014), were more likely to be mechanically ventilated at the time of transplantation (P < .0001), were less likely to develop bronchiolitis obliterans post-transplantation (P = .021), and were more likely to have speech and motor delays (P ≤ .0001). Despite advances in genetic diagnosis, immunosuppressive therapies, and supportive respiratory and nutritional therapies, mortality did not differ between infants and children (P = .076) or between epochs. Kaplan-Meier analyses demonstrated that children transplanted in epoch 1 (1993-2003) were more likely to develop systemic hypertension (P = .049) and less likely to develop post-transplantation lymphoproliferative disorder compared with children transplanted in epoch 2 (2004-2015) (P = .051). CONCLUSION: Post-lung transplantation morbidities and mortality remain substantial for infants and children with genetic disorders of surfactant metabolism.

Structural and transcriptomic response to antenatal corticosteroids in an Erk3-null mouse model of respiratory distress.

BACKGROUND: Neonatal respiratory distress syndrome in preterm infants is a leading cause of neonatal death. Pulmonary insufficiency-related infant mortality rates have improved with antenatal glucocorticoid treatment and neonatal surfactant replacement. However, the mechanism of glucocorticoid-promoted fetal lung maturation is not understood fully, despite decades of clinical use. We previously have shown that genetic deletion of Erk3 in mice results in growth restriction, cyanosis, and early neonatal lethality because of pulmonary immaturity and respiratory distress. Recently, we demonstrated that the addition of postnatal surfactant administration to antenatal dexamethasone treatment resulted in enhanced survival of neonatal Erk3-null mice. OBJECTIVE: To better understand the molecular underpinnings of corticosteroid-mediated lung maturation, we used high-throughput transcriptomic and high-resolution morphologic analysis of the murine fetal lung. We sought to examine the alterations in fetal lung structure and function that are associated with neonatal respiratory distress and antenatal glucocorticoid treatment. STUDY DESIGN: Dexamethasone (0.4 mg/kg) or saline solution was administered to pregnant dams on embryonic days 16.5 and 17.5. Fetal lungs were collected and analyzed by microCT and RNA-seq for differential gene expression and pathway interactions with genotype and treatment. Results from transcriptomic analysis guided further investigation of candidate genes with the use of immunostaining in murine and human fetal lung tissue. RESULTS: Erk3(-/-) mice exhibited atelectasis with decreased overall porosity and saccular space relative to wild type, which was ameliorated by glucocorticoid treatment. Of 596 differentially expressed genes (q < 0.05) that were detected by RNA-seq, pathway analysis revealed 36 genes (q < 0.05) interacting with dexamethasone, several with roles in lung development, which included corticotropin-releasing hormone and surfactant protein B. Corticotropin-releasing hormone protein was detected in wild-type and Erk3(-/-) lungs at E14.5, with significantly temporally altered expression through embryonic day 18.5. Antenatal dexamethasone attenuated corticotropin-releasing hormone at embryonic day 18.5 in both wild-type and Erk3(-/-) lungs (0.56-fold and 0.67-fold; P < .001). Wild type mice responded to glucocorticoid administration with increased pulmonary surfactant protein B (P = .003). In contrast, dexamethasone treatment in Erk3(-/-) mice resulted in decreased surfactant protein B (P = .012). In human validation studies, we confirmed that corticotropin-releasing hormone protein is present in the fetal lung at 18 weeks of gestation and increases in expression with progression towards viability (22 weeks of gestation; P < .01). CONCLUSION: Characterization of whole transcriptome gene expression revealed glucocorticoid-mediated regulation of corticotropin-releasing hormone and surfactant protein B via Erk3-independent and -dependent mechanisms, respectively. We demonstrated for the first time the expression and temporal regulation of corticotropin-releasing hormone protein in midtrimester human fetal lung. This unique model allows the effects of corticosteroids on fetal pulmonary morphologic condition to be distinguished from functional gene pathway regulation. These findings implicate Erk3 as a potentially important molecular mediator of antenatal glucocorticoid action in promoting surfactant protein production in the preterm neonatal lung and expanding our understanding of key mechanisms of clinical therapy to improve neonatal survival.

