Equivalent outcomes with primary and retransplantation in African-American deceased-donor renal allograft recipients.

BACKGROUND: Graft survival following renal retransplantation has been inferior to that following primary allografting, particularly in African Americans (AAs) receiving deceased-donor (DD) kidneys. METHODS: Among 166 AA DD renal allograft recipients transplanted from July 2001 through July 2007, we compared the outcomes of 26 (16%) receiving a second graft with those of 140 primary cases. All patients received either thymoglobulin (ATG) or an IL-2 receptor antagonist for induction, and were maintained on either tacrolimus or sirolimus + mycophenolate mofetil +/- prednisone. RESULTS: When compared with primary transplants, regrafts received kidneys from older donors, were younger, more sensitized, more likely to receive ATG and to be maintained on prednisone, received more doses of ATG, and were less likely diabetic. There was no difference between primary and retransplant groups in overall patient or graft survival; incidence of acute rejection, CMV infection, BK nephropathy, or new-onset diabetes mellitus; and serum creatinine at 1 year. CONCLUSION: AA renal allograft recipients can undergo a second DD transplant with intermediate-term outcomes comparable to that of a primary graft, despite the presence of multiple immunologic and non-immunologic high-risk factors, by extending the course of ATG induction and continuing prednisone therapy in the vast majority of cases.

Differentiation of alloreactive versus CD3/CD28 stimulated T-lymphocytes using Raman spectroscopy: a greater specificity for noninvasive acute renal allograft rejection detection.

Acute rejection (AR) remains problematic in renal transplantation. As a marker, serum creatinine is limited, warranting a more effective screening tool. Raman spectroscopy (RS) can detect T-cell activation with high sensitivity. In this study we explore its specificity. Seventy-five inactivated, 40 alloantigen-activated, and 75 CD3/CD28-activated T cells were analyzed using RS. CD3/CD28-activated peak magnitudes (PM) were 4.3% to 23.9% lower than inactivated PM at positions: 903, 1031, 1069, 1093, 1155, 1326, and 1449 cm(-1), with a difference in peak ratio (PR) observed at the 1182:1195 cm(-1) position (0.91 +/- 0.06 vs. 1.2 +/- 0.01, respectively: P = 0.006). Differences in CD3/CD28- and alloantigen-activated PM were observed at: 903, 1031, 1093, 1155, 1326, and 1449 cm(-1), with no PR differences at the 1182:1195 cm(-1) position (0.91 +/- 0.06 vs. 0.86 +/- 0.09: P = 0.8). Spectral signature separation of CD3/CD28-and alloantigen-activated groups was 100% specific and sensitive. We conclude that RS can differentiate T cells activated by different stimuli with high sensitivity and specificity.

Raman spectroscopic differentiation of activated versus non-activated T lymphocytes: an in vitro study of an acute allograft rejection model.

Acute rejection (AR) remains a significant complication in renal transplant patients. Using serum creatinine for AR screening has proven problematic, and thus a noninvasive, highly sensitive and specific test is needed. T cells from human peripheral blood were analyzed using Raman spectroscopy. Fifty-one Mixed Lymphocyte Culture (MLC) activated T cells (ATC), 28 Mitomycin C inactivated T cells (ITC), and 35 resting T cells (RTC), were studied utilizing 785 and 514.5 nm wavelengths. Statistical analysis following subtraction of fluorescence used Student's t test to quantify peak ratio differences and discriminant function analysis (DFA), with three distinct sectors assigned for grouping purposes: Sector I, ITC; Sector II, ATC; Sector III, RTC. Differences between ATC and non-activated T cells (ITC and RTC) were found at 1182 and 1195 cm-1 peak positions for both wavelengths. Significant differences in peak ratios for 785 and 514.5 nm wavelengths existed between ATC and RTC (p=0.001 and p=0.006, respectively) and ATC and ITC (p=0.001 and p=0.001, respectively), with a trend in differences observed between ITC and RTC (p=0.07 and p=0.08, respectively). Analysis of the DFA-derived sector distribution for the 785 and 514.5 nm wavelengths revealed a sensitivity of 95.7% and 89.3%, respectively, and a specificity of 100% and 93.8%, respectively. This data suggests that Raman spectroscopy can detect significant differences between activated and nonactivated T cells based upon cell-surface receptor expression, thereby establishing unique signatures that can aid in the development of a noninvasive AR screening tool with high sensitivity and specificity.

Intravenous immunoglobulin, HLA allele typing and HLAMatchmaker facilitate successful transplantation in highly sensitized pediatric renal allograft recipients.

