Incidence, etiology, and outcome of hospital-acquired pneumonia in patients with acute exacerbation of fibrotic idiopathic interstitial pneumonia.

BACKGROUND: Acute exacerbations (AEs) of fibrotic idiopathic interstitial pneumonia (fIIP) that require hospitalization occur in some patients. During hospitalization, these patients can develop hospital-acquired pneumonia (HAP), a common hospital-acquired infection with a high mortality rate. However, the characteristics of HAP in AE-fIIP remain unknown. The purpose of this study was to determine the incidence, causative pathogens, and outcomes of HAP in patients with AE-fIIP. METHODS: The medical records of consecutive patients who were hospitalized with AE-fIIP from January 2008 to December 2019 were analyzed for the incidence, causative pathogen, and survival of HAP. The records of patients with an obvious infection-triggered AE were excluded from analysis. RESULTS: There were 128 patients with AE-fIIP (89 with idiopathic pulmonary fibrosis [IPF] and 39 with non-IPF fIIP) who were hospitalized a total of 155 times (111 with IPF and 44 with non-IPF fIIP). HAP occurred in 49 patients (40 with IPF and 9 with non-IPF fIIP). The incidence and the in-hospital mortality rates of HAP in patients with AE-fIIP were high, at 32.2% and 48.9%, respectively. Corynebacterium spp. was the most common causative pathogen, which was followed by human cytomegalovirus (HCMV). CONCLUSIONS: The incidence and the in-hospital mortality rates of HAP in patients with AE-fIIP are high. To improve their survival, patients with fIIP who had AEs and HAP should receive prompt empirical treatment for possible infections with Corynebacterium spp. and testing for HCMV.

Chemotherapy versus best supportive care in advanced lung cancer and idiopathic interstitial pneumonias: A retrospective multi-centre cohort study.

BACKGROUND: The clinical questions of whether chemotherapy as initial treatment, compared with best supportive care (BSC), improves overall survival (OS) and whether it increases the occurrence risk of acute exacerbation of idiopathic interstitial pneumonia (IIP) in patients with advanced-stage lung cancer and IIP remain inconclusive. This study addresses these issues, given that chemotherapy-related acute exacerbation of IIP may be a direct cause of mortality in these patients. METHODS: We enrolled 1003 patients from 110 Japanese institutions and collected clinical profiles from 707 and 296 patients in the chemotherapy (men: women, 645:62; mean age, 70.4 ± 6.9 years) and BSC (men: women, 261:35; mean age, 75.2 ± 7.8) groups, respectively. We used propensity score matching to create 222 matched pairs from both groups using patient demographic data (age, sex, smoking status, performance status, history of acute exacerbation of IIP, desaturation on exertion, clinical diagnosis of IIP, high-resolution computed tomography findings, serum fibrotic markers, pulmonary function status, and lung cancer histopathology). Logistic or Cox regression analyses were performed using matched data to assess the effects of chemotherapy on the risk of acute exacerbation of IIP or OS, respectively. RESULTS: In the well-matched cohort, chemotherapy improved OS (hazard ratio: 0.629, 95% confidence interval [CI]: 0.506-0.783, p < 0.0001); however, it involved significant acute exacerbation of IIP (odds ratio: 1.787, 95% CI: 1.026-3.113) compared to BSC. CONCLUSIONS: Compared with BSC, chemotherapy can improve OS in patients with advanced-stage lung cancer and IIP; however, it increases the risk of acute exacerbation of IIP.

[The role of artificial intelligence in assessing the progression of fibrosing lung diseases].

INTRODUCTION: The widespread use of artificial intelligence (AI) programs during the COVID-19 pandemic to assess the exact volume of lung tissue damage has allowed them to train a large number of radiologists. The simplicity of the program for determining the volume of the affected lung tissue in acute interstitial pneumonia, which has density indicators in the range from -200 HU to -730 HU, which includes the density indicators of "ground glass" and reticulation (the main radiation patterns in COVID-19) allows you to accurately determine the degree of prevalence process. The characteristics of chronic interstitial pneumonia, which are progressive in nature, fit into the same density framework. Аim. To аssess AI's ability to assess the progression of fibrosing lung disease using lung volume counting programs used for COVID-19 and chronic obstructive pulmonary disease. RESULTS: Retrospective analysis of computed tomography data during follow-up of 75 patients with progressive fibrosing lung disease made it possible to assess the prevalence and growth of interstitial lesions. CONCLUSION: Using the experience of using AI programs to assess acute interstitial pneumonia in COVID-19 can be applied to chronic interstitial pneumonia.