SFTPB (rs11130866) and NR3C1 (rs41423247) gene variants as potential clinical biomarkers for personalized treatment strategy selection in patients with severe COVID-19 pneumonia.

BACKGROUND: Exploring the pathogenetic mechanisms behind severe lung damage in COVID-19 is crucial. In this study, we decided to focus on two molecular markers that affect surfactant metabolism and lung development: the surfactant protein B (SFTPB) and the glucocorticoid receptor (NR3C1) genes. The aim of our study was to determine the effect of SFTPB (rs11130866) and NR3C1 (rs41423247) gene variants on the course of the disease in patients with COVID-19, and the treatment measures they required. METHODS: The study group included 58 patients with a diagnosis of severe "viral COVID-19 pneumonia." Determination of SFTPB and NR3C1 gene variants was performed using the PCR-RFLP method. RESULTS: Our results indicate that the presence of the SFTPB gene CC genotype increases the risk of developing acute respiratory distress syndrome in patients with COVID-19 (χ2 = 4.03, p = 0.045, OR = 3.90 [1.19-12.78]). However, patients with the SFTPB gene TT genotype required respiratory support for a shorter period of time. Patients with the NR3C1 gene CC genotype underwent a longer glucocorticoid therapy. Moreover, for patients with the CC genotype, a longer stay in the intensive care unit was detected before lethal outcome. CONCLUSIONS: The obtained results confirm the influence of the SFTPB (rs11130866) and NR3C1 (rs41423247) gene variants on the therapy, course, and severity of the disease in patients with COVID-19. Of course, these results require further study, analysis, and larger, complex, systematic research.

Downregulation of pro-surfactant protein B contributes to the recurrence of early-stage non-small cell lung cancer by activating PGK1-mediated Akt signaling.

Recurrence is one of the main causes of treatment failure in early-stage non-small cell lung cancer (NSCLC). However, there are no predictors of the recurrence of early-stage NSCLC, and the molecular mechanism of its recurrence is not clear. In this study, we used clinical sample analysis to demonstrate that low levels of expression of precursor surfactant protein B (pro-SFTPB) in primary NSCLC tissue compared to their adjacent tissues are closely correlated with recurrence and poor prognosis in early-stage NSCLC patients. In vitro and in vivo experiments showed that downregulation of pro-SFTPB expression activates the Akt pathway by upregulating PGK1, which promotes metastasis and tumorigenicity in NSCLC cells. We then demonstrated that pro-SFTPB suppresses the formation of the ADRM1/hRpn2/UCH37 complex by binding to ADRM1, which inhibits PGK1 deubiquitination, thus accelerating ubiquitin-mediated PGK1 degradation. In summary, our findings indicate that low expression of pro-SFTPB in primary NSCLC compared to their adjacent tissue has potential as a predictor of recurrence and poor prognosis in early-stage NSCLC. Mechanistically, downregulation of pro-SFTPB attenuates inhibition of ADRM1-deubiquitinated PGK1, resulting in elevated levels of PGK1 protein; this activates the Akt pathway, ultimately leading to the progression of early-stage NSCLC.

The Common Haplotype GATGACA in Surfactant-Protein B Gene Is Protective for Respiratory Distress Syndrome in Preterm Neonates.

Background: Respiratory distress syndrome (RDS), a disorder of primary surfactant deficiency resulting in pulmonary insufficiency, remains a significant problem for preterm neonates. Associations between genetic variants of surfactant proteins and RDS have been reported, but haplotypes of the surfactant protein B gene (SFTPB) have not been studied. The aim of the study was to prove the hypothesis that certain haplotypes of SFTPB may be protective or risk factors for RDS. Methods: The study was performed with 149 preterm infants, born <34 weeks of gestation, with 86 infants with mild RDS or without RDS (control group) and 63 infants with severe RDS (patient group). RDS was considered severe if multiple doses of exogenous surfactant and/or mechanical ventilation within the first 72 h of life were needed. The venous blood sample was used for the analysis of gene polymorphisms associated with RDS, genotyping, and haplotype estimation. Multivariate logistic regression analysis and the odds ratio were calculated to detect the contribution of the studied variables to the development of RDS. Results: A new association of the common single nucleotide polymorphism (SNP) rs2304566 with RDS in premature infants was detected. Analysis of rs2304566 polymorphisms using a logistic regression model showed that there are two significant predictors inversely related to the occurrence of RDS (Apgar score of 5 min, CT and TT genotype in rs2304566 polymorphism). Gestational age, birth weight, and sex have border significance. Moreover, in the patient group, the frequency of the GATGACA haplotype in the SFTPB gene was lower (p = 0.037), and the GATGGCA haplotype was higher (p = 0.059) in comparison with the control group. Conclusion: The common haplotype GATGACA of the SFTPB gene can be protective against RDS in preterm infants. The trend of a higher frequency of GATGGCA in the SFTPB gene in infants with severe RDS suggests that this haplotype may be a risk factor for RDS susceptibility.

