Peter Kalhs

Early detection of relapse after bone marrow transplantation in patients with chronic myelogenous leukaemia

In patients with chronic myelogenous leukaemia (CML) treated by allogeneic bone marrow transplantation (BMT), detection of residual leukaemic cells carrying the characteristic bcr/abl rearrangement by highly sensitive techniques, such as qualitative polymerase chain reaction (PCR), is of limited value in predicting disease progression. We have therefore adapted the PCR for quantitative assessment of bcr/abl rearranged cells and applied this technique to the monitoring of residual disease in 28 CML patients during up to 106 months of follow-up after BMT. In 5 patients, quantitative PCR revealed increasing amounts of the pathological bcr/abl message, indicating the presence of a proliferating neoplastic clone, and all 5 had a subsequent relapse of disease. By contrast, the remaining 23 patients have been in maintenance-free complete remission for up to 106 months post-BMT. The monitoring by quantitative PCR of residual leukaemic cells during the post-transplant course of CML patients may allow early detection of relapse and provide a rationale for the timely initiation of treatment.

Regeneration of erythropoiesis after related- and unrelated-donor BMT or peripheral blood HPC transplantation: a major ABO mismatch means problems.

BACKGROUND: Blood group incompatibility in allogeneic BMT is common but does not appear to affect the outcome in terms of incidence of graft rejection or delayed engraftment. However, major ABO incompatibility may be associated with prolonged erythroid aplasia.

Long-term outcome and quality of life of patients who are alive and in complete remission more than two years after allogeneic and syngeneic stem cell transplantation.

We assessed long-term outcome in 155 patients who had undergone an allogeneic/syngeneic stem cell transplant (SCT) and were in complete remission for more than 2 years after transplant. Probability of late transplant-related mortality was 6%, and affected only patients with chronic graft-versus-host disease (cGVHD). Thirteen percent of patients experienced relapse. Overall survival projected at 10 and 15 years was 83% and 76%, respectively. Secondary malignancies occurred in two patients, 7.5 and 11 years after SCT. Three female and four male patients parented children 19 to 84 months after SCT. Quality of life (QoL) was assessed in a cross-sectional study by the means of a 30-item questionnaire (QLQ-C30) of the EORTC. The questionnaire was sent to 127 patients remaining alive and answered by 106 patients. Seventy-three percent reported a good to very good QoL within 5 years after SCT and 78% after this time point. However, patients with cGVHD had significant impairment of physical, role and social functioning and only 60% of them were fit for work. These results from long-term survivors show that high cure rates with good to very good QoL can be achieved by allogeneic or syngeneic SCT.

Severe immune hemolysis after minor ABO‐mismatched allogeneic peripheral blood progenitor cell transplantation occurs more frequently after nonmyeloablative than myeloablative conditioning

BACKGROUND : Hemolysis as a result of donor‐recipient minor ABO mismatching is a complication of allogeneic peripheral blood progenitor cell (PBPC) transplantation (PBPCT). The increased B‐lymphocyte content of PBPC grafts and immunosuppressive regimens without methotrexate (MTX) may increase incidence and severity of this event.

Neoplastic stem cells: a novel therapeutic target in clinical oncology.

Cancer is among the leading causes of morbidity and mortality in the Western world. Despite recent advances, most therapeutic approaches fail to eradicate the entire neoplastic clone. The remaining cells often develop metastasis and/or recurrences and therefore may represent attractive targets of therapy. A new exciting concept in this regard suggests that each neoplasm represents a heterogeneous population of cells that pertain to long‐term tumor growth both in vivo in the natural host and in experimental animals. This concept postulates the existence of small fractions of ‘tumor stem cells’ that exhibit a capacity for self‐renewal and unlimited growth and therefore are distinct from their progeny. Based on these hypotheses, the targeting of neoplastic stem cells is considered indispensable for eradication of the entire clone and for the development of curative treatment approaches. However, tumor stem cells often may be quiescent cells and may express a different profile of targets compared with ‘more mature’ tumor cells. Therefore, current efforts have attempted to characterize target expression profiles in cancer stem cells in various malignancies. In the this review, the authors have provided a brief summary of the current knowledge of neoplastic stem cells and the application of respective concepts in translational oncology with the ultimate objective of improving anticancer therapy. Cancer 2006.

ABO mismatch increases transplant-related morbidity and mortality in patients given nonmyeloablative allogeneic HPC transplantation

BACKGROUND: ABO mismatch has not been thought to affect the outcome of patients undergoing myeloablative conditioning and allogeneic HPC transplantation. Data on transplant‐related complications after ABO‐mismatched transplantation after nonmyeloablative conditioning are limited.

