Biomedical subjects

Jill Hows

Publications and source records attributed to Jill Hows.

6 recordsLinked to original sources

PubMed2006

Influence of donor/recipient sex matching on outcome of allogeneic hematopoietic stem cell transplantation for aplastic anemia.

BACKGROUND: Increased risk of transplant related mortality in male recipients of female hematopoietic stem cell grafts and in vitro reactivity of lymphocytes against H-Y encoded gene products in females with rejected male grafts have been documented. An increased rejection of male grafts in female recipients is not reported for solid organ or stem cell transplants and the role of H-Y as transplantation antigen has been controversial. METHODS: Data from 1481 patients with a hematopoietic stem cell transplant for aplastic anemia reported from 154 centers in 28 countries were analyzed. Outcome was compared between patients with donors of the same or opposite sex. RESULTS: Survival at 5 years was significantly better in patients with donors from the same sex: 68% vs. 60% (P = 0.001). Male patients with female donors had a decreased survival (relative risk of death 1.52, P < 0.001) and an increased risk of severe graft-versus-host disease (relative risk 1.33, P = 0.03) compared to recipients of sex-matched grafts. Female patients with male donors had a decreased survival (relative risk of death 1.44, P = 0.01) and an increased risk of rejection (relative risk 2.20, P = 0.01) compared to recipients of sex-matched grafts. In a subgroup analysis, the negative effects of donor/recipient sex-mismatching appeared confined to patients receiving conditioning regimens not containing antithymocyte globulin. CONCLUSIONS: These data confirm H-Y as a clinically relevant transplantation antigen, in both the graft-versus-host and the host-versus-graft direction. Wherever possible, donor-recipient sex-matching should be integrated into donor selection algorithms.

Adolescent↗

PubMed2005

Adult stem cell therapy beyond haemopoietic stem cell transplantation? An update.

The lifesaving potential of haemopoietic stem cell transplantation for the treatment of haematological malignancies and other life threatening disorders of the haemopoietic stem cell is universally accepted. In contrast, the use of adult marrow derived stem cells for tissue repair strategies in degenerative disease or after tissue damage are only in the early stages of evolution. A range of opinion exists within the general public and the scientific community about whether research with human embryonic stem cells is ethically acceptable. Further, the current paucity of human embryonic stem cell data has lead investigators to consider adult marrow as a potential source of stem cells to treat a wide range of degenerative disease and damaged tissues. Target disorders include osteoarthritis, diabetes mellitus, Parkinson's disease, ischaemic heart disease and retinal degeneration. Obvious advantages of this approach, if successful, would be fewer ethical hurdles compared with embryonic stem cells. Treatment with the patients own marrow stem cells would eliminate the possibility of allogeneic rejection.

Adult↗

PubMed2005

Bone marrow-derived mesenchymal stem cells.

Human mesenchymal stem cells (MSCs) contribute to the regeneration of mesenchymal tissues, and are essential in providing support for the growth and differentiation of primitive hemopoietic cells within the bone marrow microenvironment. Techniques are now available to isolate human MSCs and manipulate their expansion in vitro under defined culture conditions without change of phenotype or loss of function. Mesenchymal stem cells have generated a great deal of interest in many clinical settings, including that of regenerative medicine, immune modulation and tissue engineering. Studies have already demonstrated the feasibility of transplanted MSCs providing crucial new cellular therapy. In this review, many aspects of the MSC will be discussed, with the main focus being on clinical studies that describe the potential of MSCs to treat patients with hematological malignancies who are undergoing chemotherapy and/or radiotherapy.

Bone Marrow Cells↗

PubMed2003

Cytokine expansion culture of cord blood CD34+ cells induces marked and sustained changes in adhesion receptor and CXCR4 expressions.

