The Synergistic Effect of Class II HLA Epitope-Mismatch and Nonadherence on Acute Rejection and Graft Survival.

Predicting long-term outcomes in renal transplant recipients is essential to optimize medical therapy and determine the frequency of posttransplant histologic and serologic monitoring. Nonadherence and human leukocyte antigen (HLA) mismatch are risk factors that have been associated with poor long-term outcomes and may help individualize care. In the present study, class II HLA mismatches were determined at the HLA epitope level in 195 renal transplant recipients in whom medication adherence was prospectively measured using electronic monitors in medication vial caps. Recipients were grouped by medication adherence and high (≥10 HLA-DR, ≥17 HLA-DQ) or low epitope-mismatch load. We found that the combination of higher epitope mismatch and poor adherence acted synergistically to determine the risk of rejection or graft loss. Nonadherent recipients with HLA-DR epitope mismatch ≥10 had increased graft loss (35% vs. 8%, p < 0.01) compared to adherent recipients with low epitope mismatch. At the HLA-DQ locus nonadherent recipients with HLA-DQ epitope mismatch ≥17 had increased graft loss (33% vs. 10%, p < 0.01) compared to adherent recipients with low epitope mismatch. Subclinical nonadherence early posttransplant combined with HLA class II epitope mismatch may help identify recipients that could benefit from increased clinical, histologic, and serologic monitoring.

Nonadherence consensus conference summary report.

This report is a summary of a 'Consensus Conference' on nonadherence (NA) to immunosuppressants. Its aims were: (1) to discuss the state-of-the-art on the definition, prevalence and measurement of NA, its risk factors and impact on clinical and economical outcomes and interventions and (2) to provide recommendations for future studies. A two-day meeting was held in Florida in January 2008, inviting 66 medical and allied health adherence transplant and nontransplant experts. A scientific committee prepared the meeting. Consensus was reached using plenary and interactive presentations and discussions in small break-out groups. Plenary presenters prepared a summary beforehand. Break-out group leaders initiated discussion between the group members prior to the meeting using conference calls and e-mail and provided a summary afterward. Conclusions were that NA: (a) is more prevalent than we assume; (b) is hard to measure accurately; (c) tends to confer worse outcomes; (d) happens for a number of reasons, and system-related factors including the patient's culture, the healthcare provider and the setting and (e) it is not currently known how to improve adherence. This consensus report provided some roadmaps for future studies on this complicated, multifaceted problem.

Increased urologic complications in children after kidney transplants for obstructive and reflux uropathy.

In the cyclosporine era, reports on pediatric kidney transplant (KTx) patients with obstructive and reflux uropathy are limited by small numbers, short follow-up, and/or lack of control groups. Our single-center study evaluated long-term outcomes (patient and graft survival, urinary tract infections [UTIs], urologic complications) in a large cohort of KTx recipients (<20 years old). We matched our 117 study patients with obstructive and reflux uropathy with 117 controls whose KTx was needed for other reasons; all 234 underwent their KTx between April 25, 1984, and October 23, 2002. The mean age was 8.0 +/- 6.2 years; mean follow-up, 133 +/- 67 months. The urologic complication rate was higher in study patients (43%) than in controls (11%) (p < 0.0001), as was the UTI rate (45% vs. 2%; p < 0.0001). The metabolic acidosis and UTI rates were higher in study patients who did (vs. did not) undergo bladder augmentation (p < 0.0001). We found no significant difference between study patients and controls in patient or graft survival, acute or chronic rejection, or mean estimated glomerular filtration rates. Unique to our study is the finding of higher metabolic acidosis and UTI rates in study patients who underwent bladder augmentation.

The natural history of azathioprine compliance after renal transplantation.

