Serum Surfactant Protein D Levels Research Articles

The role of serum surfactant protein D as a biomarker of exacerbation of chronic obstructive pulmonary disease.

Background: The exacerbation of chronic obstructive pulmonary disease (COPD) is a major factor for the high mortality associated with the disease. There is a paucity in the lung-specific biomarkers which diagnose these exacerbations. Surfactant protein D (SP-D) is a promising biomarker in predicting clinical outcomes for patients with COPD, is lung-specific and can be detected in serum. However, the profile in which serum concentrations of SP-D change during acute exacerbation is still unclear. This study aims to estimate and compare the concentrations of serum SP-D in patients with stable disease and during the exacerbation. Methods: A cross-sectional study was conducted which composed of apparently healthy individuals (n = 28), which included 14 smokers and 14 nonsmokers, patients with stable COPD (n = 28), and patients experiencing acute exacerbations (n = 28). Pulmonary functions were performed for all groups. Serum SP-D concentrations were measured using enzyme-linked immunosorbent assay (ELISA). These concentrations were compared by analysis of variance. Results: Serum SP-D levels were significantly elevated in patients with acute exacerbations (508.733 ± 102.813 ng/ml) compared to patients with stable COPD (337.916 ± 86.265 ng/ml) and healthy subjects (177.313 ± 46.998 ng/ml; p < 0.001). Serum SP-D levels correlated inversely with lung function parameters including FEV1%pred, FVC%pred and FEV1/FVC. Conclusion: Serum SP-D levels are raised early on during acute exacerbations of COPD, which could be a potential early diagnostic biomarker for COPD exacerbations.

Interstitial lung disease in clinically amyopathic dermatomyositis with and without anti-MDA-5 antibody: to lump or split?

BackgroundInterstitial lung disease (ILD) associated with clinically amyopathic dermatomyositis (CADM-ILD) is often refractory and rapidly progressive. Although the anti-melanoma differentiation-associated gene 5 (anti-MDA-5) antibody is associated with rapidly progressive ILD (RP-ILD), differences in clinical features and prognosis of anti-MDA-5 antibody-positive and -negative CADM-ILD remain unclear.MethodsTo clarify the differences in the clinical features and prognosis between anti-MDA-5 antibody-positive and -negative cases, we retrospectively reviewed the medical records of patients diagnosed with CADM-ILD with and without anti-MDA-5 antibody at Kurashiki Central Hospital from January 2005 to September 2014.ResultsAnti-MDA-5 antibody was found in 10 of 16 patients (63 %). The levels of Krebs von den Lungen-6 (KL-6) and surfactant protein D (SP-D) at the first visit were significantly lower in positive patients than in negative patients, whereas the levels of aspartate aminotransferase (AST), γ-glutamyl transpeptidase (γ-GTP), and the CD4+/CD8+ ratio in the bronchoalveolar lavage (BAL) fluid were significantly higher in positive patients than negative patients. Subpleural ground-glass opacity (GGO) or irregular linear opacity was predominant in positive patients. Peribronchovascular consolidation was predominant in negative patients. Positive patients had significantly lower survival rates than negative patients, with all six fatal cases occurring in positive patients who died of refractory ILD within 92 days from the first visit despite intensive treatment.ConclusionsThere are clear differences in the clinical features and prognosis of anti-MDA-5 antibody-positive and -negative CADM-ILD. Low serum KL-6 and SP-D levels, high serum AST and γ-GTP levels, high CD4+/CD8+ ratio in BAL fluid, and predominance of subpleural GGO or irregular linear opacity in HRCT may help to discriminate anti-MDA-5 antibody-positive CADM-ILD with poor prognosis.

