Abstract
BACKGROUND: Cytomegalovirus is a pathogen known to aggravate the inflammatory response in autoimmune diseases via molecular mimicry. Although it is recognized that cytomegalovirus activation can happen during extended but variable periods of immunosuppression (14-90 days), it is rarely reported in conjunction with an acute flare-up of an autoimmune disease. Currently, there is no consensus on cytomegalovirus prophylaxis for patients initiating remission induction. CASE PRESENTATION: Here, we present the case of a 31-year-old male patient of South Indian ethnicity, presenting with a 2-month history of fever, conductive hearing loss, and ear discharge. This was associated with symmetrical inflammatory polyarthritis for 1 month, unilateral painful conjunctivitis, and skin erythema for 5 days. Blood analyses showed elevated inflammatory markers; strongly positive anti-proteinase 3 and cytoplasmic antineutrophil cytoplasmic antibody levels; normal procalcitonin and complement levels; and negative anti-myeloperoxidase and perinuclear antineutrophil cytoplasmic antibody levels. A nasal endoscopy revealed a midline granuloma with vasculitis features on biopsy. Imaging revealed pulmonary nodules and otomastoiditis. Now diagnosed with granulomatosis with polyangiitis, the patient developed signs of gastroduodenitis within a day of initiation of immunosuppression with high-dose "pulse" intravenous methylprednisolone. We evaluated him for mesenteric ischemia/gastrointestinal vasculitis. However, the duodenal biopsies from the bleeding ulcers revealed a probable cytomegalovirus infection, confirmed with high serum viral loads. We treated him with a ganciclovir regimen and transitioned him to steroid-sparing immunosuppressant therapy with mycophenolate mofetil, which was selected over cyclophosphamide for its noninferior effectiveness and better safety profile in non-life-threatening granulomatosis with polyangiitis disease. The patient recovered uneventfully and is currently in remission. CONCLUSION: Cytomegalovirus reactivation is possible during short-term steroid pulse therapy. Further research is needed to evaluate whether routine cytomegalovirus screening is warranted before starting immunosuppressive treatment with high-dose steroids in autoimmune conditions.