Correction of persistent thrombocytopenia by a boost of CD133+ selected stem cells in a patient transplanted for Wiskott-Aldrich syndrome 10 years ago

Immunological recovery following HLA-matched CD3+ TCR αß+/CD19+ depleted hematopoietic stem cell transplantation in children

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (HSCT) is a potentially curative option for children with both malignant and nonmalignant diseases. T-cell depletion techniques may result in reduced transplant-related mortality compared with unmanipulated grafts due to a lower incidence of GvHD.

METHODS

Immune recovery and outcome were analyzed in a cohort of 23 patients with malignant and nonmalignant diseases who received CD3+TCRαβ+ T- and B-cell-depleted allografts from matched donors after reduced-intensity or myeloablative conditioning. The median number of CD34+, CD3+TCRαβ+, and CD19+B-cells infused was 12.7 × 10⁶ /kg, 16.8 × 10³ /kg, and 96 × 10³ /kg bodyweight.

RESULTS

With a median follow-up of 36 (range 1-73) months, overall survival and disease-free survival at 3 years were 65.2% and 60.8%. Eight patients died, six due to the underlying disease and two of extended visceral cGvHD. Immune reconstitution, disease-free, and overall survivals were similar compared with a historical cohort of 23 patients transplanted with matched unmanipulated bone marrow. A significant lower rate of higher grade (III-IV) aGvHD was observed in the manipulated HSCT group (8.7% vs. 26%; p = 0.001), whereas the incidence of cGvHD was equal.

CONCLUSIONS

Our data suggest that this graft manipulation strategy could be a safe and effective alternative to conventional HSCT techniques in matched donors.

Surgical Therapy of End-Stage Heart Failure: Understanding Cell-Mediated Mechanisms Interacting with Myocardial Damage

Worldwide, cardiovascular disease results in an estimated 14.3 million deaths per year, giving rise to an increased demand for alternative and advanced treatment. Current approaches include medical management, cardiac transplantation, device therapy, and, most recently, stem cell therapy. Research into cell-based therapies has shown this option to be a promising alternative to the conventional methods. In contrast to early trials, modern approaches now attempt to isolate specific stem cells, as well as increase their numbers by means of amplifying in a culture environment. The method of delivery has also been improved to minimize the risk of micro-infarcts and embolization, which were often observed after the use of coronary catheterization. The latest approach entails direct, surgical, transepicardial injection of the stem cell mixture, as well as the use of tissue-engineered meshes consisting of embedded progenitor cells.

Perspective on the role of haploidentical transplantation in the management of hematologic malignancies: why do it?

Haploidentical hematopoietic stem cell transplantation (HSCT) using mismatched family member donors has historically been complicated by high rates of nonrelapse toxicity and the need for laboratory expertise in depleting grafts of T lymphocytes. Over the past decade, improvements in supportive care, the increased use of peripheral-blood stem cell grafts, and improved T-cell depletion techniques have reduced the incidence of graft failure and lowered the rate of nonrelapse mortality. In addition, clinical studies have demonstrated that the donor-recipient mismatch may be beneficial in this setting, stimulating an immunologic cell-mediated antileukemia effect that results in lower disease recurrence rates. All of these advances have led to improvements in outcomes following haploidentical HSCT, making it an attractive option available to some patients. Because most patients do not have a matched related donor available and time to identify an unrelated donor may be excessive, haploidentical HSCT is a potentially curative option for these patients.

Isolation, molecular cloning and in vitro expression of rhesus monkey (Macaca mulatta) prominin-1.s1 complementary DNA encoding a potential hematopoietic stem cell antigen

Human prominin-1 (CD133 or AC133) is an important cell surface marker used to isolate primitive hematopoietic stem cells. The commercially available antibody to human prominin-1 does not recognize rhesus prominin-1. Therefore, we isolated, cloned and characterized the complementary DNA (cDNA) of rhesus prominin-1 gene and determined its coding potential. Following the nomenclature of prominin family of genes, we named this cDNA as rhesus prominin-1.s1. The amino acid sequence data of the putative rhesus prominin-1.s1 could be used in designing antigenic peptides to raise antibodies for use in isolation of pure populations of rhesus prominin-1(+) hematopoietic cells. To the best of our knowledge, there has been no previously published report about the isolation of a prominin-1 cDNA from rhesus monkey (Macaca mulatta).

