Kidney Transplant Evaluation: Inferences from Qualitative Interviews with African American Patients and their Providers.

BACKGROUND: Completing pre-transplant evaluation is often a barrier to kidney waiting list placement among African American (AA) patients. Interventions are needed to provide AAs with culturally sensitive, understandable information that increases their capacity to achieve placement on the kidney transplant waiting list. Research about enabling and constraining factors for patients to complete the waitlisting process is necessary to inform such interventions; however, few such studies have been conducted specific to AA patient needs. METHODS: Semistructured qualitative focus groups and interviews were conducted with 24 AA listed or transplanted patients (along with their caregivers when available) and 14 transplant providers to explore thoughts, feelings, and assumptions about transplant evaluation. Questions also probed participants' perceptions of enabling and constraining factors to wait-listing. Interviews were recorded and transcribed and inductive thematic analysis was performed to inform message content for a future educational video intervention. RESULTS: Three themes emerged from thematic content analysis: (1) transplant center support in navigating steps to wait-listing, (2) provider attitude and messaging, and (3) education about evaluation and the waiting list. Enabling factors for evaluation completion included staff assistance with completing testing, frequent communication, and positive staff messaging. Constraining factors were staff inaccessibility, patient scheduling difficulties, and misunderstanding/misinformation regarding the role of the transplant coordinator, process of and requirements for listing, and understanding allocation. CONCLUSIONS: We identified information based on patients' expressed needs and experiences managing evaluation completion. These findings are valuable in efforts going forward to empower AAs to achieve placement on the waiting list.

Enabling Conversations: African American Patients' Changing Perceptions of Kidney Transplantation.

BACKGROUND: Racial disparities in access to kidney transplantation (KTX) among African Americans (AAs) have been attributed in part to insufficient patient education. Interventions are needed to provide AAs with culturally sensitive, understandable information that increases their capacity to pursue KTX. Research about the factors that activated patients to pursue KTX is necessary to inform such interventions; however, few studies have yielded this type of information. METHODS: We conducted focus groups and one-on-one interviews with 26 AA referred, listed, or transplanted patients and 3 nephrologists to explore decisional factors that foster pursuit of KTX. Interviews were recorded and transcribed, and qualitative analytic methods to identify themes and subthemes were applied in an effort to inform message content for a future educational video intervention. RESULTS: Three themes emerged from thematic content analysis: (1) healthcare provider communication, (2) exposure to peer transplant success, and (3) family encouragement. Enabling provider communication techniques include repetition about the KTX option, optimistic messaging about KTX access, and comforting conversations about the KTX process. CONCLUSION: We identified information based on patient views and experiences to help inspire and develop animated videos designed to activate patients towards KTX. Interventions are needed that address informational gaps and focus on emotion to improve patients' experiences and ability to understand transplant opportunities.

Combined induction therapy with rabbit antithymocyte globulin and rituximab in highly sensitized renal recipients.

Compared to non-sensitized renal transplant recipients, patients with preformed alloantibodies are at greater risk of cellular and humoral rejection and premature graft failure. We explored the effects of adding B-cell depleting agent (rituximab) to standard rabbit anti-thymocyte globulin (rATG) induction regimen for patients with panel reactive antibody levels >50%. Following induction therapy, 14 recipients were given two doses of rituximab (375 mg/m(2)) within the first month post-transplantation. Their long-term outcomes were compared to a historical control group of 23 recipients who received rATG alone. Graft survival at 5 years was superior with combination therapy compared to induction therapy alone (92.9 versus 48.3%, respectively, p = 0.02). While 30% of the rATG alone group experienced cellular rejection and 26% humoral rejection, none of rituximab plus rATG renal transplant recipients group had rejection. Thus, addition of rituximab to rATG provided superior outcomes to rATG alone. This combination induction therapy should be considered for a high-risk population.

Induction therapy in renal transplant recipients: a review.

Transplant science has improved significantly over the last decade. Influenced by novel advancements, rejection rates and short-term graft losses diminished substantially. Induction therapy was shown to reduce rejection rates and improve short-term graft survival. In this article, we discuss the most commonly used induction agents and the choice of induction therapy in different renal transplant recipient subgroups. The medical literature as well as our own experience was used to prepare this review. At this time, induction therapy is commonly used in upwards of 80%, of renal transplant recipients. Depleting agents are the most frequently used agents and they account for more than 75% of all induction therapies in the United States. Currently, there is no consensus regarding the choice of induction therapy. The type of induction therapy is generally selected based on a comprehensive evaluation of the recipient and the donor's immunological risks, the risk of developing opportunistic infection and malignancy, recipient comorbidities, financial burden and the choice of maintenance immunosuppressive regimen.

Long-term outcomes following sirolimus conversion after renal transplantation.

Long-term outcomes following renal transplantation remain limited due to chronic progressive injury partly as a result of calcineurin inhibitor (CNI) toxicity. Thus, patients have been converted to non-CNI immunosuppressives despite the lack of evidence of long-term benefits from CNI free therapy. We now report our 10-year experience converting patients with well functioning transplants from CNI to sirolimus. We retrospectively analyzed outcomes of patients receiving continuous CNI based therapy (CNI, n = 309) or who were switched to sirolimus within the first year of post-transplantation (CONV, n = 54). The groups were similar for most recipient, graft and donor characteristics, however, diabetes was more common in the CNI group and statin use was more frequent in the CONV group. The average time to conversion was 7.2 months and the creatinine level at the time of switching was 1.4 mg/dl. Ten year graft and patient survival rates were equivalent in both groups. There were no differences in the causes of death or graft loss in both groups. Renal function was available for 5 years posttransplant and was no different between groups. Thus, there is no evidence that routinely switching patients with well functioning renal allografts to sirolimus from CNI based immunosuppression provides long-term benefit.

