Severe complication during remission of Crohn's disease: hemophagocytic lymphohistiocytosis due to acute cytomegalovirus infection.

INTRODUCTION: Immunosuppressive therapy is today's standard treatment of patients with moderate to severe inflammatory bowel disease (IBD). The risk for opportunistic infections is increased due to this therapy and is a concern in the management of patient with IBD undergoing such a treatment.

CASE REPORT: In this paper, we describe a case of an acute cytomegalovirus (CMV) infection in a 35-year-old male patient with Crohn's disease being in remission while receiving azathioprine therapy. His clinical presentation was high-grade fever, night sweats, skin rash, and abdominal pain.Laboratory findings showed pancytopenia, elevated liver enzymes, and high ferritin levels. Sonographic examination revealed splenomegaly and serological analysis proved an acute CMV infection. The severity of the acute illness and these results in the setting of immunosuppressive treatment with azathioprine were highly suspicious of hemophagocytic lymphohistiocytosis (HLH).Further investigations including bone marrow biopsy, analysis of natural killer cell function, and measurement of T-cell activity confirmed the suspected diagnosis. Treatment consisted of antiviral and symptomatic therapy.

DISCUSSION AND CONCLUSION: HLH is a rare and severe condition triggered by uncontrolled stimulation of histiocytes and lymphocytes, resulting in abnormal cytokine production. The causes can be primary (genetic) or secondary due to acquired immunodeficiency or viral infections such as CMV. Several symptoms of this condition are unspecific, but the summary of clinical symptoms and signs are diagnostic. Treatment consists of specific intervention if possible and application of immunosuppressive drugs such as corticosteroids.