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PubMed2025

Epistasis of ERAP1 With 4 Major Histocompatibility Complex Class I Alleles in Frontal Fibrosing Alopecia: A Genome-Wide Association Study Meta-Analysis.

IMPORTANCE: Frontal fibrosing alopecia (FFA) is an inflammatory and scarring form of hair loss of increasing prevalence that most commonly affects women. An improved understanding of the genetic basis of FFA will support the identification of pathogenic mechanisms and therapeutic targets. OBJECTIVE: To identify novel genomic loci at which common genetic variation affects FFA susceptibility and assess nonadditive effects on genetic risk between susceptibility loci. DESIGN, SETTING, AND PARTICIPANTS: Four genome-wide association studies were combined using an SE-weighted meta-analysis. Within the major histocompatibility complex (MHC) locus, stepwise conditional analysis was undertaken to determine independently associated classical MHC class I alleles. Statistical tests for epistatic interaction were performed between risk alleles at the MHC and endoplasmic reticulum aminopeptidase 1 (ERAP1) loci. MAIN OUTCOMES AND MEASURES: Genome-wide significant locus associated with FFA and nonadditive effects on genetic risk between susceptibility loci. RESULTS: Of 6668 included patients, there were 1585 European female individuals with FFA and 5083 controls. Genome-wide significant associations were identified at 4 genomic loci, including a novel susceptibility locus at 5q15, and the association signal could be fine-mapped to a single nucleotide substitution (rs10045403) in the 5' untranslated region of ERAP1 (rs10045403; odds ratio, 1.30; 95% CI, 1.19-1.43; P = 3.6 × 10-8). Within the MHC, FFA risk was statistically independently associated with HLA-A*11:01, HLA-A*33:01, HLA-B*07:02, and HLA-B*35:01. FFA risk was affected by genetic variation at the ERAP1 locus only in individuals who carried at least 1 of the MHC class I risk alleles. CONCLUSIONS AND RELEVANCE: In this genome-wide meta-analysis, a supra-additive effect of genetic variation was found that affected peptide trimming and antigen presentation on FFA susceptibility. Patients with FFA may benefit from emerging therapeutic approaches that modulate ERAP-mediated processes.

Female↗
PubMed1996

The immunological architecture of B-lymphocyte aggregates in cryptogenic fibrosing alveolitis.

Cryptogenic fibrosing alveolitis (CFA) is believed to have a pathogenesis mediated by the cellular arm of the immune system. Previous studies have, however, indicated the presence of B-lymphocyte aggregates, as well as evidence of local immunoglobulin production and increased levels of B-cell growth factors. It has recently been shown that CFA is associated with the production of circulating IgG autoantibodies to antigen(s) associated with alveolar lining cells. This prompted an examination of the immunological architecture of the B-lymphocyte aggregates, in order to assess whether they might provide histological confirmation of a local humoral immune response in these patients. Thirty-eight consecutive open lung biopsy specimens were examined from patients with CFA and aggregates of B lymphocytes were identified in 37/38. In only five cases were germinal centres seen. The morphological appearances of the aggregates were reminiscent of those observed in mucosal associated lymphoid tissue (MALT). Using immunohistochemistry, despite the low frequency of true germinal centre formation, the B-lymphocyte aggregates were shown to contain the cellular micro-environment necessary for a humoral immune response. In addition, there was evidence of lymphocyte proliferation and activation within these aggregates. These results provide evidence of a local humoral immune response associated with B-lymphocyte aggregates in the lungs of patients with CFA.

Adult↗
PubMed2000

Percutaneous stenting of right pulmonary artery stenosis in fibrosing mediastinitis.

Pulmonary artery stenosis is an uncommon complication of fibrosing mediastinitis. Previous medical and surgical therapies have provided limited clinical efficacy without objective evidence of clinical improvement. With the advantages of limited invasiveness and absent need for prolonged drug therapy, percutaneous stent deployment to relieve pulmonary artery obstruction represents a novel treatment for this rare disorder.

Adult↗
PubMed2004

Fibrosing cholestatic hepatitis secondary to precore/core promoter hepatitis B variant with lamivudine resistance: successful retransplantation with combination adefovir dipivoxil and hepatitis B immunoglobulin.

