Quantitative real-time ARMS-qPCR for mitochondrial DNA enables accurate detection of microchimerism in renal transplant recipients

The presence of microchimerism in peripheral blood of solid organ transplant recipients has been postulated to be beneficial for allograft acceptance. Kinetics of donor cell trafficking and accumulation in pediatric allograft recipients are largely unknown. In this study, we implemented SNPs of the HVRs I and II of mitochondrial DNA to serve as molecular genetic markers to detect donor-specific cell chimerism after pediatric renal transplantation. Serial dilution of artificial chimeric DNA samples showed a linear correlation coefficient of R > 0.98 and a detection sensitivity of 0.01% with high reproducibility. Longitudinal semiquantitative analysis of donor-specific SNPs was then performed in peripheral blood mononuclear cells samples up to two yr post-transplant. Quantity of donor-specific cell chimerism in peripheral blood was highest in the early post-transplant period reaching values of ~10% after liver-kidney and 2.8% after renal transplantation. From one wk after transplantation, renal transplant patients exhibited an amount of donor-specific mtDNA ranging from 0.01% to 0.1%. We developed a highly accurate, sensitive, and rapid real-time quantitative PCR method using sequence-specific primers and fluorescent hydrolysis probes for the detection of at least 0.01% donor-specific cells in the recipient's peripheral blood after renal transplantation.     

Cell-mediated cytotoxicity in down syndrome: impairment of allogeneic mixed lymphocyte reaction,NK and NK-like activities

Peripheral blood mononuclear cells (PBMC) from 16 non-institutionalized patients with Down syndrome (DS) were studied with various monoclonal antibodies and analysed for natural killer (NK), and NK-like activity. Lymphocyte proliferation and cytotoxic T-lymphocyte (CTL) cytotoxicity generated in mixed lymphocyte culture (MLC) were also evaluated in 11 DS patients. Phenotypic characterization of PBMC from DS subjects confirms our previous findings of high numbers of CD8+ lymphocytes and HNK-1+, and CD16+ cells. Lymphocyte proliferation and CTL cytotoxicity generated in MLC were low or absent in most patients. NK activity was low in almost all DS patients, while NK-like cytotoxicity generated in MLC was normal in the majority and did not correlate with NK activity from unstimulated PBMC.Abbreviations BSA bovine serum albumin - DS Down syndrome - CTL cytotoxic T lymphocytes - FCS fetal calf serum - MLC mixed lymphocyte culture - NK natural killer - PBMC peripheral blood mononuclear cells - PBS phosphate-buffered saline - PHA phytohaemagglutinin     

Acute rejection associated with donor-specific anti-MICA antibody in a highly sensitized pediatric renal transplant recipient

Allograft rejection in HLA identical transplant recipients and in patients without detectable donor-specific anti-HLA antibodies has lead to the identification of non-HLA antigens as targets of the alloimmune response. MICA antigen has been recognized as an important non-HLA target in renal transplantation. Recent studies have shown that anti-MICA antibodies are associated with acute renal allograft rejection and failure. Current cross match procedures using donor lymphocytes fail to detect MICA antibodies. Transplant candidates are not routinely tested for pre-sensitization to MICA antigens nor are transplant donors typed for MICA alleles. Optimal classification and treatment of acute rejection associated with MICA antibody remains unknown. In this case report, we are the first to describe the clinical course and treatment of donor-specific MICA antibody associated with both Banff type II A ACR and AMR in a highly sensitized pediatric renal re-transplant recipient. This case also emphasizes the importance of pre-transplant screening for donor-specific MICA antibody especially in highly sensitized renal transplant patients.     

Pediatric renal transplantation with mycophenolate mofetil immunosuppression in a single center from Mexico

An MMF-based immunosuppression has reduced the acute rejection rate in adults and in children in the early post-transplantation period. In the present study, pediatric renal transplantation patients on a CyA, MMF, and steroids regimen were prospectively evaluated. Patients with CyA, MMF, and steroid therapy without antibody induction were evaluated for surgical aspects, renal function, rejection, and survival, growth after transplantation, adverse events and medication discontinuation. Between February 2003 and May 2005, 21 kidney transplantation patients under 18 yr old were followed for at least 12 months. Within one year after transplantation, three patients developed four episodes of acute rejection (19%). Graft loss because of rejection occurred in one patient. One-year mean serum creatinine was 1.19 +/- 0.3 mg/dL. Mean calculated CrCl by Schwartz formula was 82.3 +/- 19.7 mL/min*1.73 m(2). Major adverse events included infections of the urinary tract and diarrhea, abdominal pain, and GI symptoms. No patients have discontinued the use of MMF. Good results in pediatric kidney transplantation can be achieved by using CyA/MMF/steroids. MMF is effective and relatively safe in reducing the incidence of acute rejection even without induction therapy 12 months after transplantation.     

