Table 1.
Demographics of the study population
| Total transplants (n = 922) | MICA-matched transplants (n = 809) | MICA-mismatched transplants (n = 113) | P value* | |
|---|---|---|---|---|
| Transplantation centers† | .09 | |||
| 1 | 103 (11%) | 83 (10%) | 20 (18%) | |
| 2 | 211 (23%) | 180 (22%) | 31 (27%) | |
| 3 | 128 (14%) | 113 (14%) | 15 (13%) | |
| 4 | 166 (18%) | 144 (18%) | 22 (20%) | |
| 5 | 56 (6%) | 52 (6%) | 4 (4%) | |
| 6 | 90 (10%) | 82 (10%) | 8 (7%) | |
| 7 | 100 (11%) | 94 (12%) | 6 (5%) | |
| 8 | 68 (7%) | 61 (8%) | 7 (6%) | |
| Age at transplant, years | .02 | |||
| 0-17 | 78 (9%) | 71 (9%) | 7 (6%) | |
| 18-49 | 387 (42%) | 324 (40%) | 63 (56%) | |
| 50-64 | 400 (43%) | 363 (45%) | 37 (33%) | |
| 65 or older | 57 (6%) | 51 (6%) | 6 (5%) | |
| Year of transplantation | .81 | |||
| 1992-2003 | 88 (9%) | 79 (10%) | 9 (8%) | |
| 2004-2007 | 256 (28%) | 225 (28%) | 31 (27%) | |
| 2008-2013 | 578 (63%) | 505 (62%) | 73 (65%) | |
| Patient–donor sex | .07 | |||
| Male–Female | 159 (17%) | 132 (16%) | 27 (24%) | |
| Other combinations | 755 (82%) | 669 (83%) | 86 (76%) | |
| Missing | 8 (< 1%) | 8 (1%) | 0 (0%) | |
| Patient–donor serological status for cytomegalovirus | 1.00 | |||
| Negative–negative | 363 (39%) | 319 (39%) | 44 (39%) | |
| Other combinations | 543 (59%) | 476 (59%) | 67 (59%) | |
| Missing | 16 (< 2%) | 14 (2%) | 2 (2%) | |
| Source of cells | .86 | |||
| Bone marrow | 247 (27%) | 218 (27%) | 29 (26%) | |
| Peripheral blood stem cells | 675 (73%) | 591 (73%) | 84 (74%) | |
| Conditioning regimen | .45 | |||
| Nonmyeloablative/reduced-intensity | 563 (61%) | 496 (61%) | 67 (59%) | |
| Myeloablative without total-body irradiation | 145 (16%) | 123 (15%) | 22 (19%) | |
| Myeloablative with total-body irradiation | 211 (23%) | 188 (23%) | 23 (20%) | |
| Missing | 3 (< 1%) | 2 (< 1%) | 1 (< 1%) | |
| GVHD prophylaxis | .42 | |||
| Cyclosporin only | 198 (21%) | 172 (21%) | 26 (23%) | |
| Cyclosporin and methotrexate | 305 (33%) | 269 (33%) | 36 (32%) | |
| Cyclosporin and mycophenolate | 282 (31%) | 243 (30%) | 39 (35%) | |
| Other combinations | 123 (13%) | 113 (14%) | 10 (9%) | |
| Missing | 14 (< 2%) | 12 (< 2%) | 2 (< 2%) | |
| In vivo T-cell depletion ‡ | .39 | |||
| No | 283 (31%) | 244 (30%) | 39 (35%) | |
| Yes | 625 (68%) | 553 (68%) | 72 (64%) | |
| Missing | 14 (< 2%) | 12 (< 2%) | 2 (< 2%) | |
| Disease | .51 | |||
| Acute myeloid leukemia | 235 (25%) | 203 (25%) | 32 (28%) | |
| Chronic myeloid leukemia | 53 (6%) | 49 (6%) | 4 (4%) | |
| Acute lymphoblastic leukemia | 135 (15%) | 120 (15%) | 15 (13%) | |
| Myelodysplastic syndrome | 140 (15%) | 128 (16%) | 12 (11%) | |
| Non-Hodgkin lymphoma | 118 (13%) | 101 (12%) | 17 (15%) | |
| Others¶ | 241 (26%) | 208 (26%) | 33 (29%) | |
| Disease stage at transplantation§ | .54 | |||
| Early | 385 (42%) | 340 (42%) | 45 (40%) | |
| Late | 480 (52%) | 420 (52%) | 60 (53%) | |
| Not applicable | 34 (4%) | 28 (3%) | 6 (5%) | |
| Unknown | 23 (2%) | 21 (3%) | 2 (2%) | |
| Time from diagnosis until transplantation | .64 | |||
| <12 mo | 431 (47%) | 381 (47%) | 50 (44%) | |
| >12 mo | 491 (53%) | 428 (53%) | 63 (56%) | |
| HLA-DPB1 matching‖ | .69 | |||
| Matched | 100 (11%) | 86 (11%) | 14 (12%) | |
| Mismatched | 822 (89%) | 723 (89%) | 99 (88%) |
Results are presented as number of patients and corresponding percentages of the study population. All clinical variables of the table were used for adjustment in the multivariate models.
HLA, human leukocyte antigen.
P-values were determined with the Pearson’s χ square test.
Patients received their transplant in 6 centers of the Francophone Society of Bone Marrow Transplantation and Cell Therapies (SFGM-TC) (1 to 6; N = 754) and in 2 Dutch centers part of the Europdonor operated by Matchis Foundation network (7 and 8; N=168).
In vivo T-cell depletion was performed by addition of antithymocyte globulin or Alemtuzumab to the conditioning regimen.
Other diseases include multiple myeloma, Hodgkin lymphoma, Fanconi anemia, aplastic anemia, chronic lymphocytic leukemia, plasma cell leukemia, other acute leukemias, solid tumors (not breast), hemophagocytosis, and inherited disorders.
Early corresponds to diseases in first complete remission or in chronic phase. Late corresponds to second or higher complete remissions, accelerated phases, partial remissions, progressions, primary induction failures, relapses, or stable diseases. Not applicable corresponds to bone marrow failure (aplastic anemia, Fanconi anemia), inherited disorders, hemophagocytosis, and solid tumors. The Disease Risk index, as defined by Armand et al,49 was also evenly distributed in the MICA-matched and MICA-mismatched patients (P = 0.423) (supplemental Table 7).
HLA-DPB1 matching was defined with typing data at second-field resolution following the World Health Organization official nomenclature.