Chapuis B

Quality of life and social integration after allogeneic hematopoietic SCT

In total, 124 adult patients in remission after allogeneic hematopoietic SCT (HSCT) participated in a cross-sectional study to assess health-related quality of life (HRQL). Assessment of HRQL was carried out using two questionnaires: the (EORTC QLQ-C30) and the Functional Assessment of Cancer Therapy (FACT) with specific modules for BMT (FACT-BMT). Transplanted patients differed from healthy controls in many HRQL-related dimensions in the EORTC QLQ-C30: social functioning 73.4 versus 85.8, P<0.0001; role functioning 74.6 versus 83.3, P<0.004; physical functioning 83.9 versus 89.9, P<0.001; emotional functioning 72.2 versus 82.8, P<0.0001 but were not significant for global HRQL 71.2 versus 75.3, P<0.03. In total, 60% of the patients returned to work after HSCT; 31% part time and 29% full time. Age at HSCT and employment status were significantly associated with HRQL. Other factors such as disease and disease stage and especially the occurrence of late complications did not impact the perception of HRQL. This study suggests that the perception of HRQL after HSCT differs from the general population. Issues to increase work-related capabilities and improve social support need to be addressed.

The frequency of pretransplant donor cytotoxic T cell precursors with anti-host specificity predicts survival of patients transplanted with bone marrow from donors other than HLA-identical siblings

Transplantation with bone marrow from other than genotypically HLA-identical donors is associated with an increased incidence and severity of graft-versus-host disease (GvHD). The precise influence of HLA incompatibilities is not easy to analyze as even perfectly matched, HLA-identical unrelated donors might still express HLA differences that remain undetected by conventional typing. To measure T cell activity against serologically detectable and nondetectable HLA antigens, we analyzed the frequencies of CTL precursors (CTLp) between 11 unrelated HLA-matched and five related haploidentical donor/recipient pairs in graft-versus-host direction. Our results show that whenever HLA class I disparities could be identified by serology, high precursor frequencies (1/28,000–1/94,000) were measured. In contrast, in donor/ recipient pairs that differed for class II only, no precursors were detected. CTLp were elevated in two out of eight fully matched donor/recipient combinations. These combinations displayed activities as high (1/21,000; 1/ 52,000) as the combinations that were serologically HLA class I disparate. The incompatibilities detected by the cellular assay were highly significant for the clinical results after transplantation. High CTLp frequencies before transplantation correlated with unfavorable clinical results independent of the incidence of detected HLA differences. Five out of the six patients with high (>1/ 100,000) CTLp frequencies died within 120 days after transplantation. GvHD IV was the cause of death for all (3/5) patients who had received an unmanipulated bone marrow. In the group with intermediate or undetectable CTLp frequencies, eight out of 10 patients are alive, seven (CTLp frequency undetectable) without GvHD more severe than grade II, while one patient (CTLp frequency = 1/180,000) suffered from GvHD grade III. One patient rejected the graft and was rescued by an autologous BMT.

Bone marrow transplantation with unrelated donors: what is the probability of identifying an HLA-A/B/Cw/DRB1/B3/B5/DQB1-matched donor?

Patients transplanted with marrow from an HLA-ABDR serologically matched unrelated donor suffer from more post-transplant complications than those who are transplanted with marrow from an HLA-identical sibling. This is most likely due to either HLA-ABDR incompatibilities not resolved by standard techniques and/or HLA polymorphisms not tested for by routine tissue typing (HLA-Cw,-DQ). By resolving these incompatibilities by molecular techniques combined with the in vitro cytotoxic T lymphocyte precursor frequency (CTLpf) test, we have shown that a high degree of HLA compatibility is associated with increased patient survival. However, higher requirements for HLA matching decrease the number of available donors. We have estimated the probability of finding an HLA-A/B/Cw/DRB1/DRB3/DRB5/DQB1 compatible donor based on 104 consecutive unrelated bone marrow donor searches initiated between January 1995 and December 1997, with December 1998 as the endpoint. For 96 patients (92.3%), one or more ABDR-identical donors were listed in the Bone Marrow Donor Worldwide Registry (BMDW). After contacting the registries, we obtained at least one (mean, 5.36; range, 1–20; total, 461) blood sample for 86 patients. A highly compatible donor was identified for 33/86 patients (38.4%), after testing an average number of 4.5 donors/patients (range, 1–13). However, by accepting an HLA-DRB3 or -DQB1 or -Cw incompatibility, this number would be as high as 68.6%. Approximately half of the patients (nu2009=u200940) for whom a search had been initiated have been transplanted: 22 patients with a perfectly matched donor, 15 patients with an HLA-DRB3 or -DQB1 or -Cw mismatch and three with other mismatches. The average time needed to identify the most compatible donor was 4 months. Extremely long searches seemed to be less useful, because after testing the first seven, a more compatible donor was seldom found. These results show that even when requirements for compatibility are high, the chances of finding a donor remain considerable. Bone Marrow Transplantation (2000) 26, 437–441.

