Multiplex immune serum biomarker profiling in sarcoidosis and systemic sclerosis.

Multiplex protein technology has the potential to identify biomarkers for the differentiation, classification and improved understanding of the pathogenesis of interstitial lung disease. The aim of this study was to determine whether a 30-inflammatory biomarker panel could discriminate between healthy controls, sarcoidosis and systemic sclerosis (SSc) patients independently of other clinical indicators. We also evaluated whether a panel of biomarkers could differentiate between the presence or absence of lung fibrosis in SSc patients. We measured 30 circulating biomarkers in 20 SSc patients, 21 sarcoidosis patients and 20 healthy controls using Luminex bead technology and used Fisher's discriminant function analysis to establish the groups of classification mediators. There were significant differences in median concentration measurements between study groups for 20 of the mediators but with considerable range overlap between the groups, limiting group differentiation by single analyte measurements. However, a 17-analyte biomarker model correctly classified 90% of study individuals to their respective group and another 14-biomarker panel correctly identified the presence of lung fibrosis in SSc patients. These findings, if they are corroborated by independent studies in other centres, have potential for clinical application and may generate novel insights into the modulation of immune profiles during disease evolution.

Disseminated gonococcal infection in a homosexual man diagnosed by nucleic acid amplification testing from a skin lesion swab.

Disseminated gonococcal infection (DGI) often presents a diagnostic challenge. Through the novel application of molecular technology, a case is presented that suggests how the diagnostic sensitivity for this systemic complication of gonococcal infection can be improved. In a typical case of DGI seen in a homosexual man in whom all mucosal and blood specimens were culture negative, nucleic acid amplification testing (NAAT) helped to confirm the diagnosis. Both throat and skin lesion specimens tested positive for gonococcal DNA and this was confirmed with a supplementary porA pseudogene NAAT. The use of adjuvant NAAT assessment is recommended as part of the diagnostic work-up for suspected DGI cases.

l-selectin gene polymorphisms and complications of sickle cell disease.

We had found high expression of L-selectin and alphaMbeta2 integrin on leukocytes in patients with complications of sickle cell disease (SCD). In non-SCD patients, L-selectin polymorphisms are associated with vasculopathy and nephropathy. Our objective was to determine if L-selectin gene polymorphisms affect leukocyte expression of the protein, or the development of complications in SCD. By polymerase chain reaction with sequence-specific primers incorporating mismatches at the 3'-end, we analysed DNA from 142 HbSS patients and 102 healthy, racially matched, HbAA controls; to detect the F206L, T49S, and P213S L-selectin gene polymorphisms. All patients were assessed for complications of SCD. Steady-state expression of L-selectin on leukocytes was measured by flow cytometry in 44 patients. We excluded HbSS patients on hydroxyurea, with any other disease, pregnancy, or HbF > or = 10%. There were no significant differences in distribution of F206L, T49S or P213S l-selectin gene polymorphisms between patients and controls (chi(2) = 0.1, P > 0.05). There was no association between any of these gene polymorphisms and high expression of L-selectin by leukocytes, or the development of complications in SCD (chi(2) = 2.37, P > 0.05). The findings suggest that these three gene polymorphisms do not predispose to high leukocyte expression of L-selectin, or development of complications in SCD.

Intracellular cytokine profiles and T cell activation in pulmonary sarcoidosis.

In granulomatous inflammatory lung diseases such as sarcoidosis, the balance of cytokine production by activated T cells in the lungs may influence clinical disease outcome. To investigate the potential of T lymphocytes to produce cytokines and contribute to this process, T cells from bronchoalveolar lavage (BAL) and PB from 19 patients with active lung disease were stimulated, stained, and analysed by flow cytometry for intracellular production of cytokines and expression of the activation marker CD69. Higher proportions of BAL cells expressed CD69 compared with PB, in the absence of in vitro stimulation. The expression of IFN-gamma was similar in unstimulated BAL and PB T cells, and there was no association between the expression of CD69 and IFN-gamma. Following stimulation, there were increased numbers of IFN-gamma(+) T cells. A similar trend was found with IL-2(+) T cells, but there were lower levels of IL-4(+) T cells in BAL compared with PB, and similar levels of IL-10(+) T cells. The presence of activated T lymphocytes in BAL samples from patients with sarcoidosis, with the potential to produce Th1 type 1 cytokines may contribute to the inflammatory processes in this granulomatous lung disease. The use of intracellular flow cytometry to investigate cytokine production by BAL T cells could help to indicate potential targets for future therapy.

