Asad, Dayab

Abstract Background Pneumocystis jirovecii pneumonia (PJP) is commonly seen in immunocompromised patients. Telomere biology disorder (TBD), which is a genetic disorder marked by mutations in telomere-maintenance genes, leading to shortened telomere, accelerated aging, and multi-systems effects including the pulmonary and immune systems. Idiopathic pulmonary fibrosis (IPF) is the most common pulmonary manifestation in TBD. Opportunistic infections, such as PJP, occurring de novo are rare in TBD, presenting unique diagnostic and therapeutic challenges. Case Presentation We present a female in her seventies with chronic dry cough and exertional dyspnea referred for evaluation of interstitial lung disease (ILD). Her family history revealed early-onset pulmonary fibrosis in her mother and sister. A year before the presentation, she developed acute hypoxic respiratory failure with bilateral pulmonary infiltrates. Bronchoalveolar lavage confirmed PJP despite no established immunosuppression. She received Bactrim and prednisone without clinical improvement. High-resolution chest CT revealed progressive infiltrates and fibrotic lung disease. Surgical lung biopsy showed organizing pneumonia, diffuse alveolar damage, and fibrosis, consistent with probable usual interstitial pneumonia (UIP). Ultimately, she developed rapidly progressive ILD. Further evaluation ruled out autoimmune and connective tissue disease. Telomere studies confirmed TBD, with her lymphocyte and granulocyte telomere lengths between the 1st and 10th percentiles. (figure1) Genetic testing is underway for familial pulmonary fibrosis. Discussion This case illustrates a rare presentation of PJP de novo in a patient with TBD, highlighting opportunistic infections risk in those patients without immunosuppression and before transplantation. TBD results in quantitative and qualitative T-cell immunodeficiency, reducing CD4+ T-cell count, predisposing to opportunistic infections, including PJP. TBD patients often experience a rapidly progressive course of ILD due to inherited telomere dysfunction causing limited regenerative capacity of Alveolar epithelial type 2 cells (AEC2s) exacerbated by environmental or age-related factors such as oxidative stress or smoking. Management requires a multidisciplinary approach with early genetic testing, antifibrotic therapies, and prophylactic treatments to prevent infections. This case underscores the importance of considering TBD in patients with opportunistic infections like PJP in the absence of traditional immunosuppressive risk factor and in patients with premature or progressive pulmonary fibrosis. Conclusion Telomere biology disorder can present with rapidly progressive ILD with atypical infections like PJP while on immunosuppression. To the best of our knowledge de novo PJP pneumonia in patient with TBD is unreported in the literature. High clinical suspicion, quantitative CD4 evaluation and consideration of PJP prophylaxis prevent an otherwise fatal outcome. Figure1:

