Biomedical subjects

Joachim Müller-Quernheim

Publications and source records attributed to Joachim Müller-Quernheim.

14 recordsLinked to original sources

PubMed2006

Infliximab therapy in patients with chronic sarcoidosis and pulmonary involvement.

RATIONALE: Evidence suggests that tumor necrosis factor (TNF)-alpha plays an important role in the pathophysiology of sarcoidosis. OBJECTIVES: To assess the efficacy of infliximab in sarcoidosis. METHODS: A phase 2, multicenter, randomized, double-blind, placebo-controlled study was conducted in 138 patients with chronic pulmonary sarcoidosis. Patients were randomized to receive intravenous infusions of infliximab (3 or 5 mg/kg) or placebo at Weeks 0, 2, 6, 12, 18, and 24 and were followed through Week 52. MEASUREMENTS AND MAIN RESULTS: The primary endpoint was the change from baseline to Week 24 in percent of predicted FVC. Major secondary efficacy parameters included Saint George's Respiratory Questionnaire, 6-min walk distance, Borg's CR10 dyspnea score, and the proportion of Lupus Pernio Physician's Global Assessment responders for patients with facial skin involvement. Patients in the combined infliximab groups (3 and 5 mg/kg) had a mean increase of 2.5% from baseline to Week 24 in the percent of predicted FVC, compared with no change in placebo-treated patients (p = 0.038). No significant differences between the treatment groups were observed for any of the major secondary endpoints at Week 24. Results of post hoc exploratory analyses suggested that patients with more severe disease tended to benefit more from infliximab treatment. CONCLUSIONS: Infliximab therapy resulted in a statistically significant improvement in % predicted FVC at Week 24. The clinical importance of this finding is not clear. The results of this Phase 2 clinical study support further evaluation of anti-TNF-alpha therapy in severe, chronic, symptomatic sarcoidosis.

Adult↗

PubMed2006

A vicious circle of alveolar macrophages and fibroblasts perpetuates pulmonary fibrosis via CCL18.

RATIONALE: Recently, models of macrophage activation have been revised. Macrophages stimulated with Th2 cytokines have been classified as alternatively activated. OBJECTIVES: This article examines the expression and regulation of CC chemokine ligand 18 (CCL18), a marker of alternative activation, by human alveolar macrophages (AMs). METHODS: AM were obtained from bronchoalveolar lavage (BAL) fluid of patients with idiopathic pulmonary fibrosis, sarcoidosis, or hypersensitivity pneumonitis (n = 69) and healthy volunteers (n = 22). Expression of CCL18 was determined by quantitative reverse transcriptase-polymerase chain reaction, in situ hybridization, flow cytometry, and immunohistochemistry, respectively. MEASUREMENTS AND MAIN RESULTS: Spontaneous CCL18 production by BAL-derived cells was markedly increased in patients with pulmonary fibrosis and correlated negatively with pulmonary function test parameters. CCL18 gene expression and protein production were up-regulated in normal AMs after Th2 cytokine stimulation and/or coculture with human lung fibroblasts. Native collagen significantly up-regulated CCL18 expression in normal AMs activated with Th2 cytokines via a mechanism mediated by beta2-integrin/ scavenger receptor(s). Culture supernatants of AMs from patients with idiopathic pulmonary fibrosis increased collagen production by normal lung fibroblasts partly mediated via CCL18. CONCLUSIONS: Our findings suggest that AMs from patients with pulmonary fibrosis disclose a phenotype of alternative activation and might be a part of a positive feedback loop with lung fibroblasts perpetuating fibrotic processes.

Biopsy↗

PubMed2006

Interleukin-18 expression by alveolar epithelial cells type II in tuberculosis and sarcoidosis.

