Pablo Rubinstein

Outcomes among 562 Recipients of Placental-Blood Transplants from Unrelated Donors

BACKGROUND A program for banking, characterizing, and distributing placental blood, also called umbilical-cord blood, for transplantation provided grafts for 562 patients between August 24, 1992, and January 30, 1998. We evaluated this experience. METHODS Placental blood was stored under liquid nitrogen and selected for specific patients on the basis of HLA type and leukocyte content. Patients were prepared for the transplantation of allogeneic hematopoietic cells in the placental blood and received prophylaxis against graft-versus-host disease (GVHD) according to routine procedures at each center. RESULTS Outcomes at 100 days after transplantation were known for all 562 patients, and outcomes at 1 year for 94 percent of eligible recipients. The cumulative rates of engraftment among the recipients, according to actuarial analysis, were 81 percent by day 42 for neutrophils (median time to engraftment, 28 days) and 85 percent by day 180 for platelets (median, day 90). The speed of myeloid engraftment was associated primarily with the leukocyte content of the graft, whereas transplantation-related events were associated with the patients underlying disease and age, the number of leukocytes in the graft, the degree of HLA disparity, and the transplantation center. After engraftment, age, HLA disparity, and center were the primary predictors of outcome. Severe acute GVHD (grade III or IV) occurred in 23 percent of patients, and chronic GVHD occurred in 25 percent. The rate of relapse among recipients with leukemia was 9 percent within the first 100 days, 17 percent within 6 months, and 26 percent by 1 year. These rates were associated with the severity of GVHD, type of leukemia, and stage of the disease. CONCLUSIONS Placental blood is a useful source of allogeneic hematopoietic stem cells for bone marrow reconstitution.

Placental Blood as a Source of Hematopoietic Stem Cells for Transplantation into Unrelated Recipients

BACKGROUND Transplantation of bone marrow from unrelated donors is limited by a lack of HLA-matched donors and the risk of graft-versus-host disease (GVHD). Placental blood from sibling donors can reconstitute hematopoiesis. We report preliminary results of transplantation using partially HLA-mismatched placental blood from unrelated donors. METHODS Twenty-five consecutive patients, primarily children, with a variety of malignant and non-malignant conditions received placental blood from unrelated donors and were evaluated for hematologic and immunologic reconstitution and GVHD. HLA matching was performed before transplantation by serologic typing for class I HLA antigens and low-resolution molecular typing for class II HLA alleles. In donor-recipient pairs who differed by no more than one HLA antigen or allele, high-resolution class II HLA typing was done retrospectively. Fordonor-recipient pairs who were mismatched for two HLA antigens or alleles, high-resolution typing was used prospectively to select the best match for HLA-DRB1. RESULTS Twenty-four of the 25 donor-recipient pairs were discordant for one to three HLA antigens. In 23 of the 25 transplant recipients, the infused hematopoletic stem cells engrafted. Acute grade III GVHD occurred in 2 of the 21 patients who could be evaluated, and 2 patients had chronic GVHD. In vitro proliferative responses of T cells and B cells to plant mitogens were detected 60 days after transplantation. With a median follow-up of 12 1/2 months and a minimal follow-up of 100 days, the overall 100-day survival rate among these patients was 64 percent, and the overall event-free survival was 48 percent. CONCLUSIONS HLA-mismatched placental blood from unrelated donors is an alternative source of stem cells for hematopoietic reconstitution in children.