High-resolution histocompatibility testing of a group of sixteen B44-positive, ABDR serologically matched unrelated donor-recipient pairs. Analysis of serologically undisclosed incompatibilities by cellular techniques, isoelectrofocusing, and HLA oligotyping.

We have characterized HLA incompatibilities in a group of 16 B44-positive patients who were serologically ABDR matched with their 23 (unrelated) potential bone marrow donors. After analysis with a combination of cellular techniques, IEF for HLA-A/B and oligotyping for class II and HLA-B44, 44% of the patients revealed one or more HLA incompatibility with at least one of their potential donors. CTL activity was detected in 12 of the 22 combinations tested. CTL incompatibility occurred more frequently in DR subtype-mismatched combinations, but CTL reactivity was always directed against class I. To characterize these incompatibilities between matched unrelated individuals, we analyzed the specificity of T-cell clones from seven primary CTL cultures. In three combinations, CTL reactivity was directed against a subtype of B44. In two combinations, the CTL reactivity was directed against a non-B44 class I subtype. In two of seven combinations, the CTLs recognized an antigen that, though unconditionally associated with B4403, was expressed by 60% of the B4403+ cells only. Because all 12 of these B4403+ targets recognized could be typed for one HLA-C allele only (Cwl-Cw8), we believe that this alloreactivity might be directed against a serologically undefined Cw antigen.

HLA-B35-subtype mismatches in ABDR serologically matched unrelated donor-recipient pairs

We have characterized HLA incompatibilities in a group of 17 B35-positive patients who were ABDR matched (AB serology and oligotyping for DR1-14) with their 28 (unrelated) potential bone marrow donors. High-resolution oligotyping for DR subtypes disclosed that nine combinations were in fact DR mismatched. Cytotoxic T-lymphocyte (CTL) activity was detected in nine combinations (32%). In the group matched for DR subtypes, three (16%) of 19 combinations were CTL positive. Patient-specific cytotoxic activity appeared to be directed against HLA C (two cases) or against a subtype of B35. In the group of DR-subtype-mismatched combinations, CTL activity was found in six (67%) of nine pairs. In all four cases that were studied in detail, however, CTL reactivity appeared to be directed against a variant subtype of B35. We have studied the B35 incompatibilities recognized in five different combinations by specificity analysis of the B35-specific CTLs and by partially sequencing of relevant segments of B35 exon 3. Preliminary data show that, within this relatively small Caucasoid group, at least five B35-variant subtypes could be distinguished. This would make B35 an antigen that will be frequently subtype mismatched, in particular when DR matching is done with low resolution (DR1-14) only.

Clinical consequences of sensitisation to minor histocompatibility antigens before allogeneic bone marrow transplantation.

To study sensitisation to minor histocompatibility antigens (mHag) before and after BMT, we measured anti-donor CTL activity in five patients who had rejected their graft, and in a control group of 10 leukemic patients who engrafted without complications. All patients were transplanted with marrow from an HLA-identical sibling. Fourteen patients were conditioned with cyclophosphamide (120 mg/kg) and TBI (1350 cGy) and received a T cell-depleted graft, while one patient with aplastic anaemia received cyclophosphamide alone and unmanipulated marrow. Before transplantation, anti-donor CTL activity was detected in two of the 15 patients. These patients rejected their grafts at days 21 and 58, respectively. In the other three patients who rejected their grafts at days 41, 60 and 250, CTL activity was found only after transplantation. In contrast, no anti-donor CTLs could be detected at any time in the 10 patients who engrafted permanently. We have identified some of the mHags recognised during graft rejection by cloning and subsequent specificity analysis of the recipient CTLs. In the patient who rejected at day 41 without detectable immunisation before BMT, the response was directed against HA-1, a minor antigen known to play a role in GVHD. In the other combinations, a significant part of the CTL activity was directed against the male antigen H-Y. In the patient who rejected the marrow of her HLA-identical brother at day 250, two clones recognised H-Y, while five others recognised at least three distinct autosomal mHags. This patient had an HLA-identical sister who expressed only one autosomal mHag that had been recognised by one single T cell clone. After re-transplantation with the marrow of this second donor, the CTL activity could no longer be detected and the patient engrafted without further complications.