Retraction Notice: Retracted for use of material or data without authorization from third party. Reference: Asna Mohammed, Bo Tang, Sean Sadikot, Guido Barmaimon: Acute Eosinophilic Pneumonia Induced by Immune Checkpoint Inhibitor and Anti-TIGIT Therapy. Am J Case Rep 2024; 25: e943740; DOI: 10.12659/AJCR.943740.

Background: The standard therapeutic regimen for idiopathic chronic eosinophilic pneumonia (ICEP) involves the administration of oral corticosteroids (OCS). However, a notable proportion of individuals experience recurrent episodes after the tapering or cessation of OCS during the course of ICEP. There has been a growing interest in exploring alternative treatment modalities for patients with ICEP at heightened risk of relapse. Objective: The aim of this study was to assess the efficacy of mepolizumab at a dose of 100 mg administered every 4 weeks in preventing relapses of ICEP and its impact on the clinical outcomes. Methods: This retrospective clinical observational study used real-world data to assess the impact of mepolizumab on patients diagnosed with ICEP accompanied by severe asthma. Demographic information and clinical characteristics were extracted from medical records. The study examined the effect of mepolizumab on the annual relapse rate, OCS dose, eosinophil count, and respiratory function parameters. Results: All patients included in the study, with a median (range) follow-up period of 19 months (4-40 months), the annual relapse rate decreased from 0.33 to 0 after the initiation mepolizumab. In addition, the maintenance OCS dose, expressed in methylprednisolone equivalents, declined from 4 mg/day to 0 mg/day. A reduction in the blood eosinophil count was observed, alongside a partial improvement in respiratory function test results among the patients. Conclusıon: A dose regimen of 100 mg of mepolizumab administered every 4 weeks emerges as a promising and well-tolerated therapeutic approach for averting relapses of ICEP.

BACKGROUND Immune checkpoint inhibitors (ICIs) have been linked to various immune-related adverse events, including pneumonitis, necessitating early recognition and potential treatment discontinuation. Acute eosinophilic pneumonia (AEP) induced by ICIs, particularly with no reported cases involving anti-TIGIT therapy, is rare. This report describes a case of AEP following treatment with pembrolizumab and anti-TIGIT therapy. CASE REPORT A 46-year-old woman with lung adenoid cystic carcinoma and chronic hypoxemic respiratory failure on long-term oxygen therapy presented with fever, cough, and shortness of breath. She underwent left pneumonectomy and radiation therapy at diagnosis 9 years earlier. She was participating in a clinical trial using pembrolizumab and anti-TIGIT EOS-448, due to cancer progression. After starting therapy, she developed stable peripheral eosinophilia and a skin rash, suggestive of a drug reaction. On admission, she was in acute-on-chronic hypoxemic respiratory failure, febrile, with an elevated eosinophil count and new multifocal infiltrates in the right lung. Despite broad antibiotics coverage for pneumonia, she developed worsening respiratory symptoms and eosinophilia. She was then empirically started on intravenous methylprednisolone for acute eosinophilic pneumonia without confirmatory bronchoscopy as she was at high risk with her previous pneumonectomy. She subsequently had rapid improvement in her symptoms. CONCLUSIONS AEP should be considered in patients treated with ICIs who develop immune-related adverse effects. Although bronchoscopy findings are part of AEP\'s diagnostic criteria, this case underscores the importance of clinical judgment in the prompt initiation of steroids, even without confirmatory bronchoscopy, in rapidly progressing cases. The role of anti-TIGIT therapy in this context remains uncertain.

UNASSIGNED: A 72-year-old man with pancreatic tail cancer underwent distal pancreatectomy and splenectomy 1 year ago. Routine postoperative follow-up CT detected multiple pulmonary nodules. 18 F-FDG PET/CT showed multiple FDG-avid nodules in the bilateral lungs, which highly suggested the possibility of lung metastases of pancreatic cancer. Finally, the bronchoalveolar lavage fluid and pathology confirmed the diagnosis of simple pulmonary eosinophilia.