Gene Therapeutics for Surfactant Dysfunction Disorders: Targeting the Alveolar Type 2 Epithelial Cell.

Genetic disorders of surfactant dysfunction result in significant morbidity and mortality, among infants, children, and adults. Available medical interventions are limited, nonspecific, and generally ineffective. As such, the need for effective therapies remains. Pathogenic variants in the SFTPB, SFTPC, and ABCA3 genes, each of which encode proteins essential for proper pulmonary surfactant production and function, result in interstitial lung disease in infants, children, and adults, and lead to morbidity and early mortality. Expression of these genes is predominantly limited to the alveolar type 2 (AT2) epithelial cells present in the distal airspaces of the lungs, thus providing an unequivocal cellular origin of disease pathogenesis. While several treatment strategies are under development, a gene-based therapeutic holds great promise as a definitive therapy. Importantly for clinical translation, the genes associated with surfactant dysfunction are both well characterized and amenable to a gene-therapeutic-based strategy. This review focuses on the pathophysiology associated with these genetic disorders of surfactant dysfunction, and also provides an overview of the current state of gene-based therapeutics designed to target and transduce the AT2 cells.

Hydrophilic But Not Hydrophobic Surfactant Protein Genetic Variants Are Associated With Severe Acute Respiratory Syncytial Virus Infection in Children.

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infection-related hospitalization in the first year of life. Surfactant dysfunction is central to pathophysiologic mechanisms of various pulmonary diseases including RSV. We hypothesized that RSV severity is associated with single nucleotide polymorphisms (SNPs) of surfactant proteins (SPs). We prospectively enrolled 405 RSV-positive children and divided them into moderate and severe RSV disease. DNA was extracted and genotyped for sixteen specific SP gene SNPs. SP-A1 and A2 haplotypes were assigned. The association of RSV severity with SP gene SNPs was investigated by multivariate logistic regression. A likelihood ratio test was used to test the goodness of fit between two models (one with clinical and demographic data alone and another that included genetic variants). p ≤ 0.05 denotes statistical significance. A molecular dynamics simulation was done to determine the impact of the SFTPA2 rs1965708 on the SP-A behavior under various conditions. Infants with severe disease were more likely to be younger, of lower weight, and exposed to household pets and smoking, as well as having co-infection on admission. A decreased risk of severe RSV was associated with the rs17886395_C of the SFTPA2 and rs2243639_A of the SFTPD, whereas an increased risk was associated with the rs1059047_C of the SFTPA1. RSV severity was not associated with SNPs of SFTPB and SFTPC. An increased risk of severe RSV was associated with the 1A0 genotype of SFTPA2 in its homozygous or heterozygous form with 1A3. A molecular dynamic simulation study of SP-A variants that differ in amino acid 223, an important amino acid change (Q223K) between 1A0 and 1A3, showed no major impact on the behavior of these two variants except for higher thermodynamic stability of the K223 variant. The likelihood ratio test showed that the model with multi-allelic variants along with clinical and demographic data was a better fit to predict RSV severity. In summary, RSV severity was associated with hydrophilic (but not with hydrophobic) SPs gene variants. Collectively, our findings show that SP gene variants may play a key role in RSV infection and have a potential role in prognostication.

Corrigendum: Mouse models of lung-specific SARS-CoV-2 infection with moderate pathological traits.

[This corrects the article DOI: 10.3389/fimmu.2022.1055811.].