Quantification of minimal residual disease in patients with BCR-ABL-positive acute lymphoblastic leukaemia using quantitative competitive polymerase chain reaction

We analysed 20 patients with BCR‐ABL‐positive acute lymphoblastic leukaemia (ALL) by quantitative competitive polymerase chain reaction (QC‐PCR) to study the kinetics of the leukaemic clone. Consecutive samples of 16 patients (minor‐bcr, n = 10; major‐bcr, n = 6) were analysed after conventional chemotherapy and/or bone marrow transplantation (BMT). DNA competitor templates co‐amplifying with either p210 or p190 BCR‐ABL cDNA were used for quantification of leukaemia‐specific BCR‐ABL mRNA. In all samples, total ABL transcripts were measured as internal control, and the percentage of BCR‐ABL/ABL molecules was calculated. Following induction chemotherapy the number of BCR‐ABL transcripts was reduced by a maximum of 2–3 logs. In most patients, additional chemotherapy did not lead to further reduction of BCR‐ABL mRNA. In two patients, conventional chemotherapy plus autologous BMT in complete haematological remission resulted in a total reduction of the transcript level of more than 3 logs. In two other patients, allogeneic BMT caused a transient reduction of the BCR‐ABL transcripts below the detection level of our method (<1 blast cell in 105 normal cells) for a period of 7 and 11 months, respectively. The achievement of PCR negativity did not guarantee sustained remission. Both patients relapsed and BCR‐ABL transcript levels rose by more than 1 log prior to frank relapse. Our data demonstrate that quantification of BCR‐ABL mRNA allows the evaluation of the dynamics of the leukaemic clone and thus is valuable for the evaluation of minimal residual leukaemia following various therapies and the early detection of increasing BCR‐ABL transcripts prior to relapse.

Impact of HLA class I high-resolution mismatches on chronic graft-versus-host disease and survival of patients given hematopoietic stem cell grafts from unrelated donors

Summary:There is consensus that matching of unrelated donors (URD) and patients for HLA class II alleles improves the outcome of hematopoietic stem cell transplantation (HSCT). However, the significance of HLA class I allelic mismatches for transplant outcome is under discussion and reports on long-term effects like chronic graft-versus-host disease (GVHD) are rare. Thus, we investigated the association of human leukocyte antigen (HLA) class I allele mismatches and outcome in 144 patients given HSCT from URD who were matched for HLA-DRB1, DRB3/4/5, and DQB1 alleles. The risk of chronic GVHD was significantly increased in patients with class I mismatched donors, the mismatch either detected by low- or high-resolution typing. A single HLA class I allele mismatch significantly increased the risk of chronic GVHD in multivariate analysis. Overall survival was significantly reduced in patient/donor pairs with more than one-allele class I mismatch. Thus, selection of unrelated donors for transplantation should be based on high-resolution HLA class I typing.

Functional Asplenia after Bone Marrow Transplantation: A Late Complication Related to Extensive Chronic Graft-Versus-Host Disease

STUDY OBJECTIVE To evaluate splenic function in bone marrow transplant recipients, with relation to chronic graft-versus-host disease and infections. DESIGN Survey, outpatients geographically accessible for voluntary participation. SETTING Bone marrow transplantation referral center. PATIENTS Fifteen bone marrow graft recipients (13 allogeneic, 2 autologous), out of a total of 33 patients who received transplants at the center and survived more than 6 months after grafting. MEASUREMENTS AND MAIN RESULTS In 6 of 15 patients impaired splenic function (functional asplenia) was indicated by the presence of Howell-Jolly bodies in peripheral blood smears, reduced spleen size (P less than 0.001), higher platelet counts (P less than 0.01), higher indium-111 labeled autologous platelet recovery (P less than 0.005), reduced splenic blood flow (P less than 0.001), and reduced accumulation of radioactivity at the splenic site (P less than 0.001). All patients with functional asplenia but only 2 patients without functional asplenia had extensive chronic graft-versus-host disease. The incidence of bacterial infections was four times higher in patients with impaired splenic function. CONCLUSIONS Functional asplenia is a late complication after allogeneic bone marrow transplantation and contributes to the high susceptibility to bacterial infections in patients with extensive chronic graft-versus-host disease.

Diverse T-cell responses characterize the different manifestations of cutaneous graft-versus-host disease.

Graft-versus-host disease (GVHD) is a major complication of allogeneic hematopoietic stem cell transplantation (HCT) and can present in an acute (aGVHD), a chronic lichenoid (clGVHD), and a chronic sclerotic form (csGVHD). It is unclear whether similar or different pathomechanisms lead to these distinct clinical presentations. To address this issue, we collected lesional skin biopsies from aGVHD (n = 25), clGVHD (n = 17), and csGVHD (n = 7) patients as well as serial nonlesional biopsies from HCT recipients (prior to or post-HCT) (n = 14) and subjected them to phenotypic and functional analyses. Our results revealed striking differences between aGVHD and clGVHD. In aGVHD, we found a clear predominance of T helper (Th)2 cytokines/chemokines and, surprisingly, of interleukin (IL)-22 messenger RNA as well as an increase of IL-22-producing CD4(+) T cells. Thymic stromal lymphopoietin, a cytokine skewing the immune response toward a Th2 direction, was elevated at day 20 to 30 post-HCT in the skin of patients who later developed aGVHD. In sharp contrast to aGVHD, the immune response occurring in clGVHD showed a mixed Th1/Th17 signature with upregulated Th1/Th17 cytokine/chemokine transcripts and elevated numbers of interferon-γ- and IL-17-producing CD8(+) T cells. Our findings shed new light on the T-cell responses involved in the different manifestations of cutaneous GVHD and identify molecular signatures indicating the development of the disease.