Pretransplant risk assessment of graft failure is important for donor selection and choice of immunosuppressive treatment. We examined the relation between kidney graft failure and presence of IgG donor specific HLA antibodies (DSA) or C1q-fixing DSA, detected by single antigen bead array (SAB) in pretransplant sera from 837 transplantations. IgG-DSA were found in 290 (35%) sera, whereas only 30 (4%) sera had C1q-fixing DSA. Patients with both class-I plus -II DSA had a 10 yr graft survival of 30% versus 72% in patients without HLA antibodies (p < 0.001). No significant difference was observed in graft survival between patients with or without C1q-fixing DSA. Direct comparison of both assays showed that high mean fluorescence intensity values on the pan-IgG SAB assay are generally related to C1q-fixation. We conclude that the presence of class-I plus -II IgG DSA as detected by SAB in pretransplant sera of crossmatch negative kidney recipients is indicative for an increased risk for graft failure, whereas the clinical significance of C1q-fixing IgG-DSA could not be assessed due to their low prevalence.

No abstract

A protective role for CD8+ T cells during viral infections is generally accepted, but little is known about how CD8+ T cell responses develop during primary infections in infants, their efficacy, and how memory is established after viral clearance. We studied CD8+ T cell responses in bronchoalveolar lavage (BAL) samples and blood of infants with a severe primary respiratory syncytial virus (RSV) infection. RSV-specific CD8+ T cells with an activated effector cell phenotype: CD27+CD28+CD45RO+CCR7−CD38+HLA-DR+Granzyme B+CD127− could be identified in BAL and blood. A high proportion of these CD8+ T cells proliferated and functionally responded upon in vitro stimulation with RSV Ag. Thus, despite the very young age of the patients, a robust systemic virus-specific CD8+ T cell response was elicited against a localized respiratory infection. RSV-specific T cell numbers as well as the total number of activated effector type CD8+ T cells peaked in blood around day 9–12 after the onset of primary symptoms, i.e., at the time of recovery. The lack of a correlation between RSV-specific T cell numbers and parameters of disease severity make a prominent role in immune pathology unlikely, in contrast the T cells might be involved in the recovery process.

The presence of donor‐specific anti‐HLA antibodies (DSAs) is associated with increased risk of graft failure after kidney transplant. We hypothesized that DSAs against HLA class I, class II, or both classes indicate a different risk for graft loss between deceased and living donor transplant. In this study, we investigated the impact of pretransplant DSAs, by using single antigen bead assays, on long‐term graft survival in 3237 deceased and 1487 living donor kidney transplants with a negative complement‐dependent crossmatch. In living donor transplants, we found a limited effect on graft survival of DSAs against class I or II antigens after transplant. Class I and II DSAs combined resulted in decreased 10‐year graft survival (84% to 75%). In contrast, after deceased donor transplant, patients with class I or class II DSAs had a 10‐year graft survival of 59% and 60%, respectively, both significantly lower than the survival for patients without DSAs (76%). The combination of class I and II DSAs resulted in a 10‐year survival of 54% in deceased donor transplants. In conclusion, class I and II DSAs are a clear risk factor for graft loss in deceased donor transplants, while in living donor transplants, class I and II DSAs seem to be associated with an increased risk for graft failure, but this could not be assessed due to their low prevalence.

SummaryAntibodies recognizing denatured human leucocyte antigen (HLA) can co-react with epitopes on intact HLA or recognize cryptic epitopes which are normally unaccessible to HLA antibodies. Their specificity cannot be distinguished by single antigen beads (SAB) alone, as they carry a mixture of intact and denatured HLA. In this study, we selected pretransplant sera containing donor-specific HLA class I antibodies (DSA) according to regular SAB analysis from 156 kidney transplant recipients. These sera were analysed using a SAB preparation (iBeads) which is largely devoid of denatured HLA class I, and SAB coated with denatured HLA class I antigens. A total of 241 class I DSA were found by regular SAB analysis, of which 152 (63%) were also found by iBeads, whereas 28 (11%) were caused by reactivity with denatured DNA. Patients with DSA defined either by regular SAB or iBeads showed a significantly lower graft survival rate (P = 0·007) compared to those without HLA class I DSA, whereas reactivity to exclusively denatured HLA was not associated with decreased graft survival. In addition, DSA defined by reactivity to class I SAB or class I iBeads occurred more frequently in female patients and in patients with historic HLA sensitization, whereas reactivity to denatured HLA class I was not associated with any of these parameters. Our data suggest that pretransplant donor-specific antibodies against denatured HLA are clinically irrelevant in patients already sensitized against intact HLA.

No abstract

No abstract

Vasculitic neuropathy and chronic inflammatory demyelinating polyneuropathy (CIDP) are neuropathies characterized by a T-lymphocyte infiltrate in the peripheral nerves. The microenvironment in which these T cells become activated, and the molecules and cells that play a role in this process are incompletely understood. Using immunohistochemical analysis, we studied the effect of the presence of adhesion, costimulatory and antigen-presenting molecules on different cell types as a precondition for local T-cell activation in human sural nerve biopsies of seven patients with CIDP, three patients with vasculitic neuropathy and three healthy controls. In biopsies from CIDP and vasculitic neuropathy patients, but not in those from healthy controls, Schwann cells expressed the adhesion/T-cell stimulatory molecule CD58 (LFA-3). The CD58 molecule was also present on endothelial cells of all vasculitic neuropathy patients and one CIDP patient. In biopsies from normal controls and patients, CD54 (ICAM-1) expression was detectable on microvascular endothelial cells. In addition, expression of the costimulatory molecule CD86 was detected on vascular tissue in patients with vasculitic neuropathy. Although macrophages were always present in all subjects, expression of the major histocompatibility complex (MHC)-like molecule CD1a by macrophages was restricted to biopsies from two CIDP patients and one vasculitic neuropathy patient. Unexpectedly, Schwann cells of a single vasculitis patient strongly expressed CD1b, a molecule involved in the presentation of self-glycolipids to T cells. Schwann cells in biopsies from patients and normal controls expressed high levels of the invariant chain, CD74, a molecule involved in the intracellular sorting of MHC class II molecules. There was no evidence for the presence of dendritic cells in sural nerve biopsies. These findings support a model in which T-cell activation can be initiated and/or perpetuated locally in sural nerve biopsies of patients with CIDP and vasculitic neuropathy, and predict an important role for Schwann cells and endothelial cells.