Mouse models of lung-specific SARS-CoV-2 infection with moderate pathological traits.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing coronavirus disease 2019 (COVID-19) has been a global health concern since 2019. The viral spike protein infects the host by binding to angiotensin-converting enzyme 2 (ACE2) expressed on the cell surface, which is then processed by type II transmembrane serine protease. However, ACE2 does not react to SARS-CoV-2 in inbred wild-type mice, which poses a challenge for preclinical research with animal models, necessitating a human ACE2 (hACE2)-expressing transgenic mouse model. Cytokeratin 18 (K18) promoter-derived hACE2 transgenic mice [B6.Cg-Tg(K18-ACE2)2Prlmn/J] are widely used for research on SARS-CoV-1, MERS-CoV, and SARS-CoV-2. However, SARS-CoV-2 infection is lethal at ≥105 PFU and SARS-CoV-2 target cells are limited to type-1 alveolar pneumocytes in K18-hACE2 mice, making this model incompatible with infections in the human lung. Hence, we developed lung-specific SARS-CoV-2 infection mouse models with surfactant protein B (SFTPB) and secretoglobin family 1a member 1 (Scgb1a1) promoters. After inoculation of 105 PFU of SARS-CoV-2 to the K18-hACE2, SFTPB-hACE2, and SCGB1A1-hACE2 models, the peak viral titer was detected at 2 days post-infection and then gradually decreased. In K18-hACE2 mice, the body temperature decreased by approximately 10°C, body weight decreased by over 20%, and the survival rate was reduced. However, SFTPB-hACE2 and SCGB1A1-hACE2 mice showed minimal clinical signs after infection. The virus targeted type I pneumocytes in K18-hACE2 mice; type II pneumocytes in SFTPB-hACE2 mice; and club, goblet, and ciliated cells in SCGB1A1-hACE2 mice. A time-dependent increase in severe lung lesions was detected in K18-hACE2 mice, whereas mild lesions developed in SFTPB-hACE2 and SCGB1A1-hACE2 mice. Spleen, small intestine, and brain lesions developed in K18-hACE2 mice but not in SFTPB-hACE2 and SCGB1A1-hACE2 mice. These newly developed SFTPB-hACE2 and SCGB1A1-hACE2 mice should prove useful to expand research on hACE2-mediated respiratory viruses.

Interventional creation of an endogenous reverse Potts shunt in an infant with pulmonary hypertension and genetic surfactant disorder-a case report.

Reverse Potts shunt is a palliative procedure aimed at decompressing the pressure-overloaded right ventricle in severe pulmonary hypertension (PH). We, herein, report the first case of an interventional creation of an "endogenous" reverse Potts shunt by stenting a pre-existing small but patent ductus arteriosus (PDA) in a 2 months old female infant with severe, supra-systemic PH, associated with a novel combination of a compound heterozygous ABCA3 mutation and additional heterozygous genetic variants of surfactant protein B (SFTPB) and C (SFTPC). The aforementioned combination of human genetic mutations has not been described before in viable infants, children or adults. The catheter intervention was performed via percutaneous femoral arterial access and was well-tolerated. Subsequently, the infant improved by means of clinical status, echocardiographic systolic right ventricular (RV) function, and serum NT-proBNP levels as biomarker of right atrial and RV pressure load. In conclusion, this single case report suggests that interventional stenting of a pre-existing PDA to create an "endogenous" reverse Potts shunt is feasible and efficacious in infants less than 3 months old with severe PH and impending RV failure associated with developmental lung disease.

Association of SNP-SNP Interactions of Surfactant Protein Genes with Pediatric Acute Respiratory Failure.

