Characterization of the PF-ILD phenotype in patients with advanced pulmonary sarcoidosis.

BACKGROUND: Advanced pulmonary sarcoidosis causes significant morbidity and can lead to death. Large trials demonstrated efficacy of antifibrotics in patients with progressive fibrosing interstitial lung diseases (PF-ILD), including a few with sarcoidosis. To date, little is known about this progressive fibrosing phenotype in sarcoidosis. Diffusion capacity of carbon monoxide (DLCO) may be a useful functional marker to screen for advanced pulmonary sarcoidosis. In this study, we describe a cohort with advanced pulmonary sarcoidosis and we gain insights in the progressive fibrosing phenotype in sarcoidosis. METHODS: Patients with sarcoidosis and a DLCO < 50% predicted were included in this retrospective cohort study. First measurement of DLCO < 50% predicted was the baseline. Lung function data, HRCT, pulmonary hypertension (PH) and mortality were collected. Patients with > 10% fibrosis on HRCT meeting the criteria for ILD-progression within 24 months were labelled as PF-ILD. With Cox-regression analysis predictors of mortality were established. RESULTS: 106 patients with a DLCO < 50% predicted were included. Evolution of forced vital capacity (FVC) varied widely between patients from - 34% to + 45% after 2 years follow-up, whereas change in DLCO varied between - 11% and + 26%. Fourteen patients (15%) met the PF-ILD criteria, of whom 6 (43%) died within 10 years versus 10 (13%) in the non PF-ILD group (p = 0.006). PH was present 12 (11%), 56 (53%) demonstrated > 10% fibrosis on HRCT. Independent predictors of mortality and lung transplantation in the whole cohort are PH, PF-ILD and UIP-like pattern. CONCLUSION: In conclusion, within this group with advanced pulmonary sarcoidosis disease course varied widely from great functional improvement to death. PF-ILD patients had higher mortality rate than the mortality in the overall pulmonary sarcoidosis group. Future research should focus on the addition of antifibrotics in these patients. Trial registration retrospectively registered.

The detrimental effect of quantity of smoking on survival in progressive fibrosing ILD.

BACKGROUND AND OBJECTIVE: Patients with progressive fibrosing interstitial lung disease (PF-ILD) are prone to early mortality compared with other phenotypes of ILD. The possible effect of smoking on survival has not been investigated yet. Furthermore, it is unknown what the effect of quantity of smoking is in PF-ILD. In this study, it was determined if quantity of smoking is associated with worse survival in patients with PF-ILD. METHODS: Patients meeting the INBUILD trial-criteria for PF-ILD were included in this retrospective cohort study. Pack year (py) was tested as a prognostic variable with a multivariable Cox proportional hazard model. Also, median transplant-free survival was compared between heavy (≥20 pys) and mild-moderate smokers (0.1-19.9 pys). RESULTS: In PF-ILD (N = 377), the unadjusted and adjusted hazard ratio for py were significant, (1.014, 95% confidence interval (CI): 1.006-1.022, P < 0.001; 1.011, CI:1.002-1.021, P = 0.022 respectively). This translates to an 11%, 22%, or 44% higher risk for mortality for patients accumulating 10, 20 or 40 pys, respectively. Heavy smokers demonstrated a median transplant-free survival of 3.0 years, which was significantly reduced compared with mild-moderate smokers (3.8 years, P = 0.035). Additionally, more patients with emphysema were heavy smokers (N = 68) than never (N = 5, P < 0.001) or mild-moderate smokers (n = 21, p < 0.001). CONCLUSION: In PF-ILD, a pack year is associated with an increased risk of mortality. Furthermore, quantity of smoking is associated with worse survival and higher prevalence of emphysema. Our data indicates that limiting amount of pys will provide a survival benefit in patients developing PF-ILD.

Humoral Immune Status in Relation to Outcomes in Patients with Idiopathic Pulmonary Fibrosis.