HEMATOPOIETIC ENGRAFTMENT AND SURVIVAL IN ADULT RECIPIENTS OF UMBILICAL-CORD BLOOD FROM UNRELATED DONORS

BACKGROUND Umbilical-cord blood from unrelated donors who are not HLA-identical with the recipients can restore hematopoiesis after myeloablative therapy in children. We studied the use of transplantation of umbilical-cord blood to restore hematopoiesis in adults. METHODS Sixty-eight adults with life-threatening hematologic disorders received intensive chemotherapy or total-body irradiation and then transplants of HLA-mismatched umbilical-cord blood. We evaluated the outcomes in terms of hematologic reconstitution, the occurrence of acute and chronic graft-versus-host disease (GVHD), relapses, and event-free survival. RESULTS Of the 68 patients, 48 (71 percent) received grafts of umbilical-cord blood that were mismatched for two or more HLA antigens. Of the 60 patients who survived 28 days or more after transplantation, 55 had neutrophil engraftment at a median of 27 days (range, 13 to 59). The estimated probability of neutrophil recovery in the 68 patients was 0.90 (95 percent confidence interval, 0.85 to 1.0). The presence of a relatively high number of nucleated cells in the umbilical-cord blood before it was frozen was associated with faster recovery of neutrophils. Severe acute GVHD (of grade III or IV) occurred in 11 of 55 patients who could be evaluated within the first 100 days after transplantation. Chronic GVHD developed in 12 of 33 patients who survived for more than 100 days after transplantation. The median follow-up for survivors was 22 months (range, 11 to 51). Of the 68 patients, 19 were alive and 18 of these (26 percent) were disease-free 40 months after transplantation. The presence of a high number of CD34+ cells in the graft was associated with improved event-free survival (P=0.05). CONCLUSIONS Umbilical-cord blood from unrelated donors can restore hematopoiesis in adults who receive myeloablative therapy and is associated with acceptable rates of severe acute and chronic GVHD.

Outcomes of transplantation of unrelated donor umbilical cord blood and bone marrow in children with acute leukaemia: a comparison study

BACKGROUND Although umbilical cord blood is an accepted alternative to bone marrow for transplantation, allele-matched bone marrow is generally regarded as the preferred graft source. Our aim was to assess leukaemia-free survival after transplantations of these alternatives compared with present HLA-matching practices, and to assess the relative effect of cell dose and HLA match, and their potential interaction on leukaemia-free survival after cord-blood transplantation. METHODS Outcomes of 503 children (<16 years) with acute leukaemia and transplanted with umbilical cord blood were compared with outcomes of 282 bone-marrow recipients. All transplantation took place in the USA. Recipients of umbilical cord blood were transplanted with grafts that were HLA-matched (n=35) or HLA-mismatched for one (n=201) or two antigens (n=267) (typing at antigen level for HLA-A and HLA-B, and allele level for HLA-DRB1). Bone-marrow recipients were transplanted with grafts that were matched at the allele level for HLA-A, HLA-B, HLA-C, and HLA-DRB (n=116), or mismatched (n=166). The primary endpoint was 5-year leukaemia-free survival. FINDINGS In comparison with allele-matched bone-marrow transplants, 5-year leukaemia-free survival was similar to that after transplants of umbilical cord blood mismatched for either one or two antigens and possibly higher after transplants of HLA-matched umbilical cord blood. Transplant-related mortality rates were higher after transplants of two-antigen HLA-mismatched umbilical cord blood (relative risk 2.31, p=0.0003) and possibly after one-antigen HLA-mismatched low-cell-dose umbilical-cord-blood transplants (1.88, p=0.0455). Relapse rates were lower after two-antigen HLA-mismatched umbilical-cord-blood transplants (0.54, p=0.0045). INTERPRETATION These data support the use of HLA-matched and one- or two-antigen HLA-mismatched umbilical cord blood in children with acute leukaemia who need transplantation. Because better HLA matching and higher cell doses significantly decrease the risk of transplant-related mortality after umbilical-cord-blood transplantation, greater investment in large-scale banking is needed to increase HLA diversity.

