Early recovery of immunoglobulin levels at 3 months after allogeneic peripheral blood stem cell transplantation can predict favourable transplantation outcomes

Patients undergoing allogeneic peripheral blood stem cell transplantation (PBSCT) have an increased risk of infectious complications due to secondary hypogammaglobulinemia. Prophylactic use of immunoglobulin has been used for the purpose of decreasing the infection-related morbidity or mortality in allogeneic PBSCT recipients. We studied to determine whether prophylactic use of immunoglobulin or early immunoglobulin recovery could affect transplantation outcomes. From Jan. 2001 to Mar. 2008, the data of 124 consecutive patients with hematological diseases who received allogeneic PBSCT were retrospectively reviewed. Prophylactic immunoglobulinG was given biweekly for 3 months, then monthly up to 6 months after allogeneic PBSCT and serum ImmunoglobulinG (IgG) and immunoglobulin-M (IgM) levels were checked at 3 monthly for 1 year then yearly. Prophylactic use of immunoglobulin and maintaining high levels of IgG prevented infectious complications (p=0.026), also early recovery of humoral immunity represented by high IgM levels reduced infectious complications (p=0.001). The patients with high IgM levels at 3 months showed lower viral or fungal infection rate. Acute GVHD (grade II-IV) and steroid use affected negatively on IgM recovery (OR=0.369, p=0.027). In addition, overall survival was better in patients with high IgM levels at 3 months compared to low IgM levels (5-year OS=72% vs. 48%; HR=0.425, p=0.034). However, prophylactic IgG administration had no benefit on survival. In conclusion, early humoral immune recovery is related with favorable transplantation outcomes but prophylactic use of immunoglobulin had no benefit in terms of survival.