Partial reconstitution of cutaneous microvessels in long-term survivors after allogeneic bone marrow transplantation

BACKGROUND: Graft-versus-host disease (GVHD) is a major complication after allogeneic hematopoietic stem cell transplantation (HSCT) and skin is involved in acute and chronic disease. Immune-mediated vessel attack and subsequent microvessel loss have been observed in skin of patients with chronic GVHD. OBJECTIVES: To test whether long-term survivors (LTS) after allogeneic HSCT without cutaneous GVHD show signs of persistent vascular remodeling. METHODS: Microvessels in skin biopsies were investigated in a cohort of 32 LTS with a median follow-up of 17 years (range 11-26). Five were currently classified as having chronic GVHD other than skin involvement. RESULTS: LTS showed no significant difference in median microvessel density and relative vessel size distribution pattern compared to healthy controls. Past experience of GVHD and current status of chronic GVHD other than skin involvement had no impact on vessel density. In contrast, recipients with chronic cutaneous GVHD of sclerotic type and patients with lichen sclerosus have significant microvessel loss in the upper dermis. CONCLUSION: The complex therapy of allogeneic HSCT had no sustained effect on the microvascular architecture of LTS when clinicopathological evidence of cutaneous GVHD is absent. Microvascular remodeling as observed during chronic GVHD recovers completely after resolution of chronic cutaneous GVHD

Long-term complications and side effects after allogeneic hematopoietic stem cell transplantation: an update

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective therapy for various malignant and non-malignant diseases. Many patients have now been followed for two or three decades posttransplant and are presumed to be cured. With the tremendous advances achieved in terms of supportive care, it is reasonable to expect outcomes to improve steadily and consequently increasing numbers of transplant survivors will be facing life after the initial transplant experience. Although long-term allo-HSCT survivors generally enjoy good health, for many others, cure or control of the underlying disease is not accompanied by full restoration of health. The burden of long-term morbidity borne by allo-HSCT survivors is substantial, and long-term follow-up of patients who received allo-HSCT is now widely recommended. Immediate survival is no longer the sole concern after allo-HSCT. The goals should also include complete recovery of the overall health status with normal physical and psychological functioning. Long-term side effects after allo-HSCT include non-malignant organ or tissue dysfunction, changes in quality of life, infections related to abnormal immune reconstitution and secondary cancers. Many of these can be attributed to the deleterious effects of chronic graft-versus-host disease. The aims of this review are to provide an update on the recent research evidence in the field

Stable transduction with lentiviral vectors and amplification of immature hematopoietic progenitors from cord blood of preterm human fetuses

Umbilical cord blood (CB) from the early gestational human fetus is recognized as a rich source of hematopoietic stem cells. To examine the value of fetal CB for gene therapy of inborn immunohematopoietic disorders, we tested the feasibility of genetic modification of CD34(+) cells from CB at weeks 24 to 34 of pregnancy, using lentiviral vector-mediated transfer of the green fluorescent protein (GFP) gene. The transduction rate of CD34(+) cells was 42 +/- 9%, resulting in GFP expression in 23 +/- 4% of colonies derived from colony-forming units (CFUs) and 11 +/- 1% from primitive long-term culture-initiating cells (LTC-ICs). Cell cycle analysis demonstrated transduction and GFP expression in cells in the G(0) phase, which contains immature hematopoietic progenitors. Transduced fetal CD34(+) cells could be expanded 1000-fold in long-term cultures supplemented with megakaryocyte growth and development factor along with Flt-3 ligand. At week 10, expression of GFP was observed in 40.5 +/- 11.7% of CFU-derived colonies. While prestimulation of CD34(+) cells with cytokines prior to transduction increased the efficiency of GFP transfer 2- to 3-fold, long-term maintenance of GFP-expressing CFUs occurred only in the absence of prestimulation. The GFP gene was found integrated into the genomic DNA of 35% of LTC-IC-derived colonies initiated at week 10, but GFP expression was not detectable, suggesting downregulation of transgene activity during the extended culture period. These results indicate that human fetal CB progenitors are amenable to genetic modification by lentiviral vectors and may serve as a target for gene therapy of hematopoietic disorders by prenatal autologous transplantation