Levels and clinical significance of serum SP-D and MBL in infants with cytomegalovirus pneumonia

Objective To investigate the levels of serum surfactant protein D (SP-D) and mannose-binding lectin (MBL) in infants with cytomegalovirus (CMV) pneumonia with the severity of disease. Methods A total of 101 hospitalized infants with CMV pneumonia were enrolled from January 2011 to December 2012.These patients were divided as the severe pneumonia group (n=48) and the mild pneumonia group (n=53) according to physical sign of lung and complication.Another 55 infants who were hospitalized in the same period with non-infectious diseases were used as the control group.Serum levels of SP-D and MBL were detected by enzyme-linked immunosorbent assay.Blood gas analyzer was used to measure arterial partial pressure of oxygen (PaO2) of the blood in severe patients. Results The mean serum SP-D levels in the severe pneumonia group [(150.08±52.59)ng/ml] and the mild pneumonia group [(109.67±31.39)ng/ml] were significantly higher than those in control group [(41.33±16.42)ng/ml] (P 0.05). In severe patients, serum SP-D levels were negatively correlated with PaO2 (r=-0.565, P<0.01). Conclusion Serum SP-D is associated with the severity of CMV pneumonia, but MBL shows no relation.The serum SP-D levels has an important clinical significance in judgment the sererity of infants with CMV pneumonia. Key words: Surfactant protein D; Mannose-binding lectin; Arterial partial pressure of oxygen; Cytomegalovirus pneumonia; Infant

The usefulness of KL-6 and SP-D for the diagnosis and management of chronic hypersensitivity pneumonitis

BackgroundIt is believed that Krebs von den Lungen-6 (KL-6) and surfactant protein D (SP-D) are useful biomarkers for the diagnosis of various types of interstitial lung diseases, including hypersensitivity pneumonitis (HP). The clinical features of chronic HP are similar to those of idiopathic interstitial pneumonias, especially idiopathic pulmonary fibrosis (IPF). ObjectiveWe sought to clarify the usefulness of serum KL-6 and SP-D for the diagnosis and management of chronic HP. MethodsWe examined serum KL-6 and SP-D levels and retrospectively evaluated the clinical parameters of acute HP (n = 35), chronic HP (n = 57), IPF (n = 54), collagen vascular disease-associated interstitial pneumonia (CVD-IP) (n = 67), and sarcoidosis (n = 47). We analyzed the relations between the two biomarkers and clinical data in chronic HP. ResultsSerum KL-6 and SP-D levels in acute HP (2710 U/ml and 338 ng/ml, median) and chronic HP (1500 U/ml and 264 ng/ml, median) were significantly higher than in IPF, CVD-IP, and sarcoidosis. The area under the curve (AUC) values for serum KL-6 and SP-D between chronic HP and IPF were 0.771 and 0.729, respectively. Serum KL-6 levels in chronic HP were significantly higher during episodes of acute exacerbation than 1 month before acute exacerbation. The serum KL-6 levels had correlations with serum SP-D and the percentage of lymphocytes in bronchoalveolar lavage fluid. ConclusionsSerum KL-6 and SP-D levels are useful for the diagnosis and management of chronic HP.

Serum B cell-activating factor (BAFF) level in connective tissue disease associated interstitial lung disease.

BackgroundInterstitial lung diseases (ILDs) are common in patients with connective tissue diseases (CTDs). Although the diagnosis of an underlying CTD in ILD (CTD-ILD) affects both prognosis and treatment, it is sometimes difficult to distinguish CTD-ILD from chronic fibrosing interstitial pneumonia (CFIP). B cell–activating factor belonging to the tumour necrosis factor family (BAFF) plays a crucial role in B cell development, survival, and antibody production.MethodsWe examined serum levels of BAFF, surfactant protein D (SP-D), and Krebs von den Lungen-6 (KL-6) in 33 patients with CTD-ILD, 16 patients with undifferentiated CTD-ILD, 19 patients with CFIP, and 26 healthy volunteers. And we analysed the relationship between serum BAFF levels and pulmonary function, as well as the expression of BAFF in the lung tissue of patients with CTD-ILD.ResultsSerum levels of BAFF were significantly higher in CTD-ILD patients compared to healthy subjects and CFIP patients. However, there were no significant differences in serum levels of SP-D and KL-6. Furthermore, serum BAFF levels in CTD-ILD patients were inversely correlated with pulmonary function. BAFF was strongly expressed in the lungs of CTD-ILD patients, but weakly in normal lungs.DiscussionThis is the first study to demonstrate that serum BAFF levels were significantly higher in CTD-ILD patients compared to healthy subjects and CFIP patients. Furthermore, serum BAFF levels were correlated with pulmonary function. We consider that serum BAFF levels in patients with CTD-ILD reflect the presence of ILDs disease activity and severity.ConclusionThese finding suggest that BAFF may be a useful marker for distinguishing CTD-ILD from CFIP.