Single-nucleotide polymorphisms in the SPARC gene are not associated with susceptibility to scleroderma.

OBJECTIVE: SPARC (secreted protein, acidic and rich in cysteine) is a matricellular protein that modulates cell-cell and cell-extracellular matrix interactions. SPARC expression is restricted mainly to sites of tissue remodelling and wound repair, and is prominent in fibrotic disorders. Single-nucleotide polymorphisms (SNPs) in the SPARC gene are reportedly linked to scleroderma in four ethnic groups: Choctaw Indians, Caucasians, African Americans and Mexican Americans. We set out to reproduce and to positionally clone these disease associations in a set of UK Caucasian scleroderma patients and ethnically matched controls. METHODS: One hundred and twenty-one scleroderma subjects and 200 controls were genotyped by polymerase chain reaction with sequence-specific primers differing only in the 3' nucleotide corresponding to each allele of the biallelic SNPs. Scleroderma patients were analysed against controls and on the basis of their fibrosing alveolitis status as judged by high-resolution computed tomography evaluation and the extent of cutaneous involvement. RESULTS: Eight biallelic SNPs were genotyped: three from the last untranslated exon, which had been described previously, and an additional five novel SNPs: two in the promoter region, one in exon three and two in the 3' untranslated region. Six major haplotypes were constructed across all eight SNP positions. No significant differences in genotype, allele or haplotype frequency were observed between scleroderma and controls or within scleroderma subgroups. CONCLUSIONS: SNPs in the SPARC gene are not associated with susceptibility to scleroderma. This research adds to the genetic knowledge of the SPARC gene by identifying five novel SNPs spanning the whole gene and inserting these within the context of clearly defined haplotypes.

BAL findings in idiopathic nonspecific interstitial pneumonia and usual interstitial pneumonia.

Idiopathic pulmonary fibrosis (IPF), which has the histological pattern of usual interstitial pneumonia (UIP), is a progressive interstitial lung disease with a poor prognosis. Idiopathic interstitial pneumonias with a histological pattern of nonspecific interstitial pneumonia (NSIP) have a better prognosis than UIP, and may present with a clinical picture identical to IPF. The authors hypothesised that bronchoalveolar lavage (BAL) findings may distinguish between UIP and NSIP, and have prognostic value within disease subgroups. BAL findings were studied retrospectively in 54 patients with histologically proven (surgical biopsy) idiopathic UIP (n=35) or fibrotic NSIP (n=19), all presenting clinically as IPF. These findings were also compared with the BAL profile of patients with other categories of idiopathic interstitial pneumonias. BAL total and differential cell counts did not differ between the two groups. Survival was better in NSIP. In neither group were BAL findings predictive of survival or changes in lung function at 1 yr, even after adjustment for disease severity, smoking and treatment. BAL differential counts in fibrotic NSIP differed from respiratory bronchiolitis-associated interstitial lung disease, but not from desquamative interstitial pneumonia or cellular NSIP. The authors conclude that bronchoalveolar lavage findings do not discriminate between usual interstitial pneumonia and nonspecific interstitial pneumonia in patients presenting with clinical features of idiopathic pulmonary fibrosis, and have no prognostic value, once the distinction between the two has been made histologically.

A single round PCR method for genotyping human surfactant protein (SP)-A1, SP-A2 and SP-D gene alleles.

The genes coding for the human surfactant proteins (SP)-A and SP-D are located on chromosome 10q22-q23.1. SP-D is the product of a single gene whereas SP-A is the product of two highly homologous genes SP-A1 and SP-A2. Several single nucleotide polymorphisms (SNP) are present in the SP-A1, SP-A2 and SP-D genes. Because of this high degree of sequence homology between the SP-A1 and SP-A2 genes, current genetic analysis studies employ a nested PCR/radioactive hybridization or restriction fragment length polymorphism approach to initially isolate the genes and subsequently to detect the SNP in these isolates. In this manuscript, we report the primers and conditions of a sequence specific primer-PCR methodology that enables the identification of SP-A1, SP-A2 and SP-D gene allelic variants directly on genomic DNA material.

Increased vitronectin and endothelin-1 in the breath condensate of patients with fibrosing lung disease.