Acute Interstitial Pneumonia (Hamman-Rich Syndrome) in Lung Transplantation: A Case Series.

BACKGROUND: Acute interstitial pneumonia (AIP), also known as Hamman-Rich syndrome, is a rare and rapidly progressive idiopathic interstitial lung disease with a high mortality rate. Treatment is limited to supportive care and empirical high-dose steroids; however, outcomes are generally poor. There are few reports of lung transplantation (LTx) in patients with AIP. METHODS: We retrospectively identified patients with AIP among those who underwent LTx at our center between January 2008 and December 2020. RESULTS: During the study period, 4 patients with AIP underwent bilateral LTx: 3 men and 1 woman, between 30 and 57 years of age. The lung allocation score ranged between 71 and 89. Of the 4 patients, 2 needed extracorporeal membrane oxygenation and mechanical ventilation (MV) and 1 needed MV preoperatively. Time of onset to transplant ranged from 1 to 3 months. None of the patients had primary graft dysfunction after LTx; 2 had acute cellular rejection and 1 had chronic lung allograft dysfunction. The 4 patients are alive with survival ranging between 1 and 12 years after LTx. CONCLUSION: AIP should be considered in patients with acute respiratory failure without a clear etiology. Our study showed that LTx led to good outcomes and should be considered as a treatment option in appropriate candidates.

Acute interstitial pneumonia and the biology of 3-methylindole in feedlot cattle.

Acute interstitial pneumonia (AIP) of cattle has been recognized for many decades. While the pathogenesis and risk factors for this condition in pastured cattle are relatively well characterized, there remains a poor understanding of the disease as it occurs in intensively fed cattle such as in beef feedlots. Specifically, in pastured cattle, AIP results from excessive ruminal production of the pneumotoxicant 3-methylindole (3-MI). In feedlot cattle, the evidence to substantiate the role of 3-MI is comparatively deficient and further investigations into the cause, pathogenesis, and control are sorely needed. This review highlights our current understanding of AIP with a focus on the disease as it occurs in feedlot cattle. Additionally, it illustrates the need for further work in understanding the specific animal factors (e.g. the ruminal microbiome, and the role of concurrent diseases), management factors (e.g. animal stocking and vaccination protocols), and dietary factors (e.g. dietary supplements) that may impact the development of AIP and which are relatively unique to the feedlot setting. All stakeholders in the beef industry stand to benefit from a greater understanding of what remains a pressing yet poorly understood issue in beef production.

Síndrome de Hamman: a propósito de un caso / Hamman Syndrome, a case study / Sindrome de Hamman, relato de caso

Introducción: el síndrome de Hamman es la aparición de neumomediastino espontáneo asociado a enfisema, patología poco frecuente en pediatría. Sus síntomas principales son dolor torácico agudo, disnea y enfisema subcutáneo. Objetivo: describir una experiencia clínica en la que se sospechó este síndrome analizando el proceso diagnóstico, estudios complementarios y el tratamiento. Caso clínico: varón de 4 años, con antecedentes personales de laringitis a repetición. Presenta laringitis aguda severa, requirió ventilación no invasiva por 12 horas. A las 24 horas del ingreso instaló de forma brusca estridor inspiratorio, dificultad respiratoria, edema de cuello y cara con crepitación a nivel de cuello y cara anterior del tórax que se fue extendiendo a ambos brazos. Se realiza radiografía de tórax que evidencia enfisema subcutáneo extenso. Se realiza tomografía de cuello y tórax que descarta lesión en vía aérea. Con el planteo de síndrome de Hamman en un niño que presentaba como factor predisponente el episodio de laringitis aguda, se decidió no continuar con estudios complementarios. Se realizó tratamiento fisiopatológico con buena evolución clínica. Alta a la semana del ingreso. Conclusiones: el diagnóstico en la urgencia del neumomediastino espontáneo puede representar un desafío, con una variedad de diagnósticos diferenciales potencialmente mortales. La alta sospecha permitirá realizar una evaluación clínica e imagenológica adecuada que permitan confirmar su diagnóstico y evitar procedimientos invasivos innecesarios.