The aims of the present study were to characterize the localization of interleukin-18 (IL-18) expression in lung tissue specimens from patients with pulmonary tuberculosis, sarcoidosis and controls, and to determine whether human alveolar epithelial cells type II (AEC-II) are able to generate IL-18 in primary culture. IL-18 was determined using semiquantitative reverse-transcription-PCR and localized in lungs using in situ hybridization. IL-18 protein levels were determined using the enzyme-linked immunosorbent assay and western blot analysis. Alveolar epithelial cells type II (AEC-II) were stimulated in vitro by proinflammatory cytokines, lipopolysaccharides, and whole cell lysate from Mycobacterium tuberculosis. IL-18 mRNA expression was significantly increased in the lungs affected by tuberculosis and sarcoidosis. In situ hybridization revealed different sites of expression in tuberculosis and sarcoidosis lungs, with AEC-II as one major source of IL-18 in the alveolar compartment. Basal IL-18 expression could be detected in normal AEC-II. Whole cell lysate from M. tuberculosis, but not lipopolysaccharide, led to a strong increase of IL-18 mRNA accumulation in AEC-II. Resting AEC-II secreted only small amounts of IL-18, but intracellular IL-18 protein levels increased in a time-dependent manner during culture. Proinflammatory cytokines tumour necrosis factor-alpha, IL-1beta, and interferon-gamma altered IL-18 mRNA expression and mature protein secretion of human AEC-II. These findings indicate a possible role for AEC-II and AEC-II-derived IL-18 in pathomechanisms of granulomatous lung diseases.

Cytokines↗

PubMed2006

Impact of impaired inspiratory muscle strength on dyspnea and walking capacity in sarcoidosis.

BACKGROUND: Dyspnea and fatigue are frequent but poorly understood symptoms in sarcoidosis patients. This study was aimed at assessing the clinical impact of inspiratory muscle impairment on dyspnea and exercise tolerance. This is the first study using nonvolitional tests that are independent of the patient's cooperation and motivation in addition to volitional tests of inspiratory muscle strength in patients with sarcoidosis. METHODS: Peak maximal inspiratory mouth pressure (Pimaxpeak), maximal inspiratory pressure sustained for 1.0 s (Pimax1.0), twitch mouth pressure (TwPmo), lung function test results, blood gas measurements, 6-min walking distance (6MWD), and Borg dyspnea scale (BDS) scores were assessed in 24 male sarcoidosis patients and 24 healthy male control subjects matched for age and body mass index. RESULTS: Mean (+/- SD) Pimaxpeak (95.2 +/- 25.3% vs 124.6 +/- 23.4% predicted, respectively; p < 0.001) and Pimax1.0 (85.6 +/- 31.4% vs 125.8 +/- 26.8% predicted, respectively; p < 0.001) were lower in sarcoidosis patients compared to control subjects. TwPmo tended to be lower in sarcoidosis patients, and there were three patients who had TwPmo values of < 1.0 kPa, which is a strong indicator of inspiratory muscle weakness. The mean 6MWD was 582 +/- 97 m in sarcoidosis patients and 638 +/- 65 in control subjects (p = 0.025). The mean BDS score was higher in sarcoidosis patients (3.3 +/- 1.7 vs 0.2 +/- 0.5, respectively; p < 0.001). Compared to maximal inspiratory pressure, lung function parameters, and blood gas levels, TwPmo was the strongest predictor for 6MWD (r = 0.663; p = 0.003) and BDS score (r = 0.575; p = 0.012) in sarcoidosis patients following multiple linear regression analysis. CONCLUSIONS: Impairment of inspiratory muscle strength occurs in sarcoidosis patients, and has been suggested to be an important factor causing dyspnea and reduced walking capacity, but this is only reliably detectable when using nonvolitional tests of inspiratory muscle strength.

Adult↗

PubMed2005

CCR2 and CXCR3 agonistic chemokines are differently expressed and regulated in human alveolar epithelial cells type II.