What do changes in concentrations of serum surfactant proteins A and D in OSA mean?

Previous studies have shown that surfactant proteins are affected by oxygen concentration and mechanic stretches, although the alteration of serum surfactant proteins in individuals with obstructive sleep apnea (OSA) is still unclear. Therefore, the aim of this study is to examine whether serum concentrations of surfactant proteins A and D are altered and related to hypopnea index (HI) in OSA. This is a cross-sectional study. Consecutive 140 males, suspicious of OSA, were studied. OSA was determined by PSG and polysomnographic data examined. Subjects with HI ≥ 10.1/h were classified as higher HI group and those with HI < 10.1/h as lower HI group. Hs-CRP, HbA1C, and FBG were determined by standard methods and Krebs von den Lungen-6 (KL-6), surfactant protein-A (SP-A), and surfactant protein-D (SP-D) by ELISA. OSA was diagnosed in 110 patients (78.5%). Mild, moderate, and severe OSA constitutes 26.4, 27.8, and 24.3%, respectively. Mean age was 44.6 ± 7.65 years. Subjects with higher HI had lower SP-A (139.54. ± 32.94 vs 158.2 ± 38.9 ng/L, p = 0.005) and SP-D (16.54 ± 3.67 vs 18.10 ± 3.48 ng/L, p = 0.014) compared to those with lower HI. Nocturnal HI was strongly correlated with serum levels of SP-A (r = 0.343, p = 0.012) and SP-D (r = 0.504, p < 0.001) and are inversely associated with circulating SP-A and SP-D levels, even after adjusting for age and body mass index in nonsmoking subjects. Circulating SP-A and SP-D levels are decreased in some individuals with higher HI in OSA, possibly reflecting severity of hypoxia in OSA.

Clinical value of surfactant protein D as a biomarker of pulmonary fibrosis in patients with scleroderma systematica in relation to the presence of gastroesophageal reflux

To study the role of serum surfactant protein D (SP-D) as a biomarker of lung injury in scleroderma systematica (SDS) in relation to the presence of gastroesophageal reflux (GER). Fifty-six patients (mean age 46±14 years) with diffuse and circumscribed SDS were examined and underwent pulmonary functional tests, X-ray and, if lung injury was present, high-resolution computed tomography of the lung, echocardiography, gastroduodenoscopy, and barium X-ray of the esophagus; an enzyme-linked immunosorbent assay was used to determine serum SP-D levels. SP-D concentrations significantly correlate with the presence of lung injury in SDS and are significantly higher in the presence of pulmonary fibrosis and the signs of frosted glass and honeycomb lung patterns. SP-D levels were higher in the patients with lung injury and SDS in the group of those with pulmonary fibrosis and GER than in the group of pulmonary fibrosis patients without the latter. Serum SP-D may be considered in a number of biomarkers for the severity of lung injury in SDS, including GER-associated lung injury.

Levels of Soluble Receptor for Advanced Glycation End Products in Bronchoalveolar Lavage Fluid in Patients with Various Inflammatory Lung Diseases.

Receptor for advanced glycation end products (RAGE) is a multiligand receptor of S100/calgranulins, high-mobility group box 1, and others, and it is associated with the pathogenesis of various inflammatory and circulatory diseases. The soluble form of RAGE (sRAGE) is a decoy receptor and competitively inhibits membrane-bound RAGE activation. In this study, we measured sRAGE levels in bronchoalveolar lavage fluid (BALF) of 78 patients, including 41 with interstitial pneumonia, 11 with sarcoidosis, 9 with respiratory infection, 7 with ARDS, 5 with lung cancer, and 5 with vasculitis. Among them, sRAGE was detectable in BALF of 73 patients (94%). In patients with ARDS and vasculitis, the sRAGE levels were significantly higher than in the control subjects and those with interstitial pneumonia. The sRAGE levels were positively correlated with total cell counts in BALF and serum levels of surfactant protein-D, lactate dehydrogenase, and C-reactive protein. There was an inverse correlation between PaO2/FIO2 ratio and sRAGE levels. These results indicate that sRAGE in BALF might be considered as a biomarker of lung inflammatory disorders, especially ARDS and vasculitis.