Disseminated Kaposi's Sarcoma in Homosexual Men

Nineteen cases from an epidemic of disseminated Kaposis sarcoma in homosexual men were studied by clinical, virologic, immunologic, and genetic methods. The patients were all male homosexuals ranging in age from 29 to 52 years, with histories of multiple sexually transmitted diseases and exposure to both prescription and recreational drugs. Sites of disease included skin (16 of 19 patients), lymph nodes (13 patients), gastrointestinal tract (12 patients), spleen (three patients), and lung (one patient). Most patients had elevated levels of serum immunoglobins, positive antibody titers to hepatitis A and B virus, cytomegalovirus and Epstein-Barr virus, and impairment of cell-mediated immunologic reactions. The frequency of HLA-DR5 in these patients was significantly elevated. Two of the 19 patients died. Although the precise cause of this epidemic is unknown, it is likely that a genetic predisposition, an acquired immunoregulatory defect, and one or more infectious agents and drugs may be involved.

Isolation and characterization of mesenchymal stem cells from human umbilical cord blood: Reevaluation of critical factors for successful isolation and high ability to proliferate and differentiate to chondrocytes as compared to mesenchymal stem cells from bone marrow and adipose tissue

Human umbilical cord blood (CB) is a potential source for mesenchymal stem cells (MSC) capable of forming specific tissues, for example, bone, cartilage, or muscle. However, difficulty isolating MSC from CB (CB‐MSC) has impeded their clinical application. Using more than 450 CB units donated to two public CB banks, we found that successful cell recovery fits a hyper‐exponential function of time since birth with very high fidelity. Additionally, significant improvement in the isolation of CB‐MSC was achieved by selecting cord blood units having a volume ≥90 ml and time ≤2 h after donors birth. This resulted in 90% success in isolation of CB‐MSC by density gradient purification and without a requirement for immunoaffinity methods as previously reported. Using MSC isolated from bone marrow (BM‐MSC) and adipose tissue (AT‐MSC) as reference controls, we observed that CB‐MSC exhibited a higher proliferation rate and expanded to the order of the 1 × 109 cells required for cell therapies. CB‐MSC showed karyotype stability after prolonged expansion. Functionally, CB‐MSC could be more readily induced to differentiate into chondrocytes than could BM‐MSC and AT‐MSC. CB‐MSC showed immunosuppressive activity equal to that of BM‐MSC and AT‐MSC. Collectively, our data indicate that viable CB‐MSC could be obtained consistently and that CB should be reconsidered as a practical source of MSC for cell therapy and regenerative medicine using the well established CB banking system. J. Cell. Biochem. 112: 1206–1218, 2011.

Congenital rubella syndrome as a model for Type 1 (insulin-dependent) diabetes mellitus: increased prevalence of islet cell surface antibodies

SummaryAn increased prevalence of Type 1 (insulin-dependent) diabetes has been reported in patients with congenital rubella. Rubella virus multiplies in the pancreas, and we have hypothesized that studies of children with congenital rubella would be of great importance in following the development of Type 1 diabetes in a defined, susceptible population. Two hundred and forty-one children with congenital rubella (mean age 17.4±0.3 years; 65% black and hispanic) have been evaluated, 30 of whom already have diabetes and 17 of whom have borderline glucose tolerance. In these latter two groups, HLA-DR3 is significantly increased and HLA-DR2 significantly decreased. Pancreatic islet cell cytotoxic surface antibodies are found in 20% of the total congenital rubella population, including in more than 50% in the time period before they develop diabetes and are not related to any specific HLA type. In addition, anti-microsomal and anti-thyroglobulin antibodies are found in 34% of this population. The data demonstrate that Type 1 diabetes developing in congenital rubella patients has the genetic and immunological features of classical Type 1 diabetes, namely the presence of HLA-DR3, the absence of HLA-DR2, islet cell surface antibodies before decompensation and an increased prevalence of anti-thyroid antibodies. Patients with non-diabetic congenital rubella represent an easily identifiable group in whom other immunological factors associated with Type 1 diabetes can be elucidated and possibly modified.

PTFE-covered stents improve TIPS patency in Budd-Chiari syndrome.

