Clinical applications of blood-derived and marrow-derived stem cells for nonmalignant diseases

CONTEXT

Stem cell therapy is rapidly developing and has generated excitement and promise as well as confusion and at times contradictory results in the lay and scientific literature. Many types of stem cells show great promise, but clinical application has lagged due to ethical concerns or difficulties in harvesting or safely and efficiently expanding sufficient quantities. In contrast, clinical indications for blood-derived (from peripheral or umbilical cord blood) and bone marrow-derived stem cells, which can be easily and safely harvested, are rapidly increasing.

OBJECTIVE

To summarize new, nonmalignant, nonhematologic clinical indications for use of blood- and bone marrow-derived stem cells.

EVIDENCE ACQUISITION

Search of multiple electronic databases (MEDLINE, EMBASE, Science Citation Index), US Food and Drug Administration [FDA] Drug Site, and National Institutes of Health Web site to identify studies published from January 1997 to December 2007 on use of hematopoietic stem cells (HSCs) in autoimmune, cardiac, or vascular diseases. The search was augmented by hand searching of reference lists in clinical trials, review articles, proceedings booklets, FDA reports, and contact with study authors and device and pharmaceutical companies.

EVIDENCE SYNTHESIS

Of 926 reports identified, 323 were examined for feasibility and toxicity, including those with small numbers of patients, interim or substudy reports, and reports on multiple diseases, treatment of relapse, toxicity, mechanism of action, or stem cell mobilization. Another 69 were evaluated for outcomes. For autoimmune diseases, 26 reports representing 854 patients reported treatment-related mortality of less than 1% (2/220 patients) for nonmyeloablative, less than 2% (3/197) for dose-reduced myeloablative, and 13% (13/100) for intense myeloablative regimens, ie, those including total body irradiation or high-dose busulfan. While all trials performed during the inflammatory stage of autoimmune disease suggested that transplantation of HSCs may have a potent disease-remitting effect, remission duration remains unclear, and no randomized trials have been published. For reports involving cardiovascular diseases, including 17 reports involving 1002 patients with acute myocardial infarction, 16 involving 493 patients with chronic coronary artery disease, and 3 meta-analyses, the evidence suggests that stem cell transplantation performed in patients with coronary artery disease may contribute to modest improvement in cardiac function.

CONCLUSIONS

Stem cells harvested from blood or marrow, whether administered as purified HSCs or mesenchymal stem cells or as an unmanipulated or unpurified product can, under appropriate conditions in select patients, provide disease-ameliorating effects in some autoimmune diseases and cardiovascular disorders. Clinical trials are needed to determine the most appropriate cell type, dose, method, timing of delivery, and adverse effects of adult HSCs for these and other nonmalignant disorders.

Development of a secondary autoimmune disorder after hematopoietic stem cell transplantation for autoimmune diseases: role of conditioning regimen used

Patients undergoing autologous hematopoietic stem cell transplantation (auto-HSCT) for autoimmune disease may have an added propensity to develop a second autoimmune disorder, given the genetic predisposition to autoimmunity. Therefore, we undertook a retrospective analysis of all patients who have undergone auto-HSCT for an autoimmune disease in our institution to determine the occurrence of a second autoimmune disorder and possible risk factors. In all, 155 patients underwent auto-HSCT for various autoimmune diseases; of those patients, 6 manifested a distinct secondary autoimmune disease at a median of 8.5 months (range, 2-30 months) after auto-HSCT. There were 2 patients with systemic lupus erythematosus, conditioned with a regimen containing antithymocyte globulin (ATG), who developed factor VIII inhibitors with severe bleeding. There were 4 patients (2 with multiple sclerosis, one each with lupus and systemic sclerosis) who received an alemtuzumab-containing conditioning regimen who developed autoimmune cytopenias. Among the 155 patients, the frequency of secondary autoimmune complications was 16.0% with alemtuzumab (4/25), 1.9% for ATG (2/102), and 0% for conditioning regimens without lympho-depleting antibodies (0/28)-a difference that was found to be significantly higher with alemtuzumab exposure (P = .011). In contrast, sex, type of ATG used, and CD34-selection of peripheral blood stem cells were not found to be significantly associated with development of a secondary autoimmune disorder.