Serum surfactant protein D (SP-D) is a prognostic marker of poor outcome in patients with A/H1N1 virus infection.

IntroductionSurfactant protein D (SP-D) plays an important role in the innate responses against pathogens and its production is altered in lung disorders.MethodsWe studied the circulating levels of SP-D in 37 patients with acute respiratory distress syndrome due to the A/H1N1 virus infection and in 40 healthy controls. Cox logistic regression models were constructed to explore the association of SP-D levels and risk of death.ResultsMortality rate after a 28-day was 32.42 %. Significant higher levels of SP-D were detected in A/H1N1 patients with fatal outcome (p < 0.05). After adjusting for confounding variables, levels of SP-D ≥250 ng/mL were associated with increased the risk of death (HR = 8.27, 95 % CI 1.1–64.1, p = 0.043).ConclusionsOur results revealed that higher circulating levels of SP-D are associated with higher mortality risk in critically ill A/H1N1 patients. SP-D might be a predictive factor of poor outcomes in viral pneumonia.

Genetic variants of pulmonary SP-D predict disease outcome of COPD in a Chinese population.

Although surfactant protein-D (SP-D) has been suggested as a biomarker for chronic obstructive pulmonary disease (COPD), the relationship between genetic variants of SP-D and disease outcome of COPD remains unknown. We hypothesized that genetic polymorphisms of SP-D are associated with COPD-related phenotypes and disease prognosis. A hospital-based, case-controlled study was conducted prospectively. Six single nucleotide polymorphisms of the SFTPD gene were determined for genetic association analysis. Inflammatory cytokines and SP-D serum level were quantified. Frequency of exacerbation and change of lung function were assessed. All-cause 3-year mortality was registered. We studied 320 smokers (192 with COPD and 128 at-risk for COPD) who were prospectively monitored for at least 3 years. The serum levels of SP-D in COPD patients were significantly associated with the degree of airflow obstruction and frequency of exacerbation. Haplotype association analysis revealed that haplotype G-G-C-C-A was associated with lower risk of COPD (P = 0.03) in our study population. COPD patients with haplotype G-G-C-C-A had lower serum SP-D levels (P < 0.001), higher rates of positive response to bronchodilator treatment (P = 0.01), more improvement of forced expiratory volume in 1 s in yearly follow-up (P = 0.03) and better 3-year survival rate than COPD patients with non G-G-C-C-A haplotype (P = 0.03). Genetic haplotype of SP-D may serve as a valuable prognostic indicator in Chinese patients with COPD.

Etiopathogenic role of surfactant protein d in the clinical and immunological expression of primary Sjögren syndrome.