BACKGROUND: Non-specific interstitial pneumonia (NSIP) and fibrosing alveolitis associated with systemic sclerosis (FASSc) are diseases of unknown aetiology that are characterised by the accumulation of mononuclear cells, followed by the progressive deposition of collagen within the interstitium and subsequent destruction of lung airspace. Better understanding of mediators involved in fibrosis may be useful for early diagnosis and in clinical monitoring of disease progression. OBJECTIVE: The aim of this study was to investigate the presence of two profibrotic markers, the vitronectin and the endothelin-1 (ET-1) in the airways of NSIP and FASSc patients. METHODS: Ten NSIP (6 males, age 57 +/- 2 years) and 15 FASSc (8 males, age 55 +/- 4 years) patients were recruited along with 10 normal subjects (4 male, age 52 +/- 2 years). Vitronectin and ET-1 concentrations were measured in their breath condensate, using a specific enzyme immunoassay. RESULTS: Higher levels of vitronectin and ET-1 were observed in NSIP and FASSc patients [median 92.8 (91.7-93.9) microg/ml; median 8.3 (7.9-9.3) pg/ml] than in control subjects [median 80.3 (89.3-91.4) microg/ml; p < 0.01; median 5.3 (4.9-5.9) pg/ml, p < 0.0001]. We also found increased concentrations of vitronectin in patients with clinical deterioration compared to those remaining stable and in ex-smokers compared to non-smokers and, increased vitronectin and ET-1 in patients treated with steroids compared to untreated patients. CONCLUSION: These findings justify further studies of vitronectin and ET-1 levels in exhaled breath condensate, as a means of monitoring activity and predicting progression of pulmonary fibrosis.

Single-cell analysis: a novel approach to tumour necrosis factor-alpha synthesis and secretion in sarcoidosis.

Tumour necrosis factor (TNF)-alpha is thought to be a key early cytokine in the pathogenesis of sarcoidosis, despite conflicting data. Largely the product of mononuclear phagocyte activation, it is unclear whether TNF-alpha production at disease sites is a feature of all mononuclear phagocytes that accumulate there or whether it is secreted by a subset of these cells. Using the reverse haemolytic plaque assay, the aims of this study were to determine if the upregulation of TNF-alpha could be confirmed and to investigate whether this was monocyte or macrophage specific. The reverse haemolytic plaque assay allows the measurement of cytokine production at a single cell level. A greater number of alveolar macrophages produced TNF-alpha compared to autologous monocytes in sarcoidosis but not in controls and, based on cell size, it was confirmed that this was the product of more mature macrophages and that the secretion of TNF-alpha by monocytes and macrophages was heterogeneous: not all monocytes and macrophages secrete TNF-alpha. No differences in the average levels of TNF-alpha secretion by peripheral blood monocytes or alveolar macrophages were observed. This study has demonstrated that a subset of mononuclear phagocytes, mature macrophages, are responsible for tumour necrosis factor secretion and this could have implications for targeted management in sarcoidosis in the future.

Tumour necrosis factor-alpha production in fibrosing alveolitis is macrophage subset specific.

BACKGROUND: Previous studies have revealed that tumour necrosis factor (TNF)-alpha is upregulated in fibrosing alveolitis (FA) in humans. The aim of this study was to compare the TNF-alpha secretory profile of alveolar macrophages (AMs) and peripheral blood monocytes (Mos) of patients with cryptogenic FA and systemic sclerosis (SSc), a rheumatological disorder in which lung fibrosis can occur. In particular, we wished to assess whether TNF-alpha levels differ between SSc patients with FA (FASSc) and a nonfibrotic group. METHODS: The reverse haemolytic plaque assay was used to evaluate the secretion of cytokine at a single cell level while immunostaining allowed subtyping of AMs and Mos. RESULTS: This study demonstrated a difference in total TNF-alpha levels produced by AMs when the levels in subjects with FA (cryptogenic FA and FASSc) were compared to levels in either SSc patients without FA (P = 0.0002) or normal healthy controls (P < 0.001). In addition, AMs from patients with FASSc secreted more TNF-alpha than those of patients with no FA (P = 0.003). In contrast, there were no significant differences in Mo TNF-alpha secretion between the groups. A positive correlation was found between total TNF-alpha level and number of neutrophils obtained by bronchoalveolar lavage from patients with FA (r = 0.49, P < 0.04). Finally, it was demonstrated that there was significant heterogeneity of TNF-alpha secretion and that a numerically significant subset of mononuclear phagocytes, RFD7, was responsible for more than 80% of TNF-alpha production. CONCLUSION: By demonstrating the primary cell source of TNF-alpha in FASSc, more accurately targeted, possibly localized, anti-TNF strategies might be employed with success in the future.

