Hemophagocytic Lymphohistiocytosis Associated With Human Herpesvirus-6 (HHV-6) Infection in an Immunocompetent Adult: A Case Report.

Hemophagocytic lymphohistiocytosis (HLH) is a rare disorder characterized by extreme immune activation and excessive inflammation. It has been reported in patients with familial cases, immunodeficiencies, malignancies, stem cell transplants, and viral etiologies. This report describes acquired HLH associated with Human herpesvirus-6 (HHV-6) infection in a 76-year-old previously healthy male. The patient was admitted to the hospital due to fever, chills, and abdominal pain. The diagnostic workup revealed gallbladder wall thickening on imaging, concerning for cholecystitis. The patient was started on treatment for sepsis. Further clinical deterioration led to an extensive infectious workup. The patient was found to have elevated soluble IL-2Ra levels, and a bone marrow biopsy was performed, which revealed HLH. A positive HHV-6 polymerase chain reaction in the cerebrospinal fluid and serum confirmed the viral infection. Treatment involved the initiation of high-dose steroids, etoposide, and ganciclovir. Despite these interventions, the patient's clinical status worsened, leading to the implementation of comfort measures, and the patient eventually died. This case underscores the importance of considering HHV-6 as a potential cause of HLH in immunocompetent adults. From this case, we infer that a heightened level of vigilance is necessary to recognize and intervene in this challenging condition promptly.