Therapeutic plasma exchange in primary hemophagocytic lymphohistiocytosis: Reports of two cases and a review of the literature.

We report two children who were diagnosed as having primary hemophagocytic syndrome and who successfully underwent therapeutic plasma exchange (TPE). The first patient was a 6-month-old girl diagnosed with HLH who was admitted to the pediatric intensive care unit. The patient's clinical condition worsened on the 9th day of the HLH-2004 treatment protocol. Her ferritin level was found 50.000 ng/mL, and TPE was performed for 9 sessions, after which her clinical condition and laboratory findings improved. The patient is still on the HLH-2004 protocol and waits for a suitable stem cell transplantation donor. Case 2 involved a Syrian girl with HLH under follow-up who was receiving the HLH-2004 treatment protocol for reactivation. She presented to emergency department with fever, where her ferritin level was measured greater than 100.000 ng/mL; she was then transferred to the pediatric intensive care unit where four sessions of TPE were performed, after which her clinical condition and laboratory findings improved. However, the patient was admitted again one month later with gastrointestinal bleeding and died despite all efforts. By describing these two cases, we wish to emphasize that TPE can produce a rapid improvement until the time of stem cell transplantation in patients with hemophagocytic syndrome who do not respond to traditional treatments.