Incidence of Human Leucocyte Antigen Antibodies in Lymphoma Patients Treated with and without Rituximab

Introduction: Platelet support in patients who are pancytopenic after autologous stem-cell transplantation (auSCT) is difficult in the presence of human leukocyte antigen antibodies (HLA-AB) class I. Multiple transfusions and pregnancy are risk factors for development of HLA-AB. In renal transplantation rituximab (R-mab) is used to reduce HLA-AB levels in HLA-incompatible kidney transplantation. We evaluated whether the incidence of HLA-AB was lower in lymphoma patients who were treated with R-mab during salvage therapy prior to auSCT.

Methods: Single-centre retrospective evaluation of patients treated with DHAP-VIM-DHAP salvage (with or without R-mab) and BEAM plus auSCT for B-cell non-Hodgkin lymphoma (B-NHL) or Hodgkin's lymphoma (HL). After becoming available R-mab was given to patients with CD20-positive lymphoma; R-mab was not used before it's availability and in CD20-negative lymphoma. HLA-AB were measured in case of insufficient platelet yield after transfusion.

Results: Between January 1^st 1999 and December 31^st 2013, 164 patients with a B-NHL or HL underwent auSCT (Table). Age at auSCT was median 52.5 (17.8 – 70.2) years, 73 (45%) patients were female and 89 (54%) were treated with R-mab. Type of lymphoma was diffuse large B-NHL (DLBCL) in 82 (50%) patients, HL in 46 (28%) patients, follicular lymphoma (FL) in 30 (18%) patients and other in 6 (4%) patients. All transfused cellular blood products were leucoreduced.

Of R-mab treated patients, 42 (47%) were female versus 31 (41%) non R-mab treated patients, p=0.529 (Table). R-mab treated patients were older at auSCT than non R-mab treated patients: median 57.4 (18.3 – 70.2) years versus 48.1 (17.8 – 64.6) years, p<0.001. Type of lymphoma in R-mab patients was DLBCL in 61 (69%), HL in 2 (2%), FL in 23 (26%) and other in 3 (3%) patients. In non R-mab treated patients type of lymphoma was DLBCL in 21 (28%, p=<0.001), HL in 44 (59%, p=<0.001), FL in 7 (9%, p=0.008) and other in 3 (4%, p=1.000) patients. In R-mab treated patients median 6 (1 – 53) random platelet concentrates (rPC) were transfused versus median 5 (1 – 54) in non R-mab treated patients, p=0.529. HLA-AB were found in none of 89 R-mab treated patients and in 3 of 75 non R-mab treated patients, p=0.094.

All 3 patients who developed HLA-AB were female (100%) versus 44% (n=70) of patients without HLA-AB, p=0.086. All 3 women (100%) with HLA-AB have been pregnant versus 51 (73%) women without HLA-AB (p=0.704); in 8 women without HLA-AB their history of pregnancy was unknown. None (0%) of 3 patients with HLA-AB were treated with R-mab versus 89 of 161 (55%) patients without HLA-AB, p=0.094. Age at auSCT was median 44.2 (39.1 – 52.4) years in patients with HLA-AB and median 52.6 (17.8 – 70.2) years in patients without HLA-AB, p=0.246. Number of rPC transfused was median 7 (4 – 14) in patients with HLA-AB and median 6 (1 – 54) in patients without HLA-AB, p=0.666. There was no significant difference seen in type of lymphoma between patients with and without HLA-AB.

Conclusion: The incidence of HLA-AB in our cohort of lymphoma patients treated with DHAP-VIM-DHAP salvage with or without rituximab followed by BEAM plus auSCT for B-NHL or HL is very low. A trend was seen towards treatment without R-mab and female gender, not towards a history of pregnancy.

Denoted as median (range), categorical variables as number (%).