Continuous hemodiafiltration in the treatment of reactive hemophagocytic syndrome refractory to medical therapy

Reactive (or secondary) hemophagocytic syndrome (RHS) is a potentially lethal condition and characterized by hypercytokinemia. Immune modulating drugs sometimes fail to achieve satisfactory control. Therefore we investigate the efficacy of continuous hemodiafiltration using a polymethyl methacrylate membrane hemofilter (PMMA-CHDF) for cytokine removal in patients with RHS. Eight consecutive patients who admitted to our ICU with RHS complicating organ failures and refractory to medical therapy were initiated intensive care including PMMA-CHDF. Although remission was achieved in six patients, remaining two patients died of exacerbation of underlying diseases. Changes in blood levels of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) as indices of cytokine network activation, and serum ferritin level as an index of severity of RHS were investigated during PMMA-CHDF. PMMA-CHDF performed for 3 days significantly reduced blood TNF-α level (183 ± 159 pg/ml to 84 ± 98 pg/ml, p < 0.05) and also blood IL-6 level (1113 ± 903 pg/ml to 402 ± 411 pg/ml, p < 0.01). Furthermore, serum ferritin level was significantly decreased 3 days after initiation of PMMA-CHDF (52390 ± 65168 ng/ml to 4136 ± 2932 ng/ml, p < 0.05) although it tended to increase before initiation of PMMA-CHDF. No PMMA-CHDF-related adverse events were observed in any of the patients. PMMA-CHDF was effective to remove cytokine and improved disease severity. Thus, PMMA-CHDF may be an adjunctive treatment in RHS refractory to medical therapy.