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Biomedical subjects

Walter G Barr

Publications and source records attributed to Walter G Barr.

10 recordsLinked to original sources
PubMed2006

Nonmyeloablative hematopoietic stem cell transplantation for systemic lupus erythematosus.

CONTEXT: Manifestations of systemic lupus erythematosus (SLE) may in most patients be ameliorated with medications that suppress the immune system. Nevertheless, there remains a subset of SLE patients for whom current strategies are insufficient to control disease. OBJECTIVE: To assess the safety of intense immunosuppression and autologous hematopoietic stem cell support in patients with severe and treatment-refractory SLE. DESIGN, SETTING, AND PARTICIPANTS: A single-arm trial of 50 patients with SLE refractory to standard immunosuppressive therapies and either organ- or life-threatening visceral involvement. Patients were enrolled from April 1997 through January 2005 in an autologous nonmyeloablative hematopoietic stem cell transplantation (HSCT) study at a single US medical center. INTERVENTIONS: Peripheral blood stem cells were mobilized with cyclophosphamide (2.0 g/m2) and granulocyte colony-stimulating factor (5 microg/kg per day), enriched ex vivo by CD34+ immunoselection, cryopreserved, and reinfused after treatment with cyclophosphamide (200 mg/kg) and equine antithymocyte globulin (90 mg/kg). MAIN OUTCOME MEASURES: The primary end point was survival, both overall and disease-free. Secondary end points included SLE Disease Activity Index (SLEDAI), serology (antinuclear antibody [ANA] and anti-double-stranded (ds) DNA), complement C3 and C4, and changes in renal and pulmonary organ function assessed before treatment and at 6 months, 12 months, and then yearly for 5 years. RESULTS: Fifty patients were enrolled and underwent stem cell mobilization. Two patients died after mobilization, one from disseminated mucormycosis and another from active lupus after postponing the transplantation for 4 months. Forty-eight patients underwent nonmyeloablative HSCT. Treatment-related mortality was 2% (1/50). By intention to treat, treatment-related mortality was 4% (2/50). With a mean follow-up of 29 months (range, 6 months to 7.5 years) for patients undergoing HSCT, overall 5-year survival was 84%, and probability of disease-free survival at 5 years following HSCT was 50%. Secondary analysis demonstrated stabilization of renal function and significant improvement in SLEDAI score, ANA, anti-ds DNA, complement, and carbon monoxide diffusion lung capacity adjusted for hemoglobin. CONCLUSIONS: In treatment-refractory SLE, autologous nonmyeloablative HSCT results in amelioration of disease activity, improvement in serologic markers, and either stabilization or reversal of organ dysfunction. These data are nonrandomized and thus preliminary, providing the foundation and justification for a definitive randomized trial. Clinical Trial Registration ClinicalTrials.gov Identifier: NCT00271934.

Adult↗
PubMed2005

Prevalence and reversibility of pulmonary dysfunction in refractory systemic lupus: improvement correlates with disease remission following hematopoietic stem cell transplantation.

AIM: To report the prevalence and reversibility of pulmonary function test (PFT) abnormalities among systemic lupus erythematosus (SLE) patients, refractory to therapy, undergoing hematopoietic stem cell transplantation (HSCT). METHODS: Thirty-four SLE patients received 200 mg/kg cyclophosphamide and 90 mg/kg equine antithymocyte globulin followed by HSCT. PFTs were performed prior to, at 6 months, and yearly following HSCT. RESULTS: The prevalence of significant PFT abnormalities was high (97%). Low FEV(1) and FVC occurred in 26 of 34 patients (76%). A significant abnormality in diffusion capacity of the lung for carbon monoxide (Dlco) occurred in 26 of 32 individuals able to complete Dlco testing (81%). Dlco 18 months after HSCT. Five of 28 patients had a normal entry FVC; for each, the FVC remains normal. Of the 23 patients with an abnormal baseline FVC, 18 have improved, 15 completely and 3 partially. Eight of these 18 patients also have improved Dlco. The two patients with a diagnosis of SLS and one patient with SLE-related pulmonary hypertension improved in both parameters. Only 5 of 23 patients with an abnormal FVC did not improve. Each of these five patients retained active lupus in spite of HSCT. CONCLUSION: The prevalence of lung impairment among SLE patients requiring long-term immune suppression is high. Following HSCT, pulmonary impairments can improve, which is sustained if disease control is sustained.

