[Clinical Significance of Serum Immunoglobulin Level after Peri- pheral Blood Haploidentical Hematopoietic Stem Cell Transplantation in Patients with Hematologic Malignancies].

Objective: To investigate the clinical significance of post-transplantation serum immunoglobulin level in the outcome of patients with hemalologic malignancies treated by haploidentical peripheral hematopoietic stem cell transplanta-tion(Haplo-HSCT).

Methods: The clinical data of 157 patients treated by haplo-HSCT were analyzed retrospectively. The overall survival rate (OS), graft versus host disease (GVHD) incidence, infection incidence, serum immunoglobulin level, the relationship of immunoglobulin levels with OS and transplant complications were analyzed.

Results: The 2-year OS rate was 59.2%(95%CI:51.6%-66.9%), 2-year relapse mortality was 11.5%(95%CI: 6.4%-16.6%), and non-relapse mortality was 29.3%(95%CI:21.7%-36.9%). The cumulative incidence of III-IV aGVHD was 16.6%(95%CI:10.8%-22.9%); the cumulative incidence of extensive cGVHD was 21.7%(95%CI:15.3%-28.6%); the cumulative incidence of severe bacterial infection within 1 year was 59.2%(95%CI:51.6%-66.2%); the cumulative incidence of invasive fungal infection was 47.1%(95%CI:38.9%-54.8%). The occurrence of extensive cGVHD after haplo-HSCT related with the gender match of donor-recipient and bacterial infection. The levels of IgG in patients with 0-II aGVHD and patients with III-IV aGVHD for 1 month after haplo-HSCT were (6.96±2.47) and (4.27±2.42) g/L （P=0.003）, IgG levels at 3 months afte haplo-HSCT were (8.71±4.47) and (6.65±2.95) g/L (P=0.038); IgG levels at 1 month after haplo-HSCT showed predictive value for III-IV aGVHD susceptibility(P=0.003); for patients with IgG<4 g/L at any time after haplo-HSCT, the incidence of extensive cGVHD was significantly increased (35.5% vs 18.3%) (P=0.037), the incidence of fungal infection within 1 year after haplo-HSCT was significantly increased(71.0% vs 41.3%) (P=0.003), and the 2-year survival rate was reduced significantly (P=0.035).

Conclusion: Haplo-HSCT is effective for the treatment of hematologic malignancies. Patients with lower IgG at 1 month after haplo-HSCT are more likely to develop III-IV aGVHD, and IgG levels at 1 month after haplo-HSCT can predict its susceptibility to a certain extent. Patients with severe hypoimmunoglobulinemia (IgG<4 g/L) after haplo-HSCT are more likely to develop extensive cGVHD, fungal infection and show worse survival prognosis.