The anti-tumour activity of allogeneic cytokine-induced killer cells in patients who relapse after allogeneic transplant for haematological malignancies

We performed a Phase I/II clinical trial to study the feasibility, toxicity and efficacy of allogeneic cytokine-induced killer (CIK) cell expansion, and treatment for patients with haematological malignancies who relapsed after allogeneic haemopoietic SCT (allo-HSCT). Allogeneic CIK cells were successfully generated for a total of 24 patients, including those from patients' own leukapheresis products in 5 patients who had no access to further donor cells. The median CD3(+) T-cell expansion was 9.33 (1.3-38.97) fold, and CD3(+)CD56(+) natural killer (NK)-like T-cell expansion was 27.77 (2.59-438.93) fold. A total of 55 infusions were done for 16 patients who had either failed or progressed after initial response to various individualized chemotherapy regimens and donor lymphocyte infusion (DLI), at doses ranging from 10 to 200 million CD3(+) cells/kg. Response attributable to CIK cell infusion was observed in five patients. These included two with ALL, two with Hodgkin's disease (HD) and one with AML, and two of whom had a response sustained for more than 2 years. Acute GVHD occurred in three and was easily treatable. This study provides some evidence suggestive of the efficacy of allogeneic CIK cells even after failure of DLI in some cases.

Recanalization rates decrease with increasing thrombectomy attempts

BACKGROUND AND PURPOSE

Use of the Merci retriever is increasing as a means to reopen large intracranial arterial occlusions. We sought to determine whether there is an optimum number of retrieval attempts that yields the highest recanalization rates and after which the probability of success decreases.

MATERIALS AND METHODS

All consecutive patients undergoing Merci retrieval for large cerebral artery occlusions were prospectively tracked at a comprehensive stroke center. We analyzed ICA, M1 segment of the MCA, and vertebrobasilar occlusions. We compared the revascularization of the primary AOL with the number of documented retrieval attempts used to achieve that AOL score. For tandem lesions, each target lesion was compared separately on the basis of where the device was deployed.

RESULTS

We identified a total of 97 patients with 115 arterial occlusions. The median number of attempts per target vessel was 3, while the median final AOL score was 2. Up to 3 retrieval attempts correlated with good revascularization (AOL 2 or 3). When >or=4 attempts were performed, the end result was more often failed revascularization (AOL 0 or 1) and procedural complications (P = .006).

CONCLUSIONS

In our experience, 3 may be the optimum number of Merci retrieval attempts per target vessel occlusion. Four or more attempts may not improve the chances of recanalization, while increasing the risk of complications.

Mobilization, harvesting and selection of peripheral blood stem cells in patients with autoimmune diseases undergoing autologous hematopoietic stem cell transplantation

Peripheral blood stem cells (PBSC) were mobilized in 130 patients with autoimmune diseases undergoing autologous hematopoietic stem cell transplantation using cyclophosphamide 2 g/m(2) and either granulocyte colony-stimulating factor (G-CSF) 5 mcg/kg/day (for systemic lupus erythematosus (SLE) and secondary progressive multiple sclerosis, SPMS) or G-CSF 10 mcg/kg/day (for relapsing remitting multiple sclerosis (RRMS), Crohn's disease (CD), systemic sclerosis (SSc), and other immune-mediated disorders). Mobilization-related mortality was 0.8% (one of 130) secondary to infection. Circulating peripheral blood (PB) CD34(+) cells/microl differed significantly by disease. Collected CD34(+) cells/kg/apheresis and overall collection efficiency was significantly better using Spectra apheresis device compared to the Fenwall CS3000 instrument. Patients with SLE and RRMS achieved the lowest and the highest CD34(+) cell yields, respectively. Ex vivo CD34(+) cell selection employing Isolex 300iv2.5 apparatus was significantly more efficient compared to CEPRATE CS device. Circulating PB CD34(+) cells/microl correlated positively with initial CD34(+) cells/kg/apheresis and enriched product CD34(+) cells/kg. Mean WBC and platelet engraftment (ANC>0.5 x 10(9)/l and platelet count >20 x 10(9)/l) occurred on days 9 and 11, respectively. Infused CD34(+) cell/kg dose showed significant direct correlation with faster white blood cell (WBC) and platelet engraftment. When adjusted for CD34(+) cell/kg dose, patients treated with a myeloablative regimen had significantly slower WBC and platelet recovery compared to non-myeloablative regimens.

