Disappearing Pulmonary Nodules With Developing Demyelination: A Case of Myeloperoxidase Antibody Positive Vasculitis With IgA Deposition on Kidney Biopsy
American Journal of Respiratory and Critical Care Medicine
Introduction: Anti-Neutrophilic cytoplasmic antibodies associated vasculitides (AAV) with pulmonary and renal involvement are rare. Here we describe a rare case of Myeloperoxidase (MPO) positive vasculitis presenting with features of sarcoidosis but developed demyelinating disease. Case presentation: A 41-year-old woman presented with chronic cough for one year. Past medical history notable for recurrent migraines. She reports 10 pack-year history of smoking. She denied any occupational exposure to chemicals, fumes, or toxins. She has a pet parakeet at home. Initial workup revealed mild anemia, creatinine of 1.41mg/dL, as well as elevated serum anti-nuclear antibody (ANA), anti-double stranded DNA (ds-DNA) and angiotensin converting enzyme. Urinalysis showed proteinuria and microscopic hematuria. Initial ANCA was negative. With persistent cough and positive lupus serologies, CT scan of chest was performed, which showed scattered bilateral patchy reticular and nodular opacities in the upper lobe predominantly along with enlarged perihilar, mediastinal lymph nodes (Figure). A kidney biopsy revealed features suggestive of possible IgA nephropathy with moderate interstitial fibrosis and glomerulosclerosis with no evidence of Immune complex deposition as expected in Lupus nephritis. She had bronchoscopy with endobronchial ultrasound and transbronchial biopsy which did not show granulomas. Follow up serological work up positive for P-ANCA and Myeloperoxidase antibodies. Multidisciplinary interstitial lung disease meeting suggested features of sarcoidosis and vasculitis. A decision was made to treat with steroids 0.5mg/Kg for 1 month and taper to 5 mg for 3 months. Repeat CT scan of chest in 3 months showed significant improvement of lymphadenopathy and resolution of pulmonary opacities. At subsequent follow-up visits she reported worsening symptoms along with new-onset paresthesia and numbness of fingertips. An MRI showed moderate burden of FLAIR signal hyperintensities involving the supratentorial white matter and brainstem concerning for demyelinating lesions. There was also evidence of C2 and C6-7 areas of demyelination. She is continued on low-dose prednisone and is being evaluated at Vasculitis center. Discussion: It is uncommon for AAV to cause delayed axonal multiple mononeuropathy. (1) Pulmonary manifestations seen with AAV respond to immunosuppressive therapy, as with our patient, resulting in resolution of pulmonary nodules seen in the initial chest imaging. (2) This case illustrates the importance of early recognition of ANCA vasculitis as a cause of demyelinating disease.
Alam A, Pothugunta K, Hasan A, Nair GB. Disappearing pulmonary nodules with developing demyelination: a case of myeloperoxidase antibody positive vasculitis with IgA deposition on kidney biopsy. Am J Respir Crit Care Med. 2023 May;207(Suppl.):A5491. doi:10.1164/ajrccm-conference.2023.207.1_MeetingAbstracts.A5491