Marrow aplasia developing 13 years after HLA-identical sibling allogeneic transplantation for chronic myeloid leukaemia: successful treatment with antithymocyte globulin and peripheral blood stem cell infusion from the original donor

Secondary or late graft failure has been defined as the development of inadequate marrow function after initial engraftment has been achieved. We describe a case of profound marrow aplasia occurring 13 years after sibling allogeneic bone marrow transplantation for chronic myeloid leukaemia (CML) in first chronic phase. Although the patient remained a complete donor chimera, thereby suggesting that an unselected infusion of donor peripheral blood stem cells (PBSC) or bone marrow might be indicated, the newly acquired aplasia was thought to be immune in aetiology and some immunosuppression was therefore considered appropriate. Rapid haematological recovery was achieved after the infusion of unselected PBSC from the original donor following conditioning with anti-thymocyte globulin (ATG).

CD34+-selected stem cell boost for delayed or insufficient engraftment after allogeneic stem cell transplantation

BACKGROUND

Poor graft function without rejection may occur after stem cell transplantation (SCT). CD34(+) stem cell boost (SCB) can restore marrow function but may induce or exacerbate GvHD. We therefore investigated the feasibility and efficacy of CD34(+)-selected SCB in some patients with poor graft function. We present the results for eight patients (median age 46 years) transplanted initially for myelofibrosis, acute leukemia, myeloma and NHL. Six patients had received HLA-matched and two mismatched grafts (PB, BM; n=5, 3). After a median of 128 days post-transplant, the median leukocyte and platelet counts were, respectively, 2.05/nL and 18/nL. None had achieved platelet counts >50/nL even though donor chimerism was >95% in seven recipients.

METHODS

Positive selection of CD34(+) stem cells was performed on a CliniMACS device, observing GMP and achieving a median of 98.5% purity. The patients received a median of 1.7 x 10(6)/kg CD34(+) cells and 2.5 x 10(3)/kg CD3(+) T lymphocytes.

RESULTS

Hemograms at days +30, +60 and +90, respectively, showed steadily increasing median leukocyte (2.55, 3.15 and 4.20/nL) and platelet (29, 39 and 95/nL) counts. After a median follow-up of 144 days, five patients remained alive. No patient had developed acute or chronic GvHD. One patient died of leukemic relapse and two others of systemic mycosis.

DISCUSSION

These preliminary results point to the possibility of safely improving graft function using CD34(+) positively selected stem cells without necessarily increasing the incidence of GvHD in patients with poor graft function post-SCT. Experience with more patients and longer follow-up should clarify the optimal role for this procedure.

Outcome of boost haemopoietic stem cell transplant for decreased donor chimerism or graft dysfunction in primary immunodeficiency

Haemopoietic stem cell transplants (HSCT) cure increasing numbers of primary immunodeficiencies (PID): residual recipient T-cell function increases risk of incomplete or decreasing immune reconstitution, which may resolve following a second, unconditioned, infusion from the same donor (boost infusion). We assessed the outcome of 20 boost infusions in 19/139 patients transplanted for PID patients at our centre since 1987. Boost infusion was given 64-1226 days after the original HSCT. Follow-up was 4-124 months. In all, 12 of 19 patients cleared viral infection (6), or showed sustained increase in donor chimerism, T- and B-cell numbers and function, or other markers (6). In 7/12 patients, immunoglobulin replacement has been discontinued. Four were partially successful with stable low-level chimerism (two patients) or improved T-cell function, but not B cell function (two patients). Four failed with no change in donor chimerism or cell number. No significant association with donor source, T-cell depletion, conditioning regimen, boost infusion stem cell dose or time from original HSCT to boost was found. One patient developed grade III acute graft-versus-host disease despite cyclosporine, and one developed severe pneumonitis; both have recovered. Boost infusion was successful or partially successful in 84% of patients. The risk of adverse effects is low.