A phase I/II clinical trial of autologous cytokine-induced killer cells as adjuvant immunotherapy for acute and chronic myeloid leukemia in clinical remission

BACKGROUND AIMS

Cytokine-induced killer (CIK) cells have shown remarkable cytotoxicity against various tumors in vitro and in animal studies. We report on the clinical outcome of autologous CIK cells for patients with acute (AML) and chronic (CML) myeloid leukemia in remission.

METHODS

Eleven of the 13 recruited AML patients undergoing autologous peripheral blood stem cell transplant (autoPBSCT) were given autologous CIK cell infusion upon engraftment post-transplant and followed-up for disease relapse. Eleven CML patients on Imatinib with residual disease detectable by polymerase chain reaction (PCR) were given infusion and monitored by quantitation of the bcr-abl transcript.

RESULTS

Despite the presence of interferon (IFN)-γ-secreting T cells against various AML- and CML-associated peptides at sporadic time-points and demonstration of in vitro cytotoxicity of CIK cells against autologous and allogeneic AML targets, there was no survival benefit in AML patients post-autoPBSCT given CIK cells compared with historical controls. For CML patients, all continued to have a detectable bcr-abl transcript fluctuating within a range comparable to their pre-treatment baseline, although two had a transient but non-sustainable disappearance of bcr-abl transcript. There were no adverse reactions except for fever within the first day of infusion.

CONCLUSIONS

Our small series, while confirming safety, failed to demonstrate a clinical benefit of autologous CIK cells given in its current form for AML and CML. Further manipulation of CIK cells to improve anti-leukemic potency and specificity, together with the preparation of patients to create a more conducive milieu for in vivo expansion and persistence of infused CIK cells, should be explored.

Autologous non-myeloablative haematopoietic stem cell transplantation for refractory systemic vasculitis

OBJECTIVE

For patients with systemic vasculitis (SV) refractory to conventional therapy, new treatment strategies aimed at aggressive induction of remission and relapse prevention are being sought. We herein report our single-centre experience in treating four patients with refractory SV employing non-myeloablative autologous haematopoietic stem cell transplantation (HSCT).

METHODS

Four patients with refractory SV (two with neurovascular Behcet disease, one with neurovascular Sjögren syndrome, and one with Wegener granulomatosis) were involved in an Institutional Review Board (IRB) and US Food and Drug Administration (FDA) approved phase I clinical trial of high dose chemotherapy and autologous HSCT. Peripheral blood stem cells were mobilised with cyclophosphamide (Cy) and granulocyte-colony stimulating factor (G-CSF). Conditioning regimen consisted of Cy 200 mg/kg and rabbit anti-thymocyte globulin 5.5 mg/kg intravenously (iv).

RESULTS

All four patients tolerated HSCT well without transplant related mortality or any significant toxicity. At median follow-up of 28 (range 22-36) months all patients were alive. Three patients (one with Behcet disease, one with Sjögren syndrome, and one with Wegener granulomatosis) entered a sustained remission at 6, 6 and 24 months, respectively, after transplant. They had significant decrease in disease activity and disease or treatment related damage, as measured by the Birmingham Vasculitis Activity Score and Vasculitis Damage Index, respectively. All three patients who achieved remission discontinued immunosuppressive therapy at the time of transplant and have not required treatment since. One patient with Behcet disease and positive for human leukocyte antigen (HLA)-B51 has not improved after HSCT.

CONCLUSION

We suggest non-myeloablative autologous HSCT is an alternative therapy for select patients with SV refractory to conventional immunosuppressive therapies.