Transjugular intrahepatic portosystemic shunt (TIPS) have been shown to be an efficient portal‐systemic derivative treatment for Budd‐Chiari syndrome (BCS) patients uncontrolled by medical therapy. However, the main drawback of TIPS for this condition is a very high rate of shunt dysfunction. Recently, polytetrafluoroethylene (PTFE)‐covered stents have been shown to reduce the incidence of TIPS dysfunction in patients with cirrhosis. The aim of the study was to assess the incidence of TIPS dysfunction in 2 cohorts of BCS patients treated with bare or PTFE‐covered stents. The study included 25 TIPS procedures (16 bare stents and 9 covered stents) with a median follow‐up period of 20.4 months (range, 3.9‐124.8). Fourteen of 16 patients (87%) receiving bare stents had TIPS dysfunction compared to 3 of the 9 patients (33%) receiving PTFE‐covered stents (P = .005). The actuarial rates of primary patency in the bare‐stent group were 19% at 1 year compared with 67% in the PTFE‐covered stent group (P = .02; log‐rank test). The number of additional interventional procedures to maintain TIPS patency was significantly greater in the bare‐stent than in the PTFE‐covered stent group (1.9 ± 1.2 vs. 0.6 ± 0.9; P = .007). The number of patients with clinical relapses was greater in the bare‐stent group compared to the PTFE‐covered stent group (13 vs. 5 episodes in 9 and 3 patients, respectively). In conclusion, PTFE‐covered stents have a considerable advantage over bare stents for the TIPS treatment of BCS patients, with a lower dysfunction rate, a lower number of reinterventions, and fewer prosthesis requirements. PTFE‐covered stents are preferable in patients with Budd‐Chiari Syndrome. (HEPATOLOGY 2004;40:1197–1202.)

Umbilical cord blood regulatory T-cell expansion and functional effects of tumor necrosis factor receptor family members OX40 and 4-1BB expressed on artificial antigen-presenting cells.

Previously, we showed that human umbilical cord blood (UCB) regulatory T cells (Tregs) could be expanded approximately 100-fold using anti-CD3/28 monoclonal antibody (mAb)-coated beads to provide T-cell receptor and costimulatory signals. Because Treg numbers from a single UCB unit are limited, we explored the use of cell-based artificial antigen-presenting cells (aAPCs) preloaded with anti-CD3/28 mAbs to achieve higher levels of Treg expansion. Compared with beads, aAPCs had similar expansion properties while significantly increasing transforming growth factor beta (TGF-beta) secretion and the potency of Treg suppressor function. aAPCs modified to coexpress OX40L or 4-1BBL expanded UCB Tregs to a significantly greater extent than bead- or nonmodified aAPC cultures, reaching mean expansion levels exceeding 1250-fold. Despite the high expansion and in contrast to studies using other Treg sources, neither OX40 nor 4-1BB signaling of UCB Tregs reduced in vitro suppression. UCB Tregs expanded with 4-1BBL expressing aAPCs had decreased levels of proapoptotic bim. UCB Tregs expanded with nonmodified or modified aAPCs versus beads resulted in higher survival associated with increased Treg persistence in a xeno-geneic graft-versus-host disease lethality model. These data offer a novel approach for UCB Treg expansion using aAPCs, including those coexpressing OX40L or 4-1BBL.

A perspective on the selection of unrelated donors and cord blood units for transplantation

Selection of a suitable graft for allogeneic hematopoietic stem cell transplantation involves consideration of both donor and recipient characteristics. Of primary importance is sufficient donor-recipient HLA matching to ensure engraftment and acceptable rates of GVHD. In this Perspective, the National Marrow Donor Program and the Center for International Blood and Marrow Transplant Research provide guidelines, based on large studies correlating graft characteristics with clinical transplantation outcomes, on appropriate typing strategies and matching criteria for unrelated adult donor and cord blood graft selection.