Biomedical subjects

Edgar L Milford

Publications and source records attributed to Edgar L Milford.

13 recordsLinked to original sources

PubMed2006

Predictors of improved progression-free survival after nonmyeloablative allogeneic stem cell transplantation for advanced chronic lymphocytic leukemia.

Although chronic lymphocytic leukemia (CLL) remains an incurable disease with standard chemotherapy, the appropriate role and timing of transplantation are unclear. In this analysis, we report the outcomes of 46 patients with advanced CLL who underwent nonmyeloablative stem cell transplantation (NST) from HLA-matched unrelated (67%) or related (33%) donors. Fludarabine (30 mg/m2 x 4) and low-dose intravenous busulfan (0.8 mg/kg/day x 4) were used for conditioning. The 2-year overall survival (OS) and progression-free survival (PFS) rates in this refractory patient population were 54% and 34%, respectively, with a median follow-up of 20 months. The primary cause of treatment failure was relapse, with a 2-year cumulative incidence of 48%. High hematopoietic donor chimerism > or = 75% at day +30 was a significant predictor of 2-year PFS (47% vs 11%; P = .03). In multivariate analysis, chemotherapy-refractory disease at transplantation was associated with a 3.2-fold risk of progression (P = .01) and a 4.6-fold risk of death (P = .02). Increasing number of previous therapies and increasing bone marrow involvement were also associated with decreased PFS and OS. These results suggest that NST using fludarabine and low-dose intravenous busulfan is a reasonable treatment option for patients with advanced CLL, but that NST earlier in the disease course will likely be needed to achieve long-term disease control in a high proportion of patients.

Adult↗

PubMed2005

The HLDA8 blind panel: findings and conclusions.

There were over 600 antibodies submitted to HLDA8, with many of unknown specificity. Of these, 101 antibodies were selected for a blind panel study that also included 5 negative controls and 27 positive controls of known CD specificity making a total of 133 antibodies in the final panel. Of the 101 unknowns, 31 antibodies were identified during the course of this blind panel study as being specific for known molecules and included some specific for MHC class II antigens, CD45 isoforms and the Dombrock antigen. Several antibody pairs among those in the blind panel were found to have very similar staining patterns and were therefore compared by immunohistochemical and/or Western blot analyses for identity.

Antibodies↗

PubMed2005

Immunosuppression: evolution in practice and trends, 1993-2003.

Immunosuppression trends for solid organ transplantation have undergone a perceptible shift over the past decade. This period is of interest because it was during this time that the Food and Drug Administration (FDA) expanded the variety of medications to allow for alternatives in immunosuppressive management. An organ-by-organ review of SRTR data identifies several important trends. Antibody induction continues to be used for the majority of kidney (70%), simultaneous pancreas-kidney (SPK, 79%) pancreas after kidney (PAK, 74%), and intestine recipients (74%). It is used for under half of thoracic organ recipients and remains uncommon for liver transplant recipients (20%). The type of antibody preparation utilized has shifted from muromonab-CD3 and horse ATG to rabbit ATG and monoclonal anti-IL-2 receptor antagonists. Calcineurin inhibitors continue to be used for maintenance immunosuppression for most recipients, although there has been a shift from cyclosporine to tacrolimus. A clear transition is apparent in the choice of antimetabolite from azathioprine to mycophenolate mofetil. Although corticosteroids continue to be used as maintenance immunosuppression for most recipients prior to discharge, there is evidence that efforts of steroid avoidance protocols are having an impact across all organs, as slight decreases in their use have been observed.

Graft Rejection↗

PubMed2005

TIRC7 pathway as a target for preventing allograft rejection.

A number of leukocyte surface molecules play an essential role during immune activation. Targeting of these molecules utilizing antibodies serves as a specific therapeutic approach for the treatment of a variety of human diseases. Antibodies targeting a number of leukocyte surface molecules were shown to induce tolerance to transplants in several animal models. A novel membrane molecule, T-cell immune response cDNA 7 (TIRC7), has been shown to be an essential protein in the regulation of lymphocyte activation. TIRC7 does not share any homology with other known membrane proteins expressed during the course of lymphocyte activation and does not belong to any of the known costimulatory, cytokine, chemokine or receptor families. TIRC7, a highly conserved protein across species, is expressed in immune tissues such as spleen, lymph nodes, and T and B lymphocytes. Antibodies against extracellular domains of TIRC7 prolong allograft survival in rat and mouse transplantation models. The prevention of rejection is mediated at least partially via induction of cytotoxic T lymphocyte antigen 4 (CTLA4) in T cells. Functional cellular assays utilizing TIRC7-deficient mice splenocytes show that TIRC7 does have an impact not only on T-cell, but also on B-cell response. Subtherapeutic amounts of FK506 and anti-TIRC7 monoclonal antibody prolong graft survival, suggesting synergistic effects with calcineurin inhibitors. Targeting TIRC7 with monoclonal antibody might serve as a promising therapeutic strategy for preventing allograft rejection in humans and treatment of other immune-related diseases. Acutely rejected human kidney allografts show strong expression of TIRC7 despite treatment with calcineurin inhibitors. Therefore, monitoring TIRC7 expression may facilitate an early diagnostic tool of acute rejection. TIRC7 seems to belong to a group of targets with dual roles in disease pathogenesis, so-called theranostics, which can be utilized to treat and diagnose diseases.