BACKGROUND: Successful renal transplantation requires long-term adherence to complex medical regimens, yet knowledge of post-transplant medication compliance is still inadequate. METHODS: The natural history of medication compliance was quantitatively documented using electronic medicine bottle monitors. Azathioprine use was recorded with medication monitors beginning at hospital discharge in a prospective cohort of 180 renal transplant recipients. These patients and 87 other eligible patients, declining study participation, were followed up to five years. Compliance rates were associated with discrete clinical outcomes: acute rejection, allograft loss, and death. RESULTS: During the first six months, only 8% of all azathioprine doses were missed. However, individual compliance rates varied widely, ranging from 16 to 100%, and each month, on average, 18% of patients skipped medication for four or more days. Outcome events were not different between study participants and those refusing study. However, lower compliance rates during the first six months were associated in a "dose-response" fashion with acute rejection (P = 0.006) and allograft loss (P = 0.002). Declining compliance during the first 90 days was a strong risk factor both for later acute rejection (odds ratio = 13.9, 95% CI, 2.9 to 68, P = 0.001), and allograft loss (odds ratio = 4.3, 95% CI, 1.1 to 16, P = 0.032). CONCLUSIONS: Electronic monitoring provides a temporal description and quantitation of medication compliance. Reduced azathioprine compliance was highly associated with acute rejection and allograft loss. Trends in early compliance behavior predict later outcomes, thus providing unique opportunities for intervention.

Overview of new immunosuppressive therapies.

This review covers the new immunosuppressive drugs that have appeared in the past 5 years. It begins with the newest formulation (Neoral, Sandoz Pharmaceuticals, East Hanover, NJ, USA) of the clinically "mature" drug cyclosporin A and then reviews the literature on tacrolimus, sirolimus, and mycophenolate mofetil. In each case, the emphasis is on the evolution of experience with the drug and on the questions that the drug poses for pediatricians considering the risk-benefit ratio of the drug in children.

Management of hemodialysis catheter-related bacteremia--a 10-year experience.

Between January 1986 and December 1995, 18 episodes of bacteremia occurred in our pediatric patients undergoing chronic hemodialysis on an outpatient basis. Seven episodes were caused by coagulase-negative Staphylococcus, 6 by Staphylococcus aureus, 2 by Mycobacterium, and 1 each by Pseudomonas, Xanthomonas, and Enterococcus. In 6 cases, the catheter was retained with antimicrobial therapy alone, whereas 12 cases required removal of the catheter after some period of time. The subset of cases in which catheter removal was necessary included 2 cases of Mycobacterium fortuitum complex and 5 cases of Staphylococcus aureus. We found that Staphylococcus aureus bacteremia may be cleared with antibiotic therapy alone in a minority of cases (17%). In the 6 cases in which catheters were retained and infections cleared, the maximum length of time to sterilization of blood with appropriate antibiotics was 48 h.

Kidney transplantation in children younger than 1 year using cyclosporine immunosuppression.

OBJECTIVE: The optimal age for transplantation in children with end-stage renal disease remains controversial. Supported by national data, many centers recommend dialysis until the child reaches a certain minimum age. The authors' policy, however, has been to encourage living donor (LD) transplants for young children, with no minimum age restriction. METHODS: Between January 1, 1984, and December 31, 1996, the authors performed 248 kidney transplants in children younger than age 13 years, using cyclosporine as the primary immunosuppressive agent. Recipients were analyzed in three age groups: group 1, younger than age 1 year (n = 26); group 2, age 1 through 4 (n = 92); and group 3, age 5 through 13 (n = 130). Almost all recipients in group 1 underwent a primary LD transplant. Therefore, to compare results more meaningfully among the three age groups, only primary LD transplants were analyzed (group 1, n = 25; group 2, n = 59; group 3, n = 58). RESULTS: In primary LD transplants, no significant difference was noted among the age groups in 1-and 5-year patient or graft survival rates. To date, all 25 recipients from group 1 are alive and well; 19 still have a functional original graft. Causes of graft loss in the remaining six recipients were chronic rejection (n = 3), vascular thrombosis (n = 2), and recurrent disease (n = 1). The incidence of acute rejection in group 1 recipients was lower than in the two older groups. However, the incidence of delayed graft function was slightly higher in the youngest group than in the two older groups. For recipients in group 1, growth (as measured by weight) improved significantly posttransplant: the mean standard deviation score rose from -2.8 pretransplant to -0.2 by age 5 and to +1.8 by age 10. The improvement in height was not as dramatic: the mean standard deviation score rose from -3.2 pretransplant to -1.6 by age 5 and to -1.4 by age 10. CONCLUSIONS: Kidney transplantation in young children, including those younger than 1 year old, can achieve results comparable to those in older children. As long as an adult LD is available, the timing of the transplant should be based on renal function rather than age.

