Sclerosing mesenteritis following immune checkpoint inhibitor therapy.

PURPOSE: Sclerosing mesenteritis (SM), a fibroinflammatory process of the mesentery, can rarely occur after immune checkpoint inhibitor (ICI) therapy; however, its clinical significance and optimal management are unclear. We aimed to assess the characteristics and disease course of patients who developed SM following ICI therapy at a single tertiary cancer center. METHODS: We retrospectively identified 12 eligible adult cancer patients between 05/2011 and 05/2022. Patients' clinical data were evaluated and summarized. RESULTS: The median patient age was 71.5 years. The most common cancer types were gastrointestinal, hematologic, and skin. Eight patients (67%) received anti-PD-1/L1 monotherapy, 2 (17%) received anti-CTLA-4 monotherapy, and 2 (17%) received combination therapy. SM occurred after a median duration of 8.6 months from the first ICI dose. Most patients (75%) were asymptomatic on diagnosis. Three patients (25%) reported abdominal pain, nausea, and fever and received inpatient care and corticosteroid treatment with symptom resolution. No patients experienced SM recurrence after the completion of corticosteroids. Seven patients (58%) experienced resolution of SM on imaging. Seven patients (58%) resumed ICI therapy after the diagnosis of SM. CONCLUSIONS: SM represents an immune-related adverse event that may occur after initiation of ICI therapy. The clinical significance and optimal management of SM following ICI therapy remains uncertain. While most cases were asymptomatic and did not require active management or ICI termination, medical intervention was needed in select symptomatic cases. Further large-scale studies are needed to clarify the association of SM with ICI therapy.

CD4+CTLs in Fibrosing Mediastinitis Linked to Histoplasma capsulatum.

Although fibrotic disorders are frequently assumed to be linked to TH2 cells, quantitative tissue interrogation studies have rarely been performed to establish this link and certainly many fibrotic diseases do not fall within the type 2/allergic disease spectrum. We have previously linked two human autoimmune fibrotic diseases, IgG4-related disease and systemic sclerosis, to the clonal expansion and lesional accumulation of CD4+CTLs. In both these diseases TH2 cell accumulation was found to be sparse. Fibrosing mediastinitis linked to Histoplasma capsulatum infection histologically resembles IgG4-related disease in terms of the inflammatory infiltrate and fibrosis, and it provides an example of a fibrotic disease of infectious origin in which the potentially profibrotic T cells may be induced and reactivated by fungal Ags. We show in this study that, in this human disease, CD4+CTLs accumulate in the blood, are clonally expanded, infiltrate into disease lesions, and can be reactivated in vitro by H. capsulatum Ags. TH2 cells are relatively sparse at lesional sites. These studies support a general role for CD4+CTLs in inflammatory fibrosis and suggest that fibrosing mediastinitis is an Ag-driven disease that may provide important mechanistic insights into the pathogenesis of idiopathic fibrotic diseases.

Spontaneous community-acquired PVL-producing Staphylococcus aureus mediastinitis in an immunocompetent adult - a case report.

BACKGROUND: Mediastinitis caused by hematogenous spread of an infection is rare. We report the first known case of community-acquired mediastinitis from hematogenous origin in an immunocompetent adult. This rare invasive infection was due to Panton-Valentine Leucocidin-producing (PVL+) methicillin-susceptible Staphylococcus aureus (MSSA). CASE PRESENTATION: A 22-year-old obese man without other medical history was hospitalized for febrile precordial chest pain. He reported a cutaneous back abscess 3 weeks before. CT-scan was consistent with mediastinitis and blood cultures grew for a PVL+ MSSA. Intravenous clindamycin (600 mg t.i.d) and cloxacillin (2 g q.i.d.), secondary changed for fosfomycin (4 g q.i.d.) because of a related toxidermia, was administered. Surgical drainage was performed and confirmed the presence of a mediastinal abscess associated with a fistula between the mediastinum and right pleural space. All local bacteriological samples also grew for PVL+ MSSA. In addition to clindamycin, intravenous fosfomycin was switched to trimethoprim-sulfamethoxazole after 4 weeks for a total of 10 weeks of antibiotics. CONCLUSIONS: We present the first community-acquired mediastinitis of hematogenous origin with PVL+ MSSA. Clinical evolution was favorable after surgical drainage and 10 weeks of antibiotics. The specific virulence of MSSA PVL+ strains played presumably a key role in this rare invasive clinical presentation.