Introduction: Hamman's syndrome involves the appearance of spontaneous pneumomediastinum associated with emphysema, a rare pathology in pediatrics. Its main symptoms include acute chest pain, dyspnea and subcutaneous emphysema. Objective: to describe a clinical case of this suspected syndrome by analyzing the diagnostic process, supplementary studies, and treatment. Clinical case: 4-year-old male with personal history of repeated laryngitis. He presented severe acute laryngitis, requiring non-invasive ventilation for 12 hours. Twenty-four hours after admission he developed abrupt inspiratory stridency, respiratory distress, neck, and face edema with crepitation at neck level and front of thorax spreading to both arms. A chest X-ray shows extensive subcutaneous emphysema. A neck and chest CT scan rules out airway injury. With the suggestion of Hamman's syndrome in a child who presented acute laryngitis as a predisposing factor the episode, it was decided not to continue with additional studies. Physio-pathological treatment was carried out with good clinical evolution. He was discharged a week after admission. Conclusions: diagnosis of spontaneous pneumomediastinum can be challenging in an emergency setting and having a variety of potentially life-threatening differential diagnoses. High suspicion levels will enable an adequate clinical and imaging assessment to confirm its diagnosis and avoid unnecessary invasive procedures.

Introdução: síndrome de Hammam é o aparecimento de pneumomediastino espontâneo associado ao enfisema, uma patologia rara na pediatria. Seus principais sintomas são dor aguda no peito, dispneia e enfisema subcutâneo. Objetivo: descrever um caso clínico com suspeita dessa síndrome por meio da análise do processo diagnóstico, estudos complementares e tratamento. Caso clínico: menino de 4 anos com histórico pessoal de laringite recorrente. Teve laringite aguda grave, o que exigiu ventilação não invasiva por 12 horas. Dentro de 24 horas após a internação, instalou-se abruptamente estridor inspirador, dificuldade respiratória, edema do pescoço e rosto com estalos ao nível do pescoço e face anterior do peito, estendido para ambos braços. Raios-x do tórax mostram enfisema subcutâneo extenso. Tomografia do pescoço e tórax exclui lesões nas vias aéreas. Com a sugestão da síndrome de Hammam em uma criança que apresentou como fator predisponente o episódio de laringite aguda, decidiu-se não continuar com estudos complementares. O tratamento fisiopatológico mostrou boa evolução clínica. A alta teve lugar dentro de uma semana da data da internação. Conclusões: o diagnóstico na urgência do pneumomediastino espontâneo pode representar um desafio, além do mais quando existem uma variedade de diagnósticos diferenciais que ameaçam a vida. A alta suspeita permitirá uma avaliação clínica e de imagem adequada para confirmar o diagnóstico e evitar procedimentos invasivos desnecessários.

Expression of airway smooth muscle contractile proteins in children with acute interstitial pneumonia.

The purpose of the present study was to investigate the expression of α-SMA and SM22α in airway smooth muscle (ASM) of bronchioles from children younger than 14 years who died of acute interstitial pneumonia (AIP). This is based upon the hypothesis that as contractile marker proteins α-SMA and SM22α can serve as an index of the overcontractile phenotype of ASM that is seen in AIP. Lung tissue samples of children were obtained from autopsies and divided into the AIP group (55.9% male and 44.1% female, between 0.4 and 132 months old, n = 34) and the control group (60% male and 40% female, between 2 and 156 months old, n = 10). We recorded the post-mortem interval (PMI), height, clinical symptoms and abdominal fat thickness (AFT) of each case. Haematoxylin-and-eosin-stained sections were used to examine the luminal area and observe the morphological changes in the bronchioles. Immunohistochemistry and Masson's trichrome staining were used to detect the expression of contractile marker proteins and the degree of pulmonary fibrosis respectively. Compared with the control group, the luminal areas of bronchioles in the AIP group were smaller (p < .001). The expression differences in α-SMA and SM22α between the two groups were statistically significant (p = .01 and p = .02 respectively). Also, there was no significant correlation of the contractile marker proteins expression with PMI, height, clinical symptoms and AFT. The collagen deposition difference in lung between the two groups was not statistically significant (p = .224). These findings suggest that enhancement of ASM contractile function appears to be involved in the death mechanism of children with AIP, which affords more insights into the understanding of AIP.

Comparative Histopathology of Bovine Acute Interstitial Pneumonia and Bovine Respiratory Syncytial Virus-Associated Interstitial Pneumonia.