Universal perioperative antimicrobial prophylaxis is not necessary in kidney transplantation.

Despite significant improvements in renal transplantation, certain basic issues remain unresolved such as the routine use of perioperative antimicrobial prophylaxis (AMP). To address the need for AMP, we retrospectively evaluated the clinical course of 442 consecutive renal transplant recipients (RTRs) who did not receive any AMP except for trimethoprim/sulfamethoxazole. Three hundred and forty RTRs received induction therapy with low-dose rabbit anti-thymocyte globulin, while the other 102 patients were treated with basiliximab. All RTRs received tacrolimus, mycophenolic acid, and prednisone. Nine patients (2%) developed surgical site infection (SSI). SSIs were more common in obese and older patients. All SSIs were superficial and responded well to wound drainage and outpatient antibiotic therapy. No patient or graft was lost owing to SSI. Our study shows that despite many predisposing factors, SSIs are rare following renal transplantation even in the absence of AMP. Therefore, to avoid the emergence of antibiotic-resistant pathogens, excessive costs, and antibiotic-related adverse events, we suggest that AMP should be used only in selected circumstances such as in recipients older than 65 yr or when the body mass index (BMI) is > 35.

Score tests for independence in semiparametric competing risks models.

A popular model for competing risks postulates the existence of a latent unobserved failure time for each risk. Assuming that these underlying failure times are independent is attractive since it allows standard statistical tools for right-censored lifetime data to be used in the analysis. This paper proposes simple independence score tests for the validity of this assumption when the individual risks are modeled using semiparametric proportional hazards regressions. It assumes that covariates are available, making the model identifiable. The score tests are derived for alternatives that specify that copulas are responsible for a possible dependency between the competing risks. The test statistics are constructed by adding to the partial likelihoods for the individual risks an explanatory variable for the dependency between the risks. A variance estimator is derived by writing the score function and the Fisher information matrix for the marginal models as stochastic integrals. Pitman efficiencies are used to compare test statistics. A simulation study and a numerical example illustrate the methodology proposed in this paper.

Establishing a training set through the visual analysis of crystallization trials. Part I: approximately 150,000 images.

Structural crystallography aims to provide a three-dimensional representation of macromolecules. Many parts of the multistep process to produce the three-dimensional structural model have been automated, especially through various structural genomics projects. A key step is the production of crystals for diffraction. The target macromolecule is combined with a large and chemically diverse set of cocktails with some leading ideally, but infrequently, to crystallization. A variety of outcomes will be observed during these screening experiments that typically require human interpretation for classification. Human interpretation is neither scalable nor objective, highlighting the need to develop an automatic computer-based image classification. As a first step towards automated image classification, 147,456 images representing crystallization experiments from 96 different macromolecular samples were manually classified. Each image was classified by three experts into seven predefined categories or their combinations. The resulting data where all three observers are in agreement provides one component of a truth set for the development and rigorous testing of automated image-classification systems and provides information about the chemical cocktails used for crystallization. In this paper, the details of this study are presented.

Blocking S-adenosylmethionine synthesis in yeast allows selenomethionine incorporation and multiwavelength anomalous dispersion phasing.

Saccharomyces cerevisiae is an ideal host from which to obtain high levels of posttranslationally modified eukaryotic proteins for x-ray crystallography. However, extensive replacement of methionine by selenomethionine for anomalous dispersion phasing has proven intractable in yeast. We report a general method to incorporate selenomethionine into proteins expressed in yeast based on manipulation of the appropriate metabolic pathways. sam1(-) sam2(-) mutants, in which the conversion of methionine to S-adenosylmethionine is blocked, exhibit reduced selenomethionine toxicity compared with wild-type yeast, increased production of protein during growth in selenomethionine, and efficient replacement of methionine by selenomethionine, based on quantitative mass spectrometry and x-ray crystallography. The structure of yeast tryptophanyl-tRNA synthetase was solved to 1.8 A by using multiwavelength anomalous dispersion phasing with protein that was expressed and purified from the sam1(-) sam2(-) strain grown in selenomethionine. Six of eight selenium residues were located in the structure.

Efficient optimization of crystallization conditions by manipulation of drop volume ratio and temperature.

An efficient optimization method for the crystallization of biological macromolecules has been developed and tested. This builds on a successful high-throughput technique for the determination of initial crystallization conditions. The optimization method takes an initial condition identified through screening and then varies the concentration of the macromolecule, precipitant, and the growth temperature in a systematic manner. The amount of sample and number of steps is minimized and no biochemical reformulation is required. In the current application a robotic liquid handling system enables high-throughput use, but the technique can easily be adapted in a nonautomated setting. This method has been applied successfully for the rapid optimization of crystallization conditions in nine representative cases.

Analysis of the 2.0 A crystal structure of the protein-DNA complex of the human PDEF Ets domain bound to the prostate specific antigen regulatory site.

PDEF, a prostate epithelial specific transcription factor, is a member of the Ets family of DNA binding proteins. Here we report a 2.0 A crystal structure of the PDEF Ets domain in complex with a natural, high-affinity DNA binding site in the promoter/enhancer region of the human prostate specific antigen gene. Comparison of the PDEF-DNA complex with other Ets complexes revealed key features that are shared among Ets members, as well as important differences in substrate specification at both the "GGA" core and the flanking regions of the DNA site. The combination of the serine residue at position 308 and the glutamine at position 311 explains the previous observation that the PDEF binds preferentially to a thymine at the +4 position of its binding site. Despite the common essential features that are shared among Ets members, PDEF demonstrates distinct patterns of interactions at different positions of DNA in achieving sequence specific recognition. Collectively, the common and unique interactions with both the DNA bases and the backbone phosphates lead to substrate specificity and individual preference for certain DNA sites.