Abstract Introduction Rheumatoid arthritis (RA) is a systemic autoimmune rheumatic disease (SARD) primarily associated with articular involvement, but is often associated with lung involvement, sometimes preceding articular symptoms. Common pulmonary manifestations include interstitial lung disease (ILD), airway, and serosal involvement. RA-related pleural disease can mimic empyema due to the pleural fluid's green, pus-like appearance, exudative nature, low pH, markedly low glucose, and elevated lactate dehydrogenase (LDH) levels. Empyema sometimes yields negative cultures which can accentuate the diagnostic challenge in such cases. This report presents a patient with RA-related pleural lung disease who was referred to our hospital with trapped lung presumed to be secondary to empyema in the setting of pleural-based pulmonary abscess. Case Report A 66-year-old female with a 22-year history of RA presented with recurrent right-sided pleural effusions and progressive dyspnea over three years. Her initial presentation in 2022 involved a large right-sided pleural effusion, suspected to result from a ruptured pleural-based pulmonary abscess that led to empyema and subsequently a trapped lung. Pleural fluid analysis showed elevated LDH (1364 U/L), low glucose (45 mg/dL), high cholesterol (121 mg/dL), and low triglycerides (79 mg/dL). Due to refractory exudative effusion and a comprehensive negative infectious evaluation (bacterial, mycobacterial, and fungal cultures), RA-related pleural disease was suspected. The patient underwent video-assisted thoracoscopic surgery (VATS), which revealed pleural-based rheumatoid nodules and pleural thickening. (figure1) Lung and pleural biopsies confirmed RA-associated fibrinous pleuritis, RA-associated follicular bronchiolitis, and usual interstitial pneumonitis. Given the complexity of the infection, a thoracotomy with decortication and pleurectomy was planned and conducted in stages. Immunosuppressive regimen was switched from leflunomide to rituximab. Discussion This case underscores the diagnostic complexity in distinguishing RA-associated pleural effusion from empyema. Features such as pleural nodularity resembling a pulmonary abscess, unilateral exudative effusion, grossly purulent pleural fluid, low pH and glucose, and elevated LDH levels led to an initial misdiagnosis of empyema. Characteristic pleural fluid, along with persistent negative cultures and absence of sepsis pointed towards RA-related pleural disease. VATS and biopsy were instrumental in establishing the final diagnosis through characteristic histopathological findings of RA-associated pleural, parenchymal and airway involvement. Conclusion For RA patients with pleural effusion suggestive of empyema, especially in the context of negative cultures and no signs of sepsis, RA-related pleural disease should be a consideration. Early recognition and timely immunosuppressive therapy escalation can prevent complications such as trapped lungs and reduce the necessity for extensive surgical interventions. Figure1:

Abstract Introduction Unilateral pulmonary vein atresia (UPVA) is a rare congenital anomaly involving absent or obstructed pulmonary veins (PV), often leading to chronic pulmonary venous stasis, recurrent infections, and hemoptysis. Although typically diagnosed in infancy, UPVA can present in adulthood. This report presents a 63-year-old male referred as a case of chronic thromboembolic pulmonary disease (CTEPD) who was diagnosed with UPVA. We describe the diagnostic complexities and potential explanation for loss of pulmonary artery (PA) perfusion in such cases. Case Presentation A 63-year-old man was referred to rule out CTEPD. His past medical history included coronary artery disease and sleep apnea. He presented with chronic cough, repeated hemoptysis, recurrent pneumonias requiring prolonged antibiotics use, and progressive exertional dyspnea. Physical examination was unremarkable. Pulmonary function tests showed moderate restriction and moderately-reduced diffusion capacity. A ventilation-perfusion (V/Q) scan revealed complete absence of perfusion in the left lung. [figure1] High-resolution CT revealed a straight left atrial border sign with absent left superior and inferior PVs, left pulmonary arterial tree hypoplasia, hypoplastic left lung with fibrotic changes due to chronic venous-lymphatic engorgement and pulmonary hypoperfusion. CT also showed compensatory right lung hyperinflation and bronchial artery collaterals. Echocardiography indicated an atrial septal defect (ASD) with no pulmonary vascular disease. Based on CT angiography, UPVA was considered the leading diagnosis. Discussion UPVA is a congenital disease rarely presenting in adulthood with recurrent infections, hemoptysis, and fibrosis. It often accompanies congenital cardiac conditions, like ASD in our case. Pulmonary angiography may reveal ipsilateral PA hypoplasia and atrophied peripheral vessels. The absence of perfusion in the V/Q scan could be explained by reversed blood flow in the PA from congestion caused by the atretic PVs and ipsilateral backflow from the bronchial arteries collaterals. Differential diagnosis like CTEPD was excluded due to atypical complete loss of perfusion of the left lung, and lack of the other radiological stigmata. Swyer-James-MacLeod syndrome was excluded due to a mismatched perfusion defect. Proximal Interruption of the PA was also excluded due to normally developed proximal left and right PAs. Imaging is crucial in showing absent PVs and hypoplastic ipsilateral lung. Conservative management for UPVA is recommended. Given recurrent infections and hemoptysis, pneumonectomy can be considered. Conclusion This case illustrates the atypical presentation of UPVA as a CTEPD mimicker, presenting with absent pulmonary perfusion unilaterally, which can be explained by reversed pulmonary flow secondary to venous engorgement and backflow from bronchial artery collaterals. Figure1: