Efficacy of bortezomib desensitization among heart transplant candidates.

Allosensitization is prevalent in heart transplant candidates and is associated with prolonged waiting times and poor outcomes following transplantation. We analyzed the efficacy of a desensitization regimen consisting of plasma exchange, intravenous immunoglobulin, and bortezomib among 25 consecutive sensitized waitlisted candidates at our center from 2016 to 2021. Following desensitization therapies, all C1q negative antibodies were removed from a candidate's unacceptable antigen list. There was a significant decrease in the median number of human leukocyte antigen (HLA) class I (21-15, p = .001) but not class II antibodies (7-6.5, p = .07). There was a significant corresponding decrease in median calculated panel reactive antibodies for class I (90%-74%, p = .004) but not class II (74.5%-75.5%, p = .30). Following desensitization, 76% of patients were transplanted at a median of 91 days. One-year survival following transplant was 89% with a 33% rate of antibody-mediated rejection (AMR). In conclusion, a bortezomib desensitization protocol was modestly effective for class I antibodies and allowed successful transplant in most cases when combined with selective crossing of C1q negative antigens.

Risk factors for the development of donor-specific antibodies after pediatric heart transplantation.

DSA after HTx may have adverse effects on patient survival. The aim of this study was to assess risk factors for the development of DSA after pediatric HTx. All HTx recipients at our center with serial monitoring of DSA were identified. Cox proportional hazards model was used to estimate donor and recipient characteristics associated with the development of DSA. De novo DSA were detected in 40 (33%) of 121 HTx recipients. Characteristics associated with de novo DSA included older age, African American race, prior operations, prior ECMO, PRA > 10%, longer bypass time, mechanical support at transplant, and donor death from GSW. In a multivariable model, mechanical support (HR 3.23, 95% CI [1.02, 8.87]), African American race (HR 3.36, 95% CI [1.68, 7.32]), and donor death from GSW (HR 4.76, 95% CI [1.62, 14.01]) were significantly associated with DSA. Multiple factors appear to play a role in the development of DSA, knowledge of which may guide the frequency of post-transplant monitoring. DSA develop more frequently in those with prior sensitizing events, suggesting the possibility that these exposures predispose the immune system to respond to donor antigens, even in the presence of a negative cross-match.

Identification of molecular biomarkers for multiple sclerosis.

Multiple sclerosis is a demyelinating disease of the central nervous system with a presumed autoimmune etiology. Previous microarray analyses identified conserved gene expression signatures in peripheral blood mononuclear cells of patients with autoimmune diseases. We used quantitative real-time polymerase chain reaction analysis to identify a minimum number of genes of which transcript levels discriminated multiple sclerosis patients from patients with other chronic diseases and from controls. We used a computer program to search quantitative transcript levels to identify optimum ratios that distinguished among the different categories. A combination of a 4-ratio equation using expression levels of five genes segregated the multiple sclerosis cohort (n=55) from the control cohort (n=49) with a sensitivity of 91% and specificity of 98%. When autoimmune and other chronic disease groups were included (n=78), this discriminator still performed with a sensitivity of 79% and a specificity of 87%. This approach may have diagnostic utility not only for multiple sclerosis but also for other clinically complex autoimmune diseases.

BCRABL transcript detection by quantitative real-time PCR : are correlated results possible from homebrew assays?

BACKGROUND: Quantitative real-time PCR has become the predominant molecular technique to monitor BCRABL levels in response to treatment in Ph(+) leukemia patients. However, without some form of standardized methodology between laboratories, the correlation of results is difficult. METHODS: Using TaqMan-based assays, parallel quantitative real-time PCR analysis was performed on 70 clinical specimens at Vanderbilt University Medical Center and Virginia Commonwealth University. While the same positive control cell line (K562) and quality control gene (BCR) were used, the RNA isolation technique, cDNA synthesis, BCR control cell line, and PCR primer and probe sequences were different. RESULTS: The detection of BCRABL-positive results spanned a dynamic range from 10(0) to 10(5)/100,000 cells. Forty-three samples were negative at both facilities. A Spearman rank correlation analysis was performed for the 22 BCRABL-positive paired results. The correlation coefficient, r(s), was 0.9435 (p < 0.00001), suggesting a strong correlation of the results. One discordant result was obtained for consecutive samples from one patient with a low BCRABL copy number as a result of a minimal RNA yield at one laboratory. CONCLUSIONS: These results suggest that quantitative real-time PCR assays for BCRABL detection can be comparable between laboratories despite significant differences in methodologies if the same positive control cell line and quality control gene are used. It is imperative that some level of assay standardization be adopted between laboratories, not only for patients who are monitored at different facilities, but also for larger investigative studies in which hematologic, cytogenetic and molecular responses are to be compared.