Case Presentation: A 75 year-old man with no significant history presented with four weeks of malaise and lower extremity rash, five days of cough and rhinorrhea, and one day of pleuritic chest pain that he attributed to incessant coughing. On arrival he was febrile to 38.3 Celsius and tachycardic to 120 beats per minute. His exam was notable for petechial rash over the bilateral lower extremities. His labs were significant for leukocytosis to 14.7 x10*3/µL, hemoglobin of 6.3 g/dL and platelet count of 40 x10*3/µL. Blasts and tear drop cells were observed. Bone marrow biopsy confirmed myelodysplastic syndrome (MDS) with excessive blasts. He also tested positive for respiratory syncytial virus. A Chest CT angiogram revealed marked thickening of the proximal descending aorta with extensive infiltration in the surrounding mediastinal fat compatible with active aortitis. There were also multifocal ill-defined ground glass opacities consistent with viral infection, but no pulmonary embolism. Thorough infectious workup was performed to rule out bacterial and fungal etiologies. Rheumatologic serologies including antinuclear antibody, rheumatoid factor, and angiotensin-converting enzyme were negative. 1 mg/kg of prednisone was started for presumed paraneoplastic aortitis secondary to MDS. He was also started on azacitidine and venetoclax for high-risk MDS after discharge. A repeat CT scan after months later revealed resolution of aortitis.
Discussion: Aortitis refers to the inflammation of the aorta and can be categorized as infectious or inflammatory. Although the most common causes of aortitis are large vessel vasculitides such as giant cell arthritis and Takayasu arthritis, it is important to rule out infectious etiologies as immunosuppressive therapies can worsen an infectious process, and missing an infectious aortitis can be fatal. It was an especially important distinction in our patient who presented with a fever that could be explained by a concomitant viral infection and was also expected to start treatment for his MDS. It has been estimated that 10 to 20 percent of MDS patients present with or develop systemic inflammatory or autoimmune conditions. MDS-associated aortitis is rare but has been described in case reports. Although the exact pathogenesis is unknown, it has been postulated that dysfunctional T cells from underlying dysplastic hematopoiesis may play a role in large vessel arteritis. Patients with aortitis can present with pain, fever, arterial insufficiency, or aneurysm. The varied and non-specific symptoms can make diagnosing aortitis challenging. Because the presence of an autoimmune disorder is associated with worse prognoses in patients with MDS, it is important to not miss aortitis for its prognostic and management implications.
Conclusions: Myelodysplastic syndrome-associated aortitis is a rare autoimmune entity and can be difficult to diagnose given the nonspecific clinical presentation, but is important to consider given its prognostic and management implications.