Baig, Hassan Z

Abstract Background With recent advances in oncology, tyrosine kinase inhibitors like imatinib play a significant role in gastrointestinal stromal tumor (GIST) treatment but can cause rare pulmonary complications. When new respiratory symptoms arise after starting these agents, differentiating drug toxicity from other lung diseases is important for timely management. Case Presentation A 72-year-old man with GIST, recently started on imatinib, presented with acute dyspnea and hypoxia. His medical history included chronic obstructive pulmonary disease and a 40-pack-year smoking history. Chest CT revealed new bilateral interstitial infiltrates absent on imaging two months ago, prior to imatinib initiation. The differential diagnosis included imatinib-induced pneumonitis versus atypical infection. Bronchoscopy showed yellowish nodular mucosa throughout the trachea and bronchi, mucus plugging, and airway narrowing in the left lower lobe. Endobronchial biopsies demonstrated amyloid deposits consistent with tracheobronchial amyloidosis. The bronchoalveolar lavage was negative for infection and, therefore, corticosteroid therapy was initiated, resulting in clinical and radiographic improvement. The findings supported a diagnosis of imatinib-induced pneumonitis coexisting with tracheobronchial amyloidosis. Discussion This case highlights the diagnostic challenges when drug-induced pneumonitis occurs along with structural airway abnormalities. Tracheobronchial amyloidosis, although rare, can cause airway obstruction and coexist with inflammatory lung conditions. The temporal association with imatinib, exclusion of infection, and steroid responsiveness indicate imatinib-induced pneumonitis as the primary cause of the acute symptoms, with concurrent amyloid deposition contributing to airway pathology. Conclusion In patients developing new pulmonary symptoms after starting tyrosine kinase inhibitors, drug-induced pneumonitis should be strongly suspected. The coexistence of airway diseases such as tracheobronchial amyloidosis can complicate diagnosis and management, highlighting the need for thorough evaluation including bronchoscopy and tissue biopsy to guide treatment. This abstract is funded by: None

Microplastics may pose health risks, particularly for chronic lung diseases. Clarifying the link between circulating microplastics and pulmonary disease is vital for shaping research and interventions. The objective of this study was to evaluate whether microplastics in peripheral blood are associated with COPD or IPF vs. no lung disease. In this pilot prospective case-control study, participants were grouped as control (n = 10), COPD (n = 9), or IPF (n = 10). Relevant comorbidities and exposures were obtained from records and questionnaires. All underwent standardized blood collection (PlasticTox©). Samples were analyzed for total microplastic concentration, stratified by size (<10 µm, 10–30 µm, 30–70 µm). The primary outcome was to show a difference in total microplastic burden between lung disease and controls. Secondary measures were to determine size-specific concentrations and associations with demographic variables and smoking history. Among 29 participants (median age 70 (IQR 64–80); 14 women (48.3%)), COPD/IPF groups had significantly higher total microplastic concentrations vs. controls (median 26.0 vs. 3.5 particles/100 µL; p < 0.01). Particle burdens <10 µm and 10–30 µm were particularly elevated (both p < 0.01). After adjusting for smoking, only the <10 µm fraction remained independently associated with lung disease (adjusted odds ratio 1.94 (95% CI, 1.23–7.04)). In this pilot exploratory study, individuals with COPD or IPF showed greater circulating microplastic levels than controls. These findings should be interpreted as hypothesis-generating, and larger analytically validated studies are needed to clarify directionality, causal mechanisms, contamination control, and the clinical relevance of circulating microplastic burden.