Protection against cyclophosphamide-induced alopecia and inhibition of mammary tumor growth by topical 1,25-dihydroxyvitamin D3 in mice.

Twenty-one-day-old BALB/c mice were shaved on the back to synchronize hair growth. On day 30 or 31, when at least 90% of mice exhibited hair regrowth in the shaved area, 1,25(OH)2D3 was applied topically to the shaved area daily for 5 days. On the 6th day, cyclophosphamide (Cytoxan, CTX) was injected i.p. to induce hair loss in the shaved area. Alopecia was induced in a dose-dependent manner by CTX treatment within 1 to 2 weeks. This effect was reduced significantly if mice were pre-treated with 1,25(OH)2D3, though only slight protection was observed in female mice. Interestingly, this 1,25(OH)2D3-mediated protection against hair loss was attenuated in male mice but became more significant in female mice when they were inoculated with the EMT-6 murine mammary tumor prior to treatment. More importantly, topical treatment with 1,25(OH)2D3 alone was able to inhibit EMT-6 tumor growth in both male and female BALB/c mice. Furthermore, 1,25(OH)2D3 pre-treatment also augmented the anti-tumor effect of CTX. Our results demonstrate that topical application of 1,25(OH)2D3 can protect against CTX-induced alopecia both in tumor-free and in tumor-bearing mice in a sex-dependent manner. Moreover, 1,25(OH)2D3 was shown, either alone or in combination with CTX, to inhibit tumor growth.

Evidence that activation of protein kinase A inhibits human hair follicle growth and hair fibre production in organ culture and DNA synthesis in human and mouse hair follicle organ culture.

We have investigated the possibility that protein kinase A (PKA) may play a part in regulating the activity of human and mouse hair follicles in whole organ culture. Human hair follicles were isolated from facial skin by microdissection, and hair follicle and hair fibre length measurements were made daily during suspension culture. Incubation of human hair follicles with dibutyryl-cAMP (db-cAMP) resulted in a dose-dependent inhibition of total cumulative follicle growth (IC50 = 100 mumol/L, 85% inhibition at 1 mmol/L). db-cAMP (0.5 mmol/L) also caused a rapid, partial inhibition of follicular DNA synthesis (20.3% inhibition at 6 h, 48.0% inhibition at 24 h). Human hair follicle growth was inhibited by the phosphodiesterase inhibitors 3-isobutyl-1-methylxanthine and Ro 20-1724, and by the adenylate cyclase activator, forskolin. In addition, db-cAMP inhibited DNA synthesis in organ cultures of whisker follicles isolated from neonatal mice by microdissection. Taken together, these findings indicate that agents which increase cAMP levels are potent inhibitors of human and mouse hair follicle growth, and suggest that PKA may play a part in the regulation of hair follicle activity in vivo.

Bisindolylmaleimide protein-kinase-C inhibitors delay the decline in DNA synthesis in mouse hair follicle organ cultures.

We have used a series of bisindolylmaleimide selective protein-kinase C (PKC) inhibitors to investigate the role of this enzyme in the regulation of cell proliferation in mouse hair follicle organ cultures. Mouse whisker follicles were isolated by microdissection, and rates of DNA synthesis during culture were determined from 3H-thymidine incorporation. The bisindolylmaleimides Ro 31-7549, Ro 31-8161, Ro 31-8425 and Ro 31-8830 inhibit isolated brain PKC with IC50 values of 8-80 nM, are > 60-fold less potent against protein kinase A, and inhibit PKC-mediated protein phosphorylation in platelets with IC50 values in the range 0.25-4.4 microM. These PKC inhibitors were found to increase levels of mouse hair follicle DNA synthesis, with EC50 values in the range 1-4 microM and maximal levels in the range 151-197% of control. Ro 31-7549 had an IC50 value 50-fold lower than that of minoxidil, while the maximal level of DNA synthesis for the PKC inhibitor was 86% higher. Incubation of mouse hair follicles with Ro 31-7549 resulted in a delay of approximately 24 h in the onset of decline in follicular DNA synthesis rates. Ro 31-6045 and Ro 31-7208, bisindolylmaleimides without activity in the platelet PKC assay, did not affect mouse hair follicle DNA synthesis rates. Taken together, these findings show that PKC mediates, at least in part, the rapid loss of proliferative activity that occurs in mouse whisker follicles in culture, and provide further evidence that PKC plays a role as a negative proliferative signal in hair follicles.