Animals↗

PubMed2004

ATG induction is associated with an increase in anti-HLA antibodies after kidney transplantation.

Anti-human histocompatibility antigen antibodies (HLA-Ab) are deleterious after kidney transplant and may be increased after T-cell depleting agents are given. A retrospective case control study was conducted to evaluate increase in HLA-Ab in 27 kidney transplant recipients who had received antithymocyte globulin (ATG) induction compared with 27 control subjects. A greater than 10% increase in class I or class II HLA-Ab was found in 6 (22.2%) of ATG subjects versus only 1 (3.7%) of non-ATG subjects (p = 0.05). In females, 6/14 ATG subjects developed increased HLA-Ab > or =10% compared with none of the control subjects (p = 0.016). In sensitized subjects, 4/10 in the ATG group developed increased HLA-Ab > or =10% versus none of the controls (p = 0.043). There was no difference in number or severity of acute rejection episodes or estimated glomerular filtration rate 6 months after transplant between the two treatment groups. We conclude that ATG induction may result in increased posttransplant HLA-Ab, particularly in subjects at higher immunologic risk. Further studies are necessary to determine the natural history, clinical consequences, appropriate therapy, and mechanisms responsible for HLA-Ab in this setting.

Animals↗

PubMed2004

Diminishing significance of HLA matching in kidney transplantation.

To determine trends in the significance of HLA matching and other risk factors in kidney transplantation, we analyzed data on graft survival in a consecutive sample of 33 443 transplant recipients who received deceased donor kidneys from December 1994 to December 1998 with a mean follow-up time of 2.2 years. HLA matching and other risk factors (peak panel reactive antibody, donor age, sex and cause of death, cold ischemia time, donor and recipient body size) were examined. Mean likelihood ratios of models, fit with and without each variable of interest, were calculated by generating bootstrapped samples from each single year cohort. Pooled censored and uncensored graft survival rates were 90.6% and 89.9% at 1 year, 85.8% and 84.5% at 2 years, and 80.7% and 78.6% at 3 years. HLA matching declined in significance while other factors retained similar levels of statistical significance over the four yearly cohorts. With evolving clinical practice, including the provision of safer and more potent immunosuppressive therapy, the significance of HLA matching has diminished. Non-immunologic factors continue to impede more marked improvements in long-term graft survival. Recognizing these trends, organ allocation algorithms may need to be revised.

Adolescent↗

PubMed2003

Soluble HLA-I (s-HLA-I) synthesis in systemic lupus erythematosus.

Our objective was to study a possible contribution of major histocompatibility complex (MHC) genes to soluble HLA-I synthesis in patients with systemic lupus erythematosus (SLE). Solid-phase enzyme-linked immunoassay (ELISA) was used to measure sHLA-I in the sera of 20 patients with SLE and 76 normal controls with known HLA phenotypes. Serial serum samples ( n=108) from the above group of patients ( n=19) were further investigated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. Soluble HLA-I levels were abnormally higher in patients with SLE than normal controls ( P<0.0002). No complete HLA haplotype has been identified to be correlated with high or low sHLA-I secretion. Only the sera of HLA-A23- or -A24- (splits of HLA-A9) positive individuals were found to contain high sHLA-I concentrations in both populations studied. The difference between sHLA-I of HLA-A24 patients ( n=7) and HLA-A24 normal controls ( n=19) was statistically highly significant ( P<0.0079). The results suggest that HLA-A24 may confer additional risk of more severe disease expression in female patients with SLE. The data imply that SLE patients carrying 39-kDa sHLA-I have increased risk of developing renal disease. A higher prevalence of 35-37 kDa was observed in patients with mild disease. Interestingly, 44-46 kDa was the predominant molecular form of sHLA-I in SLE patients with lymphocytosis with no evidence of organ involvement. Notably, all these variations were not reflected by differences in HLA phenotypes, with the exception of HLA-A24-positive patients, in whom the 44-46-kDa form occurs consistently but not exclusively. In summary, the results show a genetic heterogeneity of SLE with MHC control of the expression of sHLA-I concentrations and possible involvement of disease-associated factors that might potentiate a specific sHLA-I molecule synthesis.