IgG4-related fibrosing mediastinitis diagnosed with computed tomography-guided percutaneous needle biopsy: Two case reports and a review of the literature.

RATIONALE: Immunoglobulin G4-related disease (IgG4-RD) is a fibroinflammatory disease characterized by elevated serum IgG4 levels with infiltration of IgG4+ plasma cells and severe fibrosis in affected tissues. Recently, idiopathic fibrosing mediastinitis (FM), an extremely rare fibroinflammatory disorder, has been recognized as a form of IgG4-RD. As IgG4-RD can be treated by glucocorticoids, identification of the etiology of FM by surgical biopsy is essential; however, mediastinal biopsy is often difficult. We report 2 cases of IgG4-related FM successfully diagnosed with computed tomography (CT)-guided percutaneous needle biopsy. PATIENT CONCERNS: Case 1 was a 66-year-old woman with elevated serum C-reactive protein without any symptoms and case 2 was 78-year-old woman with abnormal mediastinal contour on chest x-ray. By further work-up, both cases were found to have mediastinitis accompanied by elevated serum IgG4. CT-guided percutaneous needle biopsy revealed massive infiltration of IgG4+plasma cells along with storiform fibrosis. DIAGNOSIS: IgG4-related FM. INTERVENTIONS: Glucocorticoid therapy. OUTCOME: The treatment resulted in significant improvement of the lesions after 3 months. LESSONS: Early recognition and diagnosis of IgG4-related FM is essential because a delay in appropriate treatment initiation leads to progressive fibrosis with irreversible organ damage and poor prognosis. Our cases highlight CT-guided percutaneous needle biopsy as a promising option for histological examination in patients with IgG4-related FM.

Thoracic involvement in IgG4-related disease in a UK-based patient cohort.

IgG4-related disease (IgG4-RD) is a multi-system fibro-inflammatory disorder with classical histopathological findings, often in the context of elevated serum IgG4 levels. The thoracic manifestations of IgG4-RD are numerous and can mimic several common and better known conditions. The objective of this study was to outline the frequency and nature of thoracic involvement in a prospective cohort of IgG4-RD patients who met defined diagnostic criteria. Over 40% of IgG4-RD patients had clinicoradiological and/or histological evidence of thoracic involvement, predominantly mediastinal lymphadenopathy, the majority associated with multi-system disease outside the chest. Thoracic involvement was associated with a higher serum IgG4 level, potentially representing greater disease activity or spread. Our data highlight the diverse nature of thoracic IgG4-RD, and the importance of knowledge and recognition of the condition among respiratory physicians who are likely to encounter this disease entity on an increasing basis.

Unexpected Fibrosing Mediastinitis Shown on FDG PET/CT in a Patient With IgG4-Related Disease.

A 66-year-old man presented to our hospital because of abdominal pain for 5 days. A contrast abdominal CT raised the possibility of pancreatic carcinoma. FDG PET/CT showed increased FDG accumulation not only in the pancreas and the retroperitoneum, but also in the posterior mediastinum, which was not typical of pancreatic carcinoma. The patient was subsequently diagnosed having immunoglobulin G4-related disease following the histopathologic examination.

Idiopathic Mediastinal Fibrosis: a Systemic Immune-Mediated Disorder. A Case Series and a Review of the Literature.