PURPOSE: Idiopathic pulmonary fibrosis (IPF) is a severe fibrotic lung disease, in which inflammation is thought to only play a secondary role. Several factors associated with acute exacerbations of IPF (AE-IPF) have been identified, including infections. This study investigated whether humoral immunodeficiency or increased inflammatory markers at diagnosis were associated with AE-IPF and survival. METHODS: Four-hundred-and-nine patients diagnosed with IPF between 2011 and 2017 were retrospectively included. Immune status investigations at diagnosis included measurement of serum immunoglobulins (available in 38%), leukocyte and lymphocyte subsets in blood and bronchoalveolar lavage (BAL) fluid (available in 58%), as well as response to pneumococcal vaccination (available in 64%). RESULTS: Serum immunoglobulins or IgG subclass levels were below the lower limit of normal in 6%. The response to pneumococcal vaccination was severely impaired in 1%. Thirteen percent of patients developed an AE-IPF (4.7% per year). AE-IPF were associated with elevated lymphocytes in BAL fluid at diagnosis (p = 0.03). Higher serum IgA and IgG at diagnosis were associated with worse survival (p = 0.01; and p = 0.04), as were an increased BAL lymphocyte percentage (p = 0.005), and higher blood leukocytes and neutrophils (p = 0.01; and p = 0.0005). In a multivariate model, only BAL lymphocyte count retained statistical significance (p = 0.007). CONCLUSION: The prevalence of humoral immunodeficiencies was low in patients with IPF and not associated with AE-IPF or survival. Elevated lymphocytes in BAL were associated with the development of AE-IPF and worse survival. Higher serum immunoglobulins and immune cells in blood were also associated with worse survival. The local immune response in the lungs may be a target for future therapies.

Lung Transplantation Has a Strong Impact on the Distribution and Phenotype of Monocyte Subsets.

BACKGROUND: Lung transplantation (LTx) is a last treatment option for patients with an end-stage pulmonary disease. Chronic lung allograft dysfunction, which generally manifests as bronchiolitis obliterans syndrome (BOS), is a major long-term survival limitation. During injury, inflammation and BOS monocytes are recruited. We determined whether changes in count, subset distribution, and functionality by surface marker expression coincided with BOS development. METHODS: Fresh whole-blood samples were analyzed from 44 LTx patients, including 17 patients diagnosed with BOS, and compared with 10 age-matched healthy controls and 9 sarcoidosis patients as positive controls. Monocytes were quantified and analyzed using flow cytometry. Based on surface marker expression, classical, intermediate, and nonclassical subsets were determined, and functional phenotypes were investigated. RESULTS: The absolute count of monocytes was decreased in LTx and slightly increased in BOS patients. The relative count shifted toward classical monocytes at the expense of nonclassical monocytes in LTx and BOS. Surface marker expression was highest on intermediate monocytes. The expression of both CD36 and CD163 was significantly increased in the LTx and BOS cohort. The difference between the BOS cohort and the LTx cohort was only subtle, with a significant decrease in HLA-DR expression on nonclassical monocytes in BOS. CONCLUSIONS: Monocyte subsets and surface marker expression changed significantly in transplantation patients, while BOS-specific changes were understated. More research is needed to determine whether and how monocytes influence the disease process and how current immunosuppressants affect their normal function in vivo.

Change in Serum Biomarker CA 15-3 as an Early Predictor of Response to Treatment and Survival in Hypersensitivity Pneumonitis.