Adult↗

PubMed2003

Investigations into the role of anti-HLA class II antibodies in TRALI.

BACKGROUND: TRALI is thought to be triggered by recipient-specific anti-HLA class I or antibodies against neutrophils in donor plasma. Recently, anti-HLA class II have also been implicated. The prevalence of anti-HLA class II was investigated in normal volunteer platelet donors and in two nonfatal TRALI cases utilizing a flow-based assay. Potential target antigens also were investigated. STUDY DESIGN AND METHODS: Commercial flow cytometry-based assays (FlowPRA, One Lambda, Inc.) for anti-HLA class I and II were compared with standard lymphocytotoxicity tests. Subsequently, 151 volunteer platelet donors and two clinical cases of TRALI were screened with FlowPRA. Immunohistochemical studies were performed on lung tissue from a surgical case, an autopsy case, and a fatal TRALI case. RESULTS: The FlowPRA assays showed moderate concordance for anti-HLA class I (kappa = 0.448) and good concordance for class II antibodies (kappa = 0.801), when compared to standard lymphocytotoxicity assays. Ten and 9 percent of female platelet donors were positive for anti-HLA class I and class II, respectively. Two nonfatal cases of TRALI showed both anti-HLA class I and anti-HLA class II. Immunohistochemical analysis of a TRALI case revealed granulocyte aggregation in alveolar capillaries with activated vascular endothelial cells. HLA class II antigen expression was not present on vascular endothelium or intravascular WBCs; however, strong expression was seen on alveolar macrophages. CONCLUSION: FlowPRA assays often detect anti-HLA class I not detected by conventional lymphocytotoxicity assays. These assays reveal anti-HLA class II in normal female donor plasma and in sera implicated in TRALI. Immunohistochemical studies failed to reveal endothelial or intravascular-WBC HLA class II antigen expression in lung tissue derived from TRALI cases or controls, but demonstrated HLA class II expression on pulmonary macrophages.

Cell Adhesion↗

PubMed2003

Calcium channel blockers as the treatment of choice for hypertension in renal transplant recipients: fact or fiction.

Posttransplantation hypertension has been identified as an independent risk factor for chronic allograft dysfunction and loss. Based on available morbidity and mortality data, posttransplantation hypertension must be identified and managed appropriately. During the past decade, calcium channel blockers have been recommended by some as the antihypertensive agents of choice in this population, because it was theorized that their vasodilatory effects would counteract the vasoconstrictive effects of the calcineurin inhibitors. With increasing data becoming available, reexamining the use of traditional antihypertensive agents, including diuretics and beta-blockers, or the newer agents, angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers, may be beneficial. Transplant clinicians must choose antihypertensive agents that will provide their patients with maximum benefit, from both a renal and a cardiovascular perspective. Beta-blockers, diuretics, and ACE inhibitors have all demonstrated significant benefit on morbidity and mortality in patients with cardiovascular disease. Calcium channel blockers have been shown to possess the ability to counteract cyclosporine-induced nephrotoxicity. When compared with beta-blockers, diuretics, and ACE inhibitors, however, the relative risk of cardiovascular events is increased with calcium channel blockers. With the long-term benefits of calcium channel blockers on the kidney unknown and a negative cardiovascular profile, these agents are best reserved as adjunctive therapy to beta-blockers, diuretics, and ACE inhibitors.

Adrenergic beta-Antagonists↗

PubMed2002

Effect of anti-IL-2Ralpha antibody on IL-2-induced Jak/STAT signaling.