Acute interstitial pneumonia (AIP) is a significant disease of cattle and many aetiologies have been implicated on the basis of the characteristic pathological lesions. Bovine respiratory syncytial virus (BRSV) is one of the key aetiological factors in bovine respiratory disease complex and several studies have suggested, controversially, that BRSV may be an underlying cause of bovine AIP. BRSV infection is known to cause several distinctive histopathological changes, including epithelial syncytia formation and intracytoplasmic viral inclusions. However, distinguishing bovine AIP from BRSV-related pneumonia by clinical presentation, gross pathology or histopathology can sometimes be challenging. In order to identify the potential distinguishing features, we compared the histopathological findings of AIP that were, and were not, associated with BRSV infection in naturally occurring cases. We found that multinucleated giant cells were more frequently identified in cattle with AIP while bronchiolitis was more common in BRSV-infected cattle. However, this was not considered a sole indicator of either disease group. Statistically, we identified that a combination of several histopathological features, including alveolar septal necrosis, presence of multinucleated giant cells and bronchiolitis, can serve as an excellent indicator for distinguishing between idiopathic AIP and BRSV-related pneumonia, with a strong statistical significance (P = 0.0004). Based on the results of this retrospective study, we present a histopathological scoring system for predicting BRSV-associated AIP.

Neumomediastino espontáneo en paciente con COVID-19 / Sponteneous pneumomediastinum in patient with COVID-19

Introducción: El neumomediastino espontáneo o síndrome Hamman es una complicación poco frecuente y rara. Se define como la presencia de aire o gas dentro del mediastino sin una causa identificada. Objetivo: Presentar un caso clínico con una complicación poco frecuente, neumomediastino espontáneo, en un paciente con enfermedad por COVID-2019. Caso clínico: Paciente de 86 años con cuadro clínico manifestado por fiebre de 38o C y síntomas respiratorios (tos con secreción blanquecina, disnea de moderados esfuerzos). Se realiza prueba de reacción en cadena de polimerasa para enfermedad por coronavirus 2019, esta fue positiva. Al cuarto día de su hospitalización concurre con empeoramiento clínico dentro que lo destaca tos y disnea progresiva acompañado con saturación de oxigeno menor a 91 por ciento. Se realizaron estudios imagenológicos de alta resolución (angiotomografía computarizada de tórax) en la cual se evidencia la presencia de neumomediastino. Desarrollo: La pandemia por enfermedad por coronavirus 2019 ha dado lugar a una emergencia de salud pública a nivel mundial, en la que es importante que el personal de la salud esté familiarizados con los síntomas, los resultados de imágenes y con las complicaciones de esta enfermedad, como el neumomediastino encontrado en este caso. Conclusión . El neumomediastino espontáneo es una complicación poco frecuente que se presenta en la fase inflamatoria de esta enfermedad(AU)

Introduction: Spontaneous pneumomediastinum or Hamman syndrome is a rare and infrequent complication. It is defined as the presence of air or gas within the mediastinum without an identified cause. Objective: To report a clinical case of spontaneous pneumomediastinum in a patient with COVID-2019, a disease with a rare complication. Clinical case report: We report the case of an 86-year-old patient with a clinical condicion of fever of 38o C and respiratory symptoms (cough with whitish secretions, dyspnea on moderate exertion). He underwent a polymerase chain reaction test for coronavirus disease 2019, which resulted positive. On the fourth day of his hospitalization, he his clinical condition worsened, including cough and progressive dyspnea accompanied by oxygen saturation less than 91 percent. The presence of pneumomediastinum was revealed by high-resolution imaging studies (computed tomography angiography of the chest). Discussion: The 2019 coronavirus disease pandemic has given rise to a global public health emergency, which requires health personnel to be familiar with symptoms, imaging results, and complications of this disease, such as pneumomediastinum found in this case. Conclution: Spontaneous pneumomediastinum is a rare complication that occurs in the inflammatory phase of this disease(AU)

SUCCESSFULLY TREATED ACUTE INTERSTITIAL PNEUMONIA.

Acute interstitial pneumonia (AIP) is a rare idiopathic interstitial pneumonia with histology finding of diffuse alveolar damage (DAD). It is characterized by progressive hypoxic respiratory failure, high mortality rate, and absence of guidelines for its treatment. Here we present a case of a 64-year-old woman with progressive dyspnea, acute respiratory failure, diffuse bilateral reticulonodular opacities on standard chest radiograph, diffuse ground-glass opacities on computed tomography, and biopsy proven DAD. Diagnosis of AIP was established after extensive work-up that excluded the known risk factors for acute respiratory distress syndrome. Oxygen therapy and high-dose parenteral corticosteroids led to gradual improvement and resulted in complete respiratory recovery. Since there are no existing guidelines for treating AIP, more case reports and case series if not randomized control trials are warranted in order to define the most effective therapeutic modality.