Human leukocyte antigen-DRB1 position 11 residues are a common protective marker for sarcoidosis.

Genetic factors, in particular human leukocyte antigens (HLAs) are important determinants of susceptibility to sarcoidosis, a chronic granulomatous disease of undetermined etiology. To clarify the role of HLA in sarcoidosis we determined HLA-DR and -DQ alleles in case-control samples from three European populations (United Kingdom, Czech, and Polish) and compared these results with those published for three additional populations (Italian, Japanese, and Scandinavian) to determine whether the HLA-DR and/or -DQ alleles act as ethnic-dependent, or ethnic-independent modifiers of disease risk. Although variations were apparent in the alleles associated with susceptibility, reductions in the frequency of alleles associated with protection were remarkably consistent in the six populations. Previously detected associations between single-nucleotide polymorphisms at the TAP2 locus and sarcoidosis were shown to be due to linkage disequilibrium with the HLA-DR locus. The protective HLA-DR alleles, which encode the DR1 and DR4 antigens, were found to share characteristic small hydrophobic residues at position 11, which were replaced by small hydrophilic residues in the remaining, nonprotective, HLA-DR alleles. This residue position is within a pocket of the HLA-DR complex antigen binding groove (designated P6), where it is the only variable amino acid and therefore determines the peptide binding preferences of this pocket. A highly significant reduction in the frequency of individuals carrying HLA-DR alleles with a hydrophobic residue at position 11 was observed in the sarcoidosis cases in the three populations we examined. This suggests this HLA-DR residue is an important protective marker in sarcoidosis.

Extended genetic alterations in a patient with pulmonary sarcoidosis, a benign disease.

BACKGROUND: Genetic alterations at the microsatellite level have been detected in various human malignant tissues, but have also been found in chronically inflamed tissues. Sarcoidosis is a benign disease of unknown etiology characterized by chronic inflammation, which may be associated with an increased incidence of developing malignancy. METHODS: We examined the microsatellite alterations in a sputum cytological specimen of a patient with sarcoidosis. The DNA electrophoretic pattern of sputum was compared with that of the peripheral blood. Thirty-two microsatellite markers located at chromosomes 2p, 3p, 8p, 9p, 9q, 17p, 17q were used to reveal genetic alterations. RESULTS: Loss of heterozygosity (LOH) was detected in eleven markers in loci 2p, 9p, 9q and 17q. LOH was observed in all four markers spanning the chromosomal arm 17q11.2-q21, suggesting a potential chromosomal deletion. CONCLUSION: The observation of LOH in all four markers spanning the chromosomal arm 17q11.2-q21 may suggest a potential for malignancy development in this patient, or may be linked to the aetiopathogenesis of sarcoidosis. Further microsatellite fine mapping and clinical follow up of this patient are needed to clarify this.

Alveolar macrophages and T cells from sarcoid, but not normal lung, are permissive to adenovirus infection and allow analysis of NF-kappa b-dependent signaling pathways.

Adenovirus (Adv)-mediated gene transfer requires efficient infection of target cells. The objective of this study was to establish whether alveolar macrophages (AM) and T cells (AT) from sarcoid patients were permissive to infection with Adv vectors and if this property could be used to investigate cytokine gene regulation. Sarcoid and normal bronchoalveolar lavage (BAL) specimens infected with Adv vectors expressing either beta-galactosidase or a green fluorescent protein were analyzed for transgene expression by fluorescence-activated cell sorter (FACS) and direct immunofluorescence, respectively. Expression of surface antigens previously associated with Adv infection, the coxsackie/adenovirus receptor (CAR), alpha v beta 3, and alpha v beta 5 integrins, was also assessed using FACS analysis. Sarcoid AM and AT were found to efficiently express Adv transgenes, unlike AM from normal volunteers, peripheral blood monocytes, and peripheral blood T cells. Cells permissive to Adv infection expressed the CAR and alpha v beta 5 integrin (also alpha v beta 3 integrin for AM). The data indicate that the upregulation of Adv receptors and the ability to infect sarcoid AM and AT are related to the inflammatory environment within the lung. Having demonstrated efficient Adv-mediated transgene delivery to sarcoid AM and AT, a construct encoding porcine I kappa B alpha was then used to investigate the requirement for nuclear factor (NF)-kappa B in the regulation of cytokine gene expression in pulmonary sarcoidosis. Overexpression of I kappa B alpha in sarcoid BAL specimens indicated that tumor necrosis factor-alpha and interleukin (IL)-6 production by AM and interferon (IFN)-gamma production by AT is NF-kappa B dependent, whereas IL-4 production by AT is NF-kappa B independent. This is the first occasion that the requirement for NF-kappa B in IFN-gamma gene expression within primary human T cells has been demonstrated. The results of this study have implications for the future investigation of molecular pathways in inflammatory lung disease.