Clonal karyotype evolution involving ring chromosome 1 with myelodysplastic syndrome subtype RAEB-t progressing into acute leukemia

s Karyotypic evolution is a well-known phenomenon in patients with malignant hernatological disorders during disease progression. We describe a 50-year-old male patient who had originally presented with pancytopenia in October 1992. The diagnosis of a myelodysplastic syndrome (MDS) FAB subtype RAEB-t was established in April 1993 by histological bone marrow (BM) examination, and therapy with low-dose cytosine arabinoside was initiated. In a phase of partial hernatological remission, cytogenetic assessment in August 1993 revealed a ring chromosome 1 in 13 of 21 metaphases beside BM cells with normal karyotypes {[}46,XY,r(1)(p35q31)/46,XY]. One month later, the patient progressed to an acute myeloid leukemia (AML), subtype M4 with 40% BM blasts and cytogenetic examination showed clonal evolution by the appearance of additional numerical aberrations in addition to the ring chromosome{[}46,XY,r(1),+8,-21/45,XY,r(1),+8,-21,-22/46, XY]. Intensive chemotherapy and radiotherapy was applied to induce remission in preparation for allogeneic bone marrow transplantation (BMT) from the patient's HLA-compatible son. After BMT, complete remission was clinically, hematologically and cytogenetically (normal male karyotype) confirmed. A complete hematopoietic chimerism was demonstrated. A relapse in January 1997 was successfully treated using donor lymphocyte infusion and donor peripheral blood stem cells (PB-SC) in combination with GM-CSF as immunostimulating agent in April 1997, and the patient's clinical condition remained stable as of January 2005. This is an interesting case of a patient with AML secondary to MDS. With the ring chromosome 1 we also describe a rare cytogenetic abnormality that predicted the poor prognosis of the patient, but the patient could be cured by adoptive immunotherapy and the application of donor's PB-SC. This case confirms the value of cytogenetic analysis in characterizing the malignant clone in hernatological neoplasias, the importance of controlling the quality of an induced remission and of the detection of a progress of the disease. Copyright (c) 2006 S. Karger AG, Basel

Reduced dose of subcutaneous cladribine induces identical response rates but decreased toxicity in pretreated chronic lymphocytic leukaemia

Purpose To study the efficacy and the safety of cladribine (2-chlorodeoxyadenosine, 2-CDA) administered as 24-hour infusions or as subcutaneous bolus injections at two different doses to patients with relapsing or refractory chronic lymphocytic leukaemia (CLL). Patients and methods In this non randomised 2-cohort study, 20 patients with pretreated CLL received cladribine at a dose of 0.7 mg/kg/cycle as continuous i.v. infusions over seven days (group 1) and 35 patients were treated at a reduced dose of 0.5 mg/kg/cycle given as s.c. bolus injections for five days (group 2). After two cycles of four week duration, response was assessed. In the case of progressive disease, therapy was discontinued, otherwise a maximum of four additional cycles were administered until best response. Results A total of 130 cycles were administered (group 1: 41, group 2: 89). Patient characteristics in both groups were comparable. The median dose intensities were 0.172 mg/kg per week and 0.123 mg/kg per week for groups 1 and 2, respectively (P ≤ 0.0001). The overall response rate for all 55 patients was 38% (95% confidence interval (95% CI): 25%-52%), with 5% CR and 33% PR. Response was similar in both patient groups (35% in group 1, 40% in group 2). No association between cladribine dose intensity and response rate was found, and there was no difference between patients relapsing after or refractory to previous therapies (11 of 24 vs. 10 of 31). Median remission duration was six months in both groups. Toxicity, in particular infections (all WHO grades, 34% in group 1 versus 7% in group 2) and myelosuppression (grade 1-4 neutropenia, 72% versus 41% of cladribine cycles) were statistically significantly more frequent in group 1. Conclusion Cladribine is active in heavily pretreated patients with chronic lymphocytic leukaemias. Dose reduction by 29% led to similar response and remission duration, but to a significant decrease of myelotoxicity and risk of infection. Cladribine administered as s.c. bolus injections at 0.5 mg/kg per cycle is safe and this dose level should not be exceeded in this patient populatio