Four patients with chronic refractory immune thrombocytopenic purpura (ITP) received human umbilical cord-derived mesenchymal stem cells (hUC-MSCs). The hUC-MSC dose was 5×107 to 1×108. Complete remission (CR) was achieved in three patients in 12 months and one patient in 24 months. Three patients received the second hUC-MSC transplantation with the same dose. The median time between hUC-MSC transplantation and response was 12.5 days (range, 7–16). There were no severe adverse events during and post hUC-MSC transplantation. During follow-up (median, 17 months; range, 13–24) no other immunosuppressive drugs were used post-first hUC-MSCs transplantation. In conclusion, hUC-MSC transplantation is a reasonable salvage treatment in chronic refractory ITP. Prospective randomized large-scale clinical trials are needed to further elucidate the efficacy of hUC-MSCs transplantation therapy on ITP.
Chronic immune thrombocytopenic purpura (ITP) is an autoimmune disorder characterized by an elevated rate of platelet destruction and persistent thrombocytopenia (
The number of studies focusing on the therapeutic potentials of mesenchymal stem cells (MSCs) in experimental models and clinic trials are growing. One of the reasons for this growing interest can be explained by the fact that MSCs are assumed to be effective biological tools to treat degenerative diseases. In previous studies, we grafted MSCs derived from human umbilical cord-derived MSCs (hUC-MSCs) to treat non-union in rats and humans (
The protocol of the present study was approved by the Institutional Review Board and the Ethics Committee of Siping Hospital of China Medical University (Beijing, China). The trial was conducted in compliance with current Good Clinical Practice standards and in accordance with the principles set forth under the Declaration of Helsinki in 1989.
hUC-MSCs used in this trial were derived from two donated umbilical cords (UC) obtained from healthy mothers during routine term elective caesarean section births. Fully informed consent was obtained several weeks prior to delivery. hUC-MSCs were isolated and propagated, as previously described (
ITP was diagnosed in accordance with standard criteria and other causes of thrombocytopenia were excluded. Three adult patients with ITP having a platelet count <30×109/l that persisted for at least 3 months with an inadequate or transient response to multiple therapies were treated with hUC-MSCs. The patients were willing to sign an informed consent form where they agreed to be treated in the Siping Hospital of China Medical University. The general characteristics of the patients are presented in
hUC-MSCs (10 ml) with a cell density of 5×106 to 1×107/ml was given intravenously at a rate up to 12.5×106/min and flushed with 20 ml saline to ensure full cell dose delivery. Once the needle was fully withdrawn, the puncture site was wrapped with sterile dressing. Patients remained in the supine decubitus on the operation bed for another 30 min before off-bed activities and antibiotics were given to prevent infection. Patients' conditions were monitored (temperature, blood pressure, pulse and oxygen saturation) at 15, 30, 45 and 60 min, and then once every hour for a minimum of 4 h.
Platelet-related parameters were analyzed before the operation and at several time points post-transplantation using an automated blood cell counter model LH-750 (Beckman Coulter, Inc., Brea, CA, USA).
i) Primary safety assessments included monitoring and recording of all the adverse events as well as the serious adverse events. The patients were monitored (temperature, blood pressure, pulse and oxygen saturation) at 15, 30, 45 and 60 min, and then once every hour for a minimum of 4 h. They were discharged 24 h post-transplantation if they were not febrile and hemodynamically stable, with no signs of infection or any type of allergic reaction. Any abnormal reactions within 3 months were considered to be linked to transplantation.
ii) As exploratory secondary end-points we investigated the efficacy of hUC-MSC infusion as assessed by platelet-related parameters, at baseline and at a series of time-points (2 weeks and 3, 6, 12 and 24 months post-first hUC-MSC administration). Initial response evaluation was made at the end of the second week after treatment initiation. Complete remission (CR) was considered when the platelet count was >1×1011/l, partial remission (PR) if platelets were >5×1010/l, and minimal response (MR) if the platelet count was between 3×1010/l and 5×1010/l. No response was platelet count that remained unchanged. Response was classified as sustained (SR) when it was stable for a minimum of 6 months. Relapse was defined as a decline in platelet count to <30×109/l and/or the need for ITP rescue treatments.
Pharmacological therapy consisted of: i) inhaling high doses of steroids and prednisone (1 mg/kg, p.o., once daily); ii) vincristine (2 mg, once per month, i.v.); iii) intravenous immunoglobulins (γ globulin), 0.4 g/kg, once daily, i.p.; and iv) cyclosporine (3 mg/kg, p.o., once daily).
