[High-dose polyclonal intravenous immunoglobulin therapy for refractory viral infections including viremia after allogeneic hematopoietic cell transplantation].

Refractory viremia/viral disease is a major life-threatening complication that may arise among patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT). This study aimed to clarify the therapeutic effect of high-dose polyclonal intravenous immunoglobulin (IVIG) against viremia/viral diseases after allo-HCT. We conducted a pilot study to investigate the therapeutic effect of 400 mg/kg of IVIG given for 5 consecutive days against refractory viremia/viral disease after allo-HCT. Overall, 7 patients were drug-resistant and the other 7 had not previously received any drug for their viremia/viral disease. All patients completed the 5-day therapy regimen of IVIG. A complete response at Day 56 was observed for 8 of 14 patients (57.1%). Additionally, 10 of 14 patients (71.4%) were alive at Day 56, although only one death occurred due to the viremia/viral disease. Remarkably, all 3 cases who developed exogenous viremia/viral diseases including respiratory syncytial virus pneumonia/bronchitis and human parvovirus B19 viremia achieved a complete response, suggesting that high-dose polyclonal IVIG may be more effective against exogenous viruses rather than endogenous ones. Congestive heart failure was observed in 1 patient. High-dose polyclonal IVIG could be an effective and feasible therapy for refractory viremia/viral disease after allo-HCT.