BACKGROUND: Hypersensitivity pneumonitis (HP) is an interstitial lung disease with a heterogeneous course of disease and treatment response. Cancer antigen 15-3 (CA 15-3), part of mucin 1, is believed to reflect epithelial cell injury and lung permeability and could be a potential biomarker for treatment response in HP. OBJECTIVE: To assess the value of CA 15-3 as a predictive biomarker in non-fibrotic and fibrotic HP during immunosuppressive therapy. DESIGN: Serum levels of CA 15-3 and pulmonary function tests (PFTs) were retrospectively retrieved from 48 HP patients treated with prednisone or cyclophosphamide at initiation of therapy (baseline), after 3 and 6 months. Pearson's correlation coefficient was computed to assess correlations between change in serum levels and PFT. Survival was evaluated using Kaplan-Meier curves. RESULTS: After 6 months of immunosuppressive therapy CA 15-3 levels decreased significantly compared to baseline (p = 0.001). Change in CA 15-3 after 6 months correlated with FVC change (r = - 0.469; p = 0.001). Correlations with FVC change were observed in prednisone-treated HP (r = - 0.514; p = 0.005) and fibrotic HP (r = - 0.417; p = 0.007). Three-month CA 15-3 change correlated with 6-month FVC change (r = - 0.599; p < 0.001). CA 15-3 declines of at least 7.9% after 6 months were associated with increased survival compared to minor CA 15-3 changes (HR 0.34; p = 0.020). CONCLUSION: Serum CA 15-3 correlates with PFT during 6 months of immunosuppressive therapy in HP. Interestingly, early CA 15-3 changes could predict future PFT. Furthermore, a decrease in CA 15-3 is related to longer survival. Therefore, serum CA 15-3 is a promising biomarker for implementation in HP care.

Bronchoalveolar lavage characteristics correlate with HLA tag SNPs in patients with Löfgren's syndrome and other sarcoidosis.

Genetic susceptibility for sarcoidosis and Löfgren's syndrome (LS) has been associated with prognosis. Human leukocyte antigen (HLA)-DRB1*03 is over-represented in LS, and is associated with a good prognosis, whereas HLA-DRB1*15-positive patients have a more chronic course of sarcoidosis. These HLA-DRB1 types can be easily tagged by single nucleotide polymorphisms (SNPs). Our aim was to evaluate the association between these tag SNPs and bronchoalveolar lavage (BAL) characteristics. In 29 patients, both complete HLA-DRB1* locus genotyping and SNP tagging was performed in parallel. HLA-DRB1 type was inferred from the presence of *03 tag rs2040410 allele A and referred to as *03. HLA-DRB1*15 was inferred from the presence of tag SNP rs3135388 allele A and referred to as *15. For BAL analysis, 122 patients with LS and 165 patients with non-LS sarcoidosis were included. BAL lymphocyte subsets were analyzed by flow cytometry. The presence of tag SNPs completely corresponded with HLA-DRB1*03/*15 genotypes in all 29 patients in whom both HLA-DRB1* genotyping and SNP tagging was performed. In all patients together, *03+ /*15- patients showed a higher CD4+ /CD8+ ratio than *03- /*15+ (P = 0·004) and *03- /*15- (P = 0·001). LS patients with *03+ /*15- had a lower BAL lymphocyte count compared to *03- /*15+  patients (P = 0·011). Non-LS sarcoidosis patients with *03+ /*15- patients showed a decreased CD103+ CD4+ /CD4+ ratio compared to *03- /*15+  patients (P = 0·045) and *03- /*15- patients (P = 0·018). We found that HLA-DRB1*03 and HLA-DRB1*15 can be approximated by genotyping of tag SNPs and corresponds with the degree of lymphocytosis and cell phenotypes in BAL in both LS and non-LS sarcoidosis patients.

Infliximab therapy balances regulatory T cells, tumour necrosis factor receptor 2 (TNFR2) expression and soluble TNFR2 in sarcoidosis.