Síndrome de Hamman - rich: Reporte de caso / Hamman-Rich Syndrome: case report

Resumen La neumonía intersticial aguda, también conocida como síndrome de Hamman-Rich, se caracteriza por la presencia de insuficiencia respiratoria aguda, hallazgo imagenológico de infiltrados difusos bilaterales del parénquima pulmonar y daño alveolar difuso en histopatología pulmonar. Es una patología con una mortalidad mayor al 50% debido a la falta de una terapia específica más allá del manejo sintomático y soporte ventilatorio. Se expone el caso de un paciente masculino de 56 años quien se presenta con síntomas respiratorios inespecíficos, deterioro progresivo de la oxigenación y hallazgo de opacidades en vidrio esmerilado difusas bilaterales. Además, biopsia pulmonar en la que se evidencia daño alveolar difuso en fase fibroproliferativa en quien se descarta proceso infeccioso, enfermedades autoinmunes y toxicidad medicamentosa, por lo que se hace el diagnóstico. Recibió manejo con pulsos de metilprednisolona con recuperación completa del cuadro. MÉD.UIS.2021;34(3): 103-8.

Abstract Acute interstitial pneumonitis, also known as Hamman Rich syndrome, characterised by acute respiratory failure, bilateral lung infiltrates on radiographs and diffuse alveolar damage (DAD) on lung histopathology, is an exclusion diagnosis which requires a complete study of other possible etiologies of DAD. It is a pathology with a mortality greater than 50% due to not having a specific therapy beyond symptomatic management and ventilatory support. We present a case of a 56 year old male with respiratory symptoms, who has progressive worsening oxygen levels and bilateral ground glass opacities on chest images. Lung biopsy with diffuse alveolar damage, infection, autoimmune diseases, and drug adverse reaction were ruled out. Managed with mechanical ventilation and high dose systemic corticoids with complete recovery. MÉD.UIS.2021;34(3): 103-8.

Diagnostic imaging in acute interstitial pneumonia in foals: High variability of interpretation of chest radiographs and good conformity between ultrasonographic and post-mortem findings.

Acute interstitial pneumonia (AIP) in foals is a rare but challenging syndrome. Diagnostic imaging is crucial for its diagnosis. While there are some reports on radiographic findings, ultrasound is sparsely described. Variability in the evaluation of radiographs in AIP has been well described in human literature. Part one of this study is a prospective, observational, observer agreement study investigating inter- and intraobserver agreement in the assessment of thoracic radiographs. Part two is a prospective, controlled, descriptive study on thoracic ultrasonography in foals with AIP. Eighteen foals with AIP were examined daily by thoracic ultrasound. Thoracic radiographs were taken on three successive occasions. Blinded radiographs were assessed by three observers based on two semi-quantitative scores (pattern recognition, subjective evaluation). Foals that died underwent postmortem examination (n = 9); postmortem findings were compared to ultrasound findings on the day of death. Ultrasonographic findings were consistent with postmortem findings. Comet tail scores in foals with AIP were significantly higher (p < 0.0001) than in control foals. Interrater agreement for the assessment of radiographs was none to moderate (κ = 0.07-0.65) for pattern recognition and weak to moderate (κ = 0.58-0.62) for subjective scoring. Intrarater agreement varied from minimal to strong (κ = 0.30-0.80) for pattern recognition but was strong (κ = 0.83) for subjective scoring. In conclusion, the diagnostic value of thoracic ultrasound in foals with AIP is high due to good conformity with postmortem findings. The evaluation of thoracic radiographs showed high variability in inter- and intra-agreement.

Acute interstitial pneumonia in foals: A severe, multifactorial syndrome with lung tissue recovery in surviving foals.

