Protein abnormalities in adult respiratory distress syndrome, tuberculosis, and cystic fibrosis sera

A Prospective Cohort Study of Bioavailable 25-Hydroxyvitamin D Levels as a Marker of Vitamin D Status in Nontuberculous Mycobacterial Pulmonary Disease

Research on vitamin D in patients with nontuberculous mycobacterial (NTM) pulmonary disease (PD) is limited. We aimed to compare the vitamin D parameters of patients with NTM-PD to those of a healthy control group, and to assess the possible predictive markers for a clinical response. We prospectively enrolled 53 patients with NTM-PD between January 2014 and December 2016. The clinical data and vitamin D indices, including total, free, bioavailable 25-(OH)D, and vitamin D binding protein (VDBP) genotyping, were measured at baseline and six months after enrollment. An external dataset of 226 healthy controls was compared with the NTM-PD group. The mean age of subjects was 53 years; 54.5% were male. The NTM-PD group was older, predominantly female, and had a lower body mass index (BMI) than the controls. The proportion of patients with vitamin D concentration <50 nmol/L was 52.8% in the NTM-PD group and 54.9% in the control group (p = 0.789). The bioavailable 25-(OH)D concentrations of the NTM-PD group and the controls were similar (6.9 nmol/L vs. 7.6 nmol/L, p = 0.280). In the multivariable analysis, bioavailable 25-(OH)D concentrations were associated with NTM-PD, adjusting for age, sex, BMI, and VDBP levels. Bioavailable 25-(OH)D concentrations were significantly associated with susceptibility to NTM-PD, but not with treatment outcomes. Lower bioavailable 25-(OH)D might be a risk factor for NTM-PD.

Vitamin D-binding protein is inversely associated with the incidence of gastrointestinal and ear infections in school-age children

Circulating 25-hydroxy vitamin D (25(OH)D) is related to decreased rates of gastrointestinal and ear infections in school-age children. Vitamin D-binding protein (DBP) transports 25(OH)D and exerts immunological functions; however, it is unknown whether DBP is associated with infectious morbidity in children. We quantified plasma DBP concentrations in 540 school-age children at the time of recruitment into a cohort study in Bogotá, Colombia and obtained daily information on infectious morbidity symptoms and doctor visits during the school year. We compared the incidence rates of gastrointestinal and respiratory symptoms across quartiles of DBP concentration by estimating adjusted incidence rate ratios (IRRs) with 95% confidence interval (CI). We also estimated the per cent of the associations between DBP and morbidity that were mediated through 25(OH)D using a counterfactual frame. Mean ± s.d. DBP concentration was 2650 ± 1145 nmol/l. DBP was inversely associated with the rates of diarrhoea with vomiting (IRR for quartiles 2-4 vs. 1 = 0.48; 95% CI 0.25-0.92; P = 0.03) and earache/ear discharge with fever (IRR for quartiles 2-4 vs. 1 = 0.29; 95% CI 0.12-0.71; P = 0.006). The DBP-morbidity associations were not mediated through 25(OH)D. We conclude that plasma DBP predicts lower incidence of gastrointestinal and ear infections in school-age children independent of 25(OH)D.

Vitamin D treatment modulates immune activation in cystic fibrosis

Persistent inflammatory response in cystic fibrosis (CF) airways is believed to play a central role in the progression of lung damage. Anti-inflammatory treatment may slow lung disease progression, but adverse side effects have limited its use. Vitamin D has immunoregulatory properties. We randomized 16 CF patients to receive vitamin D2, vitamin D3 or to serve as controls, and investigated the effect of vitamin D supplementation on soluble immunological parameters, myeloid dendritic cells (mDCs) and T cell activation. Three months of vitamin D treatment were followed by two washout months. Vitamin D status at baseline was correlated negatively with haptoglobin, erythrocyte sedimentation rate and immunoglobulin A concentration. Total vitamin D dose per kg bodyweight correlated with the down-modulation of the co-stimulatory receptor CD86 on mDCs. Vitamin D treatment was associated with reduced CD279 (PD-1) expression on CD4⁺ and CD8⁺ T cells, as well as decreased frequency of CD8⁺ T cells co-expressing the activation markers CD38 and human leucocyte antigen D-related (HLA-DR) in a dose-dependent manner. There was a trend towards decreased mucosal-associated invariant T cells (MAIT) cell frequency in patients receiving vitamin D and free serum 25-hydroxyvitamin D (free-s25OHD) correlated positively with CD38 expression by these cells. At the end of intervention, the change in free-s25OHD was correlated negatively with the change in CD279 (PD-1) expression on MAIT cells. Collectively, these data indicate that vitamin D has robust pleiotropic immunomodulatory effects in CF. Larger studies are needed to explore the immunomodulatory treatment potential of vitamin D in CF in more detail.