Sarcoidosis is a systemic granulomatous disease of unknown aetiology that most commonly affects the lungs. Although elevated levels of regulatory T cells (Tregs ) have been reported, the extent to which they play a role in sarcoidosis pathogenesis remains unclear. Tumour necrosis factor (TNF) is thought to be one of the driving forces behind granuloma formation, illustrated by the efficacy of infliximab in severe sarcoidosis. Tregs express TNF receptor 2 (TNFR2) highly. Here, we examined the influence of infliximab therapy on Tregs and (soluble) TNFR2 levels in sarcoidosis, and correlated these with response to therapy. We observed that relative frequencies of Tregs were significantly higher in patients (n = 54) compared to healthy controls (n = 26; median 6·73 versus 4·36%; P < 0·001) and decreased following therapy (4·95; P < 0·001). Baseline TNFR2 expression on Tregs was increased significantly in patients versus controls (99·4 versus 96·2%; P = 0·031), and also in responders to therapy versus non-responders (99·6 versus 97·3%; P = 0·012). Furthermore, baseline soluble TNFR2 (sTNFR2) was higher in responders than in non-responders (mean 174 versus 107 pg/ml; P = 0·015). After treatment, responders showed a significant reduction in sTNFR2 levels in peripheral blood (-44·7 pg/ml; P < 0·001), in contrast to non-responders (+3·59 pg/ml). Our results demonstrated that Treg frequencies and TNFR2 expression on Tregs are increased in sarcoidosis, followed by a decline during infliximab therapy, suggesting a pathophysiological role of this T cell subset. Interestingly, sTNFR2 levels at baseline differed significantly between responders and non-responders, making it a potential marker in predicting which patients might benefit from infliximab.

TINF2 Gene Mutation in a Patient with Pulmonary Fibrosis.

Pulmonary fibrosis is a frequent manifestation of telomere syndromes. Telomere gene mutations are found in up to 25% and 3% of patients with familial disease and sporadic disease, respectively. The telomere gene TINF2 encodes an eponymous protein that is part of the shelterin complex, a complex involved in telomere protection and maintenance. A TINF2 gene mutation was recently reported in a family with pulmonary fibrosis. We identified a heterozygous Ser245Tyr mutation in the TINF2 gene of previously healthy female patient that presented with progressive cough due to pulmonary fibrosis as well as panhypogammaglobulinemia at age 52. Retrospective multidisciplinary evaluation classified her as a case of possible idiopathic pulmonary fibrosis. Telomere length-measurement indicated normal telomere length in the peripheral blood compartment. This is the first report of a TINF2 mutation in a patient with sporadic pulmonary fibrosis, which represents another association between TINF2 mutations and this disease. Furthermore, this case underlines the importance of telomere dysfunction and not telomere length alone in telomere syndromes and draws attention to hypogammaglobulinemia as a manifestation of telomere syndromes.

Immunoglobulin A in serum: an old acquaintance as a new prognostic biomarker in idiopathic pulmonary fibrosis.

Immunoglobulin (Ig)A is an important immunoglobulin in mucosal immunity and protects the lungs against invading pathogens. The production of IgA is regulated by transforming growth factor (TGF)-ß, a versatile cytokine and key player in the pathogenesis of pulmonary fibrosis. TGF-ß is up-regulated in patients with idiopathic pulmonary fibrosis (IPF), but difficult to use as a biomarker. The aim of this study was to evaluate the prognostic value of IgA in serum in patients with IPF. We examined IgA levels at time of diagnosis in 86 patients diagnosed with IPF. Mean serum IgA level in IPF is 3·22 g/l and regression analyses showed a significant association with mortality (hazard ratio = 1·445, P = 0·002). A significantly worse survival was found in patients with IgA serum levels > 2·85 g/l compared to patients with lower IgA serum levels (P = 0·003). These findings were confirmed in a duplication cohort. In conclusion, the level of IgA in blood is a promising prognostic marker in IPF and can be implemented easily in the hospital setting. Future studies are warranted to investigate if repeated measurements of serum IgA can further improve the performance of serum IgA as a prognostic marker.

Macrophage migration inhibitory factor (MIF) -173 polymorphism is associated with clinical erythema nodosum in Löfgren's syndrome.