Adult↗
PubMed2004

Induction of remission of severe and refractory rheumatoid arthritis by allogeneic mixed chimerism.

This report describes the first allogeneic hematopoietic stem cell transplantation (HSCT) performed for the indication of rheumatoid arthritis (RA). We used nonmyeloablative allogeneic HSCT to treat a 52-year-old woman who had treatment-refractory RA and a poor prognosis (24 swollen and 38 involved joints). She was treated with fludarabine, cyclophosphamide, CAMPATH-1H, and CD34-selected HSCT (8 million CD34+ donor cells/kg); the donor was the patient's HLA-matched, rheumatoid factor-negative sister. One year post-HSCT, the patient has had no infection except dermatomal varicella-zoster virus infection and no acute or chronic graft-versus-host disease (GVHD). Her RA has remained in remission with no immunosuppressive or immunomodulatory medications. The patient is a mixed chimera, with 55% donor T (CD3+) cells and 70% donor myeloid (CD33+) cells. This is the first published report of allogeneic HSCT performed for the indication of RA. Mixed chimerism has resulted in marked amelioration of RA, without GVHD.

Alemtuzumab↗
PubMed2004

Scleroderma renal crisis: new insights and developments.

Scleroderma renal crisis (SRC) was once a uniformly fatal complication of systemic sclerosis (SSc). With the introduction of angiotensin-converting enzyme inhibitors as treatment, outcomes have improved significantly, though 39% to 50% of SSc patients who develop SRC continue to have poor outcomes, including permanent dialysis and death. Early recognition and treatment with angiotensin-converting enzyme inhibitors are important in the effective management of SRC, though given the continuing morbidity and mortality caused by SRC, they are clearly not sufficient. Newer therapies based on the pathophysiologic mechanisms underlying the development and perpetuation of SRC are needed. This article reviews the epidemiology, pathogenesis, risk factors, clinical features, and treatment of SRC, with an emphasis on recent insights and developments.

Humans↗
PubMed2002

Hematopoietic stem cell transplantation for severe and refractory lupus. Analysis after five years and fifteen patients.

OBJECTIVE: To determine the safety and long-term efficacy of immune ablation and autologous hematopoietic stem cell transplantation (HSCT) in severe systemic lupus erythematosus (SLE). METHODS: Fifteen patients with persistently active SLE after intravenous (IV) cyclophosphamide (CYC) therapy underwent HSCT. Stem cells were mobilized with CYC (2.0 gm/m(2)) and granulocyte colony-stimulating factor (5 microg/kg/day). Lymphocytes were depleted from the graft by selection of CD34-positive cells. The conditioning regimen used was CYC (200 mg/kg), antithymocyte globulin (90 mg/kg), and methylprednisolone (3 mg/kg). Outcome was evaluated by the SLE Disease Activity Index (SLEDAI), serum complement levels, serologic features, function of diseased organs, and immunosuppressive medication requirements. RESULTS: Fifteen patients with persistent, severe SLE, 7 of whom were critically ill, were treated. No deaths occurred following treatment. The median followup after HSCT has been 36 months (range 12-66 months). All patients demonstrated a gradual, but marked, improvement. The SLEDAI score has declined to 1 year after HSCT, 10 have discontinued immunosuppressive medications, and the prednisone dosage has been tapered to 15 mg/day in 1. Only 2 patients have demonstrated clinical evidence of recurrence of active lupus. One of these patients currently requires no immunosuppressive medication and has a normal performance status. The other patient is currently receiving IV CYC. CONCLUSION: In patients experiencing the persistence of organ-threatening lupus following standard, aggressive therapy, HSCT may be performed safely, with marked improvement and sustained withdrawal of all immunosuppressive medication for most patients. A phase III randomized trial is warranted to determine the relative efficacy and durability of remission of HSCT compared with standard therapies.

Adolescent↗