Fibrosing cholestatic hepatitis (FCH) is a peculiar variant of hepatitis B virus (HBV) infection in immunocompromised patients characterized by rapid viral replication. Posttransplant patients receiving lamivudine for prophylaxis or treatment of HBV infection may develop drug resistance due to viral mutants, but FCH is rare because escape mutants are usually replication deficient. We report the development of FCH due to lamivudine-resistant HBV mutants in 2 patients at 12 and 13 months after liver transplantation. Rapidly progressive graft failure, accompanied by an escalating HBV DNA level, developed within weeks of onset. Analysis of gene sequence variation by polymerase chain reaction (PCR) and direct sequencing showed that both had a core promoter variant A1762T/G1764A and 1 had a concomitant precore stop codon G1896A variant in prelamivudine and postrecurrence serum samples. Comparison of the HBV polymerase gene in the 2 serum samples revealed a single mutation with methionine-to-isoleucine substitution at codon 552 (M552I) in both patients. "Add-in" treatment with adefovir dipivoxil resulted in a more than 2 to 3log10 reduction in HBV DNA level within 2 weeks and retransplantation was performed with adefovir dipivoxil and hepatitis B immunoglobulin (HBIG) prophylaxis. Both patients were alive at 15 months and 48 months after retransplantation, with normal graft function and serum negative for HBsAg and HBV DNA by quantitative PCR (< 200 copies/mL). The current report demonstrates that recurrent graft infection by precore/core promoter variant with lamivudine-resistant escape mutation may result in FCH. With combination of adefovir and high-dose HBIG, however, long-term survival can be achieved after retransplantation.

Adenine↗
PubMed2007

Early histologic changes in fibrosing cholestatic hepatitis C.

Recurrent hepatitis C (RHCV) after liver transplantation is almost universal, and occasional patients will have an aggressive course characterized histologically by pericellular/sinusoidal fibrosis and cholestasis, known as fibrosing cholestatic hepatitis (FCH). The early stages and evolution of this disease have not been well characterized. A total of 77 liver biopsies performed for indication (nonprotocol) were evaluated for necroinflammation, rejection, cholestasis, and fibrosis. Control groups were composed of protocol biopsies from HCV transplant patients (10 biopsies) as well as non-HCV transplant patients (6 biopsies). Scoring for necroinflammation, rejection, and fibrosis were compiled using standard criteria (hepatic activity index, Banff, Ishak, METAVIR). Pericellular fibrosis was staged with a novel "sinusoidal" system. A cholestasis scoring system was developed to quantitate parenchymal and portal features of cholestasis. Biopsies were categorized as rejection, RHCV, FCH, and stable based on histology and clinical information. FCH was found to have a higher fibrosis stage overall when compared to most diagnostic groups, regardless of the staging system used. Additionally, sinusoidal fibrosis was significantly higher in the FCH diagnosis group. Cholestasis was more prominent in biopsies of FCH in all comparisons. In conclusion, the presence of cholestasis and fibrosis with mild to moderate RHCV should raise the suspicion of FCH. When studying the evolution of these cases, the first abnormality to appear is RHCV and cholestasis, fibrosis develops soon after, and both continue to worsen until the point of allograft failure or patient death.

Adult↗
PubMed1999

Fibrosing cholestatic hepatitis in renal transplant recipients with hepatitis C virus infection.

Fibrosing cholestatic hepatitis (FCH) has been described as a specific manifestation of hepatitis B virus (HBV) infection in liver allograft recipients characterized by a rapid progression to liver failure. Only sporadic cases have been reported in other immunocompromised groups infected with HBV and in a few transplant recipients with hepatitis C virus (HCV) infection. We present the occurrence of FCH in 4 HCV-infected renal transplant recipients within a series of 73 renal transplant recipients with HCV infection followed up closely serologically and with consecutive liver biopsies. All 4 patients received the triple-immunosuppressive regimen (azathioprine, cyclosporine A, methylprednisolone). The interval from transplantation to the appearance of liver dysfunction was 1 to 4 months and to histological diagnosis, 3 to 11 months. The biochemical profile was analogous to a progressive cholestatic syndrome in 3 patients, whereas the fourth patient had only slightly increased alanine aminotransferase and gamma-glutamyl transferase (gammaGT) levels. Liver histological examination showed the characteristic pattern of FCH in 2 patients, whereas the other 2 patients had changes compatible with an early stage. All patients were anti-HCV negative at the time of transplantation, whereas 2 patients, 1 with incomplete and 1with complete histological FCH features, seroconverted after 3 and 31 months, respectively. The patients were HCV RNA positive at the time of the first liver biopsy and showed high serum HCV RNA levels (14 to 58 x 10(6) Eq/mL, branched DNA). HCV genotype was 1b in 3 patients and 3a in 1 patient. After histological diagnosis, immunosuppression was drastically reduced. Two patients died of sepsis and liver failure 16 and 18 months posttransplantation, whereas the seroconverted patients showed marked improvement of their liver disease, which was histologically verified in 1 patient. In conclusion, FCH can occur in HCV-infected renal transplant recipients. It seems to develop as a complication of a recent HCV infection during the period of maximal immunosuppression and is associated with high HCV viremia levels. There are indications that drastic reduction of immunosuppression may have a beneficial effect on the outcome of the disease.

