B63-05 Kidneys, Eyes and Lungs: A Rare Rheumatologic Diagnosis With Associated Pulmonary Disease

Abstract Introduction Tubulointerstitial nephritis and uveitis (TINU) is a rare syndrome characterized by renal and ocular inflammation. There are few published cases that describe lung disease associated with TINU. Here, we report the presence of interstitial lung disease in a pediatric patient with TINU who improved after treatment with immunomodulatory agents. Case Description A 14-year-old previously healthy boy developed malaise, nausea, vomiting, cough, weight loss and fever for two weeks, and was hospitalized for evaluation of fever of unknown origin. He had elevated markers of systemic inflammation (ESR 100 mm/hr, CRP 49.1 mg/L) and kidney injury (Cr 0.98 mg/dL). Urine beta-2 microglobulin was significantly elevated (3000 µg/L), suggesting tubular dysfunction. On day two of admission, he developed pain and redness in both eyes and slit-lamp examination confirmed the presence of bilateral anterior uveitis. Chest CT revealed diffuse ground-glass opacities in the lungs with small foci of consolidation. He underwent robot-assisted bronchoscopy with intraoperative 3D imaging, endobronchial ultrasound, robot-assisted lung biopsy with cryotherapy, and bronchoalveolar lavage (BAL). BAL cell count showed lymphocytic and neutrophilic inflammation, and infectious studies were negative. Histopathologic evaluation of biopsied lung tissue demonstrated focal intraalveolar fibrin and fibromyxoid tissue, consistent with organizing pneumonia. A thorough multidisciplinary evaluation ruled out infectious, gastrointestinal, and oncologic processes. Specific rheumatologic diagnoses including SLE, Sjogren’s syndrome, and ANCA-associated vasculitides were considered less likely based on negative ANA and ANCA testing. He was empirically treated for TINU with mycophenolate and prednisolone, with clinical improvement in his ocular and constitutional symptoms. A follow up chest CT showed complete resolution of ground glass opacities. Pulmonary function testing at the time of his follow up showed normal spirometry, diffusing capacity, and lung volumes. Over the next months, his symptoms were limited to uveitis flares, with no respiratory limitation. Discussion Published literature documenting lung disease in TINU is limited, with one case report describing lymphoid interstitial lung disease in an adult patient that responded to steroid treatment. Our case suggests a potential overlap between a rare renal and ocular inflammatory condition and interstitial lung disease, which responded well to immunomodulatory therapy. Future studies on the pulmonary manifestations of TINU are warranted to explore this association further. This abstract is funded by: None