Risk Factors for Type 1 Diabetes Recurrence in Immunosuppressed Recipients of Simultaneous Pancreas-Kidney Transplants.

Patients with type 1 diabetes (T1D) who are recipients of pancreas transplants are believed to rarely develop T1D recurrence in the allograft if effectively immunosuppressed. We evaluated a cohort of 223 recipients of simultaneous pancreas-kidney allografts for T1D recurrence and its risk factors. With long-term follow-up, recurrence was observed in approximately 7% of patients. Comparing the therapeutic regimens employed in this cohort over time, lack of induction therapy was associated with recurrence, but this occurs even with the current regimen, which includes induction; there was no influence of maintenance regimens. Longitudinal testing for T1D-associated autoantibodies identified autoantibody positivity, number of autoantibodies, and autoantibody conversion after transplantation as critical risk factors. Autoantibodies to the zinc transporter 8 had the strongest and closest temporal association with recurrence, which was not explained by genetically encoded amino acid sequence donor-recipient mismatches for this autoantigen. Genetic risk factors included the presence of the T1D-predisposing HLA-DR3/DR4 genotype in the recipient and donor-recipient sharing of HLA-DR alleles, especially HLA-DR3. Thus, T1D recurrence is not uncommon and is developing in patients treated with current immunosuppression. The risk factors identified in this study can be assessed in the transplant clinic to identify recurrent T1D and may lead to therapeutic advances.

Insulin2 gene (Ins2) transcription by NOD bone marrow-derived cells does not influence autoimmune diabetes development in NOD-Ins2 knockout mice.

Insulin is a critical autoantigen for the development of autoimmune diabetes in non-obese diabetic (NOD) mice. About 80% of NOD females and 30-40% of NOD males develop diabetes. However, Insulin2 (Ins2) knockout NOD mice develop autoimmune diabetes with complete penetrance in both sexes, at an earlier age, and have stronger autoimmune responses to insulin. The severe diabetes phenotype observed in NOD-Ins2-/- mice suggests that lack of Ins2 expression in the thymus may compromise immunological tolerance to insulin. Insulin is a prototypical tissue specific antigen (TSA) for which tolerance is dependent on expression in thymus and peripheral lymphoid tissues. TSA are naturally expressed by medullary thymic epithelial cells (mTEC), stromal cells in peripheral lymphoid tissues and bone marrow (BM)-derived cells, mainly CD11c(+) dendritic cells. The natural expression of TSA by mTEC and stromal cells has been shown to contribute to self-tolerance. However, it is unclear whether this also applies to BM-derived cells naturally expressing TSA. To address this question, we created BM chimeras and investigated whether reintroducing Ins2 expression solely by NOD BM-derived cells delays diabetes development in NOD-Ins2-/- mice. On follow-up, NOD-Ins2-/- mice receiving Ins2-expressing NOD BM cells developed diabetes at similar rates of those receiving NOD-Ins2-/- BM cells. Diabetes developed in 64% of NOD recipients transplanted with NOD BM and in 47% of NOD mice transplanted with NOD-Ins2-/- BM (P = ns). Thus, NOD-Ins2-/- BM did not worsen diabetes in NOD recipients and Ins2 expression by NOD BM-derived cells did not delay diabetes development in NOD-Ins2-/- mice.

Comparative analysis of methods for collection and measurement of cytokines and immunoglobulins in cervical and vaginal secretions of HIV and HPV infected women.

The goal of these studies was to distinguish which of two techniques [cervicovaginal lavage (CVL) and cervical wick (SS)] is the optimal collection method for the measurement of the local immunological response in human papillomavirus (HPV) and HIV infected women. The following parameters were measured in 24 paired samples from 15 women (9 HIV+, 6 HIV-): total protein, immunoglobulin levels, HPV-specific antibodies, and Th1-Th2 cytokines. In addition, relative mRNA levels from CVL cell pellets were compared to protein levels from CVL supernatants. The total protein (2-fold) and IgG concentration (10-fold) are higher in the SS samples, were reproducible (%CV<3) and these levels correlated (P<0.0001) with their paired CVL sample. Type-specific HPV-L1 IgG and IgA antibodies were detected in CVL and SS (r>0.28, P<0.008) with excellent reproducibility (CV<3.0%). However, SS (%CV>18) failed to yield reproducible results for the cytokine assays as compared to the CVL (%CV<5.0). Furthermore, no correlations were found between relative mRNA levels from CVL cell pellet and cytokine protein levels in CVL supernatants. The CVL sample's superior reproducibility in the cytokine assays makes this the better collection method. In addition, cytokine protein level's failure to correlate with mRNA suggests tight regulation of cytokine genes or production from a different cell population.