Ace gene I/D polymorphism and sarcoidosis pulmonary disease severity.

Previous studies of the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene in sarcoidosis have revealed both ethnic heterogeneity of I/D frequencies and controversy surrounding the association between the polymorphism and severity of disease. The objective of this study was, therefore, to clarify the role of the ACE I/D polymorphism in (1) disease susceptibility, (2) pulmonary disease severity (with particular reference to pulmonary fibrosis), and (3) pulmonary disease progression, in two distinct European sarcoidosis populations. Standard chest radiographic staging was performed on 118 UK and 56 Czech white patients with sarcoidosis at 2 yr from presentation. Pulmonary function data were analyzed, and patients were then categorized according to disease severity. A PCR-SSP assay was used to determine the ACE I/D genotype of each patient studied. The I/D allele frequencies from these patients were compared with frequencies from ethnically matched UK (n = 386) and Czech (n = 179) control subjects using a chi-square contingency table. No significant differences were seen in the distribution of the ACE I/D genotypes, allele frequencies or phenotype frequencies. Furthermore, no association was found between the ACE I/D polymorphism and pulmonary disease severity, fibrosis, and progression. We conclude that the ACE I/D polymorphism has no role in sarcoidosis susceptibility in European whites and that it is not a regulatory variant in this disease.

Analysis of tumor necrosis factor-alpha, lymphotoxin-alpha, tumor necrosis factor receptor II, and interleukin-6 polymorphisms in patients with idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is characterized by chronic inflammation that is associated with structural damage of the lung and fibrosis. Although the etiology of IPF is unknown, it is likely to involve an interaction between environmental and multiple genetic components. Animal models of pulmonary fibrosis have shown that proinflammatory mediators are critical at both the inflammatory and fibrotic stages of the disease. Genetic variants exist in genes encoding proinflammatory mediators, as well as in genes encoding their receptors, which makes these genes candidates for the pathogenesis of IPF. In the present study, we examined 12 biallelic polymorphisms in the genes for tumor necrosis factor (TNF)-alpha (+488[G/A], -238[G/A], -308[G/A]), lymphotoxin (LT)-alpha (+720[C/A], +365[C/G], and +249[A/G], determining haplotypes LT-alpha1 to LT-alpha4), tumor necrosis factor-receptor 2 (TNF-RII) (gb:M32315: 676[T/G], 1663[A/G], 1668[T/G], 1690[C/T]), and interleukin- (IL)-6 (promoter -174[G/C], intron 4[A/G]). We also examined the haplotypes determined by the three biallelic polymorphisms in each of the TNF-alpha and LT-alpha genes. As compared with a normal control population, the IPF group showed no significant deviations in genotype, allele, or haplotype frequencies. Surprisingly, in the IPF population, but not in the control population, an increased frequency of cocarriage of the IL-6 intron 4G and the TNF-RII 1690C alleles was observed, despite the location of the two genes on different chromosomes. Moreover, using impairment of carbon monoxide transfer (DL(CO)) adjusted for duration of dyspnea as a marker of rapidity of disease progression, we found that the IL-6 intron 4GG genotype was the only genotype independently associated with lower DL(CO) levels. These findings, if independently confirmed, will be the first to suggest that disease progression in IPF may be linked to a particular genetic marker or to functional polymorphisms in other genes near that marker.

The effect of lung biopsy on lung function in diffuse lung disease.

The aim of this study was to investigate the effect on lung function of lung biopsy used in the diagnosis of diffuse lung disease carried out by an open procedure or by video-assisted thoracoscopy. One hundred and sixteen patients with diffuse lung disease who attended the Royal Brompton Hospital were studied retrospectively. Thirty five patients underwent open lung biopsy, and 33 video-assisted thoracoscopic biopsy and 48 had their diagnosis made without biopsy. All patients underwent lung function tests before and after surgery, or at an interval of 3-6 months in those who did not undergo biopsy. No significant differences were found in changes in lung function between those who had and had not undergone biopsy, and the proportions of patients whose lung function improved or deteriorated were similar. Lung biopsy by an open procedure or by video-assisted thoracoscopy did not differ in its effects on lung function. The results for older patients, those with severe disease and those with fibrosing alveolitis were the same as for the whole group. Open lung biopsy for the diagnosis of diffuse lung disease does not deleteriously affect lung function whether carried out by an open or a minimally invasive procedure.