BACKGROUND: The phenotyping of chronic obstructive pulmonary disease (COPD) has increasingly gained attention in recent years, as it leads to new and individualized therapeutic concepts.
OBJECTIVE: The aim is to provide an overview of the heterogeneity of COPD and to summarize current drug therapy concepts, particularly in the context of eosinophilic airway inflammation.
METHODS: Several prospective, randomized, placebo-controlled studies have shown a reduction in exacerbations and overall mortality with inhaled triple therapy using an inhaled corticosteroid and dual bronchodilation. The higher the eosinophils in the blood, the greater the expected effect. In addition, a reduction in exacerbations with biologics in COPD with eosinophilia has been demonstrated for dupilumab. Eosinophil-guided therapy for acute exacerbations is the subject of current research.
CONCLUSIONS: For COPD without exacerbations, dual bronchodilation forms the basis of inhaled therapy. With exacerbations, inhaled triple therapy is indicated for patients with a blood eosinophil count of ≥ 300/µl. This type of treatment may also be useful when eosinophils are between 100 and 300/µl. Therapy with dupilumab is a possible option for the eosinophilic phenotype in the near future.
UNASSIGNED: HINTERGRUND: Die Phänotypisierung der chronisch-obstruktiven Lungenerkrankung („chronic obstructive pulmonary disease“ [COPD]) ist in den letzten Jahren zunehmend in den Fokus gerückt, da sich hierdurch neue und individualisierte Therapiekonzepte ergeben.
UNASSIGNED: Ziel ist es, eine Übersicht über die Heterogenität der COPD zu bieten und aktuelle medikamentöse Therapiekonzepte insbesondere vor dem Hintergrund der eosinophilen Atemwegsentzündung darzustellen.
UNASSIGNED: Einige prospektive, randomisierte und placebokontrollierte Studien haben eine Reduktion von Exazerbationen sowie der Gesamtmortalität durch eine inhalative Triple-Therapie mit einem inhalativen Kortikosteroid und einer dualen Bronchodilatation gezeigt. Je höher die Zahl der eosinophilen Granulozyten im Blut, desto größer ist auch der hierdurch zu erwartende Effekt. Zudem konnte eine Exazerbationsreduktion durch das Biologikum Dupilumab bei COPD mit Eosinophilie gezeigt werden. Eine eosinophilengesteuerte Therapie akuter Exazerbationen ist Gegenstand aktueller Forschung.
UNASSIGNED: Bei COPD ohne Exazerbationen bildet die duale Bronchodilatation die Basis der inhalativen Therapie. Bei Exazerbationen und Eosinophilenzahl von ≥ 300/µl im Blut ist eine inhalative Triple-Therapie indiziert. Bei Eosinophilenzahl von 100 bis 300/µl ist ein solcher Therapieversuch ebenfalls sinnvoll. Eine Therapie mit Dupilumab ist eine mögliche zeitnahe Option für den eosinophilen Phänotyp.

Acute eosinophilic pneumonia (AEP) is a rare cause of acute respiratory failure. Clinical presentations can range from dyspnoea, fever and cough, to rapidly progressive and potentially fulminant respiratory failure. While its exact cause is often unknown, associations with inhalational injuries and exposures to new medications have been described.We report a case of a middle-aged, non-smoking man with a history of alcohol use disorder. He presented with 4 days of shortness of breath that started hours after taking injectable naltrexone (Vivitrol). The patient had rapidly worsening hypoxaemia, necessitating emergent bronchoscopy with transbronchial biopsies and bronchoalveolar lavage which showed 66% eosinophils. The patient was intubated for the procedure and unable to get extubated due to worsening hypoxaemic respiratory failure with high fractional inspired oxygen requirements. Chest radiograph showed worsening lung infiltrates and with a high index of suspicion for AEP, he was started empirically on methylprednisolone. He had rapid improvement in his respiratory status and was extubated on day 5 of admission then discharged on day 8. Histopathological examination confirmed acute/subacute eosinophilic pneumonia. A 3-week post-discharge follow-up chest radiograph confirmed the full resolution of pulmonary infiltrates.Naltrexone-induced AEP is rare, with only six other cases reported in the literature. Careful history taking and prompt evaluation for AEP are important given the potential for rapid progression to acute hypoxic respiratory failure and the excellent response to steroid treatment.

