DETERIORATION OF RESPIRATORY STATUS IN A CVID PATIENT WITH GLILD AND COVID-19

INTRODUCTION: Granulomatous Lymphocytic Interstitial Lung Disease (GLILD) is a serious inflammatory complication of Common Variable Immunodeficiency (CVID), typically requiring immunomodulation in an already immunodeficient patient. CASE DESCRIPTION: A 34-year-old male with CVID, heterozygous for pathogenic variant c.310T>C (p.Cys104Arg) in TNFRSF13B, on immunoglobulin replacement therapy, and biopsy-confirmed GLILD that was in remission in Fall 2020 presented for follow up. GLILD was treated with rituximab weekly from March-April 2019 and azathioprine 150 mg daily. His azathioprine dose was decreased in June 2019 to 100 mg daily secondary to recurrent infections while on therapy. Despite the decreased azathioprine dose, he felt well and follow up CT Chest in September 2019 showed near-complete resolution of lung nodules. Treatment was discontinued after two of the anticipated 3-4 cycles. His second rituximab course was completed from September-November 2019, and azathioprine was decreased to 50 mg maintenance dose and stopped in November 2020. He contracted COVID-19 in Winter 2021 requiring hospitalization and treatment with remdesivir and dexamethasone. He recovered from COVID-19 and his respiratory symptoms returned to baseline. In June 2021, however, he developed progressive dyspnea, lymphadenopathy, and CT Chest performed in September showed multiple pulmonary nodules concerning for recurrence of GLILD. A second round of rituximab and mycophenolate mofetil has been started due to concern for relapse vs. inadequate treatment of GLILD. DISCUSSION: Our case highlights the diagnostic dilemma of determining the cause of this patient's ongoing respiratory disease. The possibilities include GLILD relapse due to incomplete treatment or ineffective treatment, or sequelae of COVID-19 infection.