The attraction of leukocytes from circulation to inflamed lungs depends on the activation of both the leukocytes and the resident cells within the lung. In this study we determined gene expression and secretion patterns for monocyte chemoattractant protein-1 (MCP-1/CCL2) and T-cell specific CXCR3 agonistic chemokines (Mig/CXCL9, IP-10/CXCL10, and I-TAC/CXCL11) in TNF-alpha-, IFN-gamma-, and IL-1beta-stimulated human alveolar epithelial cells type II (AEC-II). AEC-II constitutively expressed high level of CCL2 mRNA in vitro and in situ , and released CCL2 protein in vitro . Treatment of AEC-II with proinflammatory cytokines up-regulated both CCL2 mRNA expression and release of immunoreactive CCL2, whereas IFN-gamma had no effect on CCL2 release. In contrast, CXCR3 agonistic chemokines were not detected in freshly isolated AEC-II or in non-stimulated epithelial like cell line A549. IFN-gamma, alone or in combination with IL-1beta and TNF-alpha resulted in an increase in CXCL10, CXCL11, and CXCL9 mRNA expression and generation of CXCL10 protein by AEC-II or A549 cells. CXCL10 gene expression and secretion were induced in dose-dependent manner after cytokine-stimulation of AEC-II with an order of potency IFN-gamma > > IL-1beta > or = TNF-alpha. Additionally, we localized the CCL2 and CXCL10 mRNAs in human lung tissue explants by in situ hybridization, and demonstrated the selective effects of cytokines and dexamethasone on CCL2 and CXCL10 expression. These data suggest that the regulation of the CCL2 and CXCL10 expression exhibit significant differences in their mechanisms, and also demonstrate that the alveolar epithelium contributes to the cytokine milieu of the lung, with the ability to respond to locally generated cytokines and to produce potent mediators of the local inflammatory response.

Cells, Cultured↗

PubMed2005

Function associated transforming growth factor-beta gene polymorphism in chronic beryllium disease.

Chronic beryllium disease (CBD) is a rare occupational, granulomatous lung disease clinically resembling sarcoidosis. The immune response to beryllium is thought to depend on genetic susceptibility. Although a glutamic acid in position 69 of the human leukocyte antigen-DP beta chain (HLA-DPB1-Glu69) is associated with the development of CBD, it cannot fully explain susceptibility. It is likely that additionally other genes are involved in regulating the immune and inflammatory response in the pathogenesis of this disease. Functional gene polymorphisms (PMs) of the tumor necrosis factor (TNF)A and transforming growth factor (TGF) beta(1) genes are suspected to modify the course of granulomatous disorders. We analyzed the TGF-beta(1) (codon 25) PM in 59 patients with CBD and 164 matched healthy controls, from two groups of European/Israeli and United States origin. Additionally, patients were genotyped for HLA class II gene variants and the TNFA (-308) PM. The most significant results were found for the TGF-beta(1) (codon 25) PM with a shift towards the low producing non-GG genotypes in the subgroup of European and Israeli patients with CBD (62.50% vs. 13.82% in healthy controls; P<0.001). This phenomenon was not observed in the group from the United States. Moreover, TGF-beta(1) (codon 25) PM genotype frequencies from United States CBD patients differed significantly from those of European and Israeli patients. In contrast, increased frequencies for the high producing TNFA2 allele were found only in the patients from the United States (28.20% vs. 8.96% in healthy controls; P<0.005) but not in the group of Europe and Israel. In conclusion, the increase in TGF-beta(1) (codon 25) PM genotype frequency associated with a low TGF-beta release suggests that immunoregulatory cytokines such as TGF-beta are involved in the pathogenesis of CBD. Moreover, based on the interaction of gene PMs associated with the control of the immune response, such as TNF-alpha and TGF-beta(1), with a specific immune response gene such as HLA-DPB1-Glu69 or other HLA-class II PMs driving the immune response to Be, the present data suggest that a combination of different genetic backgrounds determine susceptibility for the same immunopathological reaction and disease.

Adult↗

PubMed2005

Study of C-C chemokine receptor 2 alleles in sarcoidosis, with emphasis on family-based analysis.