UNASSIGNED: Recurrences occur when corticosteroid therapy is discontinued or reduced during the treatment of chronic eosinophilic pneumonia (CEP). The probability of recurrence is once in 50% of patients and twice or more in 25%. In such instances, new treatment options are deemed necessary. This study aims to assess the efficacy of omalizumab treatment as a steroid-sparing drug in patients with CEP.
UNASSIGNED: The clinical features of patients treated with omalizumab for recurrent CEP were evaluated retrospectively before and after treatment. All data from patients and diagnoses were reviewed. The effects of treatment on recurrence rate, oral corticosteroid (OCS) use and lung functions, peripheral eosinophil values, and symptom scores were evaluated. Radiological regression was also evaluated.
UNASSIGNED: In the final analysis, we included ten patients with a median follow-up of 22 months after initiation of omalizumab. During this follow-up period, the results were associated with a significant reduction in the number of asthma attacks per year, the number of CEP relapses, the rate of hospitalization, the amount of corticosteroids consumed daily, and the total corticosteroid dose. In addition, improvement was observed in the symptom scores and lung functions of the patients. Systemic steroids were completely discontinued in two patients receiving omalizumab treatment. In other patients, the mean steroid dose was reduced by 77.2 percent in the first year of omalizumab treatment and 82 percent in the second year, respectively. Nevertheless, there was no elevation in peripheral eosinophil count, and radiological regression was observed.
UNASSIGNED: Omalizumab can be an effective treatment for CEP and can be used as a steroid-sparing agent.

BACKGROUND: Eosinophilic pulmonary disease (EPD) is a general term for a large group of diseases with complex etiology. Ulcerative colitis is an inflammatory bowel disease (IBD). Patients with IBD may have pulmonary involvement. We herein present a case of ulcerative colitis complicated with EPD.
METHODS: A 34-year-old woman with ulcerative colitis presented with dry cough. She had peripheral eosinophilia and apical ground glass opacities on CT (computed tomography) of her chest. Antibiotic treatment was ineffective.
METHODS: Lung biopsy revealed eosinophil infiltration in the alveolar space and interstitial space, so EPD was considered.
METHODS: After oral administration of prednisone, the lung shadow on CT disappeared when the cough symptoms resolved. However, the symptoms recurred after drug withdrawal, and the lung shadow reappeared on imaging. The cough symptoms and lung shadow disappeared after oral prednisone was given again. Prednisone was slowly discontinued after 6 months of treatment.
RESULTS: The patient stopped prednisone for half a year. No recurrence or abnormal CT findings were detected during the half-year follow-up.
CONCLUSIONS: The clinical manifestations of EPD are atypical, laboratory and imaging findings are not specific, and it is difficult to make a definite diagnosis before lung biopsy. The diagnosis depends on pathological examination. Glucocorticoid treatment is effective, but some patients may relapse after drug withdrawal. Active follow-up after glucocorticoid treatment is very important for identifying disease recurrence. Patients with IBD are relatively prone to developing EPD. The etiology of EPD is complex. In clinical practice, we need to make a diagnosis and differential diagnosis to clarify its etiology.

Daptomycin-induced eosinophilic pneumonia (DIEP) is a rare but serious complication associated with the use of this broad-spectrum antibiotic. We present the case of a teenager with a history of nasopharyngeal cancer who developed DIEP while receiving daptomycin to treat an infection associated with an implanted chamber catheter. Symptoms included recurrent dyspnea and peripheral eosinophilia, with radiological findings consistent with DIEP. The pathophysiology involves an immune response triggered by daptomycin, resulting in eosinophilic pulmonary inflammation. Diagnosis requires a thorough evaluation of medical history, clinical laboratory tests, and radiological findings. The main treatment involves discontinuation of daptomycin and, in severe cases, the use of steroids. It is essential to consider DIEP in patients with respiratory failure and bilateral pulmonary opacities who have used daptomycin and to suspect it in those with blood eosinophilia or in bronchoalveolar lavage.

Eosinophilic asthma is the most prevalent and well-defined phenotype of asthma. Despite a majority of patients responding to corticosteroid therapy and T2 biologics, there remains a subset that have recurrent asthma exacerbations, highlighting a need for additional therapies to fully ameliorate airway eosinophilia. Group 2 innate lymphoid cells (ILC2) are considered key players in the pathogenesis of eosinophilic asthma through the production of copious amounts of type 2 cytokines, namely IL-5 and IL-13. ILC2 numbers are increased in the airways of asthmatics and with the greatest numbers of activated ILC2 detected in sputa from severe prednisone-dependent asthma with uncontrolled eosinophilia. Although epithelial-derived cytokines are important mediators of ILC2 activation, emerging evidence suggests that additional pathways stimulate ILC2 function. The tumor necrosis factor super family (TNFSF) and its receptors (TNFRSF) promote ILC2 activity. In this review, we discuss evidence supporting a relationship between ILC2 and TNFSF/TNFRSF axis in eosinophilic asthma and the role of this relationship in severe asthma with airway autoimmune responses.