A69-28 The Diagnostic Dilemma of a Rare Case of Nocardia and Aspergillus Co-infection in a Patient With Focal Segmental Glomerulosclerosis

Abstract Introduction Concurrent infections with Nocardia species and Aspergillus species are incredibly rare with 20 reported cases in severely immunocompromised patients between 1984 and 2023. These infections are often facilitated by impaired immune response, and have multiple clinical, and radiographic overlap, resulting in significant diagnostic challenges. We present a case of a patient with severe immunocompromise due to focal segmental glomerulosclerosis (FSGS) who was found to have bilateral cavitary lesions with work-up that was remarkable for Nocardia brasiliensis/vulneris, and Aspergillus niger. Case Presentation A 60-year-old male with FSGS on prednisone who presented with worsening bilateral lower extremity edema and dyspnea for two months. Over the past month while on steroids, he developed a cough with hemoptysis, but denied fevers, and weight loss. He was originally from Mexico but has been residing in the US since the 1980s without traveling back. He worked in construction for over 30 years. On presentation, vitals were stable. Physical exam noted clear lungs, oropharyngeal thrush, and pitting edema with ecchymosis. Further work up with Computed tomography (CT) chest reviewed bilateral pulmonary emboli, and left upper and right upper lobe cavitary lesions, with apical nodule. Further imaging also noted a right occlusive peroneal vein thrombosis. Infectious work up included fungal serology were negative for Coccidioides immunodiffusion / complement fixation / antigen, Blastomyces antibodies, Cryptococcus antigen, Histoplasma urine antigen, and Aspergillus galactomannan. Bronchoalveolar lavage was pursued with tissue and lavage cultures ultimately growing Nocardia brasiliensis/vulneris, and Aspergillus niger. Given the patient’s clinical symptoms, radiographic findings and immunosuppression, he was empirically treated for both organisms with meropenem and voriconazole pending susceptibilities. Discussion This case illustrates the diagnostic difficulties of Aspergillus and Nocardia co-infections in immunocompromised patients. The diagnostic challenge arises from the nonspecific pulmonary symptoms, the overlapping radiographic findings of cavitary lesions with both species, and the low fungal serology sensitivity. Although Aspergillus Niger is a pulmonary colonizer, due to these diagnostic uncertainties in the setting of severe immunocompromise, clinicians ought to empirically treat both organisms. Conclusion Although Nocardia and Aspergillus co-infections are rare, they individually carry significant mortality. Clinicians should maintain a high index of suspicion for both organisms causing infections in patients with evidence of immunocompromise regardless of radiographic findings, or serology results. Early bronchoscopic evaluation and cultures are essential for timely diagnosis and treatment, as bronchoalveolar lavage sampling sensitivity is less dependent on host immunologic status. This abstract is funded by: None