Hypogammaglobulinemia in Pediatric ICU Patients

The authors retrospectively review their experience with low immunoglobulin G (IgG) levels in a pediatric ICU population over a 12-month period. The total IgG level was below the normal for age in 14 of the 20 patients. The 14 patients with a low IgG level were younger and weighed less when compared with the 6 patients who had a normal IgG level. There was no difference in the risk of mortality between the 2 groups. In the 14 patients with an IgG level less than normal for age, the IgG level was 33% to 99% of normal, with 4 patients having a level less than 50% of normal for their age. Prospective trials are needed to determine the incidence of this problem, its impact on survival, and the appropriate therapy in the pediatric ICU population.

Proteomic profiling of serum from patients with tuberculosis

Background

Effective treatment and monitoring of tuberculosis (TB) requires biomarkers that can be easily evaluated in blood samples. The aim of this study was to analyze the serum proteome of patients with TB and to identify protein biomarkers for TB.

Methods

Serum samples from 26 TB patients and 31 controls were analyzed by using nano-flow ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry in data-independent mode, and protein and peptide amounts were calculated by using a label-free quantitative approach. The generated data were analyzed by using principal component analysis and partial least squares discriminant analysis, a multivariate statistical method.

Results

Of more than 500 proteins identified, alpha-1-antitrypsin was the most discriminative, which was 4.4 times higher in TB patients than in controls. Peptides from alpha-1-antitrypsin and antithrombin III increased in TB patients and showed a high variable importance in the projection scores and coefficient in partial least square discriminant analysis.

Conclusions

Sera from patients with TB had higher alpha-1-antitrypsin levels than sera from control participants. Alpha-1-antitrypsin levels may aid in the diagnosis of TB.

Vitamin d-binding protein levels in plasma and gingival crevicular fluid of patients with generalized aggressive periodontitis

Vitamin D-binding protein (DBP) is the main transport protein of vitamin D and plays an important role in the immune system and host defenses. The purpose of this study was to measure DBP levels in plasma and gingival crevicular fluid (GCF) of patients with generalized aggressive periodontitis (GAgP), in comparison to healthy controls, with the goal of elucidating the relationship between DBP and GAgP. Fifty-nine GAgP patients and 58 healthy controls were recruited for the study; clinical parameters of probing depths (PD), bleeding index, and attachment loss (AL) were recorded. DBP levels were measured by enzyme-linked immunosorbent assay. From the results, GAgP patients had higher plasma DBP concentrations (P < 0.001) but lower GCF DBP concentrations (P < 0.001) than healthy controls. In GAgP group, after controlling the potential confounders of age, gender, smoking status, and BMI index, GCF DBP concentrations correlated negatively with PD (P < 0.001) and AL (P = 0.009). Within the limits of the study, we concluded that decreased GCF DBP level and increased plasma DBP level are associated with periodontitis.

Vitamin D binding protein: a multifunctional protein of clinical importance

Since the discovery of group-specific component and its polymorphism by Hirschfeld in 1959, research has put spotlight on this multifunctional transport protein (vitamin D binding protein, DBP). Besides the transport of vitamin D metabolites, DBP is a plasma glycoprotein with many important functions, including sequestration of actin, modulation of immune and inflammatory responses, binding of fatty acids, and control of bone development. A considerable DBP polymorphism has been described with a specific allele distribution in different geographic area. Multiple studies have shed light on the interesting relationship between polymorphisms of the DBP gene and the susceptibility to diseases. In this review, we give an overview of the multifunctional character of DBP and describe the clinical importance of DBP and its polymorphisms. Finally, we discuss the possibilities to use DBP as a novel therapeutic agent.

Beneficial role of vitamin D3 in the prevention of certain respiratory diseases

There is evidence of aberrations in the vitamin D-endocrine system in subjects with respiratory diseases. Vitamin D deficiency is highly prevalent in patients with respiratory diseases, and patients who receive vitamin D have significantly larger improvements in inspiratory muscle strength and maximal oxygen uptake. Studies have provided an opportunity to determine which proteins link vitamin D to respiratory pathology, including the major histocompatibility complex class II molecules, vitamin D receptor, vitamin D-binding protein, chromosome P450, Toll-like receptors, poly(ADP-ribose) polymerase-1, and the reduced form of nicotinamide adenine dinucleotide phosphate. Vitamin D also exerts its effect on respiratory diseases through cell signaling mechanisms, including matrix metalloproteinases, mitogen-activated protein kinase pathways, the Wnt/β-catenin signaling pathway, prostaglandins, reactive oxygen species, and nitric oxide synthase. In conclusion, vitamin D plays a significant role in respiratory diseases. The best form of vitamin D for use in the treatment of respiratory diseases is calcitriol because it is the active metabolite of vitamin D3 and modulates inflammatory cytokine expression. Further investigation of calcitriol in respiratory diseases is needed.

Inflammatory biomarker profile in children with cystic fibrosis: preliminary study

The aim of this preliminary study was to determine specific proteins, related to inflammation process and nutritional status as well as to total antioxidant capacity, in children suffering from cystic fibrosis (CF). The study was performed on 17 nonhospitalized children (12 boys and 5 girls) with CF aged 3 months to 10 years, who were assisted at the Nutrition Service from Pedro de Elizalde Hospital. Transferrin, transthyretin, ceruloplasmin (Cp), haptoglobin, C-reactive protein (CRP) and fibrinogen were measured by single radial immunodiffusion techniques. Total antioxidant capacity (TAC) was determined by a decolorization assay. Statistical analyses were performed by the Student's t test. Transferrin and transthyretin values were lower in CF patients in comparison with data obtained from healthy children (reference group, RG). The decreased transferrin concentration and the tendency towards low plasma transthyretin values suggested an abnormal nutritional status. However, higher Cp and haptoglobin levels were shown in patients than in RG. The fact that 23 and 50% of patients exceeded the desirable values for fibrinogen (<285·0 mg/dl) and CRP (<0·2 mg/dl), respectively, should be highlighted. The TAC (mM; Trolox equivalents) was shown to be lower in the CF group than in RG. The diminished TAC concomitant with an increased plasma Cp concentration would exacerbate the inflammatory status and could explain the depression of the immune system. These preliminary results could explain the need to include biochemical and functional parameters in the early nutritional status evaluation in CF patients in order to use appropriate nutritional and pharmacological therapies and consequently to improve their survival and quality of life.

Alterations in the human lung proteome with lipopolysaccharide

Background

Recombinant human activated protein C (rhAPC) is associated with improved survival in high-risk patients with severe sepsis; however, the effects of both lipopolysaccharide (LPS) and rhAPC on the bronchoalveolar lavage fluid (BALF) proteome are unknown.

Methods

Using differential in gel electrophoresis (DIGE) we identified changes in the BALF proteome from 10 healthy volunteers given intrapulmonary LPS in one lobe and saline in another lobe. Subjects were randomized to pretreatment with saline or rhAPC.

Results

An average of 255 protein spots were detected in each proteome. We found 31 spots corresponding to 8 proteins that displayed abundance increased or decreased at least 2-fold after LPS. Proteins that decreased after LPS included surfactant protein A, immunoglobulin J chain, fibrinogen-γ, α₁-antitrypsin, immunoglobulin, and α₂-HS-glycoprotein. Haptoglobin increased after LPS-treatment. Treatment with rhAPC was associated with a larger relative decrease in immunoglobulin J chain, fibrinogen-γ, α₁-antitrypsin, and α₂-HS-glycoprotein.

Conclusion

Intrapulmonary LPS was associated with specific protein changes suggesting that the lung response to LPS is more than just a loss of integrity in the alveolar epithelial barrier; however, pretreatment with rhAPC resulted in minor changes in relative BALF protein abundance consistent with its lack of affect in ALI and milder forms of sepsis.

Usefulness of serum IgG4 in the diagnosis and follow up of autoimmune pancreatitis: A systematic literature review and meta-analysis

High circulating serum immunoglobulin G4 (IgG4) levels have been proposed as a marker of autoimmune pancreatitis (AIP). The aim of the present study was to review the data existing in the English literature on the usefulness of the IgG4 serum levels in the diagnosis and follow up of patients with AIP. A total of 159 patients with AIP and 1099 controls were described in seven selected papers reporting the usefulness of serum IgG4 in diagnosing AIP. In total, 304 controls had pancreatic cancer, 96 had autoimmune diseases, and the remaining 699 had other conditions. The summary receiver-operating characteristic curve analysis was carried out by means of Meta-DiSc open-access software. Serum IgG4 showed good accuracy in distinguishing between AIP and the overall controls, pancreatic cancer and other autoimmune diseases (area under the curve [+/- SE]: 0.920 +/- 0.073, 0.914 +/- 0.191, and 0.949 +/- 0.024, respectively). The studies analyzed showed significantly heterogeneous specificity values in each of the three analyses performed. The analysis of the four studies comparing AIP and pancreatic cancers also showed significantly heterogeneous values of sensitivities and odds ratios. Regarding the usefulness of IgG4 as a marker of efficacy of steroid treatment, a decrease in the serum concentrations of IgG4 was found in the four available studies. The serum IgG4 subclass is a good marker of AIP, and its determination should be included in the diagnostic workup of this disease. However, the heterogeneity of the studies published until now means that more studies are necessary in order to better evaluate the true accuracy of IgG4 in discriminating AIP versus other autoimmune diseases.

Proteomic analysis of pericardial effusion: Characteristics of tuberculosis-related proteins

The aim of this study has been designed to identify the tuberculosis (TB)-related proteins in pericardial effusion by proteomic approaches. TB is one of the major infectious diseases causing pericardial effusion. This study details protein profiles in pericardial effusion from three TB patients and three heart failure patients. Pericardial effusions were analyzed using 2-DE combined with the nano-HPLC-ESI-MS/MS. Eleven protein spots with differential expression in pericardial effusion were identified between the two groups of TB and heart failure patients (the control group). Seven protein spots were upregulated and four were downregulated. The composition of the pericardial effusion proteome may reflect the pathophysiological conditions affecting the progression of tuberculous pericarditis. The proteins in the tuberculous pericardial effusion with differential expression may serve as new and direct indicators of drug treatment. A possible conclusion is indicated that fibrinogen may play an important role for fibrin assembly in tuberculous pericardial effusion.

Plasminogen activator inhibitor-1 is an inhibitor of factor VII-activating protease in patients with acute respiratory distress syndrome

Factor VII-activating protease (FSAP) is a novel plasma-derived serine protease structurally homologous to tissue-type and urokinase-type plasminogen activators. We demonstrate that plasminogen activator inhibitor-1 (PAI-1), the predominant inhibitor of tissue-type and urokinase-type plasminogen activators in plasma and tissues, is an inhibitor of FSAP as well. We detected PAI-1·FSAP complexes in addition to high levels of extracellular RNA, an important FSAP cofactor, in bronchoalveolar lavage fluids from patients with acute respiratory distress syndrome. Hydrolytic activity of FSAP was inhibited by PAI-1 with a second-order inhibition rate constant (K_a) of 3.38 ± 1.12 × 10⁵m^–1·s^–1. Residue Arg³⁴⁶ was a critical recognition element on PAI-1 for interaction with FSAP. RNA, but not DNA, fragments (>400 nucleotides in length) dramatically enhanced the reactivity of PAI-1 with FSAP, and 4 μg·ml^–1 RNA increased the K_a to 1.61 ± 0.94 × 10⁶m^–1·s^–1. RNA also stabilized the active conformation of PAI-1, increasing the half-life for spontaneous conversion of active to latent PAI-1 from 48.4 ± 8 min to 114.6 ± 5 min. In contrast, little effect of DNA on PAI-1 stability was apparent. Residues Arg⁷⁶ and Lys⁸⁰ in PAI-1 were key elements mediating binding of nucleic acids to PAI-1. FSAP-driven inhibition of vascular smooth muscle cell proliferation was antagonized by PAI-1, suggesting functional consequences for the FSAP-PAI-1 interaction. These data indicate that extracellular RNA and PAI-1 can regulate FSAP activity, thereby playing a potentially important role in hemostasis and cell functions under various pathophysiological conditions, such as acute respiratory distress syndrome.

Proteomic analysis of pulmonary edema fluid and plasma in patients with acute lung injury

Proteomics is the large-scale analysis of protein profiles. This approach has not yet been reported in the study of acute lung injury (ALI). This study details protein profiles in plasma and pulmonary edema fluid (EF) from 16 ALI patients and plasma and bronchoalveolar lavage fluid (BALF) from 12 normal subjects. More than 300 distinct protein spots were evident in the EF and BALF of both normal subjects and ALI patients. Of these, 158 were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. In the plasma and EF protein profile of ALI patients, there were multiple qualitative changes. For instance, in all normal subjects, but in only one of the ALI patients, seven distinct surfactant protein A isoforms were evident. Nearly all ALI patients also had protein spots that indicate truncation or other posttranslational modifications. Several of these novel changes could serve as new biomarkers of lung injury.