Adult↗
PubMed2004

Involvement of skeletal muscle in dialysis-associated systemic fibrosis (nephrogenic fibrosing dermopathy).

Nephrogenic fibrosing dermopathy (NFD), a newly recognized scleroderma-like disease, was originally described as a purely cutaneous disorder. More widespread involvement, including fibrosis of pulmonary and cardiac tissues, has been documented only recently, and it has been suggested that a more appropriate designation is dialysis-associated systemic fibrosis. We report five cases of this novel disorder, spanning a spectrum of primarily skin to primarily muscle involvement. Clinical, radiological, electrophysiological, and pathological studies revealed moderate to severe fibrosis of striated muscles. All patients had end-stage renal failure on chronic dialysis, subacute to chronic hardening of the skin and muscles, restriction of limb movements with joint contractures, but normal to only mildly weak muscle strength. Limitation of movements was caused predominantly by skin tightness and induration, and by joint contractures rather than muscle weakness. Computerized tomography showed fibrosis of the fascia and muscles in the most severely affected patients, and electromyography showed mild to severe myopathic changes. Histopathology of affected muscles revealed a spectrum of mild to severe fibrosis, degenerating fibers, and chronic inflammatory cells. These results further support the contention that NFD is not a purely cutaneous disease, but is part of a larger systemic fibrotic process that may involve muscles.

Adult↗
PubMed1985

Fine structural changes in cryptogenic fibrosing alveolitis and asbestosis.

Lung biopsies from 17 patients with cryptogenic fibrosing alveolitis of a cellular rather than fibrotic pattern were examined by transmission electron microscopy in the hope that such cases would show features of pathogenetic significance. Further selection was made by choosing minimally affected areas. There was no ultrastructural evidence of immune complex deposition but alveolar epithelial and capillary damage was frequently found (17 and 14 of the 17 cases respectively). Alveolar epithelial injury consisted of patchy necrosis and regenerative hyperplasia. Alveolar capillary injury consisted of cytoplasmic swelling and basement membrane thickening and reduplication. Many of these features have not been emphasized in previous reports and their prominence in early stages of the disease suggest that they may have pathogenetic significance, possible mechanisms of which are discussed. Similar findings identified during the course of this study in 8 asbestos workers suggest that similar pathogenetic mechanisms may operate in asbestosis.

Asbestosis↗
PubMed1992

Apposition of fibroblasts to mast cells and lymphocytes in normal human lung and in cryptogenic fibrosing alveolitis. Ultrastructure and cell perimeter measurements.

The perimeters of mast cells and lymphocytes in human lungs were measured in electron micrographs by digitizer to determine the percentage of perimeter apposed to fibroblast (PPAF). Fibroblasts were apposed to the majority of mast cells. The median PPAF for mast cells in normal lung was 50.3 per cent, and in cryptogenic fibrosing alveolitis (CFA), 35.7 per cent. Although the value in CFA was lower, the difference was not statistically significant (median difference 11.8; 95 per cent confidence interval (-19.6, 25.1); P = 0.65). The PPAF range overall was 3.8-94.1 per cent. There was similar apposition of fibroblasts to lymphocytes, and no statistical differences were found when median PPAF results for mast cells and lymphocytes were compared for normal and CFA lung. The high degree of percentage apposition, accurately quantified in this study, shows that fibroblasts, mast cells, and lymphocytes are ideally arranged structurally in normal alveolar walls, to facilitate the many physiological interactions which are currently being uncovered. The present study also shows that apposition persists in pathological states, e.g., CFA lung, but because all these cells are increased in number in CFA lung, apposition is easier to identify here than in normal lung.

Adult↗
PubMed1995

Tenascin immunoreactivity in cryptogenic fibrosing alveolitis.