Clinician and therapist perceptions on radiation therapist-led treatment reviews in radiation oncology practice

BACKGROUND AND PURPOSE

To determine whether radiation therapists (RTTs) and radiation oncologists (ROs) believe RTTs can lead patient treatment reviews.

MATERIALS AND METHODS

Phase 1 involved the construction of a checklist of the procedures followed during RO treatment reviews. Phase 2 employed the checklist to monitor the frequency of review procedures. From these data, questionnaires regarding RTTs' ability to carry out these procedures to be used in Phase 3 were developed. The questionnaires were distributed to RTTs and ROs at two large public cancer centres.

RESULTS

The majority of RTTs and ROs believed that RTTs could provide assurance and answer questions about side effects, treatment techniques, cancer, nutrition and logistics. ROs and RTTs agreed that RTTs were not capable of recommending medication or answering medical questions. Most RTTs thought they could decide if a patient should take a break from treatment if a standard protocol existed, but the ROs disagreed (P < 0.01). ROs believed that RTTs were capable of using the Common Toxicity Criteria system to grade side effects, but RTTs disagreed (P < 0.01). Concerns were raised about training, legalities, workloads, logistics, cost, patients' perspectives and remuneration.

CONCLUSION

RTTs and ROs believed RTTs could lead treatment reviews with training, and support this role development.

The risk of acute radiocontrast-mediated kidney injury following endovascular therapy for acute ischemic stroke is low

BACKGROUND AND PURPOSE

Endovascular therapy is an alternative for the treatment of AIS resulting from large intracranial arterial occlusions that depends on the use of iodinated RCM. The risk of RCM-mediated AKI following endovascular therapy for AIS may be different from that following coronary interventions because patients may not have identical risk factors.

MATERIALS AND METHODS

All consecutive patients with large-vessel AIS undergoing endovascular therapy were prospectively recorded. We recorded the baseline kidney function, and RCM-AKI was assessed according to the AKIN criteria at 48 hours after RCM administration. We compared the rate of RCM-AKI 48 hours after the procedure and sought to determine whether any preexisting factors increased the risk of RCM-AKI.

RESULTS

We identified 99 patients meeting inclusion criteria. The average volume of contrast was 189 ± 71 mL, and the average creatinine change was -4.6% at 48 hours postangiography. There were 3 patients with RCM-AKI. Although all 3 patients died as a result of their strokes, return to baseline creatinine levels occurred before death. There was a trend toward higher rates of premorbid diabetes mellitus, chronic renal insufficiency, preadmission statin and NSAID use, and a higher serum creatinine level on admission for the RCM-AKI group. The volume of procedural contrast was similar between groups (those with and those without RCM-AKI) (P = .5).

CONCLUSIONS

In this small study, the rate of RCM-AKI following endovascular intervention for AIS was very low. A much larger study is required to determine its true incidence.

Autologous hematopoietic stem cell transplantation in systemic lupus erythematosus patients with cardiac dysfunction: feasibility and reversibility of ventricular and valvular dysfunction with transplant-induced remission

Patients with cardiac dysfunction may be at increased risk of cardiac toxicity when undergoing hematopoietic stem cell transplantation (HSCT), which may preclude them from receiving this therapy. Cardiac dysfunction is, however, common in systemic lupus erythematosus (SLE) patients. While autologous HSCT (auto-HSCT) has been performed increasingly for SLE, its impact on cardiac function has not previously been evaluated. We, therefore, performed a retrospective analysis of SLE patients who had undergone auto-HSCT in our center to determine the prevalence of significant cardiac involvement, and the impact of transplantation on this. The records of 55 patients were reviewed, of which 13 were found to have abnormal cardiac findings on pre-transplant two-dimensional echocardiography or multi-gated acquisition scan: impaired left ventricular ejection fraction (LVEF) (n = 6), pulmonary hypertension (n = 5), mitral valve dysfunction (n = 3) and large pericardial effusion (n = 1). At a median follow-up of 24 months (8-105 months), there were no transplant-related or cardiac deaths. With transplant-induced disease remission, all patients with impaired LVEF remained stable or improved; while three with symptomatic mitral valve disease similarly improved. Elevated pulmonary pressures paralleled activity of underlying lupus. These data suggest that auto-HSCT is feasible in selected patients with lupus-related cardiac dysfunction, and with control of disease activity, may improve.