INTRODUCTION: Macrophage migration inhibitory factor (MIF) has been shown to be a key regulator in innate and adaptive immune responses. A single nucleotide polymorphism in the 5' region of the MIF gene, MIF -173∗G/C, is associated with increased MIF protein production, in vivo and in vitro. Associations have been shown between the minor MIF -173C allele and sarcoidosis patients with erythema nodosum (EN). Löfgren's syndrome is an acute and usually self-remitting phenotype of sarcoidosis. It is defined as having an acute onset with bilateral hilar lymphadenopathy (BHL), fever, erythema nodosum (EN) and/or arthritis. The aim of this study was to investigate whether MIF -173G/C associates with the susceptibility to and the clinical manifestations, i.e. arthritis or EN, of Löfgren's syndrome. A total of 171 patients with Löfgren's syndrome and 313 controls were genotyped for a single nucleotide polymorphism at position -173 of the MIF gene (SNP rs755622), using a PCR and a restriction enzyme technique. RESULTS: There were no significant differences found in the MIF -173C allele frequencies between patients with Löfgren's syndrome and controls. In patients with Löfgren's syndrome with only EN, a significantly increased frequency of the C minor allele was observed compared to patients with arthritis only (p=0.0095; OR 3.08, CI: 1.28-7.39). Patients with only EN compared to patients with EN and arthritis showed a significantly increased frequency of the minor C allele (p=0.044; OR 1.97, CI: 1.01-3.85). But patients with only arthritis compared to patients with EN and arthritis did not show a significant difference in C allele frequency (p=0.270; OR 0.64, CI: 0.29-1.42). CONCLUSIONS: The MIF -173C allele is associated with erythema nodosum in Löfgren's syndrome, but not with susceptibility to sarcoidosis. This indicates a role for MIF after antigen presenting to the T cell has taken place and the sarcoid inflammatory response has begun.

YKL-40 and matrix metalloproteinases as potential biomarkers of inflammation and fibrosis in the development of bronchiolitis obliterans syndrome.

BACKGROUND AND OBJECTIVE: The development of bronchiolitis obliterans syndrome (BOS) after lung transplantation is characterized by inflammation, remodeling and fibrosis. Both YKL-40 and matrix metalloproteinase (MMP)-9 have shown to be involved in these processes. We measured serial YKL-40 and MMP-9 serum levels in lung transplant recipients and assessed their usefulness as biomarker for BOS. Furthermore, we investigate the relationship between these two potential biomarkers of BOS and MMP-7. DESIGN: Ten patients with BOS (BOS(pos)) and 10 matched patients without BOS (BOS(neg)) were included. Serial serum samples were collected after lung transplantation and prior to BOS. YKL-40, MMP-9 and MMP-7 serum levels were determined by ELISA. RESULTS: The median concentrations of YKL-40 did not differ between BOS(pos) and BOS(neg) patients (p > 0.05). The median concentration of MMP-9 in BOS(pos) patients was significantly higher than in BOS(neg) patients (p < 0.0001). For MMP-9 as possible risk factor for BOS, a cut off value of 145 ng/ml has a sensitivity of 90% and a negative predictive value of 83%. Longitudinal analysis of YKL-40 and MMP-9 serum levels from the early post-transplant period onwards did not reveal a significant trend in time in both serum levels preceding BOS. In BOS(neg) patients MMP-9 showed an inverse relationship with MMP-7, that was absent in BOS(pos) patients. CONCLUSIONS: From the moment of transplantation onwards, patients who eventually developed BOS had significantly increased MMP-9 serum levels in comparison with patients who did not develop BOS. Therefore, increased MMP-9 serum levels might be useful as risk factor for BOS.

Genetic variation in the Toll-like receptor gene cluster (TLR10-TLR1-TLR6) influences disease course in sarcoidosis.

