Michael Koldehoff

Early human cytomegalovirus replication after transplantation is associated with a decreased relapse risk: evidence for a putative virus-versus-leukemia effect in acute myeloid leukemia patients

The impact of early human cytomegalovirus (HCMV) replication on leukemic recurrence was evaluated in 266 consecutive adult (median age, 47 years; range, 18-73 years) acute myeloid leukemia patients, who underwent allogeneic stem cell transplantation (alloSCT) from 10 of 10 high-resolution human leukocyte Ag-identical unrelated (n = 148) or sibling (n = 118) donors. A total of 63% of patients (n = 167) were at risk for HCMV reactivation by patient and donor pretransplantation HCMV serostatus. In 77 patients, first HCMV replication as detected by pp65-antigenemia assay developed at a median of 46 days (range, 25-108 days) after alloSCT. Taking all relevant competing risk factors into account, the cumulative incidence of hematologic relapse at 10 years after alloSCT was 42% (95% confidence interval [CI], 35%-51%) in patients without opposed to 9% (95% CI, 4%-19%) in patients with early pp65-antigenemia (P < .0001). A substantial and independent reduction of the relapse risk associated with early HCMV replication was confirmed by multivariate analysis using time-dependent covariate functions for grades II to IV acute and chronic graft-versus-host disease, and pp65-antigenemia (hazard ratio = 0.2; 95% CI, 0.1-0.4, P < .0001). This is the first report that demonstrates an independent and substantial reduction of the leukemic relapse risk after early replicative HCMV infection in a homogeneous population of adult acute myeloid leukemia patients.

Mutations in innate immune system NOD2/CARD 15 and TLR-4 (Thr399Ile) genes influence the risk for severe acute graft-versus-host disease in patients who underwent an allogeneic transplantation.

Background. NOD2 and TLR-4 genes belong to the innate immune system that detects invading pathogens through several pattern-recognition receptors. Here we analyzed 403 patients for NOD2 gene mutations and 307 patients for TLR-4 gene mutations (Thr399Ile) with their respective donors and correlated the results with the incidence of acute graft-versus-host disease (aGVHD), severe acute GVHD (saGVHD), the risk for transplant-related mortality (TRM), overall survival (OS) and incidence of infectious complications. Methods. We performed a retrospective single-center study. Genotyping of TLR-4 and NOD2 were evaluated by real-time polymerase chain reaction. Results. Surprisingly, we found a significant reduced incidence of aGVHD, saGVHD, and intestinal GVHD for patients with NOD2 gene mutations on the donor side with 50%, 0% and 2% compared to patients with the wild-type NOD2 gene with 65%, 17%, and 26%, respectively (P<0.02). However, the incidence of saGVHD increased in patients with NOD2 mutations on the patient and donor (P/D) side with 44% versus 17% compared to patients with the wild-type gene (P<0.03). TLR-4 gene mutations at P/D side had an increased risk for saGVHD with 42% versus 15% of patients with wild-type gene (P<0.04). OS, TRM, and incidence of infectious complications were not influenced by the mutated genes. Multivariate analysis confirmed that NOD2 gene mutations on the donor side had a reduced risk for saGVHD (P<0.001), whereas mutations of the NOD2 gene on P/D side had an increased risk for saGVHD (P<0.01) in our analysis. Conclusions. These results suggest that NOD2 mutations have influence on the occurrence of acute GVHD after transplantation.

Therapeutic application of small interfering RNA directed against bcr-abl transcripts to a patient with imatinib-resistant chronic myeloid leukaemia

RNA interference is referred to as the recently discovered process of sequence-specific, post-transcriptional gene silencing that is initiated by double-stranded RNA molecules known as small interfering RNAs (siRNA). We herein present a first report on the in vivo application of targeted non-virally delivered synthetic bcr-abl siRNA in a female patient with recurrent Philadelphia chromosome-positive chronic myeloid leukaemia (CML) resistant to imatinib (Y253F mutation) and chemotherapy after allogeneic haematopoietic stem cell transplantation. We found a remarkable inhibition of the overexpressed bcr-abl oncogene resulting in increased apoptosis of CML cells. In vivo siRNA application was well tolerated without any clinically adverse events. Our findings imply that the clinical application of synthetic siRNA is feasible, safe and has real potential for genetic-based therapies using synthetic non-viral carriers.