Tenascin is a hexameric extracellular matrix (ECM) glycoprotein which has been demonstrated to have a temporal relationship with active scar formation in adult tissues. We hypothesized that this ECM protein might therefore serve to identify areas of active scarring in lung biopsies from patients with cryptogenic fibrosing alveolitis (CFA). The distribution of tenascin was examined in open lung biopsies from ten patients with CFA, six patients with sarcoidosis, and six pulmonary resection specimens from patients with no evidence of interstitial lung disease, using an immunohistochemical technique. Immunoreactive tenascin was not identified in histologically normal control lung parenchyma and was only focally found around large aggregates of granulomas in sarcoidosis. In the CFA, tenascin production was demonstrated in minimally damaged alveolar walls and areas of active disease but not in end-stage scarred lung. There was considerable local heterogeneity of staining within cases, which did not appear to relate to the density of the local inflammatory infiltrate. Large plaques of tenascin were noted to be particularly associated with hyperplastic type II alveolar epithelial lining cells, which are recognized to produce fibrogenic cytokines. The examination of tenascin expression in open lung biopsies from patients with CFA may be useful in assessing fibrogenic activity and may thus provide additional prognostic information.

Biomarkers↗
PubMed1994

Fibrosing alveolitis and desquamative interstitial pneumonitis.

We report the experience with and evaluation of treatment strategies in fibrosing alveolitis and desquamative interstitial pneumonitis (FA/DIP) over the last 16 years by a review of all cases referred to a tertiary referral center. There were 25 cases, 16 boys and 9 girls (mean age at onset, 2.3 years; range, 7 days to 11.6 years). In each case the diagnosis was confirmed by open lung biopsy at a mean age of 3.3 years (range, 7 weeks to 15.1 years). Presently features were tachypnea (19), cyanosis (15), cough (12), exertional dyspnea (7), recurrent chest infections +/- wheezing (9), and clubbing (8). Four patients recovered without antiinflammatory medication. The others received specific treatment. Of 11 patients given only prednisolone, six improved, two did not, and three died despite treatment. Of five patients receiving only chloroquine, four responded. Five patients received both prednisolone and chloroquine; one died, two responded well. There was poor progress in the remaining two. Of the 10 patients receiving chloroquine six (60%) showed a good response. A younger presentation carried a worse prognosis, but chest radiology at presentation and outcome were not interrelated. Those with mild histological changes all survived, but severe desquamation or fibrosis at biopsy was not related to outcome. In four cases there was a family history (16%). Patients with FA/DIP probably represent a disease spectrum of multiple etiology with a variable prognosis and response to treatment.

Child↗
PubMed1996

In situ production of angiotensin II by fibrosed rat pericardium.

Following pericardiotomy in rats, subsequent fibrosis of the visceral pericardium becomes a site of high-density angiotensin-converting enzyme (ACE) binding. This study was undertaken to determine whether this exteriorized site of ACE activity is associated with angiotensin II (AngII) production. Four weeks after pericardiotomy, hearts were isolated and maintained by Krebs-Henseleit perfusion: coronary venous and Thebesian drainage were removed by cannulae. Following a 30-min period of stabilization, a balloon containing superfusate was placed around the heart. Superfusate composition was controlled and included either lisinopril (10(-7) mol/l), angiotensin I (AngI, 10(-7) mol/l), or angiotensinogen (10(-6) mol/l). Sixty min later, superfusate AngII concentration was determined (high-performance liquid chromatography followed by radioimmunoassay). Pericardial fibrosis was confirmed by picrosirius red staining and its high-density ACE binding by quantitative in vitro autoradiography (125I-351A). ACE activity was measured by hippuryl-histidyl-leucine degradation. In coronary effluent, AngII concentration and ACE activity were not different between controls and hearts with pericardial fibrosis. Compared to unoperated, age/sex-matched control hearts, however, we found those with pericardial fibrosis to have: (a) significantly (P < 0.05) greater tissue ACE activity (118.42 +/- 6.66 v 89.45 +/- 7.70 nmol/min/g): (b) significantly (P < 0.01) greater superfusate AngII concentration (4.98 +/- 0.94 v 1.43 +/- 0.28 pg/ml); (c) lisinopril markedly attenuated superfusate AngII concentration to that seen in controls; (d) exogenous AngI markedly increased AngII production (13.76 +/- 1.65 v 4.98 +/- 0.94 pg/ml); and (e) exogenous angiotensinogen did not alter superfusate AngII. Thus, high-density ACE binding and ACE activity of fibrosed pericardium is responsible for AngII production in this in vitro model. Cells involved in generating AngI at this site are uncertain and may involve fibroblast-like cells that express ACE and have ACE activity. The role of local AngII production is unknown, but its autocrine/paracrine properties may regulate collagen turnover of these cells.

Angiotensin I↗
PubMed1993

The fibrosing process in so-called organized diffuse alveolar damage. An immunohistochemical study of the change from hyaline membrane to membranous fibrosis.