Outcome of chickenpox in 66 pediatric renal transplant recipients.

Although chickenpox can cause severe morbidity and mortality in pediatric renal transplant recipients, published reports describing treatment of these patients are few, especially in the cyclosporine era. Sixty-nine episodes of chickenpox occurring in 66 patients were diagnosed in our transplant population between January 1984 and May 1996. Immunosuppression consisted of prednisone and azathioprine (30 cases); prednisone, azathioprine, and cyclosporine (38 cases); or prednisone alone (1 case). Azathioprine was temporarily discontinued in 66 of 68 cases. Cyclosporine was continued at the preexisting dose in 36 of 38 cases. Acyclovir was administered parenterally in 62 of 69 cases. Sixty-five of 66 patients survived. Cyclosporine use did not increase the incidence of severe disease (p > 0.1). Acute allograft rejection occurred in three patients and responded to prednisone. Chickenpox in children with renal transplants can be successfully treated with intravenous acyclovir and temporary withdrawal of azathioprine. Allograft rejection is uncommon with this approach. Patients receiving cyclosporine do not appear to experience increased morbidity or mortality with chickenpox.

The importance of early cyclosporine levels in pediatric kidney transplantation.

We studied the impact of early cyclosporine (CSA) levels on the incidence of rejection in pediatric transplant recipients. Between 1 January 1984 and 31 December 1994, a total of 234 pediatric patients underwent kidney transplants and received CSA immunosuppression. We analyzed the impact of CSA levels (at 1 wk, 2 wk, 1 month, 2 months, and 3 months) on the incidence of rejection in the first 3 and the first 6 months post-transplant. We found that CSA levels at all timepoints correlated, i.e. recipients with low levels in the early post-transplant period tended to have low levels throughout the first 12 months. Multivariate analysis for risk factors by biopsy-proven rejection in the first 3 months revealed that the CSA trough level was the critical factor (p < 0.05). Recipients with CSA trough levels < 100 ng/ml had 2.24 times the risk of rejections vs. those with blood levels > 100 ng/ml. Similarly, the CSA trough level at 1 month was the critical risk factor for biopsy-proven rejection within the first 6 months (p < 0.05). The major risk factor for graft loss within the first 12 months was a biopsy-proven rejection episode. We conclude that in pediatric kidney transplant recipients, early CSA trough levels < 100 ng/ml are associated with a significantly increased incidence of rejection in the first 6 months post-transplant.

Impact of age on renal graft survival in children after the first rejection episode.

Infants are thought to be more immunoreactive and at a greater risk for developing irreversible rejection compared with older children. We investigated this by analyzing patient and graft survival rates, incidence of acute rejection, reversibility of acute rejection, development of a subsequent acute rejection, and incidence of graft loss due to rejection in 154 children (< 18 years of age) after primary renal transplantation. Most patients (n = 139) were treated with quadruple immunosuppression (antibody, azathioprine, prednisone, cyclosporine). Treatment of the first acute rejection episode (ARE) consisted of antibody and increased prednisone (68%) or increased prednisone alone (30%), and was not significantly different between the age groups. Transplants were from living donors (LRD) in 80% of cases. Patients were followed for at least 1 year (mean 58 +/- 30 months); 68% (105/154) of recipients experienced 1 or more ARE. The incidence of ARE was significantly lower in patients < 2 years of age (45%) compared with patients 2-5 (76%, P = 0.01), 6-12 (78%, P = 0.005), and 13-17 (76%, P = 0.009) years of age. There was no significant difference in the 1-, 2- and 5-year patient or graft survival rates, the development of a subsequent acute rejection, or the incidence of graft loss due to acute rejection when analyzed by age group. These data suggest that the impact of an ARE is similar for younger and older children in our population receiving predominantly LRD transplants and quadruple immuno-suppression.