Sarcoidosis is an inflammatory disease of unknown etiology. Various microorganisms have been proposed as etiologic agent suggesting a role for pattern-recognition receptors such as Toll-like receptors (TLRs) in disease pathogenesis, with a special interest in TLR-2. TLR-10, TLR-1, and TLR-6 act as co-receptors for TLR-2 and the genes encoding these receptors are located in a gene cluster on chromosome 4. The aim of our study was to assess differences in genetic variation in the TLR10-TLR1-TLR6 gene cluster between patients and controls. A total of eight single nucleotide polymorphisms were genotyped in 447 healthy controls and 533 patients, divided in 425 with sarcoidosis and 108 with Löfgren's syndrome. Comparison of the total patient cohort with controls showed that the allele frequencies of rs1109695, rs7658893 (TLR-10), and rs5743604 as well as rs5743594 (TLR-1) differed significantly. Haplotype analysis showed that the most common haplotype found was significantly decreased in patients with chronic sarcoidosis. Furthermore, a less common haplotype was found to be significantly increased in patients with Löfgren's syndrome as well as sarcoidosis patients with self-remitting disease, indicating that it could act as a disease modifying haplotype. In conclusion, our study suggests that absence of the common haplotype in the TLR10-TLR1-TLR6 gene cluster increases the risk of developing chronic disease in patients already affected by sarcoidosis. Based on their role as co-receptors for TLR-2, this study supports the growing evidence that aberrant TLR-2 function is important in sarcoidosis disease pathogenesis.

Genetic variability in the IL1RN gene and the balance between interleukin (IL)-1 receptor agonist and IL-1ß in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a rapidly progressive interstitial lung disease of unknown aetiology. Interleukin (IL)-1ß plays an important role in inflammation and has been associated with fibrotic remodelling. We investigated the balance between IL-1ß and IL-1 receptor antagonist (IL-1Ra) in bronchoalveolar lavage fluid (BALF) and serum as well as the influence of genetic variability in the IL1B and IL1RN gene on disease susceptibility and cytokine levels. In 77 IPF patients and 349 healthy controls, single nucleotide polymorphisms (SNPs) in the IL1RN and IL1B genes were determined. Serum and BALF IL-1Ra and IL-1ß levels were measured using a multiplex suspension bead array system and were correlated with genotypes. Both in serum and BALF a significantly decreased IL-1Ra/IL-1ß ratio was found in IPF patients compared to healthy controls. In the IL1RN gene, one SNP was associated with both the susceptibility to IPF and reduced IL-1Ra/IL-1ß ratios in BALF. Our results show that genetic variability in the IL1RN gene may play a role in the pathogenesis of IPF and that this role may be more important than thought until recently. The imbalance between IL-1Ra and IL-1ß might contribute to a proinflammatory and pro-fibrotic environment in their lungs.

Genetic variation in GREM1 is a risk factor for fibrosis in pulmonary sarcoidosis.

Sarcoidosis is a granulomatous systemic disorder most often affecting the lung. Pulmonary fibrosis develops in approximately 10%-15% of patients with sarcoidosis. The human gene GREM1 encodes gremlin, a member of the bone morphogenetic protein antagonist family. Bone morphogenetic proteins are essential for the maintenance of tissue homeostasis and regeneration after injury. We examined associations between genetic variation in GREM1 and pulmonary disease outcome in patients with pulmonary sarcoidosis. Four common tag single nucleotide polymorphisms spanning GREM1 were genotyped in 483 controls and in 237 sarcoidosis patients with radiographic data at pulmonary disease outcome, defined by chest X-ray after a minimum of 4 years follow-up. Highly significant differences were found between GREM1 genotype frequencies in sarcoidosis patients without chest X-ray abnormalities (stage 0) (n = 116) versus patients who had fibrosis on chest X-ray (stage IV) (n = 59) at pulmonary disease outcome. The most significant association was with GREM1 rs1919364. The recessive model resulted in an increased risk of fibrosis development for homozygous carriers of the C allele at GREM1 rs1919364 versus carriers of the G allele [P = 9.3 × 10⁻7, χ² = 24.1, odds ratio (OR) = 6.37 (2.89-14.1)]. This study is the first to suggest that genetic variation of GREM1 predisposes to pulmonary fibrosis in sarcoidosis patients. Carriers of the GREM1 CC genotype at position rs1919364 were at 6.4 times greater risk for developing fibrosis.

Systemic cytokine response in patients with community-acquired pneumonia.

