Quiescent Crohn’s Disease in Clinical Remission With 6-Mercaptopurine: A Breeding Ground for CMV Pneumonia as Part of a Viral Infection Domino

Abstract

Cytomegalovirus (CMV) infection is frequently associated with inflammatory bowel disease (IBD). CMV pneumonitis has been reported infrequently in patients with IBD, while there has been one such report in a patient with quiescent Crohn's disease (CD) under long-term immunosuppressant treatment with 6-mercaptopurine (6-MP). We present an unusual case of a 24-year-old male, with fistulized CD in clinical remission under 6-MP, who presented with fever and increased seropurulent fistulae effusion. Shortly after admission, he presented nonproductive cough, pancytopenia, elevated serum aminotransferases, hypoxemia and bilateral pulmonary reticulonodular infiltrates expanding from basal bronchopulmonary segments towards the hila. Positive CMV IgM/IgG, pp65 antigen and CMV-PCR confirmed the diagnosis of CMV pneumonitis. Enterococcus faecium and faecalis were also separately isolated from cultures of two different, concurrent enterocutaneous fistulae. Successful treatment included antiviral and appropriate antibiotic therapy. A subsequent adenovirus co-infection in this patient, demonstrating a viral domino phenomenon, illustrates the difficulty of establishing a final diagnosis in a complex case.