Regulation of human dermal papilla cell production of insulin-like growth factor binding protein-3 by retinoic acid, glucocorticoids, and insulin-like growth factor-1.

Insulin-like growth factor-1 (IGF1) has been reported to stimulate hair elongation and to facilitate maintenance of the hair follicle in anagen phase. However, little is known about IGF1 signaling in the hair follicle. In this study we investigate the effects of IGF1, glucocorticoids, and retinoids on dermal papilla (DP) cell production of insulin-like growth factor binding proteins (IGFBPs). IGFBPs comprise a family of IGF binding proteins that are produced and released by most cell types. They bind to IGFs to either enhance or inhibit IGF activity. In the present report we identify IGFBP-3 as being produced and released by cultured human dermal papilla (DP) cells. IGFBP-3 levels are increased fivefold by retinoic acid, eightfold by dexamethasone, and tenfold by IGF1. DP cells are known to produce IGF1, and so the observed stimulation of DP cell IGFBP-3 production by IGF1 is consistent with the idea that DP cells possess the IGF transmembrane receptor kinase and are autoregulated by IGFs. The level of another IGFBP, tentatively identified as IGFBP-2, is, in contrast, not regulated by these agents. IGFBP-3 has been shown to inhibit the activity of IGFs in a variety of systems. Our results are consistent with a model in which retinoids and glucocorticoids inhibit IGF action on DP cells and surrounding matrix cells by stimulating increased DP cell production of IGFBP-3. The IGFBP-3, in turn, forms a complex with free IGF1 to reduce the concentration of IGF1 available to stimulate hair elongation and maintenance of anagen phase.

Recipient evaluation, preparation, and care in pediatric transplantation: the University of Minnesota protocols.

At the University of Minnesota, outcome of renal transplants for infants and young children is the same as outcome for older children and adults. We reviewed our decision-making process in the pre-, peri-, and postoperative care of these recipients.

Chronic renal allograft rejection in the first 6 months posttransplant.

Between May 1, 1986 and May 31, 1992 at the University of Minnesota, we interpreted 129 renal allograft biopsy specimens (done in 48 grafts during the first 6 months posttransplant) as showing changes consistent with chronic rejection. For this retrospective analysis, we reexamined these biopsies together with clinical information to determine: (a) whether a diagnosis other than chronic rejection would have been more appropriate, (b) how early posttransplant any chronic rejection changes occurred, and (c) if the diagnosis correlated with outcome. We found that (1) chronic rejection is uncommon in the first 6 months posttransplant; it was documented in only 27 (2.4%) of 1117 renal allografts and was preceded by acute rejection in all but 3 recipients (for these 3, the first biopsy specimen showed both acute and chronic rejection). (2) Chronic vascular rejection was seen in 1 recipient as early as 1 month posttransplant; the incidence increased over time and was associated with an actual graft survival rate of only 35%. (3) The most frequent cause of arterial intimal fibrosis in the first 6 months posttransplant was arteriosclerotic nephrosclerosis (ASNS) of donor origin. Long-term graft function for recipients with ASNS was 67%. (4) Early-onset ischemia or thrombosis was seen in 14 recipients and predicted poor outcome: only 35.7% of these recipients had long-term graft function. (5) Cyclosporine (CsA) toxicity was implicated in only 3 recipients, who had mild diffuse interstitial fibrosis in association with elevated CsA levels. Other variables (including systemic hypertension, urinary tract infection, obstructive uropathy, neurogenic bladder, cobalt therapy, and recurrent disease) were not significantly associated with chronic renal lesions in the first 6 months posttransplant. A significant number of biopsies were originally interpreted as showing chronic rejection, but the diagnosis was changed upon reevaluation in conjunction with clinical data. We conclude that many factors coexist to produce chronic lesions in biopsies during the first 6 months posttransplant, so clinical correlation is needed before establishing a diagnosis of chronic rejection.

Protein kinase C inhibits human hair follicle growth and hair fibre production in organ culture.