On the assumption that some cases of organized diffuse alveolar damage (DAD) result from organization of hyaline membrane, we collected nine autopsy cases of DAD in various stages of the fibrosing process from hyaline membrane to membranous fibrosis and studied changes in the basement membrane and epithelial cells immunohistochemically. In the majority of cases, the following sequence of events was assumed: the hyaline membrane is first formed at the tip of the alveolar septum, a part of the alveolar duct wall where epithelial cells have disappeared. With time it elongates and completely covers alveolar mouths. In the organizing stage, fibroblasts start to permeate through the alveolar duct walls to replace the hyaline membrane completely and to form membranous fibrous tissue. In a few cases, however, fibrous tissue will fill alveolar spaces to form intraluminal diffuse fibrosis. Alveolar epithelial cells and the basement membrane of the alveolar walls are well preserved until the end of the organizing stage when the basement membrane becomes distorted. We believe that membranous fibrosis represents a form of "alveolar duct damage" and that it differs from diffuse fibrosis, which is indicative of diffuse alveolar damage in the true sense.

Adult↗
PubMed1991

Prevention of bleomycin-induced fibrosing alveolitis with indomethacin: stereological studies on rat lungs.

The prevention of the pulmonary toxicity of bleomycin (BLM) has been investigated in experimental models where pulmonary damage was induced with one intra-tracheal dose of BLM. The present investigation was carried out as a pre-clinical study in which BLM was administered systemically. The non-steroid anti-inflammatory drug indomethacin (INDO) was chosen as a possible candidate for pulmonary protection. Twenty female Wistar rats were treated daily with 4 mg/kg (7.3 units) BLM intra-peritoneally for 50 days and 20 rats with BLM and with 1 mg/kg INDO subcutaneously for 62 days. There were 20 animals as controls. Histological examination revealed fibrosing alveolitis in the BLM-treated group which was markedly suppressed in the combination group. Quantitative morphological (stereological) parameters demonstrate that BLM induced alveolar wall thickening (+45%), pulmonary fibrosis (+110%), and an increase of alveolar wall nuclei and of intra-alveolar macrophages (volume densities +43% and +133%, P less than 0.001). In contrast, after combination with INDO significant differences to the control group could not be detected except for a slight increase of intra-alveolar macrophages (+62%). Thus, INDO is a highly efficient agent in the prevention of BLM-induced pulmonary damage.

Animals↗
PubMed1995

Rapid progression of fibrosing alveolitis and thyrotoxicosis after antithymocyte globulin therapy for aplastic anemia.

Antithymocyte globulin (ATG) therapy is an established form of treatment for aplastic anaemia and has also been used as prophylaxis against graft rejection of bone marrow and renal allografts. Administration of ATG preparations has been associated with many mild clinical reactions, as have other forms of immunomodulatory therapy. However, serious adverse effects appear to be rare. We report a case of rapidly progressive fibrosing alveolitis and thyrotoxicosis in relation to ATG therapy, highlighting its potential toxicity and emphasising that its administration should be undertaken by experienced physicians in specialised centres.

Anemia, Aplastic↗
PubMed1989

The influence of fibronectin on the fibrosing of a nerve anastomosis in the rat.

Although the fibrin adhesion enjoys increasing success in many areas of surgery, it has not, however, become fully established in nerve anastomosis. It was in this area particularly that significant advantages were expected, especially by the avoidance of suture granulomas. As the fibrin clot dissolved prematurely, however, and dehiscences ensued, antifibrinolytic substances had to be added to the adhesive. Fibroses occurred frequently as a result, which to date encumber nerve adhesive. We examined fibronectin for its fibrosis-inducing effect, comparing both presently available fibrin adhesive systems, because one contained up to 5 times more fibronectin per milliliter than the other. On the basis of a test grouping using 100 and 1000 KIU aprotinin/ml, we were able to establish that fibronectin in fibrin adhesives possesses a fibrosis-promoting effect.

Action Potentials↗
PubMed1989

The influence of factor XIII on the fibrosing of a nerve anastomosis in the rat.

Although the fibrin adhesion enjoys increasing success in many areas of surgery, it has not become fully established in nerve anastomosis. It was in this area particularly that significant advantages were expected. As the fibrin clot dissolved prematurely, however, and dehiscences ensued, antifibrinolytic substances had to be added to the adhesive. Fibroses occurred frequently as a result, which to date encumber nerve adhesive. We examined Faktor XIII for his fibrosis-inducing effect because both presently available fibrin adhesives contain unphysiologically high concentrations of it. We were able to establish that Factor XIII possesses a fibrosis-promoting effect.

Anastomosis, Surgical↗