The shared epitope phenomenon-A potential impediment to virtual crossmatch accuracy.

With the implementation of the new kidney allocation system (KAS), there is increased reliance on a virtual crossmatch/histocompatibility risk assessment (vXM) for evaluating potential presence, as well as strength, of HLA antibodies against a potential donor. The accuracy of such an assessment depends on the precision in the identification of the recipient's antibody profile and the potential donor's HLA typing. While the development of the single antigen bead (SAB) multiplex assay has improved the sensitivity and specificity of HLA antibody detection, several limitations of the assay (specific to certain sensitized patients) can complicate accurate interpretation of results.

Can solid phase assays be better utilized to measure efficacy of antibody removal therapies?

Antibody removal therapies are used for patients with antibody-mediated-rejection or those requiring desensitization to become transplantable. Accurate measurement of antibody levels prior to, and during treatment, are required to choose the best therapeutic approach, and to provide measure of treatment efficacy. Currently, the FDA does not regard solid-phase assays for HLA-antibody identification as a reliable surrogate-marker for treatment efficacy.

Mycophenolic acid inhibits maturation and function of human dendritic cells and B cells.

Mycophenolic acid (MPA) is considered an immunosuppressive compound mainly because of its inhibitory effects on lymphocyte proliferation. Here we studied specifically the effects of MPA on the ability of dendritic cells (DCs) to activate T cells via the indirect pathway and on the maturation and function of B-lineage cells. We demonstrated that DC cell-surface receptors, associated with antigen uptake and antigen processing and presentation (CD83 and CD205), were differentially downregulated in the presence of MPA, translating into a decreased uptake of alloantigens and reduced stimulation of T cells with decreased cytokine secretion (interleukin (IL)-1Ra and transforming growth factor (TGF)-alpha).

The presence of HLA-directed antibodies after heart transplantation is associated with poor allograft outcome.

Background: The clinical significance of HLA-directed antibodies newly detected after transplantation (HT) is controversial.

Methods: Seventy-one HT recipients consented to enroll. Mean follow-up time was 28 months (range 6-48).

Donor-specific hyporesponsiveness in ELISPOT assay is associated with early recurrence of hepatitis C in liver transplant recipients.

Recurrence of hepatitis C in liver transplant recipients is a common event that often leads to loss of the allograft. There are no means to prevent, or even predict, those patients who are more prone to early aggressive recurrence. Therefore there is an increased need for tailored immunosuppression protocols specific to this patient population.