Mediastinal fibrosis is a rare disease characterised by fibrous proliferation in the mediastinum. It can be idiopathic or secondary to several conditions such as infections and malignancies. Anecdotal reports have described idiopathic mediastinal fibrosis (IMF) in association with other fibro-inflammatory or autoimmune diseases. We report nine new IMF cases recently seen at our Fibro-Inflammatory Disease Clinic and reviewed the IMF cases reported in the English language literature throughout 2006-2016. The purposes of our literature search were to assess the frequency of the association between IMF and other immune-mediated disorders and to analyse which disorders most often coexist with IMF. Of our nine IMF cases, one was associated with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, one with large-vessel arteritis, three with idiopathic retroperitoneal fibrosis (one of which was IgG4-related), one with pancreatitis and one with IgG4-related seminal vesicle involvement. The remaining two cases, in which IMF was not associated with any other disease, were both classifiable as IgG4-related. The literature review showed that, of the 84 IMF cases identified, 27 (32 %) were associated with other idiopathic autoimmune or fibro-inflammatory disorders, particularly small-vessel vasculitis, Behçet disease, retroperitoneal fibrosis and other conditions belonging to the IgG4-related disease spectrum. Based on our own data and the literature review, we conclude that IMF is often associated with other autoimmune or fibro-inflammatory diseases; therefore, its clinical management requires an accurate screening of associated conditions. Immune-mediated mechanisms may be shared by these disorders.

A 44-Year-Old Man With Chronic Cough, Weakness, and a Mediastinum Mass.

A 44-year-old white man presented with a 3-month history of dry cough and weakness. He had already been treated with antibiotics without any relief. He did not report dyspnea, fever, or expectoration. The patient's medical history was significant for mild arterial hypertension and autoimmune thyroiditis with normal thyroid hormone levels. He was a nonsmoker and had been in excellent health until symptom onset.

Fibrosing mediastinitis complicating prior histoplasmosis is associated with human leukocyte antigen DQB1*04:02 - a case control study.

BACKGROUND: Fibrosing mediastinitis (FM) is an idiosyncratic reaction to infection with Histoplasma capsulatum with a prevalence of 3:100,000 people infected. The rarity of post-histoplasmosis fibrosing mediastinitis (PHFM) in areas where H. capsulatum is endemic suggests that an abnormal immunological host response may be responsible for the development of fibrosis. Our group previously reported an association between subjects with PHFM and human leukocyte antigen (HLA)-A*02. We sought to confirm or extend those findings with application of high resolution HLA typing in a cohort of subjects with PHFM. METHODS: High-resolution HLA typing was performed on DNA samples from a new cohort 34 patients with PHFM. Control cohorts included 707 subjects from the "European American" subset of the National Marrow Donor Program(®) (NMDP) and 700 subjects from Dialysis Clinic, Inc. (DCI). The carriage frequencies of the HLA alleles identified in the PHFM, NMDP, and DCI cohorts were calculated and then all were compared. RESULTS: We found an increase in the carriage frequency of HLA-DQB1*04:02 in PHFM subjects relative to the controls (0.15 versus 0.07 in DCI and 0.05 in NMDP; p = 0.08 and 0.03). Multiple logistic regression showed that DQB1*04:02 was statistically significant (p = 0.04), while DQB1*03:02 and C*03:04 had point estimates of OR > 1, though they did not reach statistical significance. The HLA-A*02 association was not replicated. CONCLUSIONS: HLA-DQB1*04:02 is associated with PHFM, which supports the premise that an aberrant host immune response contributes to the development of PHFM.

Invasive Trichosporon infection in solid organ transplant patients: a report of two cases identified using IGS1 ribosomal DNA sequencing and a review of the literature.

Trichosporon species are rare etiologic agents of invasive fungal infection in solid organ transplant (SOT) recipients. We report 2 well-documented cases of Trichosporon inkin invasive infection in SOT patients. We also conducted a detailed literature review of Trichosporon species infections in this susceptible population. We gathered a total of 13 cases of Trichosporon species infections. Any type of organ transplantation can be complicated by Trichosporon infection. Bloodstream infections and disseminated infections were the most common clinical presentations. Liver recipients with bloodstream or disseminated infections had poor prognoses. Although the most common species was formerly called Trichosporon beigelii, this species name should no longer be used because of the changes in the taxonomy of this genus resulting from the advent of molecular approaches, which were also used to identify the strains isolated from our patients. Antifungal susceptibility testing highlights the possibility of multidrug resistance. Indeed, Trichosporon has to be considered in cases of breakthrough infection or treatment failure under echinocandins or amphotericin therapy. Voriconazole seems to be the best treatment option.