Prevailing models of sarcoidosis pathogenesis involve the activation of alveolar macrophages, aggregation of CD4+ T lymphocytes, and their accumulation in epithelioid cell granulomas. Increasing evidence suggests that each of these steps is modified by the host genetic constitution. Consequently, candidate susceptibility genes have been selected based on their potential function under this model. The C-C chemokine receptor 2 (CCR2) is involved in Th1 immune activity by recruiting competent cells and possibly by balancing response. CCR2 gene variants have been shown to be associated with sarcoidosis or, more specifically, with Löfgren's syndrome, a distinct form of acute sarcoidosis. We have studied three CCR2 gene polymorphisms (c.190G>A, c.840C>T, and c.4385A>T) in an extended sample of 1,203 patients with sarcoidosis and their relatives. Case-control comparisons and family-based genetic analyses did not support previous findings of an association between CCR2 gene variability and the risk of sarcoidosis. However, they confirmed linkage disequilibrium and showed positive linkage results (p = 0.034) and therefore suggest a susceptibility gene in the surrounding chromosomal region.

Adolescent↗

PubMed2005

Sarcoidosis is associated with a truncating splice site mutation in BTNL2.

Sarcoidosis is a polygenic immune disorder with predominant manifestation in the lung. Genome-wide linkage analysis previously indicated that the extended major histocompatibility locus on chromosome 6p was linked to susceptibility to sarcoidosis. Here, we carried out a systematic three-stage SNP scan of 16.4 Mb on chromosome 6p21 in as many as 947 independent cases of familial and sporadic sarcoidosis and found that a 15-kb segment of the gene butyrophilin-like 2 (BTNL2) was associated with the disease. The primary disease-associated variant (rs2076530; P(TDT) = 3 x 10(-6), P(case-control) = 1.1 x 10(-8); replication P(TDT) = 0.0018, P(case-control) = 1.8 x 10(-6)) represents a risk factor that is independent of variation in HLA-DRB1. BTNL2 is a member of the immunoglobulin superfamily and has been implicated as a costimulatory molecule involved in T-cell activation on the basis of its homology to B7-1. The G --> A transition constituting rs2076530 leads to the use of a cryptic splice site located 4 bp upstream of the affected wild-type donor site. Transcripts of the risk-associated allele have a premature stop in the spliced mRNA. The resulting protein lacks the C-terminal IgC domain and transmembrane helix, thereby disrupting the membrane localization of the protein, as shown in experiments using green fluorescent protein and V5 fusion proteins.

Bronchoalveolar Lavage↗

PubMed2004

Differential gene expression pattern in alveolar macrophages of patients with sarcoidosis and tuberculosis.

Sarcoidosis is a multisystem granulomatous disorder of unknown origin characterized by the presence of epithelioid granulomata in the affected organs. Histological and clinical similarities between sarcoidosis and tuberculosis caused by M. tuberculosis suggest a shared underlying pathophysiology. However, specific markers are needed. This study examined the differential gene expression pattern in alveolar macrophages of patients with granulomatous disorders. The differential mRNA regulation pattern of alveolar macrophages in the bronchoalveolar lavage of healthy controls was compared to that of patients with sarcoidosis and tuberculosis by means of differential display reverse transcription PCR. Comparative analysis of 2,498 PCR products in controls, sarcoidosis, and tuberculosis revealed a differential regulation of expressed sequence tags in only 6.5%. 1.8% showed a shared expression pattern between sarcoidosis and tuberculosis in contrast to the control. It can be assumed that these alterations are associated with common granulomatous features. In contrast, 3.0% of the amplified sequence tags showed specific up- or downregulation in sarcoidosis and 1.6% in tuberculosis. These data indicate a significant proportion of common granuloma-associated features, independent of the origin of the granulomatous disorder.

Adult↗

PubMed2003

Different gender-associated genotype risks of Wegener's granulomatosis and microscopic polyangiitis.

Wegener's granulomatosis (WG) and microscopic polyangiitis (MPA) are systemic small vessel vasculitides associated with ANCA (AAV). Predominant Th1 and Th2 cytokine patterns have been reported for WG and MPA, respectively. Consequently, genotypes suppressing Th1 responses or augmenting Th2 responses may be more frequent in MPA than in WG. Transforming growth beta1 (TGF-beta1) and interleukin-10 (IL-10) genes may modify the course of vasculitis. Therefore, we investigated associations between genotype frequencies of functional polymorphisms of these cytokine genes and clinical manifestations in AAV. One hundred sixty-one AAV patients and 153 healthy blood donors were genotyped for the biallelic polymorphism in codon 25 of the TGF-beta1 gene and the biallelic polymorphism at position -1082 of the IL-10 gene. No difference was found for TGF-beta1 codon 25 polymorphism between control and patient groups. In contrast, a significant shift toward the homozygous AA genotype of the IL-10 (-1082) polymorphism was found in WG (25%, p<0.005) and MPA patients (39%; p<0.00001) compared to controls (10.5%). Furthermore, in MPA the AA homozygous genotype was significantly more frequent in females (62.5%) compared to males (20%, p<0.05). A contribution of the TGF-beta1 codon 25 polymorphism to the susceptibility-defining genetic backgrounds of AAV appears unlikely. In contrast, our findings suggest a role of the enhanced IL-10 (-1082) PM in WG and MPA with a significant gender difference in MPA.

Alleles↗

PubMed2002

Exaggerated TNFalpha release of alveolar macrophages in corticosteroid resistant sarcoidosis.

BACKGROUND AND AIM OF WORK: The aim of the present study was to determine the TNFalpha release of cultured alveolar macrophages (AM) and the bronchoalveolar lavage (BAL) cellular profile in 35 patients suffering from long lasting sarcoidosis. METHODS: The AM TNFalpha release and the BAL cellular profile of 35 patients with a mean duration of sarcoidosis of 10.4 +/- 1.3 years at the time of BAL was compared to 35 healthy controls. RESULTS: The BAL profile of 12 sarcoid patients with a stable disease was similar to that known from acute sarcoidosis. Sarcoid patients with progressive disease (n = 12) and sarcoid patients with corticosteroid resistant disease (n = 11) were characterised by a normal CD4/CD8 ratio and a significant increase of BAL neutrophils (2.7 +/- 1.0% and 3.8 +/- 1.1%, respectively). The AM TNFalpha release of sarcoid patients with stable disease did not differ significantly from controls (523 +/- 124 pg/ml vs. 410 +/- 104 pg/ml). In contrast, we observed a significantly elevated TNFalpha release in sarcoid patients with progressive (2,124 +/- 550 pg/ml; p < 0.01) as well as in those with a corticosteroid resistant disease (1,585 +/- 520 pg/ml; p < 0.01) compared to controls. CONCLUSION: Chronic sarcoid patients in a progressive phase of the disease and those with a corticosteroid resistant disease are characterised by a significantly increased TNFalpha release of cultured AM. Our results support the usage of chimeric anti-TNFalpha antibodies as an alternative therapeutic regimen in chronic corticosteroid resistant sarcoidosis.

Bronchoalveolar Lavage Fluid↗

PubMed2001

Genotyping in the MHC locus: potential for defining predictive markers in sarcoidosis.

In sarcoidosis, host genetic factors are discussed as contributing to disease susceptibility and course. Since tumor necrosis factor (TNF)-alpha is a central mediator of granuloma formation and since elevated TNF-alpha levels are found during active phases of sarcoidosis, genetic polymorphisms correlating with influences on TNF-alpha levels are of special interest. The complete sequencing of the MHC region and the increase in the number of identified gene polymorphisms in this locus associated with TNF-alpha production offer the opportunity of detecting new genes associated with sarcoidosis and perhaps of defining disease-associated haplotypes that bear the potential of serving as predictive markers for this disease.

