Adult hemophagocytic lymphohistiocytosis with severe pulmonary hypertension and a novel perforin gene mutation.

Adult hemophagocytic lymphohistiocytosis (HLH) is a rare and deadly hyperinflammatory syndrome presenting both diagnostic and therapeutic challenges. HLH may be primary, due to an underlying genetic abnormality, and/or secondary to infection, malignancy, or rheumatologic conditions. We describe a case of HLH-associated severe pulmonary hypertension paralleling Epstein-Barr virus (EBV) reactivation in a 52-year-old male in whom a novel perforin missense mutation was found (PRF1 1517C>T). Although intolerant of standard therapy (HLH-2004 protocol), a 6-week course of anti-CD52 (alemtuzumab) was associated with freedom-from-transfusion from weeks 4 to 13. However, 15 weeks after the onset of salvage therapy, he succumbed to polymicrobial sepsis despite treatment with prophylactic anti-infectives, with necropsy revealing disseminated blastomycosis and relapsed HLH. This case illustrates uncertainties in the relationships between pulmonary hypertension, a newly described PRF1 mutation, and possible pre-existing latent infectious risk factors (such as EBV or Blastomyces) in the pathogenesis and therapeutic perils of adult HLH.