Distribution of novel polymorphisms of the interleukin-8 and CXC receptor 1 and 2 genes in systemic sclerosis and cryptogenic fibrosing alveolitis.

OBJECTIVE: To search for single-nucleotide polymorphisms in the interleukin-8 (IL-8) and IL-8 receptor CXCR-1 and CXCR-2 genes, and to compare their distribution among patients with systemic sclerosis (SSc) with fibrosing alveolitis (FASSc) or without fibrosing alveolitis (NFASSc), or patients with cryptogenic fibrosing alveolitis (CFA), and normal healthy subjects. METHODS: Fifty control subjects were screened for potential polymorphisms by using polymerase chain reaction in association with sequence-specific primers incorporating mismatches at the 3' end. The novel polymorphisms were subsequently examined in British Caucasian subjects, including 194 healthy controls, 71 patients with CFA, and 128 patients with SSc who were further subdivided into 78 FASSc patients and 50 NFASSc patients. RESULTS: Three novel biallelic polymorphisms were identified in the IL-8 gene (all in noncoding areas of the gene), 1 was found in the CXCR-1 gene (resulting in a conservative amino acid change), and 3 were observed in the CXCR-2 gene, of which the first resulted in a silent codon change and the others were in the 3' untranslated area of exon 3. Compared with controls, a significant increase in the frequency of the CXCR-2 +785 CC homozygote and of the CXCR-2 +1208 TT homozygote was found in the SSc patients (37% versus 22% [P = 0.01] and 33% versus 17% [P = 0.003], respectively). A subgroup analysis revealed this association to be significant both in the FASSc patients and in the NFASSc patients. CONCLUSION: This report describes an association between SSc and 2 polymorphisms occurring close to each other in the CXCR-2 gene. This finding and its functional significance need to be confirmed and analyzed in future studies.

Mannose-binding lectin promoter and structural gene variants in sarcoidosis.

BACKGROUND: Sarcoidosis is a chronic granulomatous disease of unknown aetiology. Studies have suggested that the causative agent may be an infectious micro-organism. The mannose binding lectin (MBL) is involved in innate immunity to a wide range of micro-organisms. Mutations in the promoter region and exon 1 of the MBL gene occur with high frequency and are associated with reduced serum levels of MBL and increased susceptibility to microbial diseases. This study investigated whether MBL variants predispose to sarcoidosis by increasing their susceptibility to micro-organisms. METHODS: MBL gene promoter and exon 1 variants were detected by sequence specific primer polymerase chain reaction (SSP-PCR) in 167 UK Caucasian sarcoidosis patients and 164 control subjects. Severity of pulmonary disease outcome among patients was assessed by radiography after a minimum of 4 years from disease onset and classified as mild, moderate, and severe disease categories, accordingly. RESULTS: MBL variant frequencies were similar in patients and controls studied. Among sarcoidosis patients, the frequencies of variants were similar regardless of severity of disease outcome. The average patient ages at time of diagnosis were similar for all MBL genotypes. CONCLUSIONS: MBL gene variants do not appear to influence susceptibility to sarcoidosis, age of disease onset, or severity of disease.

Identification of four novel interleukin-13 gene polymorphisms.

The development of allergic asthma is thought to involve environmental and inherited genetic components and has pathophysiological features reflecting in part the activity of T cell cytokines. Interleukin-13, a product primarily of activated lymphocytes, is considered to be a critical effector molecule in allergic airway response and has been found to be overexpressed in the airways of patients with asthma. The IL-13 gene is located on chromosome 5q31, one of the major loci to be linked to asthma susceptibility, and amongst a cluster of genes which dominate the immunopathology of allergic disease. Recently, an IL-13 promoter polymorphism was found to be associated with allergic asthma. In the present study we report the identification of four novel biallelic polymorphisms in the IL-13 gene, two intronic and two exonic, one of which results in a basic to hydrophilic amino acid change. We characterised the frequencies of these four biallelic polymorphisms and the frequencies of the haplotypes, resulting from the combination of these four biallelic polymorphisms, in a population of 196 UK Caucasoid healthy individuals.