Acute HIV infection presenting as hemophagocytic lymphohistiocytosis: case report and review of the literature.

Background: Hemophagocytic lymphohistiocytosis (HLH) is an uncommon systemic inflammatory condition that can result from infections, autoimmune diseases and malignancies. It is a rarely reported life threatening complication of an acute HIV infection, with only ten documented case reports per our literature search. We present a case of HLH secondary to acute HIV infection with a negative HIV antibody-based assay and high plasma viral load.
Case Presentation: A 45 year old male with a past medical history of well controlled hypertension presented with fever, dizziness and non-bloody diarrhea. Initial lab work revealed a new thrombocytopenia, marked renal failure and an elevated creatine kinase, ferritin, lactate dehydrogenase and D-dimer. A bone marrow biopsy revealed HLH. As part of the work up for thrombocytopenia, a rapid HIV antibody based assay was done and was negative. The sample was later routinely tested with a fourth generation antigen/antibody assay as per local protocol and was strongly positive. The plasma RNA viral load was >10,000,000 copies /mL confirming the diagnosis of an acute HIV infection. The patient was urgently started on antiretroviral therapy and recovered.
Conclusion: This case illustrates a diagnostic approach to HLH which is an uncommon but life threatening multisystem disease, requiring the involvement of a multidisciplinary team of experts. Following any diagnosis of HLH, rapid identification and treatment of the underlying condition is critical. A negative rapid HIV antibody test can be misleading in the context of early HIV infection and the additional use of fourth generation antigen/antibody test or plasma RNA viral load may be required within the right clinical context for diagnosis.