To analyze the etiopathogenic role of genetic polymorphisms and serum levels of surfactant protein-D (SP-D) in primary Sjögren syndrome (pSS). We analyzed 210 consecutive patients with pSS. SFTPD genotyping (M11T polymorphism rs721917) was analyzed by sequence-based typing and serum SP-D by ELISA. Thirty-two patients (15%) had the Thr11/Thr11 genotype, 80 (38%) the Met11/Met11 genotype, and 96 (46%) the Met11/Thr11 genotype; 2 patients could not be genotyped. Patients carrying the Thr11/Thr11 genotype had a higher prevalence of renal involvement (13% vs 1% and 4% in comparison with patients carrying the other genotypes, p = 0.014). Serum SP-D levels were analyzed in 119 patients (mean 733.94 ± 49.88 ng/ml). No significant association was found between serum SP-D levels and the SP-D genotypes. Higher mean values of serum SP-D were observed in patients with severe scintigraphic involvement (851.10 ± 685.69 vs 636.07 ± 315.93 ng/ml, p = 0.038), interstitial pulmonary disease (1053.60 ± 852.03 vs 700.36 ± 479.33 ng/ml, p = 0.029), renal involvement (1880.64 ± 1842.79 vs 716.42 ± 488.01 ng/ml, p = 0.002), leukopenia (899.83 ± 661.71 vs 673.13 ± 465.88 ng/ml, p = 0.038), positive anti-Ro/SS-A (927.26 ± 731.29 vs 642.75 ± 377.23 ng/ml, p = 0.006), and positive anti-La/SS-B (933.28 ± 689.63 vs 650.41 ± 428.14 ng/ml, p = 0.007), while lower mean values of serum SP-D were observed in patients with bronchiectasis (489.49 vs 788.81 ng/ml, p = 0.019). In pSS, high SP-D levels were found in patients with severe glandular involvement, hypergammaglobulinemia, leukopenia, extraglandular manifestations, and positive anti-Ro/La antibodies. The specific association between SP-D levels and pulmonary and renal involvements may have pathophysiological implications.

Surfactant Protein-D–Encoding Gene Variant Polymorphisms Are Linked to Respiratory Outcome in Premature Infants

Associations between the genetic variation within or downstream of the surfactant protein-D-encoding gene (SFTPD), which encodes the collectin surfactant protein-D (SP-D) and may lead to respiratory distress syndrome or bronchopulmonary dysplasia, recently were reported. Our aim was to investigate whether SFTPD variations affect serum SP-D levels in infants and pulmonary outcome in premature infants. Serum SP-D levels were measured in 211 mature and 202 premature infants, and 7 SFTPD single-nucleotide polymorphisms (SNPs) were genotyped. SNP analysis and haplotype analysis were used to associate genetic variation to SP-D, respiratory distress (RD), oxygen requirement, and respiratory support. The 5'-upstream SFTPD SNP rs1923534 and the 3 structural SNPs rs721917, rs2243639, and rs3088308 were associated with the SP-D level. The same SNPs were associated with RD, a requirement for supplemental oxygen, and a requirement for respiratory support. Haplotype analyses identified 3 haplotypes that included the minor alleles of rs1923534, rs721917, and rs3088308 that exhibited highly significant associations with decreased SP-D levels and decreased ORs for RD, oxygen supplementation, and respiratory support. These findings extend and validate previous observations of SFTPD association with the risk of respiratory outcomes and suggest SFTPD as an essential factor affecting pulmonary adaptation in premature infants.

Circulating surfactant protein-D as a biomarker of severity in stable chronic obstructive pulmonary diseases

Pulmonary surfactant protein D (SP-D) is considered a candidate biomarker for lung integrity and for disease progression. In the present study, we aimed to estimate the serum levels of SP-D in patients with chronic obstructive pulmonary disease (COPD) and to assess the correlation of these biomarkers with indices of COPD severity. Subjects and methodsThe study was carried out on 30 COPD male patients and 15 apparently healthy age-matched males as control. COPD patients were divided by GOLD stages into 10 patients stage I–II (group 1), and 20 patients stage III–IV (group 2). A detailed history and clinical examination, pulmonary function testing by spirometry, right ventricular function assessment by conventional echocardiography and tissue Doppler imaging were done. Serum levels of total protein and albumin were determined as well as serum SP-D by enzyme-linked immunosorbent assay in both patient and control groups was determined. ResultsThe serum level of SP-D was significantly higher in COPD patients than controls (P<0.001). Also, these biomarkers were significantly higher in stages III and IV (group 2) compared to stages I and II (group 2) (P<0.01). SP-D was significantly negatively correlated with serum albumin (P<0.01) and FEV1 (P<0.05) and not correlated with any of right ventricular function indices measured by echocardiography. ConclusionSP-D is a promising biomarker for severity in stable COPD patient. The low serum albumin could contribute to elevated serum SPD with deteriorated lung functions in stable COPD patient.