Recent studies have demonstrated defective bone marrow homing of hematopoietic stem cells after cytokine expansion culture. Adhesion receptors (ARs) are essential to the homing process, and it is possible that cytokine culture modulates AR expression. We studied changes in expression of very late antigen-4 (VLA-4), VLA-5, L-selectin, leukocyte function-associated antigen-1 (LFA-1), CD44, and the stromal cell-derived factor-1 (SDF-1) receptor, CXCR4, during cytokine culture of cord blood (CB) CD34(+) cells. Expression of ARs was studied by flow cytometry on CB CD34(+) cells in whole blood, after purification and during culture for up to 10 days. Cells were cultured with stem cell factor (SCF), thrombopoietin (TPO), Flt3-ligand (Flt3), and G-CSF. Results showed that 80% or more of uncultured CD34(+) cells were positive for VLA-4, L-selectin, LFA-1, CD44, and CXCR4 while 50% were positive for VLA-5. Purification of CD34(+) cells did not affect AR expression, but cytokines increased expression three- to nine-fold throughout the 10-day culture period. In contrast, expression of CXCR4 decreased. Expression changes of ARs and CXCR4 on CD34(+)/CD38(-) cells mirrored those of the total CD34(+) population. The results indicate that cytokine culture significantly increases AR expression on CB CD34(+) cells, which may be related to the decrease in homing of cytokine-cultured hematopoietic stem cells.

ADP-ribosyl Cyclase↗

PubMed2003

Cobblestone area-forming cells in human cord blood are heterogeneous and differ from long-term culture-initiating cells.

The long-term culture-initiating cell (LTC-IC) assay is a physiological approach to the quantitation of primitive human hematopoietic cells. The readout using identification of cobblestone area-forming cells (CAFC) has gained popularity over the LTC-IC readout where cells are subcultured in a colony-forming cell assay. However, comparing the two assays, cord blood (CB) mononuclear cell (MNC) samples were found to contain a higher frequency of CAFC than LTC-IC (126 +/- 83 versus 40 +/- 31 per 10(5) cells, p = 0.0001). Overall, 60% of week-5 cobblestones produced by CB MNC were not functional LTC-IC and were classified as "false." Separation of CB MNC using immunomagnetic columns showed that false cobblestones were CD34(-)/lineage(+). Purified CD34(+) cells, as expected, gave very similar readouts in the two assays, with 4,084 and 3,468/10(5) cells being CAFC and LTC-IC, respectively. CD34(-)/lineage(-) cells did not form cobblestones or become CD34(+) on stroma or in cytokine culture. Human CB MNC contain a population of mature lineage(+) cells, possibly mature T or B cells, which, although producing cobblestone areas (CA), are not functional LTC-IC. The CAFC readout by this method, therefore, is unreliable for estimation of primitive hematopoietic cells by limiting dilution analysis in whole human CB or MNC and also may not detect CD34(-) CA stem cells.

Antigens, CD34↗

PubMed2002

Outcome of pregnancy and disease course among women with aplastic anemia treated with immunosuppression.

BACKGROUND: Aplastic anemia may develop during pregnancy and sometimes improves spontaneously after delivery. The effects of pregnancy on aplastic anemia after immunosuppressive treatment and of aplastic anemia on the outcome of pregnancy have not been described. OBJECTIVE: To determine the outcome of pregnancy and the disease course among women with aplastic anemia who received immunosuppressive therapy. DESIGN: Retrospective multicenter study. SETTING: Twelve centers participating in the European Group for Blood and Marrow Transplantation. PATIENTS: 36 women who received immunosuppressive therapy to treat aplastic anemia. MEASUREMENTS: Outcomes of pregnancy and aplastic anemia and blood counts before, during, and after delivery. RESULTS: The 36 pregnancies resulted in 34 live births (one set of twins), 2 elective abortions, and 1 spontaneous abortion. Of the 36 pregnancies, 22 were uncomplicated and 14 involved medical complications. Seven pregnancies (19%) were complicated by relapse of aplastic anemia, and 5 patients without relapse (14%) needed transfusions during delivery. After delivery, 3 of the 7 patients who had relapse recovered spontaneously and 3 recovered after retreatment. One patient who did not respond to treatment died of aplastic anemia. A woman with aplastic anemia and paroxysmal nocturnal hemoglobinuria had a fatal cerebral thrombosis after delivery. Women with uneventful pregnancies had better prepregnancy remission status (8 complete and 11 partial remissions) and a higher median platelet count (146 x 10(9) cells/L) than did women with complicated pregnancies (2 complete remissions, 8 partial remissions, and 4 cases of paroxysmal nocturnal hemoglobinuria; median platelet count, 92 x 10(9) cells/L). CONCLUSIONS: Successful pregnancy with normal outcome is possible in women with aplastic anemia previously treated with immunosuppression. Complications appear to be more likely in patients with low platelet counts and paroxysmal nocturnal hemoglobinuria-associated aplastic anemia.

Adult↗