Measuring radiotherapy setup errors at multiple neck levels in nasopharyngeal cancer (NPC): A case for differential PTV expansion

BACKGROUND AND PURPOSE

We aim to quantify the magnitude of the systematic and random setup errors at three different anatomical levels of the neck in Nasopharyngeal Carcinoma (NPC) when clivus matching is used, and recommend appropriate PTV margins for each level.

MATERIAL AND METHODS

Thirty-six patients undergoing image-guided radiotherapy (IGRT) each with 9 scheduled CBCTs were reviewed. The magnitude of setup errors were measured at the level of the clivus, C4 and C7 vertebrae, before and after CBCT correction. The 3D displacements, systematic and random errors were calculated for each level. The appropriate PTV expansion was determined using Van Herk's formula.

RESULTS

Mean 3D displacement was 1.88, 2.66 and 3.35 mm at the clivus, C4 and C7 before correction. The differences were statistically significant (p<0.05). The PTV margin required without correction was 2.33, 4.33 and 6.52 mm respectively. These were reduced to 1.20, 3.72 and 6.08 mm after CBCT corrections.

CONCLUSIONS

Variability is seen in setup errors at the clivus, C4 and C7 vertebral levels. A variable planning margin approach with reduced margin at the clivus is recommended. Use of daily CBCT allows the PTV expansion to be reduced to 1.2 mm.

Pre-transplant achievement of negativity in minimal residual disease and French-American-British L1 morphology predict superior outcome after allogeneic transplant for Philadelphia chromosome positive acute lymphoblastic leukemia: an analysis of Southeast Asian patients

To better understand predictive factors and improve the clinical outcome of allogeneic transplant for patients with Philadelphia positive acute lymphoblastic leukemia, we analyzed 67 Southeast Asian patients transplanted in our institutions. Multivariate analysis showed that disease status before transplant, year of transplant and, interestingly, French-American-British (FAB) subtype had a significant impact on overall survival (OS) and non-relapse mortality. Patients who were minimal residual disease (MRD) negative at transplant had a 3-year OS of 73% compared to those who were MRD positive (45%) and refractory (0%). The 3-year cumulative incidence of relapse was 18% and 36% for the MRD negative and positive groups, respectively. FAB L1 subtype had a significantly superior 3-year OS of 63% vs. 29% for L2 subtype. Pre-transplant use of a tyrosine kinase inhibitor significantly improved outcomes in univariate but not multivariate analysis, as it served to induce more patients into MRD negativity, which was the factor that directly improved transplant outcome.

Successful treatment of primary granulocytic sarcoma by non-myeloablative stem cell transplant

Pre-leukemic granulocytic sarcoma (GS) may pose an initial diagnostic problem and its therapeutic approach has never been formally established. To our knowledge, non-myeloablative stem cell transplantation has been reported in cases of leukemic GS, but not in primary GS. We report a case of primary GS with extensive and aggressive presenting features and successfully treated with intensive chemotherapy followed by non-myeloablative allogeneic stem cell transplant. This resulted in complete remission with minimal complications. Our case demonstrates the potential of graft-vs.-tumour effect in the treatment of GS and suggests that non-myeloablative allogeneic stem cell transplant may be a feasible therapeutic approach for primary GS.

Comprehensive Venous Outflow Predicts Functional Outcomes in Patients with Acute Ischemic Stroke Treated by Thrombectomy

BACKGROUND AND PURPOSE

Cortical venous outflow has emerged as a robust measure of collateral blood flow in acute ischemic stroke. The addition of deep venous drainage to this assessment may provide valuable information to further guide the treatment of these patients.

MATERIALS AND METHODS

We performed a multicenter retrospective cohort study of patients with acute ischemic stroke treated by thrombectomy between January 2013 and January 2021. The internal cerebral veins were scored on a scale of 0-2. This metric was combined with existing cortical vein opacification scores to create a comprehensive venous outflow score from 0 to 8 and stratify patients as having favorable-versus-unfavorable comprehensive venous outflow. Outcome analyses were primarily conducted using the Mann-Whitney U and χ2 tests.