BACKGROUND: Acute interstitial pneumonia in foals has been sparsely described in literature, and the individual authors disagree on the underlying aetiology. Histopathological follow-up from surviving foals is not available. OBJECTIVES: Description of clinical and histopathological findings in the course of acute interstitial pneumonia and in recovery. Investigating the aetiology and possible triggering factors of acute interstitial pneumonia. STUDY DESIGN: Case series. METHODS: Post-mortem examination of nine affected foals; seven died during the acute phase, and two had recovered from acute interstitial pneumonia. Data from clinical examinations on the day of death were recorded for all foals. Complete necropsy, special histological staining, virological and microbiological examinations were performed. RESULTS: Seven foals died during the acute phase with severe respiratory distress, fever and increased numbers of comet tail artefacts in lung ultrasound. In post-mortem examination, a wide variety of possible triggering factors was identified. Microbiology revealed Escherichia coli, Rhodococcus equi and Klebsiella pneumoniae as the most common bacterial pathogens. Equine herpesvirus 2 was detected in all foals by PCR. Those with high viral loads also displayed histopathological changes suggestive of viral infections. Pneumocystis carinii was detected in all acutely affected foals. Histopathological changes in lung parenchyma clearly differed between the foals that had recovered from acute interstitial pneumonia and those dying in the acute phase. While lungs in acute phase featured marked parenchymal collapse and necrosis, the recovered foals revealed nearly normal ventilated lung parenchyma and alveolar structure. MAIN LIMITATIONS: Small number of cases. Because all foals are from the same breeding farm with endemic occurrence of pathogens, it is not certain whether the results of this study can be transferred to other foals without restrictions. CONCLUSIONS: Acute interstitial pneumonia seems to be based on a multifactorial aetiology. Lungs from foals that have survived acute interstitial pneumonia appear to be able to regenerate completely, leaving no permanent changes.

Is unclassifiable idiopathic interstitial pneumonia a result of idiopathic pleuroparenchymal fibroelastosis?

The present article reports the case of a 51-year-old female patient who was clinically diagnosed with idiopathic pleuroparenchymal fibroelastosis in the initial phase of the disease. The upper and lower lobes showed a pleuroparenchymal fibroelastosis pattern and reticular shadow, respectively. Both upper and lower shadows gradually progressed. Five years following the first detection of the chest shadow, left single-lung transplantation was performed. In the multidisciplinary discussion held after the lung transplantation, most participants recognized this end-stage lung disease as unclassifiable idiopathic interstitial pneumonia though the major pathological findings showing a pleuroparenchymal fibroelastosis pattern.

Resecting a giant malignant lung tumor in a patient with unilateral acute interstitial pneumonitis.

Acute interstitial pneumonia is a rare and fulminant form of idiopathic interstitial lung disease. Here, we report a case of a giant malignant sarcomatoid tumor of the left lung with unilateral lung infiltration. The tumor was resected under venovenous extracorporeal membrane oxygenation support. Right middle lung lobe biopsy revealed alveolar epithelial hyperplasia, mild interstitial fibrosis, and interstitial edema. The patient was diagnosed with acute interstitial pneumonitis, and effectively treated with steroid pulse therapy followed by prednisolone. In this case, the contralateral lung expansion accomplished with tumor resection, definitive diagnosis based on lung biopsy, and corticosteroid treatment possibly improved the outcome.

Immune Checkpoint Inhibitor Therapy-related Pneumonitis: Patterns and Management.

In recent years, the use of immune checkpoint inhibitor (ICI) therapy has rapidly grown, with increasing U.S. Food and Drug Administration approvals of a variety of agents used as first- and second-line treatments of various malignancies. ICIs act through a unique mechanism of action when compared with those of conventional chemotherapeutic agents. ICIs target the cell surface receptors cytotoxic T-lymphocyte antigen-4, programmed cell death protein 1, or programmed cell death ligand 1, which result in immune system-mediated destruction of tumor cells. Immune-related adverse events are an increasingly recognized set of complications of ICI therapy that may affect any organ system. ICI therapy-related pneumonitis is an uncommon but important complication of ICI therapy, with potential for significant morbidity and mortality. As the clinical manifestation is often nonspecific, CT plays an important role in diagnosis and triage. Several distinct radiographic patterns of pneumonitis have been observed: (a) organizing pneumonia, (b) nonspecific interstitial pneumonia, (c) hypersensitivity pneumonitis, (d) acute interstitial pneumonia-acute respiratory distress syndrome, (e) bronchiolitis, and (f) radiation recall pneumonitis. Published guidelines outline the treatment of ICI therapy-related pneumonitis based on the severity of symptoms. Treatment is often effective, although recurrence is possible. This article reviews the mechanism of ICIs and ICI therapy complications, with subsequent management techniques and illustrations of the various radiologic patterns of ICI-therapy related pneumonitis.©RSNA, 2019.