Abstract Introduction: Acute Eosinophilic pneumonia (AEP) is an eosinophilic pulmonary condition defined by symptoms of less than or equal to 1 month's duration, pulmonary infiltrates on imaging, pulmonary eosinophilia of 25% or greater on bronchoalveolar lavage (BAL) cell count or eosinophilic pneumonia on lung biopsy, and absence of other eosinophilic pulmonary diseases. It can be associated with a multitude of exposures, including medications, inhalants as well as systemic conditions. We report a case of AEP associated with intramuscular (IM) progesterone administration. Case: A 36-year-old female presented to the emergency department with dyspnea on exertion, cough productive of yellow sputum, and subjective fever of two days’ duration. She had undergone in vitro fertilization using IM Progesterone as luteal phase support and experienced a miscarriage one week prior. She had a heart rate of 132 and required oxygen at 2 Liters per minute via nasal cannula to maintain her saturation at 92%. Her complete blood count showed an absolute eosinophil count of 1800 cells/uL. She underwent a computed tomography angiography scan of the chest, which was negative for a pulmonary embolism but showed diffuse bilateral peripheral ground-glass opacities as well as consolidations in both lung bases. She was empirically started on prednisone 40 mg per day. She later underwent a flexible bronchoscopy with BAL of the right middle lobe as well as transbronchial cryobiopsies of the right lung. The BAL cell differential showed 63% eosinophils confirming the diagnosis of AEP. Pathology revealed patchy organizing pneumonia with scattered eosinophils. Autoimmune workup was negative, including antineutrophil antibodies, Anti-myeloperoxidase, and anti-proteinase-3 antibodies. Infectious workup, including blood, sputum, and BAL cultures, was also negative. The patient dramatically improved with steroid administration. Her symptoms resolved, and she was discharged on room air with a 4-week prednisone taper. A follow-up chest x-ray revealed resolution of the infiltrates. Discussion: AEP is a rare condition. One epidemiological study estimated the incidence of AEP at 9.1/100,000 person-years in a population of United States military personnel. Given the lack of other inciting medications and negative autoimmune and infectious workup, IM progesterone administration was deemed the likely etiology of her presentation. There are four case reports of IM progesterone as a cause of AEP. This case represents a classic presentation of AEP with the secondary to progesterone administration and with symptoms resolving promptly with steroid administration.

Abstract Introduction Medullary thyroid cancer (MTC) is an uncommon malignancy arising from the C-cells of the thyroid gland. It makes up 2% of all thyroid cancers, with both familial and sporadic patterns noted. It is most commonly diagnosed in the fourth to sixth decade of life, with the lungs being a common site of metastasis. We present a case of metastatic MTC with a rare pulmonary presentation. Case Description The patient presented at the age of 28 after having a chronic complaint of stomach pain and diarrhea. Imaging of the abdomen revealed small nodules in the lower pulmonary fields. Dedicated imaging of the chest was subsequently ordered. This study was notable for an enlarged left lobe of the thyroid extending into the mediastinum with two large mediastinal lymph nodes. A fine-needle aspiration of the left neck lymph node was consistent with MTC and there were hematologic findings of elevated calcitonin and CEA. Testing for the RET proto-oncogene was negative. Pathology on total thyroidectomy confirmed the diagnosis, with further sampling identifying metastasis in the thoracic spine (T12). Initial therapy with pazopanib was commenced. After some time on stable therapy, the patient was noted to have waxing and waning pulmonary micro-nodularity associated with increase in his calcitonin levels. There was a finding of a miliary pattern of disease on chest imaging. The pulmonary service was consulted due to these findings in conjunction with sub-acute cough. Pulmonary biopsy was performed, with findings of nodular amyloidosis; Congo red stain highlighted amyloid deposition. Immunohistochemical studies were performed, revealing rare cell groups that were positive for calcitonin, CEA, CAM5.2, TTF-1, chromogranin, and synaptophysin. After further discussion with the Pathology service, the patient was given formal diagnosis of amyloid deposition of the Acal subtype due to metastatic medullary thyroid cancer. Discussion This case highlights a patient diagnosed with sporadic MTC, later found to have metastatic related pulmonary amyloid deposition. While local amyloid deposition can be seen in MTC, it is unusual to have diffuse parenchymal disease due todiffuse parenchymal disease due to distant deposition. There are only four other instances in the literature of a similar presentation. Amyloid deposition is associated with worse outcomes, but the patient had a good outcome with treatment by a tyrosine-kinase inhibitor.