Relation of an interleukin-23 receptor gene polymorphism to graft-versus-host disease after hematopoietic-cell transplantation

Polymorphisms in cytokine genes can influence immune responses and inflammation and thereby affecting the outcome of hematopoietic stem-cell transplantation. We analyzed a single-nucleotide polymorphism in the gene for the interleukin-23 receptor (IL-23R) (1142G>A) in a cohort of 221 transplant recipients and their human leukocyte antigen (HLA)-identical sibling donors and in a second cohort of 186 transplant recipients and their HLA-identical unrelated donors. Genotypes were tested for an association with graft-versus-host disease (GVHD) by multivariate analysis. The donors IL-23R genotype was significantly associated with a reduced risk of acute GVHD in both cohorts for patients after transplant. Analysis of all 407 transplant recipients showed that IL-23R (1142G>A, Arg381Gln) genotype of the donor was associated with a decreased risk of grades 2–4 acute GVHD (31.6 compared to 51.0%, P=0.02) and grades 3–4 severe acute GVHD (3.9 compared to 23.4%, P=0.003). Death in remission was significantly lower in patients transplanted from donors with variant IL23-R (11.7 versus 27.7%, P=0.028), whereas overall survival or relapse rates were not influenced significantly by the IL-23R genotype. Among recipients of hematopoietic cells from HLA-identical donors, the IL-23R (Arg381Gln) gene variant on the donor side has a protective effect on the occurrence of acute GVHD in recipients after transplantation.

Outcome of allogeneic stem cell transplantation in patients with myelofibrosis

Summary:Myelofibrosis, either de novo or following pre-existing hematologic diseases, can be cured by allogeneic hematopoietic stem cell transplantation (SCT), but SCT is associated with significant morbidity and mortality, making the choice and timing of transplantation difficult. In all, 20 patients (seven female and 13 male), with a median age of 45 years (range 22–57 years), with idiopathic myelofibrosis (n=12), post-thrombocythemic (n=3) or post-polycythemic (n=2) myeloid metaplasia or leukemic transformation (n=3), underwent allogeneic SCT at our center between 1994 and 2003. With regard to the pre-transplant presence of risk factors such as hemoglobin levels ⩽10 mg/dl, grade III marrow fibrosis or peripheral blast counts >1%, patients were divided into high- and low-risk groups. The estimated 3-year survival post transplant was 38.5% for all patients. The 3-year probability of survival within the high-risk group (n=11) characterized by the presence of at least two risk factors was 16%. Low-risk patients (n=9) with at most one risk factor had an estimated 3-year survival of 67%. Thus, previously defined risk determinants for the outcome of allogeneic transplantation for myelofibrosis may provide useful information facilitating treatment strategies. Our data suggest that transplantation should be taken into consideration before poor prognostic variables develop.

Reduced risk for molecular disease in patients with chronic myeloid leukemia after transplantation from a KIR-mismatched donor.

Background. To examine how killer-cell immunoglobulin-like receptor (KIR) ligand incompatibilities effect molecular relapse (MR), we compared the occurrence of bcr–abl-positive reverse-transcriptase polymerase chain reaction (RT-PCR) results in 236 CML patients (pts) after human leukocyte antigen (HLA)-identical (n=158) (group 1), HLA class I antigen mismatched and KIR-ligand compatible (n=49) (group 2), and HLA class I antigen mismatched and KIR-ligand incompatible (n=29) (group 3) hematopoietic stem-cell transplantation. Methods. We performed a retrospective single-center study. MR was evaluated using the real-time RT-PCR method for the detection of bcr-abl transcripts. Results. In the first group, 133 of 158 (84%) pts were in the first chronic phase of CML, and the corresponding figures were 33 of 49 (67%) pts in group 2 and 19 of 29 (64%) in group 3 (P<0.05). MR occurred in 1 of 29 (3%) pts in group 3 compared with 62 of 158 (39%) pts in group 1 and in 11 of 49 (22%) pts in group 2 (P<0.001). A hematologic relapse developed in 20 of 158 (13%) pts in group 1, 2 of 49 (4%) pts in group 2, and in 0 of 29 (0%) pts in group 3 (P<0.05). Multivariate analysis confirmed that KIR mismatches are a strong independent predictor for the occurrence of MR after transplantation (P<0.02). The 5-year overall survival rate did not vary greatly between the three groups (67% in group 1, 52% in group 2, and 66% in group 3). Conclusions. These results suggest that KIR-ligand incompatibility is an important prognostic factor in the occurrence of MR after transplantation for CML.

Dynamic International Prognostic Scoring System scores, pre-transplant therapy and chronic graft-versus-host disease determine outcome after allogeneic hematopoietic stem cell transplantation for myelofibrosis.