The use of intravenous immunoglobulin (IVIG) in sensitized transplant candidates has resulted in reduced HLA antibody levels and shorter transplant wait times. In addition, the HLAMatchmaker program has been used to identify acceptable mismatches to permit transplantation in highly sensitized patients. We used IVIG desensitization in conjunction with high resolution HLA allele typing and HLAMatchmaker grading of donor offers to facilitate successful transplantation in two highly sensitized children who were awaiting second renal transplants. Both patients lost their initial transplant in <10 days to accelerated acute rejection, and were on dialysis for an average of 50 months with high panel reactive antibody (PRA) levels. They were started on monthly IVIG infusions (2 g/kg/dose). Within one wk following their third and fifth IVIG doses, both patients received a crossmatch compatible, deceased donor renal transplant selected by HLAMatchmaker as a suitable donor offer. Both patients remain rejection free with excellent renal function 19 and 15 months post-transplant, respectively. In conclusion, combining IVIG therapy and donor selection by HLA humoral epitope matching permitted successful transplantation of two highly sensitized children. Further studies in larger numbers of patients with longer follow-up are needed to determine the individual role played by, and relative importance of each component of this combined strategy.

Predictive value of human leucocyte antigen epitope matching using HLAMatchmaker for graft outcomes in a predominantly African-American renal transplant cohort.

The HLAMatchmaker program is based on the donor/recipient comparison of the polymorphic triplet amino-acid sequences of the antibody-accessible regions on the human leucocyte antigen (HLA) molecule. The previous reports on its predictive value for renal allograft outcomes are conflicting. We conducted a retrospective study in a predominantly African-American (AA) cohort (N = 101, 94% AA). HLA typing was performed by molecular methods and triplet matching using HLAMatchmaker. Study end points included graft survival and incidence of acute rejection. The relationship between the number of triplet mismatches (TMM) and the degree of HLA antigen MM was evaluated using Pearson's correlation coefficient. Logistic regression models were used to examine the association between triplet matching and the study end points. Kaplan-Meier and Cox proportional hazard models were used for graft survival analysis. The strongest relationship between the number of TMM and HLA antigen MM was observed for HLA-DQ (r = 0.88). The association between triplet matching at HLA-A, -B, -DR and -DRw HLA loci and the study end points was not statistically significant. However, after grouping, the unadjusted estimates of graft survival for those with more than 10 Class I TMM were significantly worse than the others (p = 0.03). Adjusting for the effect of donor source, recipient characteristics and the immunosuppressive regimen did not change this association (hazard ratio = 0.2, confidence interval = 0.04-1.1). We conclude that triplet matching using HLAMatchmaker can provide useful prognostic information in kidney transplantation and that more than 10 donor/recipient Class I HLA TMM is predictive of worse graft outcome.

Influence of carbohydrate and age on lymphocyte function following a marathon.

The influence of 6% carbohydrate ingestion and age on PHA-induced lymphocyte proliferation and in vitro cytokine production was studied in 48 runners following a competitive marathon. Runners were randomly assigned to carbohydrate (C; n = 23) and placebo (P; n= 25) groups, with blood samples taken before, immediately after, and 1.5 hr post-race. C versus P ingestion resulted in higher plasma glucose, lower plasma cortisol, reduced neutrophilia, and monocytosis during recovery, but had no effect on the post-exercise reduction in T-lymphocytes or NK cells, or on race times. No group differences were observed for PHA-induced lymphocyte proliferation or cytokine production. However, for all subjects combined, lymphocyte proliferation and IFN-gamma secretion decreased significantly below pre-race values by 1.5 hr of recovery, and these were negatively correlated with plasma cortisol. Young (<50 years; n = 36) and old (>or=50 years; n = 12) runners exhibited parallel post-race declines in lymphocyte proliferation and IFN-gamma secretion, with the older group exhibiting a 33-59% lower proliferation at each time point. In conclusion, PHA-induced lymphocyte proliferation and cytokine production decreased significantly following a marathon, and this decrease was strongly linked to cortisol and only partially linked to T-cell changes. This decrease occurred in both younger and older runners and was not influenced by carbohydrate.

Nephrogenic fibrosing dermopathy after liver transplantation successfully treated with plasmapheresis.

Nephrogenic fibrosing dermopathy (NFD) is a recently described cutaneous fibrosing disorder associated with renal dysfunction. It appears similar to scleromyxedema but with some notable exceptions, including the lack of involvement of the face and absence of plasma cells on histology, systemic involvement, and paraproteinemia. Patients can present with thickened or edematous skin with indurated papules and plaques involving the extremities and the trunk. We report the first three cases of NFD after liver transplantation successfully treated with plasmapheresis. Two patients underwent liver transplantation for hepatitis C virus-induced cirrhosis and one for hepatitis B virus-induced cirrhosis. All the patients had encephalopathy, refractory ascites, and malnutrition prior to transplantation. Like those patients with NFD, all three of our patients had renal dysfunction and required hemodialysis before and after transplantation. Two were not dependent on dialysis at the time of diagnosis, however. These patients had excellent liver allograft function, but the other patient had allograft failure secondary to recurrent hepatitis C. Immunosuppression therapy consisted of basiliximab, mycophenolate mofetil, calcineurin inhibitor, and prednisone. The patients developed "woody" skin induration of the distal extremities, erythematous papules, and contractures at 1, 2, and 120 months after transplantation. Skin biopsies resembled NFD. No paraproteinemia was evident. One to three 5-day courses of plasmapheresis resulted in moderate to marked clinical improvement. The improvement of the kidney function in two of our patients did not appear to correlate with that of the skin disorder, because the kidney function was improving at the time the diagnosis of NFD was made. In conclusion, we report the first three cases of NFD after liver transplantation. Plasmapheresis was moderately successful in resolving the skin-indurated papules, severe skin induration, and associated joint contractures. Preliminary studies (unpublished data) show that decreasing plasma levels of transforming growth factor-beta1 after plasmapheresis appear to correlate with the amelioration of this clinical condition.