The role of individual cytokines and polymorphisms in pneumonia has been described, but the relationship between different cytokines and polymorphisms in relation to causative microorganisms, antibiotics, corticosteroids and clinical course has not. This study questions the relationship between cytokines, polymorphisms and clinical characteristics of pneumonia. Patients diagnosed with pneumonia were included in the study. Serum cytokine levels were measured during hospital stay, genotyping was performed, causative microorganisms were identified and patients were monitored throughout the hospital stay. In 201 patients with pneumonia interleukin (IL)-1 receptor antagonist (IL-1RA), IL-6, IL-8 and IL-10 acted as acute phase proteins. After admission, the levels of these cytokines decreased rapidly. Single nucleotide polymorphisms did not influence cytokine production and were not associated with clinical outcome. Cytokine serum levels were significantly higher in patients with pneumococcal pneumonia. The decrease in levels of cytokines was independently influenced by the start of corticosteroid therapy. IL-1RA, IL-6, IL-8 and IL-10 are acute phase proteins, independent of genotype. Their levels are influenced by the nature of the causative microorganism and the start of corticosteroids therapy.

Toll-like receptor (TLR)-9 genetics and function in sarcoidosis.

Sarcoidosis is a systemic disorder characterized by the formation of non-caseating granulomas in variable organs. Toll-like receptor (TLR)-9 is important in the innate immune response against both Mycobacterium tuberculosis and Propionibacterium acnes, candidate causative agents in sarcoidosis. The aim of our study was to investigate possible genetic and functional differences in TLR-9 between patients and controls. TLR-9 single nucleotide polymorphisms were genotyped in 533 patients and divided into a study cohort and validation cohort and 185 healthy controls. Furthermore, part of the promotor as well as the entire coding region of the TLR-9 gene were sequenced in 20 patients in order to detect new mutations. No genetic differences were found between patients and controls. In order to test TLR-9 function, peripheral blood mononuclear cells (PBMCs) of 12 healthy controls and 12 sarcoidosis patients were stimulated with a TLR-9 agonist and the induction of interleukin (IL)-6, interferon (IFN)-γ and IL-23 was measured. Sarcoidosis patients produce significantly less IFN-γ upon stimulation with different stimuli. Regarding IL-23 production, a significant difference between patients and controls was found only after stimulation with the TLR-9 agonist. In conclusion, we did not find genetic differences in the TLR-9 gene between sarcoidosis patients and controls. Sarcoidosis patients produce less IFN-γ regardless of the stimulating agent, probably reflecting the anergic state often seen in their peripheral blood T lymphocytes. The differences in TLR-9-induced IL-23 production could indicate that functional defects in the TLR-9 pathway of sarcoidosis patients play a role in disease susceptibility or evolution.

MRP14 is elevated in the bronchoalveolar lavage fluid of fibrosing interstitial lung diseases.

Pulmonary fibrosis is defined by an overgrowth of fibroblasts and extracellular matrix deposition, and results in respiratory dysfunction that is often fatal. It is the end stage in many chronic inflammatory interstitial lung diseases (ILD) such as sarcoidosis and idiopathic pulmonary fibrosis (IPF). The myeloid-related proteins (MRPs) belong to the S100 family of calcium-binding proteins and are highly expressed by neutrophils, macrophages and epithelial cells during chronic inflammation. MRP14 stimulates fibroblast proliferation in vitro and is expressed in granulomas from sarcoidosis patients. We hypothesized that MRP14 may be a biomarker for fibrotic interstitial lung diseases. The objective of this study was to investigate whether levels of MRP14 in the bronchoalveolar lavage fluid (BALF) of patients with sarcoidosis and IPF correlate with clinical parameters. We used an enzyme-linked immunosorbent assay (ELISA) to measure MRP14 in BALF of 74 sarcoidosis patients, 54 IPF patients and 19 controls. Mean BALF levels of MRP14 were elevated significantly in IPF (P < 0.001) and sarcoidosis (P < 0.05) patients compared to controls. MRP14 levels were associated linearly with sarcoidosis disease severity based on chest radiographic stage. Moreover, BALF MRP14 levels were correlated inversely with diffusion capacity and forced vital capacity in sarcoidosis patients. In IPF patients, a correlation with BALF neutrophil percentage was found. In conclusion, BALF MRP14 levels are elevated in IPF and sarcoidosis and are associated with disease severity in sarcoidosis. The results support the need for further studies into the role of MRP14 in the pathogenesis of lung fibrosis.