Post‐transplant lymphoproliferative disorder: No relationship to recombinant human growth hormone use in Australian and New Zealand pediatric kidney transplant recipients

PTLD is a potentially life‐limiting complication of pediatric transplantation. Previous registry‐based studies in renal transplantation have suggested a link between rhGH use and PTLD. In this study, demographic and transplant data on those aged <18 yr and transplanted between 1991 and 2008 were collected from the ANZDATA Registry. Associations between gender, age at time of transplant, recipient CMV and EBV status, use of monoclonal antibody therapy, and use of rhGH were studied as potential predictors of PTLD. Among 650 transplants, there were 20 cases (3.1%) of PTLD, with half presenting within two yr post‐transplant. Eight patients exposed to rhGH at any time developed PTLD, and this association was not statistically significant (RR = 1.5[0.6–3.4], p = 0.36). On multivariate analysis, there were no significant predictors for PTLD. In this study, previously identified potential risk factors were not identified as significant predictors for the development of PTLD. Although limited sample size may affect our ability to infer safety, this large retrospective cohort study does not suggest an increased risk of PTLD in pediatric kidney transplant recipients who received rhGH treatment.     

Lipid profile during rhGH therapy in pediatric renal transplant patients

To evaluate the effect of recombinant human growth hormone (rhGH) treatment on the lipid profile of pediatric renal transplant patients, we studied nine children treated with rhGH for 1 yr and a control group of 12 untreated patients matched in terms of age, renal transplant function and post-transplant follow-up. The levels of lipoprotein (a [Lp(a)], cholesterol, triglycerides, apolipoprotein A (APO A) and apolipoprotein B (APO B), and the APO B/APO A ratio, were determined at baseline and after 6 and 12 months of follow-up. RhGH therapy had no effect on cholesterol, triglycerides or apolipoproteins. Mean serum Lp(a) levels increased from 6.7 +/- 5.7 mg/dL at baseline to 11.8 +/- 10.7 after 6 months (p = 0.018) and 13.6 +/- 15.1 after 12 months of rhGH treatment (p = 0.04), but did not change in the control group. Lp(a) is a risk factor for cardiovascular morbidity, and increased Lp(a) levels may be a side-effect of rhGH treatment in renal transplant patients. Although long-term follow-up of a large number of patients is needed to establish the duration and extent of the effects of rhGH treatment on Lp(a) levels in transplanted children, serum Lp(a) levels should be carefully monitored in those receiving rhGH therapy.     

In vitro evidence for impaired cellular immune responsiveness in children with chronic renal failure

We used mixed lymphocyte culture (MLC) as an assay to evaluate in vitro the cellular immune functions of children with chronic renal insufficiency (CRI) or with chronic renal failure (CRF). The proliferative response of lymphocytes from both groups of patients was significantly reduced as compared to the response of control individuals. In addition, the proliferative response of CRF patients treated with hemodialysis was significantly lower than the response of continuous ambulatorial peritoneal dialysis (CAPD) patients. These data confirm that a marked depression of the cellular immune response is detectable in a pediatric population, as predicted from data from the literature on the adult renal failure population.     

In Vitro Evidence for Impaired Cellular Immune Responsiveness in Children with Chronic Renal Failure

ABSTRACT. We used mixed lymphocyte culture (MLC) as an assay to evaluate in vitro the cellular immune functions of children with chronic renal insufficiency (CRT) or with chronic renal failure (CRF). The proliferative response of lymphocytes from both groups of patients was significantly reduced as compared to the response of control individuals. In addition, the proliferative response of CRF patients treated with hemodialysis was significantly lower than the response of continuous ambulatorial peritoneal dialysis (CAPD) patients. These data confirm that a marked depression of the cellular immune response is detectable in a pediatric population, as predicted from data from the literature on the adult renal failure population.     

The impact of recombinant human growth hormone treatment during chronic renal insufficiency on renal transplant recipients

OBJECTIVE: To evaluate post-transplant outcomes for patients treated with human growth hormone (rhGH) during the course of chronic renal insufficiency (CRI). STUDY DESIGN: Patients (the "cohort" group) were identified who had been enrolled in 2 controlled studies to determine the efficacy and safety of rhGH in growth-retarded children with CRI and were subsequently enrolled in the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) and received a renal transplant. Patient survival, graft survival, time to first acute rejection episode, causes of graft failure, adverse events, and serial growth data from transplant to 60 months were evaluated. Data from the cohort group of 102 patients were compared with data from 4913 primary transplants from "other NAPRTCS" recipients (the "control" group). RESULTS: No significant difference was seen in patient survival or graft survival, incidence of acute rejection episode, or time to first rejection episode between the cohort and control groups. No specific adverse events were attributable to previous rhGH treatment. Only 2 patients had post-transplant lymphoproliferative disease in the cohort group, with no other malignancies reported. The mean height z scores in the cohort group at baseline and 60 months after transplant were -1.92 and -1.90, and the Deltaz score at 60 months was +0.20 compared with the control group (-1.88 and -2.10). CONCLUSIONS: Treatment of growth-retarded patients with CRI does not adversely affect graft function after renal transplantation. "Catch-down" growth does not occur after renal transplantation.     