RESULTS

Six hundred seventy-eight patients met the inclusion criteria. Three hundred fifteen were stratified as having favorable comprehensive venous outflow (mean age, 73 years; range, 62-81 years; 170 men), and 363, as having unfavorable comprehensive venous outflow (mean age, 77 years; range, 67-85 years; 154 men). There were significantly higher rates of functional independence (mRS 0-2; 194/296 versus 37/352, 66% versus 11%, P < .001) and excellent reperfusion (TICI 2c/3; 166/313 versus 142/358, 53% versus 40%, P < .001) in patients with favorable comprehensive venous outflow. There was a significant increase in the association of mRS with the comprehensive venous outflow score compared with the cortical vein opacification score (-0.74 versus -0.67, P = .006).

CONCLUSIONS

A favorable comprehensive venous profile is strongly associated with functional independence and excellent postthrombectomy reperfusion. Future studies should focus on patients with venous outflow status that is discrepant with the eventual outcome.

Partial recanalization of concomitant internal carotid-middle cerebral arterial occlusions promotes distal recanalization of residual thrombus within 24 h

OBJECTIVES

Acute, simultaneous, concomitant internal carotid artery (ICA) and middle cerebral arteries (MCA) occlusions almost invariably lead to significant neurological disability if left untreated. Endovascular therapy is frequently the method of treatment in such situations but there remains a chance of incomplete recanalization. Successful recanalization of the proximal aspect of the occlusion may allow for endogenous thrombolysis and facilitate further endogenous recanalization of any residual MCA occlusion.

METHODS

Consecutive patients with acute ischemic stroke undergoing endovascular therapy for tandem extracranial ICA-MCA or contiguous intracranial ICA-MCA occlusions were retrospectively analyzed. Rates of facilitated endogenous recanalization at 24 h (FER(24)) were compared by imaging within the immediate post-intervention 5-24 h period in those with proximal recanalization and in those without.

RESULTS

17 patients were included in the analysis. 12 patients had good initial proximal recanalization but a residual partial or total occlusion of the MCA while five patients failed any recanalization. Seven patients (58.3%) in the first group and none in the second had FER(24) on interval imaging after intervention (p=0.04). The probability of death and disability at discharge was less in patients with FER(24) than those without (p=0.05).

CONCLUSIONS

More than half of all patients who present with both ICA and MCA occlusions who are only partially recanalized will undergo facilitated endogenous recanalization within the subsequent 24 h following intervention.

The unexplained success of stentplasty vasospasm treatment : Insights using Mechanistic Mathematical Modeling

BACKGROUND

Cerebral vasospasm (CVS) following subarachnoid hemorrhage occurs in up to 70% of patients. Recently, stents have been used to successfully treat CVS. This implies that the force required to expand spastic vessels and resolve vasospasm is lower than previously thought.

OBJECTIVE

We develop a mechanistic model of the spastic arterial wall to provide insight into CVS and predict the forces required to treat it.

MATERIAL AND METHODS

The arterial wall is modelled as a cylindrical membrane using a constrained mixture theory that accounts for the mechanical roles of elastin, collagen and vascular smooth muscle cells (VSMC). We model the pressure diameter curve prior to CVS and predict how it changes following CVS. We propose a stretch-based damage criterion for VSMC and evaluate if several commercially available stents are able to resolve vasospasm.

RESULTS

The model predicts that dilatation of VSMCs beyond a threshold of mechanical failure is sufficient to resolve CVS without damage to the underlying extracellular matrix. Consistent with recent clinical observations, our model predicts that existing stents have the potential to provide sufficient outward force to successfully treat CVS and that success will be dependent on an appropriate match between stent and vessel.

CONCLUSION

Mathematical models of CVS can provide insights into biological mechanisms and explore treatment approaches. Improved understanding of the underlying mechanistic processes governing CVS and its mechanical treatment may assist in the development of dedicated stents.