[The immune reactions by the esophagus injuries, complicated by mediastinitis].

The comparative analysis of 56 immunograms of patients with mediastinitis, caused by the esophagus trauma is represented. The mean values of 9 immunologic parameteres (the so called "norm of the pathology") were set for patients with noncomplicated mediastinitis. A novel method of the immune status evaluation for the patients with the acute surgical conditions and SIRS has been suggested. If early applied, the method allows substantive immunotherapy for such patients.

Fibrosing mediastinitis: clinical presentation, therapeutic outcomes, and adaptive immune response.

Fibrosing mediastinitis (FM) is a rare disorder characterized by the invasive proliferation of fibrous tissue within the mediastinum. FM frequently results in the compression of vital mediastinal structures and has been associated with substantial morbidity and mortality. Its pathogenesis remains unknown. However, in North America most cases are thought to represent an immune-mediated hypersensitivity response to Histoplasma capsulatum infection. To characterize the clinical disease spectrum, natural disease progression, responses to therapy, and overall survival, we retrospectively analyzed all 80 consecutive patients with a diagnosis of FM evaluated at Mayo Clinic, Rochester, MN, from 1998 to 2007. Furthermore, we characterized the adaptive immune response in 15 representative patients by immunohistochemistry. The majority of patients presented with nonspecific respiratory symptoms due to the compression of mediastinal broncho-vascular structures. Chest radiographic imaging most frequently revealed localized, invasive, and frequently calcified right-sided mediastinal masses. Most patients had radiographic or serologic evidence of previous histoplasmosis. In contrast to earlier reports summarizing previously reported FM cases, the clinical course of our patients appeared to be more benign and less progressive. The overall survival was similar to that of age-matched controls. There were only 5 deaths, 2 of which were attributed to FM. These differences may reflect publication bias associated with the preferential reporting of more severely affected FM patients in the medical literature, as well as the more inclusive case definition used in our consecutive case series. Surgical and nonsurgical interventions effectively relieved symptoms caused by the compression of mediastinal vascular structures in these carefully selected patients. In contrast, antifungal and antiinflammatory agents appeared ineffective. Histologic examination and immunostaining revealed mixed inflammatory infiltrates consistent with a fibroinflammatory tissue response in these histoplasmosis-associated FM cases. The immune cell infiltrates included large numbers of CD20-positive B lymphocytes. As B lymphocytes may contribute to the pathogenesis of the disease, therapeutic B-cell depletion should be investigated as a therapeutic strategy for FM.

Comparison of the therapeutic efficacy of linezolid and vancomycin and correlation of serum and tissue malondialdehyde and myeloperoxidase in an experimental mediastinitis model.

BACKGROUND: We aimed to investigate the therapeutic efficacy of linezolid in an experimental mediastinitis model and to compare it with vancomycin, which is commonly used. The objective of this study was also to evaluate the role of the immune system in mediastinitis. MATERIALS AND METHODS: Fifty adult Wistar rats were randomly divided into five groups: an uncontaminated and contaminated untreated control groups; a group that received sefazolin prophylaxis; and two groups treated with vancomycin or linezolid. Median sternotomy without access to pleural spaces was performed on all rats. All groups, except the uncontaminated one, were inoculated with 0.5 mL 10(8) colony-forming units/mL methicillin-resistant Staphylococcus aureus in the mediastinal and sternal layers. Postoperatively, vancomycin and linezolid groups were given antibiotic treatment for 7 d, starting 24 h after the end of the procedure. After 7-d treatment tissue samples from the upper ends of the sternotomy line and mediastinum were obtained and evaluated microbiologically. Additionally, serum, heart, lung, liver, kidney, and mediastinal tissues samples were obtained to determine malondialdehyde (MDA) and myeloperoxidase (MPO). RESULTS: The study showed that either vancomycin or linezolid successfully reduced bacterial counts in mediastinum and sternotomy line. MDA and MPO levels were found to be decreased in the treated groups. There was a positive correlation between serum and tissues MDA and MPO in all of the groups. CONCLUSIONS: Our study showed that linezolid appears to be a promising option for treating mediastinitis due to methicillin-resistant S. aureus. Additionally, it was demonstrated that a wide inflammatory process occurred after mediastinitis.