In this study we have used a human hair follicle whole-organ culture system to examine the effects of 12-O-tetradecanoyl-phorbol-13-acetate (TPA), a potent activator of protein kinase C (PKC), on hair follicle growth and hair fibre production. Anagen hair follicles were isolated from human facial skin by microdissection and placed in suspension culture in supplemented Williams E medium. Hair follicle and hair fibre lengths were measured daily using an inverted microscope and cumulative growth values were calculated. Treatment with TPA resulted in a potent, dose-dependent inhibition of total cumulative hair follicle growth (IC50 = 1 nM). Hair follicles grew at a comparable rate for 4 days in the presence or absence of 10 nM TPA, after which growth of TPA-treated follicles ceased while control follicles grew by a further 0.8 mm over the subsequent 6 days. In contrast, 10 nM TPA treatment did not affect hair fibre elongation for a period of 8 days, after which TPA-treated fibre production ceased while control fibres grew by a further 0.79 mm over the subsequent 7 days. Incubation of hair follicles with TPA resulted in a 41% inhibition of hair fibre protein synthesis, as measured biochemically from the incorporation of 3H-leucine using a differential akali extraction method. The inhibitory effect of TPA on follicle growth was partially prevented by preincubation with the selective PKC inhibitor H-7, and almost completely prevented by preincubation with the more potent PKC inhibitor Ro 31-7549. Neither agent alone significantly affected follicle growth at concentrations that reversed the TPA response. These findings indicate that PKC is a negative regulator of hair follicle growth, and suggest that PKC may play a part in the transduction of follicular growth-inhibitory signals.

Effects of growth hormone on kidney function in pediatric transplant recipients.

Recent evidence suggests that treatment with recombinant human growth hormone (rhGH) after a successful kidney transplant improves the growth rate of children with short stature. We prospectively investigated eight children (6 boys, 2 girls), focusing on acute rejection episodes and changes in serum creatinine levels during rhGH treatment. The children (mean age 11.6 +/- 3.4 years) received rhGH daily (0.04-0.05 mg/kg subcutaneously). Seven patients completed at least 12 months (20 +/- 8 months) of rhGH treatment. Their mean serum creatinine level was 1.3 +/- 0.7 mg/dl 12 months before, and increased to 3.4 +/- 4.2 mg/dl after 12 months of rhGH treatment, but did not achieve statistical significance (P = 0.06). Their mean calculated glomerular filtration rate was 58 +/- 20 ml/min per 1.73 m2 12 months before, and decreased to 38 +/- 21 ml/min per 1.73 m2 after 12 months of rhGH treatment, but did not achieve statistical significance (P = 0.08). Of the seven patients, two developed acute rejection after 5 and 6 rejection-free years; three lost their grafts and returned to dialysis. These preliminary observations describe untoward renal events in children receiving rhGH treatment after a kidney transplant.

Biphasic effect of 1,25-dihydroxyvitamin D3 on human hair follicle growth and hair fiber production in whole-organ cultures.

We have used a whole-organ culture system to investigate the effects of 1,25(OH)2D3 on human hair follicle growth and hair fiber production. Relatively low concentrations (1-10 nM) of 1,25(OH)2D3 stimulated the cumulative growth of hair follicles and hair fibers, by 52% and 36%, respectively (concentration producing 50% of the maximal response [EC50] values of 0.3 nM). The initial rates of follicle and fiber growth were increased, whereas the respective growth periods were unaffected. At higher concentrations of 1,25(OH)2D3, there was a dose-dependent inhibition of both follicle and fiber growth (IC50 values of 100 nM), in part due to reduction in the growth periods. There was a marked delay between the onset of 1,25(OH)2D-induced hair follicle and hair fiber growth inhibition. Incubation of hair follicles with 100 nM 1,25(OH)2D3 resulted in a rapid, transient inhibition of DNA synthesis (55% inhibition at 24 h), followed by a gradual return to control levels at day 4. Prolonged (> 5 h), incubation in the presence of 100 nM of 1,25 (OH)2D3 was required for follicle growth inhibition to be manifest. Ro 31-7549, a selective inhibitor of protein kinase C, did not prevent 1,25(OH)2D3-induced inhibition of hair follicle growth. These data suggest that 1,25(OH)2D3 may play a physiologic role in maintaining optimal hair follicle activity, and that elevation of 1,25(OH)2D3 may inhibit hair growth in vivo.