Preparation and properties of a therapeutic inter-alpha-trypsin inhibitor concentrate from human plasma

Inter-alpha-trypsin inhibitor (ITI) is a serine protease inhibitor found in human plasma. Its antiprotease activity is due to bikunin which is effective in various types of experimental shock and pancreatitis. Therefore ITI, which releases bikunin by proteolytic cleavage, could be of therapeutic interest. A method for the large-scale isolation of ITI from human plasma is described. ITI was purified from the prothrombin complex concentrate (PCC) by diethylaminoethyl-Sepharose fast-flow chromatography followed by a chromatographic step on immobilized heparin designed to remove C4, factor X and protein C. With this procedure, which was performed under mild conditions, a homogeneous preparation of native ITI was obtained, as demonstrated by electrophoretic and chromatographic analyses. ITI maintained its biological activity, as exhibited by its specific antitryptic activity of 420 +/- 65 IU/g. In order to decrease or eliminate the risk of transmission of viral disease due to lipid-enveloped viruses, the process incorporated a solvent-detergent treatment. Animal studies on the final product revealed no adverse side-effects in terms of toxicity, thrombogenicity or hypotension. This preparation appears suitable for therapeutic evaluation in animal experimental models.

Concentration of twelve plasma proteins at birth in very low birthweight and in term infants

Plasma samples obtained at birth from 70 very low birth weight (VLBW) infants (gestational age 24 to 34 weeks) and from 20 term infants were analysed for concentrations of 12 different proteins. The plasma concentrations of albumin, transthyretin (TTR), retinol-binding protein (RBP), vitamin D-binding protein, apolipoprotein A I, fibronectin, orosomucoid and alpha 1-antichymotrypsin were significantly lower in the VLBW infants than in the term infants, whereas the values of alpha-fetoprotein (AFP) were significantly higher in the VLBW infants. No differences were found between the two groups for apolipoprotein A II, apolipoprotein B and transferrin. Birth asphyxia and sex had no influence on the measured plasma protein concentrations. The plasma concentrations of apolipoprotein A I and A II were significantly lower in small-for-gestational age (SGA), VLBW infants compared with appropriate-for-gestational age (AGA), VLBW infants. Possible acute inflammation (defined as raised concentrations of orosomucoid or alpha 1-antichymotrypsin) was associated with significantly higher values of vitamin D-binding protein in both VLBW and term infants, suggesting that this protein may act as an acute phase protein in newborn infants.

Functional similarities of hepatic cystic and biliary epithelium: studies of fluid constituents and in vivo secretion in response to secretin

Hepatic cysts are a frequent manifestation of autosomal dominant polycystic kidney disease, but little is known about their functional characteristics. The goals of our study were to define the composition of hepatic cyst fluid and to determine whether hepatic cysts secrete in response to intravenously administered secretin. We percutaneously punctured five hepatic cysts and one proximal renal cyst from six subjects with autosomal dominant polycystic kidney disease and one solitary hepatic cyst from a subject without autosomal dominant polycystic kidney disease. Most fluids had an electrolyte composition similar to serum. Fluid from all hepatic cysts had glutamyltranspeptidase concentrations above those found in serum [( cyst]/[serum] = 4.93 +/- 5.92), contained secretory component (the epithelial receptor for polymeric IgA) and had glucose concentrations less than 15 mg/dl. Fluid from both hepatic and renal cysts of subjects with autosomal dominant polycystic kidney disease, but not from the subject with the solitary hepatic cyst, demonstrated extensive changes in the electrophoretic mobility of several serum proteins. Initial intracystic pressures ranged from 16 to 40 cm H2O, were reduced 57% to 97% after aspiration of a portion of cyst fluid and were held constant during the secretion study. Within 8 min of the intravenous administration of secretin, secretion of fluid increased in two of three hepatic cysts and in the renal cyst. The electrolyte composition of cyst fluids was not altered by secretin. These data suggest that hepatic cystic epithelium has functional characteristics of biliary epithelium and that secretion by both hepatic and renal cysts may be hormonally regulated.