Treatment of acute respiratory distress syndrome with allogeneic adipose-derived mesenchymal stem cells: a randomized, placebo-controlled pilot study

BackgroundRecent studies have demonstrated that mesenchymal stem cells (MSCs) modulate the immune response and reduce lung injury in animal models. Currently, no clinical studies of the effects of MSCs in acute respiratory distress syndrome (ARDS) exist. The objectives of this study were first to examine the possible adverse events after systemic administration of allogeneic adipose-derived MSCs in ARDS patients and second to determine potential efficacy of MSCs on ARDS.MethodsTwelve adult patients meeting the Berlin definition of acute respiratory distress syndrome with a PaO2/FiO2 ratio of < 200 were randomized to receive allogeneic adipose-derived MSCs or placebo in a 1:1 fashion. Patients received one intravenous dose of 1 × 106 cells/kg of body weight or saline. Possible side effects were monitored after treatment. Acute lung injury biomarkers, including IL-6, IL-8 and surfactant protein D (SP-D), were examined to determine the effects of MSCs on lung injury and inflammation.ResultsThere were no infusion toxicities or serious adverse events related to MSCs administration and there were no significant differences in the overall number of adverse events between the two groups. Length of hospital stay, ventilator-free days and ICU-free days at day 28 after treatment were similar. There were no changes in biomarkers examined in the placebo group. In the MSCs group, serum SP-D levels at day 5 were significantly lower than those at day 0 (p = 0.027) while the changes in IL-8 levels were not significant. The IL-6 levels at day 5 showed a trend towards lower levels as compared with day 0, but this trend was not statistically significant (p = 0.06).ConclusionsAdministration of allogeneic adipose-derived MSCs appears to be safe and feasible in the treatment of ARDS. However, the clinical effect with the doses of MSCs used is weak, and further optimization of this strategy will probably be required to reach the goal of reduced alveolar epithelial injury in ARDS.Trial registrationClinical trials.gov, NCT01902082

Genetic Polymorphisms of Surfactant Protein D rs2243639, Interleukin (IL)-1β rs16944 and IL-1RN rs2234663 in Chronic Obstructive Pulmonary Disease, Healthy Smokers, and Non-Smokers

Chronic obstructive pulmonary disease (COPD) is a complex chronic inflammatory disease that involves the activity of various inflammatory cells and mediators. It has been suggested that susceptibility to COPD is, at least in part, genetically determined. The primary aim of this study was to investigate the association between surfactant protein D (SFTPD) rs2243639, interleukin (IL)-1β rs16944 and IL-1 receptor antagonist (IL-1RN) rs2234663 gene polymorphisms and COPD susceptibility, as well as examining the association between the various IL-1RN/IL-1β haplotypes and pulmonary function tests (PFT). Secondly, we aimed to examine the influence of SFTPD rs2243639 polymorphism on serum surfactant protein D (SP-D) level. A total of 114 subjects were recruited in this study and divided into three groups: 63 COPD patients, 25 asymptomatic smokers, and 26 healthy controls. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed for the detection of SFTPD rs2243639 and IL-1β rs16944 polymorphisms. Detection of variable numbers of an 86-bp tandem repeat (VNTR) of IL-1RN was done using PCR. Serum SP-D level was measured using enzyme linked-immunosorbent assay. PFTs were measured by spirometry. Carriers of the SFTPD AG and AA polymorphic genotypes constituted 71.4% of COPD patients versus 48% in asymptomatic smokers, with a statistically significant difference between the two groups (p=0.049). Smokers who were carriers of the polymorphic SFTPD rs2243639 A allele (AG and AA genotypes) have a 2.708 times risk of developing COPD when compared with wild-type GG genotype carriers [odds ratio (OR) 2.708 (95% CI 1.041-7.047)]. Forced expiratory flow (FEF) 25-75% predicted was higher in IL-1RN*1/*1 when compared with *1/*2 (p=0.013). FEF25-75% predicted in carriers of haplotype IL-1RN *1/IL-1β T (49.21±10.26) was statistically significantly higher than in carriers of IL-1RN *2/IL-1β T (39.67±12.64) [p=0.005]. Forced expiratory volume in 1s (FEV1)/forced vital capacity (FVC) in carriers of haplotype IL-1RN *1/IL-1β T (64.09±6.39) was statistically significantly higher than in carriers of IL-1RN *2/IL-1βT (59.44±7.71) [p=0.048]. There was no association between SFTPD rs2243639 genotypes and serum SP-D level. Smokers who are carriers of the SFTPD AG and AA polymorphic genotypes may be at a higher risk of developing COPD when compared with wild-type GG genotype carriers. IL-1RN rs2234663/IL-1β rs16944 haplotypes influence FEF25-75% predicted and FEV1/FVC. SFTPD rs2243639 polymorphism did not influence serum SP-D levels in our group of recruited subjects.