[Immunological aspects of the early application of extracorporeal hemocorrection techniques in the complex therapy of purulent mediastinitis].

Acute purulent mediastinitis (APM) is one of the most complicated forms of surgical infection, showing a high incidence of sepsis--from 45 to 100%, mortality rates of 17 to 80%. Sixty-eight patients with APM admitted to the N. V. Sklifosovsky Research Institute of Emergency Care in October 2002 to March 2007 were examined. Postoperatively, all the patients received extracorporeal hemocorrection techniques (EHT): plasmapheresis (PA) via filtration and continuous venovenous hemofiltration (CVVHF). According to the time of initiation of EHT, the patients were divided into 2 groups: 1) 34 patients in whom EHT was initiated within the first 24 hours after surgery; 2) 34 patients in whom it was started on postoperative day 2. The efficiency of early use of EHT in the complex therapy of APM was evaluated. The early initiation of EHT (PA and CVVHF) caused a reduction in endogenous intoxication and the magnitude of a systemic inflammatory reaction, which resulted in the rapidest restoration of the size of major populations and subpopulations of lymphocytes and prevented the development of immune system incompetence. The early use of EHT caused a significant reduction in hospital mortality (11.8 and 35.3% in the early and late EHT use groups, respectively).

Fibrosing mediastinitis as a rare sequel of iatrogenic rupture of bronchogenic cyst--a case report.

Fibrosing mediastinitis is a chronic disease process with a spectrum of etiology. We report a 51-year-old female who underwent incision and drainage procedure in the neck for deep neck and mediastinal abscess. Five years later she developed fibrosing mediastinitis. This lesion infiltrated from neck base into the upper mediastinum with tracheal compression and vessel encasement. She had resection of the lesion which proved to be a ruptured bronchogenic cyst with chronic inflammation. This rare case illustrates the importance of including inflammatory bronchogenic cyst in the etiology of deep neck abscess formation. And we further find a ruptured bronchogenic cyst with chronic inflammation as an etiology of fibrosing mediastinitis.

Successful treatment of sclerosing mediastinitis with a high serum IgG4 level.

Sclerosing mediastinitis is not a common condition in the thoracic cavity and is difficult to cure. Several medications have been used; however, most of the cases do not achieve satisfactory results, and the most successful treatment is operative resection. We report the first case of IgG4-related sclerosing mediastinitis that showed IgG4-positive plasma cells infiltrated into the fibrous tissue and a high serum IgG4 level. The patient clearly showed remission of the symptoms after steroid therapy. Our findings suggest that the serum IgG4 level is a good selection indicator for steroid therapy in sclerosing mediastinitis.

[Clinical assessment of immune parameters at surgical patients with syndrome of systemic inflammatory reaction].

Results of immunological examination of 423 patients with syndrome of systemic inflammatory reaction of different ethiology (mediastinitis--78 patients, peritonitis--85, severe acute pancreatitis--91, trauma of thorax and abdomen complicated with massive hemorrhage--111, severe burn trauma--40 patients) are analyzed. For complex and objective assessment of immune reaction the system of scores has been developed. This scale permitted to detect the immune disorders, to diagnose the degree of immune insufficiency at early stages of disease, to predict the purulent complications and to start timely immune therapy.