Animals↗

PubMedDate not supplied

Analysis of differentially regulated mRNAs in monocytic cells induced by in vitro stimulation with Kveim-Siltzbach test reagent.

Sarcoidosis is a granulomatous disorder of unknown origin. The sarcoid spleen-derived Kveim-Siltzbach test reagent (KSTR) elicits a sarcoid-specific, granulomatous response and was used to diagnose sarcoidosis. The active component and the pathomechanism by which KSTR induces granuloma are still unknown. This study investigated the KSTR-associated gene expression pattern in cells of patients with sarcoidosis or chronic beryllium disease (CBD). The monocytic-like cell line U937, alveolar macrophages of sarcoidosis patients, and peripheral blood monocytes of patients with CBD were stimulated with KSTR and other granuloma-associated stimuli. The KSTR-associated gene expression pattern was analyzed by means of differential display reverse transcription-polymerase chain reaction in combination with a multiple comparison of expressed sequence tags induced in response to KSTR and other granuloma-associated stimuli. Depending on the origin of cells tested, 3.7% to 14.6% of the analyzed sequence tags showed differential regulation induced by granuloma-associated stimuli. Alterations restricted to KSTR stimulation could be observed in 1.2% for the cell line U937, in 2.8% for blood monocytes of patients with CBD, and 1.3% for alveolar macrophages of sarcoidosis patients. These data are comparable to those achieved for the other granuloma-associated stimuli tested in this study. Therefore, it can be assumed that KSTR induces pathomechanisms for granuloma formation in sarcoidosis as beryllium in CBD.

Adult↗

PubMedDate not supplied

Systemic immune cell activation in a subgroup of patients with idiopathic pulmonary fibrosis.

BACKGROUND: The prognosis of idiopathic pulmonary fibrosis (IPF/UIP) is poor and its immunopathogenesis is insufficiently understood. OBJECTIVES: The aim of our study was to elucidate the compartmentalization of cell activation and the influence of corticosteroid therapy upon this activation in IPF/UIP. We determined the concentrations of proinflammatory cytokines released by bronchoalveolar lavage (BAL) cells and peripheral blood mononuclear cells (PBMNC) in treated and untreated patients with IPF/UIP. We chose tumor necrosis factor-alpha (TNFalpha) since it is a cytokine predominantly secreted by cells of the monocyte/macrophage lineage and interleukin-2 (IL-2) exclusively by T lymphocytes. METHODS: The release of TNFalpha and IL-2 by BAL cells and PBMNC was measured in cell culture supernatants of 72 treated and untreated IPF/UIP patients. Additionally, in the blood compartment serological parameters reflecting the monocyte/macrophage and lymphocyte activation, such as neopterin and soluble IL-2 receptor (sIL-2R), were determined. RESULTS: The TNFalpha release by BAL cells was significantly elevated in both groups compared to controls but did not differ between treated and untreated patients with IPF/UIP. In 7 of 19 untreated patients with IPF, PBMNC were activated and released increased amounts of TNFalpha. In only 1 of 17 treated patients with IPF, TNFalpha release by PBMNC could be found. The serum level of neopterin, a marker of cell activation of the monocyte/macrophage lineage did not differ between treated and untreated patients. The BAL lymphocyte and PBMNC IL-2 release was significantly elevated in IPF/UIP patients without therapy compared to controls (p < 0.05). In contrast, no IL-2 release of BAL cells or PBMNC was observed in treated IPF/UIP patients. Lymphocyte activation was furthermore identified in untreated IPF patients by elevated soluble IL-2 receptor serum concentrations (p < 0.0001). CONCLUSIONS: Cells of the monocyte/macrophage lineage and T lymphocytes are activated in BAL cells and PBMNC of patients with IPF/UIP. During treatment, the systemic and local activation of T cells is suppressed. BAL macrophages, however, maintain their activated status, which might be the cause for the frequent chronic progression of the disease.

Bronchoalveolar Lavage Fluid↗