Renal function after combined liver‐kidney transplantation: A longitudinal study of pediatric and adult patients

It has been proposed that the liver protects the kidney in CLKT. However, few studies have examined long‐term renal function after CLKT and contrasted renal function of CLKT patients to KT patients beyond one year after transplantation. We studied long‐term renal function of CLKT patients and compared renal function of CLKT patients to KT patients between one and five years after transplantation. Patients who underwent CLKT between 1993 and 2011 were included (n = 34; 11 children and 23 adults). Ninety‐six (27 children and 69 adults) KT patients were selected as controls. GFR was estimated (eGFR) and measured (mGFR) with ⁵¹Cr‐EDTA clearance. Mean mGFR was 63 at one and 70 at ten years after pediatric CLKT. Mean eGFR was 75 at one and 50 at ten years after adult CLKT. Difference in mean mGFR between pediatric CLKT and KT patients was 8 (95% CI ?7 to 23) and 11 (95% CI ?4 to 26) at one and five years after transplantation, respectively. Difference in mean eGFR between adult CLKT and KT patients was 8 (95% CI ?5 to 20) and 1 (95% CI ?10 to 12) at one and five years after transplantation, respectively. Longitudinal changes in GFRs were somewhat similar in CLKT and KT patients in both age‐groups but pediatric CLKT patients had on average higher GFRs than pediatric KT patients. In long‐term follow‐up, renal function remains stable in pediatric CLKT patients but declines in adult CLKT patients.     

Impact of growth hormone treatment on a Belgian population of short children with renal allografts

We retrospectively analyzed the effects of recombinant human growth hormone (rhGH) in a Belgian population of 36 short children with renal allografts. Seven children were dropped from the growth study: 1 had skeletal dysplasia and in 6 cases rhGH was given for less than 1 yr (1 died, 1 developed genu valgum, 2 were non-compliant and 2 grafts deteriorated). Final height was reached in 17 patients, and 12 children were still growing at the end of the study. Median height standard deviation score (SDS) in the 29 patients was -2.3 at the time of transplantation, and -2.7 when rhGH therapy was initiated. During rhGH therapy (median duration 3.2 yr, range 0.6-7.7 yr), height SDS increased by a mean of 0.4 per year, and bone maturation was not accelerated. Final height reached was 162.7 (149.0-169.5) cm (median SDS -1.8) in males and 151.0 (130.5-169.5) cm (median SDS -1.9) in females. Final height is significantly greater in males than females compared with a historical control group of untreated patients. Final height is within the parental target height range in 6 out of the 17 patients. The increase in height SDS in patients who were at an advanced stage of puberty (Tanner stages 4-5) when rhGH therapy was initiated exceeded our expectations (mean height gain 14.2 cm in boys and 10 cm in girls). In the cohort of 36 children, 4 patients developed an acute allograft rejection, all of whom had an underlying chronic rejection. This resulted in 3 graft losses within 5 yr. Our results indicate that rhGH treatment has a positive effect in short children with renal allografts, even if it is started in late puberty. In the presence of underlying chronic rejection, rhGH treatment needs careful monitoring to minimize the risk of graft loss.     

ABO-mismatched renal transplantation in children: a report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) and the Midwest Organ Bank (MOB)