Surfactant Protein D in Chornic Obstructive Pulmonary Disease (COPD)

In the recent years, a large number of potential biomarkers for Chronic Obstructive Pulmonary Disease (COPD) have been described. One of the important biomarkers is Surfactant Protein D (SPD) since serum SPD levels have been associated with lung function or health status in patients with severe COPD. Several interesting evidences of the protein and gene polymorphisms have been described. The present review highlights the current literature, recent patents and, future prospects of this important collection.

The effectiveness of the serum surfactant protein D (Sp-D) level to indicate lung injury in pulmonary embolism.

Surfactant protein D (SP-D) is a biomarker specific to the lungs. Our aim was to investigate the relationship between clinical probability scores and the serum levels of SP-D to indicate the severity of lung injury that develops secondary to hypoxia in pulmonary embolism (PE). We included three groups in the study: non-massive PE (n = 20), sub-massive PE (n = 20), and the control group (n = 20), which consisted of healthy volunteers. The modified Geneva and Wells clinical probability scoring systems were performed for PE, and the patients were classified as low risk, moderate risk, and high risk. SP-D levels were determined by the enzyme-linked immunosorbent assay. For risk factors, the most significant were deep vein thrombosis (DVT) and immobilization. There was no significant difference in SP-D levels between the patients identified with risk factors and those without risk factors in either the Geneva or Wells scores. Atelectasis was the most common radiographic finding, while tricuspid valve regurgitation was predominant in echocardiography. There was no significant difference between the non-massive PE group and the control group, while SP-D levels of the sub-massive group were significantly higher than the control group. In our study, SP-D levels were significantly higher in the sub-massive PE group overall. However, further prospective studies are required with a larger number of cases, including patients with massive PE, in order to clarify the findings.

Marked increase in serum KL-6 and surfactant protein D levels during the first 4 weeks after treatment predicts poor prognosis in patients with active interstitial pneumonia associated with polymyositis/dermatomyositis

Objective The aim of this study is to determine whether serum KL-6 and surfactant protein D (SP-D) levels predict the prognosis of patients with interstitial pneumonia (IP) in cases of polymyositis (PM) and dermatomyositis (DM).Patients and methods Fifty consecutive patients with PM (n = 17) or DM (n = 33) and active IP, 6 of whom died of respiratory failure, were enrolled in this study. Serum KL-6 and SP-D levels were measured every 2–4 weeks. Medical records were reviewed retrospectively. Univariate analyses and multivariate analyses with a logistic regression model were conducted.Results Serum KL-6 and SP-D levels were elevated in patients with active IP. At the time of diagnosis of active IP, the serum KL-6 level was within the normal range in 28 % of patients and the SP-D level was within the normal range in 46 % of patients. Serum KL-6 level increased up to 3 months after starting treatment and then decreased gradually to baseline, whereas SP-D level peaked within the first 4 weeks after treatment and decreased rapidly to normal levels. Patients with poor prognosis showed increases in KL-6 and SP-D levels during the first 4 weeks after treatment, which was confirmed by uni- and multivariate analyses. Comparing the marker levels at 2–4 weeks after treatment with those at 0 weeks, an increase in the ratio over 1.70 for KL-6 and over 1.75 for SP-D, and an increase in KL-6 over 850 U/ml during the first 4 weeks after treatment, were poor prognostic factors.Conclusions Increases in serum KL-6 and SP-D levels during the first 4 weeks after starting therapy, but not their levels at any one time point, predict poor prognosis in patients with PM/DM. When marked increases of KL-6 and SP-D levels during the first 4 weeks are found or are predicted by serial measurement of the markers, patients have risks of poor prognosis and additional therapy should be considered.