Statistical analyses were performed using SPSS 16.0 software (Chicago, IL, USA). Safety and exploratory efficacy secondary endpoints were observed for each patient against the baseline values. P<0.05 was considered statistically significant.
Cells derived from UC were observed 24 h after they were seeded (
Clinical characteristics of patients who participated in the present study are summarized in
Results of hUC-MSC treatment are shown in
No serious or clinically significant side effects were observed during the entire study period. During the whole follow-up period, neither ectopic tissue formation nor other illnesses related to the hUC-MSCs treatment were recorded in the patients.
In the present study, we evaluated the response rate achieved in 4 patients with chronic and refractory ITP after hUC-MSC intravenous infusion in 24 months. The clinical median relieved time of symptoms after one transplant was 17 months. To the best of our knowledge, this is the first study on the efficiency of hUC-MSC transplantation treatment for ITP patients. Our experimental results supported cell therapy for ITP.
The hUC-MSCs used in the present study met the criteria of the International Society for Cell Therapy (
In addition, the pathophysiology of ITP is complex and abnormalities of the B- and T-cell compartments have been identified. Furthermore, MSCs in ITP patients have a reduced proliferative capacity and a lower inhibitory effect on activated T-cell proliferation compared with MSC from healthy donors (
In conclusion, hUC-MSC transplantation is safe and effective for treating ITP. Our data suggest that MSC therapy may be a reasonable salvage treatment in severe, potentially life-threatening, refractory ITP. The optimal period of hUC-MSC transplantation for treating ITP is once a year. Prospective randomized clinical trials are needed to elucidate the efficacy of hUC-MSC transplantation therapy on ITP in the future.
The present study has been supported by the National High Technology Research and Development Program, 863 Program, nos. 2011AA020101 and 2012A020905.
Evaluation of hUC-MSCs. (A) The cells derived from UC were observed at 24 h after they were seeded; (B) three days after inoculation; (C) hUC-MSC surface markers: CD105 and CD45, (D) hUC-MSC surface markers, HLA-DR and CD90. hUC-MSCs, human umbilical cord-derived mesenchymal stem cells; UC, umbilical cord.
Patient characteristics before and post hUC-MSC transplantation.
Characteristics | Patient 1 | Patient 2 | Patient 3 | Patient 4 |
---|---|---|---|---|
Age (years) | 26 | 49 | 54 | 50 |
Gender | M | F | F | F |
Duration of disease (months) | 43 | 71 | 62 | 120 |
Previous treatments | P, V, C, IVIg, S | P, V, C, IVIg | P, IVIg, C, De, S | P, IVIg, V |
HUC-MSC transplantation times | 1 | 2 | 2 | 2 |
Platelet counts (x109/l) |
||||
Before therapy | 8 | 9 | 5 | 3 |
After therapy |
56 | 94 | 103 | 56 |
After therapy |
80 | 96 | 105 | 59 |
After therapy |
82 | 101 | 118 | 61 |
After therapy |
189 | 84 | 234 | 116 |
After therapy |
134 | |||
Bleeding |
||||
Before therapy bleeding | Skin, genitourinary | Skin | Epistaxis | Skin, genitourinary bleeding |
After therapy | No | No | Mucosal | Skin |
Time to response (days) | 7 | 13 | 16 | 14 |
Time to maximum response (days) | 31 | 53 | 42 | 58 |
Overall response | Yes | Yes | Yes | Yes |
Response duration (months) |
Yes, 24 | Yes, 18 | Yes, 13 | Yes, 13 |
Platelet count measurements were carried out at the end of the following time points post hUC-MSC transplantation.
Major skin indicates diffuse ecchymosis; mucosal, intrabuccal hemorrhagic vesicles, or prolonged epistaxis; and intestinal and menorrhagia, gastrointestinal, and genitourinary bleeding, respectively.
These four patients had a relapse within 13 months after the first hUC-MSC administration but responded to the second hUC-MSC treatment, and they all sustained response for >8 months. hUC-MSCs, human umbilical cord-derived mesenchymal stem cells; M, male; F, female; P, prednisone; V, vincristine; C, cyclosporin; IVIg, intravenous immunoglobulins; S, splenectomy; De, dexamethasone.