The impact of HLA matching on outcome of single unit unrelated cord blood transplantation: a retrospective single center clinical analysis / 中华血液学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To retrospectively study the impact of human leukocyte antigen (HLA) mtyping mismatching between donor and recipient on outcome of single unit unrelated cord blood transplantation (sUCBT).</p><p><b>METHODS</b>139 patients with hematological malignancies received sUCBT in single center from May 2008 to August 2012 were analyzed. Of 139 patients at enrollment, 22 were 0 mismatched (mm), 69 1 mm, 48 2 mm by low-resolution HLA-A, -B, and high-resolution (HR) DRB1. All patients'conditioning regimen was myeloablative, and a combination of cyclosporine A (CsA) and mycophenolate mofetil (MMF) was given for graft-versus-host disease (GVHD) prophylaxis for all patients. The cohort of patients were followed-up until December 15, 2013.</p><p><b>RESULTS</b>Patients of 0 mm had a statistically significant higher cumulative incidence of neutrophil engraftment by day 42 than those of 1 and 2 mm (P=0.042 and 0.002, respectively), patients of 0 mm with either a higher prefreeze total nucleated cell (TNC) dose (>5 × 10⁷/kg) or lower dose (<5 × 10⁷/kg) had a statistically significant higher cumulative incidence of neutrophil engraftment by day 42 than those of 2 mm (P=0.01 and 0.02, respectively). Patients of 0 mm had a statistically significant lower cumulative incidence of acute GVHD by day 100 than those of 1 and 2 mm (P=0.006 and 0.001, respectively). The difference of 1-year transplant-related mortality (TRM) between 0 and 2 mm patients was statistically significant (P=0.03). Patients of 2 mm received UCB units with a TNC dose less than 5 × 10⁷/kg had a higher 1-year TRM than of 0 mm patients (P=0.03). Patients of 0 mm had a statistically significant higher 3-year disease free survival (DFS) than those of 2 mm (P=0.03), compared with patients of 2 mm given CB units with a TNC dose less than 5 × 10⁷/kg, 0 mm patients and 1mm patients received UCB units with a TNC dose greater than 4 × 10⁷/kg had higher DFS rates (P=0.02 and 0.02, respectively).</p><p><b>CONCLUSION</b>The HLA typing mismatching between donor and recipient had a great impact on neutrophil engraftment and long term DFS after sUCBT, 2mm cord blood unit with less TNC (<5 × 10⁷/kg) was not an optimum UCB graft.</p>