The hallmarks of pediatric acute respiratory failure (ARF) are dysregulated inflammation and surfactant dysfunction. The objective is to study association of surfactant protein (SP) genes' single nucleotide polymorphisms (SNPs) with ARF and its morbidity: pulmonary dysfunction at discharge (PDAD), employing a single-, two-, and three-SNP interaction model. We enrolled 468 newborn controls and 248 children aged ≤ 24 months with ARF; 86 developed PDAD. Using quantitative genetic principles, we tested the association of SP genes SNPs with ARF and PDAD. We observed a dominant effect of rs4715 of the SFTPC on ARF risk. In a three-SNP model, we found (a) 34 significant interactions among SNPs of SFTPA1, SFTPA2, and SFTPC associated with ARF (p = 0.000000002-0.05); 15 and 19 of those interactions were associated with increased and decreased risk for ARF, respectively; (b) intergenic SNP-SNP interactions of both hydrophobic and hydrophilic SP genes associated with PDAD (p = 0.00002-0.03). The majority of intra- and intergenic interactions associated with ARF involve the SFTPA2 SNPs, whereas most of the intra- and intergenic interactions associated with PDAD are of SFTPA1 SNPs. We also observed a dominant effect of haplotypes GG of SFTPA1 associated with increased and AA of SFTPC associated with decreased ARF risk (p = 0.02). To the best of our knowledge, this is the first study showing an association of complex interactions of SP genes with ARF and PDAD. Our data indicate that SP genes polymorphisms may contribute to ARF pathogenesis and subsequent PDAD and/or may serve as markers for disease susceptibility in healthy children.

SNP and Haplotype Interaction Models Reveal Association of Surfactant Protein Gene Polymorphisms With Hypersensitivity Pneumonitis of Mexican Population.

Background: Hypersensitivity pneumonitis (HP) is an interstitial lung disease caused by inhalation of common environmental organic particles. Surfactant proteins (SPs) play a role in innate immunity and surfactant function. We hypothesized that single nucleotide polymorphisms (SNPs) or haplotypes of the SP genes associate with HP. Methods: Seventy-five HP patients caused by avian antigen and 258 controls, asymptomatic antigen exposed and non-exposed were enrolled. SNP association was performed using logistic regression analysis and SNP-SNP interaction models. Results: Based on odds ratio, regression analyses showed association of (a) rs7316_G, 1A3 (protective) compared to antigen exposed; (b) male sex, smoking, rs721917_T and rs1130866_T (protective) compared to non-exposed controls with HP; (c) compared to antigen exposed, 25 interactions associated with HP in a three-SNP model; (d) compared to non-exposed, (i) rs1136451 associated with increased, whereas rs1136450 and rs1130866 associated with lower HP risk, (ii) 97 interactions associated with HP in a three-SNP model. The majority of SNP-SNP interactions associated with increased HP risk involved SNPs of the hydrophilic SPs, whereas, the majority of interactions associated with lower HP risk involved SNPs of both hydrophilic and hydrophobic SPs; (e) haplotypes of SP genes associated with HP risk. Conclusions: The complexity of SNPs interactions of the SFTP genes observed indicate that the lung inflammatory response to avian antigens is modulated by a complex gene interplay rather than by single SNPs.

Association of SP-B gene 9306 A/G polymorphism (rs7316) and risk of RDS.

BACKGROUND: Respiratory distress syndrome (RDS) is a severe pulmonary disease predominantly affects preterm newborns. Polymorphisms of surfactant-protein genes have been mostly evaluated as the candidate contributors in genetics of RDS. However the results are divers in different studies. We aimed at investigating the association of surfactant protein B (SPB) gene 9306 A/G polymorphism (rs7316) with RDS development. METHOD: Three hundred and eighty newborns with gestational age of less than 34 weeks were included in a multicenter case-control study. Respiratory distress (RD) was scored according to Downes' scoring system. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used for genotyping. RESULT: One hundred and eighty-four neonates showed RDS and 196 did not. Gestational age (GA) was significantly lower in the RDS group compared with the controls. AA genotype and A allele were found more frequently in the RDS group than the controls (96.2% versus 63.8% and 98.1% versus 80.6%, respectively) (p =.0001). CONCLUSIONS: This is the first report of association of SFTPB rs7316 polymorphism with RDS development in Iranian newborns. The current study suggests that GA <28-weeks is the most important factor in predisposition to RDS. Genetic background in terms of SP-B gene might be involved in predisposition to RDS in premature neonates.

Novel ABCA3 mutations as a cause of respiratory distress in a term newborn.

We report here the case of a term female newborn that developed severe respiratory distress soon after birth. She was found to be a compound heterozygote for both novel mutations in the ABCA3 gene. ABCA3 deficiency should be considered in mature babies who develop severe respiratory distress syndrome.