Acute allograft rejection is driven by production of cytokines such as interleukin-2 (IL-2) that activate and expand alloreactive T cells by ligating high-affinity IL-2 receptors composed of three subunit chains: alpha, beta, gamma The alpha chain, expressed only on activated T cells, has become an important therapeutic target. Monoclonal antibodies (mAbs) that bind IL-2Ralpha chains significantly decrease transplant rejection. We examined the ability of the humanized anti-IL-2Ralpha antibody daclizumab to block high-affinity IL-2Rs and interrupt T-lymphocyte signaling. Our evaluation focused on a pathway critical for T-cell proliferation, the Jak/STAT pathway. Daclizumab markedly inhibited phosphorylation of the Jak1, Jak3 and STAT5a/b components of the IL-2R-dependent pathway. Suppression by daclizumab was associated with internalization of IL-2Ralpha but not IL-2Rbetagamma chains. High IL-2 doses overcame daclizumab-induced blockade of Jak/STAT phosphorylation despite absent cell surface highaffinity IL-2Rs. Under these circumstances, IL-2-mediated Jak/STAT pathway activation might be generated through residual intermediate affinity IL-2Rbetagamma receptors, and this was demonstrated by complete blockade of signaling when anti-IL-2Rbeta monoclonal antibody was added. Humanized antibodies are an important part of strategies to induce alloantigen tolerance. Understanding the molecular events associated with their beneficial clinical effect is critical to design of future immunosuppressive strategies.

Antibodies, Monoclonal↗

PubMed2002

Chemokine receptor polymorphism and risk of acute rejection in human renal transplantation.

Chemokines regulate the trafficking of leukocytes in immunity and inflammation and have been implicated in mouse models in acute cardiac and renal allograft rejection; however, their significance to human transplantation is not yet defined. The association of human chemokine receptor genetic variants, CCR5-Delta32, CCR5-59029-A/G, CCR2-V64I, CX3CR1-V249I, and CX3CR1-T280M, with outcome in 163 renal transplant recipients was examined here. Significant reductions were found in risk of acute renal transplant rejection in recipients who possessed the CCR2-64I allele (odds ratio [OR], 0.30; 95% confidence interval [CI], 0.12 to 0.78; P = 0.014) or who were homozygous for the 59029-A allele (OR, 0.37; 95% CI, 0.16 to 0.85; P = 0.016). There were no significant differences in the incidence of rejection among patients stratified as with or without CCR5-Delta32 or by the CX3CR1-V249I or CX3CR1-T280M genotypes. Adjustment for known risk factors for transplant rejection confirmed the univariate findings for possession of the CCR2-64I allele (OR, 0.20; P = 0.032) and homozygosity for the 59029-A allele (OR, 0.26; P = 0.027). It was concluded that the risk of acute rejection in renal transplantation is associated with genetic variation in the chemokine receptors CCR2 and CCR5.

Acute Disease↗

PubMed2002

Matching of flow-cytometry histograms using information theory in feature space.

Flow cytometry is a widely available technique for analyzing cell-surface protein expression. Data obtained from flow cytometry is frequently used to produce fluorescence intensity histograms. Comparison of histograms can be useful in the identification of unknown molecules and in the analysis of protein expression. In this study, we examined the combination of a new smoothing technique called SiZer with information theory to measure the difference between cytometry histograms. SiZer provides cross-bandwidth smoothing and allowed analysis in feature space. The new methods were tested on a panel of monoclonal antibodies raised against proteins expressed on peripheral blood lymphocytes and compared with previous methods. The findings suggest that comparing information content of histograms in feature space is effective and efficient for identifying antibodies with similar cell-surface binding patterns.

Animals↗

PubMed2000

Avoidance of cyclosporine in renal transplantation: effects of daclizumab, mycophenolate mofetil, and steroids.

Cyclosporine (CsA) has been implicated in both acute and chronic graft dysfunction. The addition of humanized IL-2 receptor antibody daclizumab (DZB) to CsA-based immunosuppression decreases the rate of acute renal transplant rejection. Therefore, 45 patients were evaluated in an immunosuppressive protocol that included DZB, mycophenolate mofetil (MMF), and steroids without CsA. This was a prospective, nonrandomized, open-label trial of the efficacy and safety of the treatment. DZB was given intravenously at 2 mg/kg before transplantation and then at 1 mg/kg every 2 wk for four doses, MMF was given orally at 3 g/d, and methylprednisolone/prednisone was given at 7 mg/kg per day and tapered to 15 mg/d at 6 mo. CsA was added to the regimen when patients developed acute rejection episodes or adverse effects to steroids or MMF; 49% of patients were spared CsA maintenance. Patients without CsA had lower serum creatinine at 6 mo and needed fewer medications to control BP. Incidence of biopsyproven rejections was 31% and occurred early (median, 10 d). These rejection episodes occurred earlier in cadaver transplants (median, 7 d) and later in living donor transplants (median, 62 days). Acute rejections occurred at a higher frequency (46% versus 34%) and earlier (6.5 versus 15 d) in patients with delayed graft function compared with patients without delayed graft function. Most of the rejections were moderate and easily reversible. The actuarial 1-yr graft survival was 95% with 100% patient survival.

Acute Disease↗