Decreased insulitis and blood glucose levels after injection of GAD-transduced lymphocytes into NOD mice.

We used NOD mice to investigate the effects of injecting transduced lymphocytes on insulitis, nonfasting blood glucose levels, and immune responses. Syngeneic splenocytes were transduced with retroviral particles carrying a cDNA construct encoding the beta cell antigen glutamic acid decarboxylase (GAD65), a secreted form of GAD65 (SGAD55), or secreted alkaline phosphatase (SEAP) as a control antigen. Different multiplicities of infection (m.o.i.) were used with different constructs. Four-week-old NOD mice received intravenous injection of CD4(+) cells isolated from transduced splenocytes, and insulitis and blood glucose levels were determined at 10 weeks of age. No significant effects were observed with lymphocytes transduced with gad65 and sgad55 constructs at low m.o.i. By contrast, at high m.o.i., lymphocytes transduced with the sgad55 and seap constructs caused a decrease in insulitis and blood glucose levels and in insulitis alone, respectively. ELISA of anti-GAD antibody isotypes indicated that GAD-transduced lymphocytes induced similar Th2-like responses at all m.o.i. These results suggest that retroviral particles carrying sgad55 can be used for engineering cell vaccines for type 1 diabetes and provide further evidence that Th2-like responses induced by immunization may not always be a primary cause of diabetes suppression in NOD mice.

Ontogenic development of Th1 and Th2 cytokine capabilities in random bred mice.

Neonatal mouse Th1 capabilities mature by postnatal day 5. Neonatal T cells have been reported to exhibit a bias towards Th2 cytokine production when co-cultured with adult antigen presenting cells (APC). We studied mouse T cells co-cultured with contemporary APC to evaluate neonatal cytokine production capabilities. In response to allogeneic stimulation, T cells co-cultured with contemporary APC from day 5 pups produced 37-fold greater IFNgamma and 1.4-fold greater IL-2 levels than day 20 weanling mice. After CD3 ligation, cells from day 5 pups produced 4- (IL-2) and 10-fold (IFNgamma) greater levels than adults (day 45), and concentrations were 27- (IL-2) and 18-fold (IFNgamma) higher than with allogeneic stimulation alone. On average, the percent difference in concentrations was 418 (IL-4), 286 (IL-2) and 1140% (IFNgamma) higher in unseparated spleen cells than in isolated splenic CD4 cells and APC. These results demonstrate that, in response to allogeneic stimulation with or without CD3 ligation, lymphocytes of neonatal mice (day 5) have the capacity to produce equivalent or greater TcR-dependent Th1 cytokine (IL-2 and IFNgamma) levels than adult mice. Findings also support the idea that the reported Th2 bias of neonatal T cells may be the result of in vitro manipulation and choice of mouse strain, not of an inherent bias.

Maternal modulation of neonatal immune system development.

Changes in programming of neonatal immune development were effected through maternal immune modulation (Leishmania major inoculation). In progeny of these dams, immune profiles in both blood and spleen were changed throughout the neonatal period and were pronounced after weaning. White blood cell (WBC) and lymphocyte counts in blood of 45-day-old progeny were two-fold less than control animals. In blood, proportions of B cells were greater, while T helpers, Tc/s and NK cells were less than in controls. In contrast, proportions of splenic B and NK cells were greater than controls. But, proportions of all T and Tc/s cells on d20 and 45 were lower than controls. In blood, absolute numbers of all T, Th naïve and Th memory cells were lower than in controls. In contrast, in the spleen, numbers of NK, T and Th naive and memory cells were up to 200% greater than in control pups. Cytokine responses of splenic lymphocytes stimulated through CD3 ligation revealed no difference in IL-4 production. In contrast, IL-2 and IFNgamma were lower on d45 and 5, respectively, in the experimental compared to control mice. These data support the hypothesis that maternal immune events during gestation can modulate the pattern of immune development in offspring.

Sex differences in photoperiod control of antigen-specific primary and secondary humoral immunity in Siberian Hamsters.

Photoperiod was hypothesized to mediate T cell-dependent B cell production of IgM and IgG. Antigens induced production of specific immunoglobulins; serum IgM but not IgG, was higher in males in long vs. short days (16 vs. 8 h light/day) and similarly among all groups of females. A second immunization with KLH robustly enhanced serum IgM, as well as IgG; increases were blunted in short- vs. long-day males but not in females. Thus, in male but not female hamsters, winter-like short days restrain aspects of primary and secondary humoral immune responses to xenoantigens. Actions on lymphocyte activities or clonal expansion are in considerations.