Objective: Pulmonary involvement is commonly observed in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), presenting with manifestations such as diffuse alveolar hemorrhage, inflammatory infiltrates, pulmonary nodules, and tracheobronchial disease. We aimed to identify distinct subgroups of tracheobronchial disease patterns in patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) using latent class analysis (LCA), and to evaluate their clinical characteristics and outcomes. Methods: We conducted a retrospective cohort study using electronic medical records of patients aged >18 years diagnosed with AAV and tracheobronchial disease between 1 January 2002 and 6 September 2022. Patients with follow-up <6 months were excluded. LCA was employed to identify disease subtypes based on 10 pre-defined indicators. Maximum likelihood estimation with 10 repetitions per model ensured robustness in model selection, guided by the Akaike information criterion (AIC). Patient and disease characteristics were summarized and compared across predicted classes. Statistical analyses included Kruskal–Wallis and Fisher’s exact tests for continuous and categorical variables, respectively. The primary outcome was time to relapse of the tracheobronchial inflammation after starting immunosuppressive medication, analyzed using the Kaplan–Meier method and log-rank tests. Secondary outcomes included severity of pulmonary disease on pulmonary function tests, endoscopic interventions, tracheostomy, or mortality during follow-up. Results: Among 136 identified AAV patients assessed for tracheobronchial involvement, 111 (81.6%) were included after excluding 25 without tracheal or bronchial disease. Predominant findings included subglottic stenosis (91.0%), lower tracheal stenosis (16.2%), and bronchial stenosis (17.1%). LCA identified a three-class model as optimal: tracheal predominant (n = 94), tracheobronchial (n = 12), and bronchial predominant (n = 5). Tracheal predominant patients showed reduced risk of ear, eye, and lower respiratory manifestations, with milder obstruction on pulmonary function testing (PFT). Tracheobronchial-class patients were prone to saddle nose deformity (50%), extensive lower respiratory involvement (91.7%), and renal disease (66.7%). Bronchial predominant patients exhibited severe obstructive disease (median forced expiratory volume in 1 s (FEV1)% predicted: 58, IQR 34–66; FEV1/forced vital capacity (FVC) ratio: 56.9, interquartile range (IQR) 43–63.3) but lacked systemic AAV manifestations. LCA classes did not predict outcomes such as endoscopic intervention, tracheostomy, recurrent tracheobronchial narrowing, or mortality. Conclusion: LCA shows promise in subtype stratification of AAV patients, yet its utility in predicting outcomes and guiding treatment remains limited based on our analysis. Future studies with enhanced phenotypic data and larger cohorts are warranted to improve predictive accuracy.

Background/Objectives: Peri-intubation hypotension is a known complication of endotracheal intubation. In the hospital setting, peri-intubation hypotension has been shown to increase hospital mortality and length of stay. The use of prophylactic vasopressors at the time of sedation induction to prevent peri-intubation hypotension has been raised. This systematic review and meta-analysis aims to review the safety and efficacy of this practice. Methods: The study was fully registered with PROSPERO on 13 October 2022, and screening for eligibility was initiated on 20 September 2024. Randomized controlled trials, along with retrospective or prospective cohort studies, were included in the search. The terms “peri-intubation hypotension”, “vasopressors”, “intubation”, and “anesthesia induced hypotension” were used to search the title/summary in PubMed, Cochrane Library, and Google Scholar databases. An assessment of bias for each study was conducted using the Newcastle-Ottawa Quality Assessment Scale. The primary outcome was the rate of hypotension peri-intubation. Any complications secondary to hypotension or vasopressors were the secondary outcome. Results: We identified 13 studies, which were all randomized controlled studies, to include in the final analysis. The risk ratio for preventing peri-intubation hypotension was 1.6 (95% CI, 1.2–2.14) with the use of prophylactic phenylephrine while giving propofol versus no prophylactic vasopressors and 1.28 (95% CI 1.03–1.60) with the use of ephedrine. Conclusions: These findings suggest that in patients undergoing intubation in the operating room with propofol, prophylactic vasopressors given with induction for intubation decrease the odds of hypotension.

Background/Objective: To investigate the effect of mycophenolate mofetil (MMF) and rituximab (RTX) on pulmonary function test (PFT) results in a mixed cohort of patients with connective tissue disease-associated interstitial lung disease (CTD-ILD), longitudinally followed up for 1 year in a single academic center. Methods: Patients with CTD-ILD were identified in electronic medical records from 1 January 2009 to 30 April 2019. Prescribed MMF and RTX doses, dosage changes, and therapy plans were analyzed individually with improvement in PFT outcomes determined using multivariable linear regression models during 12-month follow-up. Results: Forty-seven patients with CTD-ILD, treated with MMF, RTX, or both, were included. Patients on combined MMF and RTX had worse PFT outcomes at baseline compared with patients on monotherapy. Substantial improvement was observed among all PFT outcomes from baseline to 12 months, regardless of medication dosage or therapy plans. The diffusing capacity of the lungs for carbon monoxide (DLCO) worsened by an average of 7.21 mL/(min*mmHg) (95% CI, 4.08–10.33; p < 0.001) among patients on RTX compared to combined therapy. Patients on higher doses of MMF at baseline experienced an average increase of 0.93 (95% CI, 0.04–1.82) units in DLCO from baseline to 6 months (p = 0.04) and a 2.79% (95% CI, 0.61–4.97%) increase in DLCO from 6 to 12 months (p = 0.02) within patients on concurrent RTX at 6-month follow-up. Conclusions: The treatment of CTD-ILD with MMF and/or RTX was associated with overall improvement in PFT outcomes. Combined therapy resulted in significant improvements in DLCO compared with monotherapy. Higher doses of MMF also provided greater improvements in DLCO.