Predicting prognosis in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a parenchymal lung disease characterized by progressive interstitial fibrosis. In 2002, the ATS/ERS published new criteria that significantly changed the definition of IPF, resulting in a more homogeneous group of patients. IPF has a poor prognosis with a median of 2.5-3.5 years, but varying from a few months to a decade. In order to predict survival at diagnosis or during follow-up, a considerable number of studies were conducted identifying promising prognostic biomarkers. However, many had been performed before the new ATS/ERS consensus and included patients who would not meet current IPF criteria. This review provides an overview of prognostic markers of survival in IPF after the ATS/ERS consensus statement in 2002. Molecular biomarkers in serum, especially so-called pneumoproteins are relatively easy to obtain and have been independently replicated as predictors of prognosis. Cellular constituents of bronchoalveolar lavage (BAL) have been investigated as predictors of survival, but results remain contradictory. Further, a robust marker of prognosis is the change in lung function over time. However, calculating change in lung function is usually only possible over a 6-12 months period, and is therefore not useful at first presentation. The extent of fibrosis on HRCT scan and the number of fibroblast foci on lung biopsy can be measured at presentation and correlate with prognosis, but the applicability of these markers is being hampered by the lack of user- and patient friendliness. In conclusion, a number of biomarkers are potential candidates for an individualised prognosis of IPF, of which so-called pneumoproteins appear most promising and should be a major focus of fu-

Effect of variation in ITGAE on risk of sarcoidosis, CD103 expression, and chest radiography.

The integrin alpha(E)beta(7) is believed to play a key role in retention of lymphocytes in mucosal tissues of gut, urogenital tract and lung. Five common single nucleotide polymorphisms spanning ITGAE, the gene encoding the alpha(E) (CD103) unit, were genotyped in 556 sarcoidosis patients and 465 controls. The -1088 A/G polymorphism was associated with sarcoidosis (P=0.004). An increased risk of disease was found for homozygous carriers of the A allele vs. carriers of the G allele (P=0.001, odds ratio=1.63 [1.22-2.17]). Analysis of lymphocytes from bronchoalveolar lavage and in vitro functional tests showed higher percentages of CD103+CD4+ T cells for the sarcoidosis risk genotype. Radiographic staging at disease outcome revealed prevalence of -1088 AA genotype in patients with fibrosis (P=0.01). A higher proportion of CD103+CD4+ T cells and ITGAE -1088 AA genotype might be associated with fibrosis formation in pulmonary sarcoidosis.

Variation in IL7R predisposes to sarcoid inflammation.

Sarcoidosis is a chronic granulomatous disorder characterized by a massive influx of Th1 lymphocytes. Both naive and memory T cells express high levels of interleukin 7 receptor-alpha (IL7R alpha), encoded by the IL7R gene. The purpose of this study was to investigate the role of the IL7R gene region in susceptibility to sarcoidosis. Six common single-nucleotide polymorphisms (SNPs) spanning IL7R were genotyped and analyzed in 475 sarcoidosis patients and 465 healthy controls. Replication of one significant associated SNP was carried out in 206 independent sarcoidosis patients, 127 controls and 126 patients with Löfgren's disease. The rs10213865 SNP was associated with sarcoidosis (P=0.008), and in silico analysis showed a complete linkage (r(2)=1, D'=1) with a functional nonsynonymous coding SNP in exon 6 (rs6897932, T244I). Combined analysis of 663 individuals with sarcoidosis and 586 controls (homozygous carriers of risk allele, P=5 x 10(-4), odds ratio=1.49 (1.19-1.86)) provided strong statistical support for a genuine association of IL7R with the risk of sarcoidosis. In addition, we report the same trend between variation in the IL7R gene and patients with Löfgren's disease, suggesting that variation in IL7R may confer general risk for developing granulomatous lung disease.