HLH is a systemic disorder caused by immune dysregulation that occurs in primary and secondary forms. Secondary HLH refers to cases caused by infections, malignancy and autoimmune diseases. HLH secondary to infections can occur with viral, bacterial, fungal or parasitic infections[1]. Malaria is rarely reported to cause HLH. We report a case of a 29-year-old young woman with fever, hepatosplenomegaly, pancytopenia, high serum ferritin, hypertriglyceridemia, hypofibrinogenemia and bone marrow hemophagocytosis, consistent with hemophagocytic syndrome. Plasmodium falciparum (P. falciparum) was identified on a peripheral blood smear. Rapid recovery was observed after treatment with antimalarial medications, immunomodulatory therapy and supportive care.
Case presentation
A 29-year-old young woman was admitted to the hospital due to intermittent fever for 12 days. The patient had an unexplained fever (Tmax 41℃), chills and anorexia after a trip to Nigeria and Dubai in September 2018. However, the patient concealed her travel history while visiting the local hospital. She was diagnosed with pneumonia and received antibiotic treatment. With poor response to antibacterial treatment, the patient developed nausea, vomiting, upper abdominal pain, respiratory distress and oliguria. Further investigations showed negativity for Epstein–Barr virus (EBV) DNA but positivity for EBV-IgM. Bone marrow biopsy revealed hemophagocytosis. The patient was diagnosed suspiciously with EBV-related HLH, and she was transferred to our hospital for emergency treatment.
We obtained a detailed medical history from the patient and learned about her history of travel. Physical examination revealed a blood pressure of 105/64 mmHg, wet rales in the lower lung and upper abdominal tenderness. Blood tests showed cytopenias, increased liver transaminases, increased bilirubin, hypertriglyceridemia, increased serum ferritin and splenomegaly on abdominal ultrasonography and CT (computed tomography) (Figure 1). Tests for EBV and cytomegalovirus DNA were negative. There was no evidence of a tumor. A peripheral blood smear showed P. falciparum (Figure 2a), which was determined to have a 3D7 genotype. Bone marrow aspiration showed the presence of hemophagocytosis (Figure 3), with a soluble CD25 (sCD25) level of 21,574 pg/ml and negative results for natural killer cell (NK cell) activity. A final diagnosis of malaria-associated secondary HLH was made.
The treatment regimen for malaria included artemether at 80 mg q12h for 4 days and then 80 mg qd for 5 days, which was changed to dihydroartemisinin and piperaquine phosphate 2 tablets qd for 5 days. At the same time, the patient received treatment with methylprednisolone 80 mg qd for 4 days. Since we considered the HLH to be secondary to malaria, we treated the primary disease and used intravenous immunoglobulin (IVIG) for 5 days (total dose of 2 g/kg). After 7 days of treatment, no P. falciparum was found in the peripheral blood smear (Figure 2b), and tests for malarial antigens were negative. The patient’s condition improved gradually, and her clinical and laboratory manifestations were normalized (Table 1).
Subsequently, the patient manifested multiorgan dysfunction. She exhibited acute kidney injury (creatine 569 µmol/l with oliguria), acute liver injury, acute respiratory distress syndrome (P/F 100 mmHg) and coagulopathy and was treated with continuous renal replacement therapy, high-flow nasal cannula oxygen therapy (HFNC), blood transfusion and nutritional support in the critical care unit. After 7 days of organ support treatment, the patient’s respiratory and renal function recovered to normal, and her liver-enzyme and bilirubin levels decreased. She was discharged in normal physical condition after 25 days. No relapses were documented at her six-month and 1-year follow-ups.