The evidence on indications, outcomes, and complications with the use of extracorporeal membrane oxygenation (ECMO) in the setting of interstitial lung disease (ILD) is limited in the existing literature. We performed a systematic review and meta-analysis for the use of ECMO in the setting of ILD to study the prognostic factors associated with in-hospital mortality. Eighteen unique studies with a total of 1,356 patients on ECMO for ILD were identified out of which 76.5% were on ECMO as a bridge to transplant (BTT) and the rest as a bridge to recovery (BTR). The overall in-hospital mortality was 45.76%, with 71.3% and 37.8% for BTR and BTT, respectively. Among the various prognostic factors, mortality was lower with younger age (mean difference = 3.15, 95% confidence interval [CI] = 0.82–5.49), use of awake veno-arterial (VA)-ECMO compared to veno-venous (VV)-ECMO (unadjusted odds ratio [OR] = 0.22, 95% CI = 0.13–0.37) in the overall cohort. In the setting of BTT, the use of VA-ECMO had a decreased hazard ratio (HR) compared to VV-ECMO (adjusted HR = 0.34, 95% CI = 0.15–0.81, p = 0.015). The findings of our meta-analysis are critical but are derived from retrospective studies with small sample sizes and thus are of low to very low-GRADE certainty.

Objective The aims of this study were to assess whether a relationship between anti–SSA-52 and interstitial lung disease (ILD) can be further defined, and to enhance screening, detection, and potentially guide treatment. Methods A historical cohort study of 201 patients was conducted at a single tertiary care center between January 1, 2016 and December 31, 2020. All included patients were anti–SSA-52 antibody positive. Chart review was performed for laboratory values, symptoms, pulmonary function tests, treatment, and imaging. Chest computed tomographies were reviewed by chest radiologists. Results Among anti–SSA-52 antibody–positive patients, ILD was found in 125 (62.2%) compared with 76 (37.8%) with no ILD (p = 0.001). For those with ILD, 78 (62.4%) were diagnosed with connective tissue disease (CTD)–associated ILD, 28 (22.4%) were diagnosed ILD only, and 19 (15.2%) met the criteria for interstitial pneumonia with autoimmune features. In patients with CTD-ILD, 18 (23.0%) had their ILD diagnosis made over 6 months before a CTD diagnosis, and an additional 43 (55.1%) had their ILD and CTD diagnosed within 6 months of each other (p < 0.001). Common computed tomography patterns were nonspecific interstitial pneumonia/organizing pneumonia overlap in 44 (35.2%), 25 (20.0%) nonspecific interstitial pneumonia, and 15 (12%) usual interstitial pneumonia. Twenty-eight (35.9%) had antisynthetase syndrome, followed by 16 (20.5%) with dermatomyositis, 10 (12.8%) with CTD overlap, and 6 (7.7%) with systemic scleroderma. Conclusions There was a significant association between anti–SSA-52 antibodies and ILD across a wide spectrum of rheumatological diagnoses. A significant portion of patients were diagnosed with ILD either at the same time or before their CTD diagnosis. Further study will be needed to assess effective treatment and response.

ABSTRACT Background and Objectives: Comorbid risk factors in chronic hypersensitivity pneumonitis (CHP) are poorly characterised. Gastroesophageal reflux disease (GERD) is linked to interstitial lung diseases like idiopathic pulmonary fibrosis (IPF), but its association and treatment in CHP is less understood. This study aims to understand the role and prevalence of GERD in CHP, plus the effect of GERD treatment on lung function and mortality. Methods: A tertiary referral centre panel was retrospectively reviewed for 214 patients diagnosed with CHP based on clinical history, bronchoalveolar lavage fluid analysis, imaging and histopathology. GERD diagnostic criteria included symptomology, acid suppressive therapy use and diagnostic testing. CHP patients with GERD ( n = 89) and without GERD ( n = 125) were compared via descriptive statistical analysis. Pulmonary function, GERD diagnosis plus treatment and other comorbidities were evaluated against CHP outcomes. Results: Respective differences between diagnosis and study termination dates in the GERD population versus without GERD for functional vital capacity (FVC) were − 1 L vs − 2.5 L, diffusing capacity of the lungs for carbon monoxide (DLCO) were − 2 mL/min/mmHg versus − 1 mL/min/mmHg, per cent alive at the time of study 88% versus 81%, median date of survival 574.5 versus 850 and supplemental oxygen requirement 41% versus 37%. GERD prevalence was higher in CHP patients relative to the general population. No statistical significance was found between survival curves, oxygen requirement, smoking history, FVC, or DLCO. Conclusions: GERD could be a harmful comorbidity in CHP though may not necessarily affect survival or functional outcomes. This aligns with previous IPF studies, though remains controversial. Further research is needed regarding this association and treatment benefit.