Value of serum and induced sputum surfactant protein-D in chronic obstructive pulmonary disease

Background: Surfactant Protein D (SP-D) is an important marker in chronic obstructive pulmonary disease (COPD). Serum SP-D levels increase while lung production of SP-D decreases in COPD. SP-D is a specific biomarker for monitoring COPD, assessment of exacerbation frequency and arrangement of treatment modalities. In the present study, we aimed to investigate the correlation between serum and induced sputum SP-D levels with severity and acute exacerbations of COPD. Method: 20 healthy subjects, older than 40 years, with at least 10 pack/years smoking history (group 1), 20 stage I-II COPD patients (group 2) , and 20 stage III-IV COPD patients (group 3) were enrolled in the study. All subjects performed pulmonary function tests. Venous blood samples were taken to determine complete blood count, C-reactive protein(CRP) and serum SP-D levels. Induced sputum samples were obtained to determine SP-D level. COPD patients were followed up for acute exacerbations for 6 months. Results: Serum SP-D levels of group 3 were the highest and induced sputum SP-D levels of group 2 were the lowest among the three groups. SP-D levels of induced sputum decreased in patients with increasing number of cigarette pack/years (p = 0.03, r = −0.115), whereas serum SP-D levels increased in these patients (p = 0.0001, r = 0.6 ). Induced sputum SP-D levels in COPD patients receiving inhaled corticosteroid treatment were significantly higher than in patients who were not receiving inhaler corticosteroid treatment (p = 0.005). An inverse correlation between serum SP-D levels and FEV1 (%) was found and there was a positive correlation between the serum SP-D levels and exacerbations frequency in 6-month follow up period (p = 0.049 ,r = −0.252; p = 0.0001, r = 0.598 respectively). Conclusion: Our study demonstrates the adverse effects of smoking on local SP-D levels since low levels of induced sputum SP-D were found in the group of current smokers, who were not receiving inhaled corticosteroid treatment. Relationship between serum SP-D and COPD exacerbations frequency suggests that serum SP-D level may be used as a lung-specific biomarker during the follow up and progression of COPD.

Serum surfactant protein D is associated with the prognosis in patients with chronic kidney disease

Circulating surfactant protein D (SP-D) has been proved to be associated with cardiovascular disease and total mortality in European patients with coronary artery disease (CAD). This study was to determine whether serum SP-D levels are associated with 1-year prognosis in patients with chronic kidney disease (CKD) in a Chinese population. Serum SP-D levels were examined by ELISA kit in 264 patients undergoing coronary angiography. An estimated glomerular filtration rate (eGFR) was used to determine the presence of CKD. Gensini scores were calculated to reflect the severity of coronary lesions. The correlations between SP-D, Gensini scores, white blood cells, high-sensitivity C-reactive protein (hs-CRP) and eGFR were calculated. Patients with eGFR less than 60 ml/min per 1.73 m2 were followed up for an average of 14 months, and major adverse cardiac events (MACEs) were recorded and analyzed. Patients with CKD compared with patients without CKD were more often men, with a higher prevalence of hypertension, CAD, average age, levels of fasting glucose, hs-CRP and SP-D (179.73 ± 72.80 versus 131.65 ± 94.29 ng/ml; all P < 0.05). Serum SP-D levels were positively correlated with Gensini scores and eGFR, but not with white blood cells or hs-CRP. CKD patients suffering from MACEs had higher levels of serum SP-D (217.02 ± 102.34 versus 172.26 ± 70.27 ng/ml) and patients with SP-D at least 200 ng/ml had higher risk of MACEs (all P < 0.05). Multivariable analysis showed that smoking, multivessel disease, CKD and SP-D (OR: 1.396, 95% CI: 1.058-2.718, P = 0.028) were associated with 1-year MACEs (all P < 0.05). SP-D levels are associated with 1-year prognosis in patients with CKD.