Background Myelofibrosis is a myeloproliferative stem cell disorder curable exclusively by allogeneic hematopoietic stem cell transplantation and is associated with substantial mortality and morbidity. The aim of this study was to assess disease-specific and transplant-related risk factors that influence post-transplant outcome in patients with myelofibrosis. Design and Methods We retrospectively assessed 76 consecutive patients with primary (n=47) or secondary (n=29) myelofibrosis who underwent bone marrow (n=6) or peripheral blood stem cell (n=70) transplantation from sibling (n=30) or unrelated (n=46) donors between January 1994 and December 2010. The median follow-up of surviving patients was 55±7.5 months. Results Primary graft failure occurred in 5% and the non-relapse mortality rate at 1 year was 28%. The relapse-free survival rate was 50% with a relapse rate of 19% at 5 years. The use of pharmacological pre-treatment and the post-transplant occurrence of chronic graft-versus-host disease were significant independent unfavourable risk factors for post-transplant survival in multivariate analysis. Using the Dynamic International Prognostic Scoring System for risk stratification, low-risk patients had significantly better overall survival (P=0.014, hazard ratio 1.4) and relapse-free survival (P=0.02, hazard ratio 1.3) compared to the other risk groups of patients. The additional inclusion of thrombocytopenia, abnormal karyotype and transfusion need (Dynamic International Prognostic Scoring System Plus) resulted in a predicted 5-year overall survival of 100%, 51%, 54% and 30% for low, intermediate-1, intermediate-2 and high-risk groups, respectively. The relapse incidence was significantly higher in the absence of chronic graft-versus-host disease (P=0.006), and pharmacological pre-treatment (n=43) was associated with reduced relapse-free survival (P=0.001). Conclusions The data corroborate a strong correlation between alloreactivity and long-term post-transplant disease control and confirm an inverse relationship between disease stage, pharmacotherapy and outcome after allogeneic hematopoietic stem cell transplantation for myelofibrosis. The Dynamic International Prognostic Scoring System was demonstrated to be useful for risk stratification of patients with myelofibrosis who are to undergo hematopoietic stem cell transplantation.

Caspofungin as second-line therapy for fever of unknown origin or invasive fungal infection following allogeneic stem cell transplantation

Summary:Caspofungin (CAS) is the first of a new class of antifungal agents, the echinocandins, that interfere with fungal cell wall synthesis by inhibition of glucan synthesis. Here, we report the results of 31 patients treated with CAS following allogeneic SCT. CAS was administered as a second-line agent to patients with invasive fungal infection (IFI) (n=15) or fever of unknown origin (n=16) who were recalcitrant to or intolerant of prior antifungal therapy. Unsuccessful first-line regimes included amphotericin B (n=17), liposomal amphotericin B (n=5), fluconazole (n=3), itraconazole (n=1), and voriconazole (n=2). All patients received concomitant immunosuppressive therapy for graft-versus-host disease. In 23 patients, cyclosporin A (CSA) and CAS were administered concurrently without any major side effects detected. Observed increases in GPT were not clinically significant. Normalization of serum creatinine and significant reductions in C-reactive protein were observed in response to CAS. Favorable outcome to CAS were documented in eight of 15 patients with IFI and in 15 of 16 patients with fever of unknown origin. CAS is a promising alternative in patients with IFI and fever of unknown origin in the setting of allogeneic SCT.

Growth factor-independent 1B gene (GFI1B) is overexpressed in erythropoietic and megakaryocytic malignancies and increases their proliferation rate

Growth factor‐independent 1B (GFI1B) is a transcription factor essential for the development and differentiation of erythroid and megakaryocytic lineages. We evaluated the GFI1B expression in erythroleukaemia and megakaryocytic leukaemia, as well as in patients with other subtypes of acute myeloid leukaemia (AML), acute lymphoblastic leukaemia (ALL), chronic myeloid leukaemia (CML), myelodysplastic syndrome (MDS), severe aplastic anaemia (SAA), myelofibrosis with myeloid metaplasia (MMM) and in healthy volunteers. GFI1B expression was increased at least threefold in patients with erythroleukaemia (P < 0·01 compared with controls) and megakaryocytic leukaemia (P < 0·05) as well as in their corresponding leukaemic cell lines HEL, K562, CMK and M‐07e. Patients with undifferentiated or monocytic AML, ALL, MMM, MDS and CML had no significantly altered GFI1B expression, whereas GFI1B expression was decreased 10‐fold in patients with SAA (P < 0·0001 compared with controls). Silencing GFI1B by transfection with small interfering RNA (siRNA) markedly reduced the proliferation rate in the leukaemic cell lines HEL, K562 and NB4 (P < 0·01). Concomitantly, we observed a two‐ to threefold increase in the apoptosis rate in these cells after transfection with siRNA towards GFI1B. Our data indicate that GFI1B plays a major role in AML‐M6 and AML‐M7 and qualifies as a target for anti‐leukaemic strategies in these malignancies.

Use of the activating gene mutation of the tyrosine kinase (VAL617Phe) JAK2 as a minimal residual disease marker in patients with myelofibrosis and myeloid metaplasia after allogeneic stem cell transplantation

Here we report on the use of a new real-time polymerase chain reaction (PCR) method to detect and quantify the activating gene mutation of the tyrosine kinase JAK2. We evaluated patients with myelofibrosis with myeloid metaplasia (MMM; n=25) for the gene mutation prior to allogeneic stem cell transplantation and monitored them in the long-term follow up of 125 months (median 15, range 4–125) after transplant. The results obtained were correlated to the chimerism status of these patients. The JAK2 gene mutation was detected in 15 of 25 analyzed patients prior to transplant. Three patients who were again positive for JAK2 after transplant also had mixed chimerism status. These three patients relapsed from MMM shortly after JAK2 gene mutation was detected for the first time after transplant. Our presented data shows the feasibility of the detection of JAK2 gene mutation by real-time PCR as a minimal residual disease marker after transplant.