Successful ABO-mismatched renal transplantation (RT) (blood group A2 donor to blood group B or O recipient) has occurred in adults in the setting of a low titer (< or =4) natural isoagglutinin (anti-A) level in the recipient of the mismatched organ. Similar experiences have rarely occurred in children. Between 1986-1996, 11 pediatric patients (6 male and 5 female) received 11 ABO-mismatched kidneys [7 cadaveric (CAD) and 4 living related donor (LRD)]. There were 8 O recipients/A2 donor pairs, 2 B recipients/A2 donor pairs and 1 B recipient/A2B donor pair. Recipient age at the time of RT was 14.7+/-3.0 yr (mean +/- SD). Prior to RT, 2 recipients underwent splenectomy and none received donor-specific transfusions. Induction and early maintenance immunosuppression consisted of corticosteroids (11 pts), ALG/ATG (6 pts), OKT3 (3 pts), azathioprine (11 pts) and cyclosporine (8 pts). The mean 30-d cyclosporine dosage was 10.6+/-4.0 mg/kg/d. Eight patients suffered > or =1 acute rejection episodes, the initial episode occurring within the first 31 d post-transplant in 7 of them. Five grafts (45.4%) failed secondary to vascular thrombosis (1), acute rejection (2) and chronic rejection (2). The remaining grafts (54.5%) all functioned for >1000 d (range: 1023-3746 d). The pre-transplant anti-A titer was determined in 6 pts; in 4 it was low (2) and in 2 it was high (8). Graft survival in all but one of these patients (whose titer was 8 and who suffered a non-rejection-related vascular thrombosis) was > or =2 yr. In summary, ABO-mismatched RT in pediatric patients is an uncommon practice. However, the adult experience and our preliminary pediatric experience suggests that evaluation of recipient isoagglutinin levels in this setting may be helpful in the selection of donor/recipient pairs in whom mismatched transplantation can be successful.     

Antiviral treatment of chronic hepatitis B with lamivudine in pediatric renal transplantation

Renal transplantation in patients with chronic hepatitis B virus (HBV) infection is known to be associated with an increased risk for exacerbation of liver dysfunction. Lamivudine has been proven to be a potent inhibitor of hepatitis B virus replication in adults after kidney transplantation. Little is known about its efficacy and safety in pediatric renal transplant recipients. Three cases serve for the discussion to demonstrate the complexity of the clinical course and effective treatment of chronic hepatitis B in pediatric patients awaiting renal transplantation. Two patients on dialysis with a high HBV replication rate were treated with lamivudine before transplantation. After the viral load had decreased below the detection limit, they underwent transplantation successfully. Despite intensified immunosuppression to treat a rejection episode in one and a relapse of the nephrotic syndrome in the other patient, the viral load remained <2.5 pg/mL. Both patients developed a mutation in the YMDD motif of the HBV genome associated with an increase in the HBV replication rate >10,000 pg/mL without deterioration of the liver function. In a third patient with a chronic HBV infection with a low replication rate, lamivudine was started about nine months after kidney transplantation due to an increasing viral load after treatment of an acute rejection episode. Six months later, the HBV DNA was no longer detectable. The patient had no signs of liver dysfunction. Lamivudine in the treatment of chronic HBV infection in pediatric renal recipients seems to be safe and effective in preventing acute liver deterioration. Three clinical cases are discussed with regard to current options in monitoring and antiviral treatment of chronic HBV in pediatric renal transplant recipients.     

Successful low-dose immunotherapy after kidney transplantation in a 10-year-old girl with Schimke immuno-osseous dysplasia

Background

This case report highlights a successful steroid-free, low-dose immunosuppressive protocol for renal transplantation in a pediatric patient with Schimke immuno-osseous dysplasia with excellent 7-year patient and graft survival. Schimke immuno-osseous dysplasia is a rare multisystem disorder involving the kidney. Renal transplantation is a therapeutic option, but posttransplant mortality is high due to severe infections and posttransplant lymphoproliferative disease.

Methods

A 10-year-old girl diagnosed with Schimke immuno-osseous dysplasia and end-stage renal disease underwent an AB0-compatible living-related kidney transplantation, with no donor-specific antibodies. Our standard immunosuppression protocol was modified due to the risk of infection. Basiliximab was used as induction therapy, and a reduced dose of mycophenolate mofetil and tacrolimus was initiated following transplantation, maintaining the patient on a low tacrolimus target (3–5 μg/L). Mycophenolate mofetil was discontinued after 8 weeks due to neutropenia and the patient was kept on tacrolimus as monotherapy. Five years posttransplant the patient developed acute onset of neurological symptoms, consisting of ataxia, lack of voluntary coordination, balance, aphasia and dysphagia, and diplopia. She recovered without neurological deficits within 6 weeks. Extensive evaluation revealed no pathology. To avoid a possible a component of tacrolimus-induced cerebral vasoconstriction, the immunosuppressive therapy was changed to everolimus.

Results

Seven years posttransplant, the patient has experienced no serious infections, no rejections, and had excellent graft function, and no de novo donor-specific antibodies.

Conclusions

The present results indicate that low-dose immunosuppressive therapy after renal transplantation with low immunological risk should be considered for patients with Schimke immuno-osseous dysplasia.     

Growth hormone therapy before and after pediatric renal transplant

Children undergoing successful renal transplantation anticipate optimal growth and development. The use of rhGH pre- and post-Tx has been evaluated and supported by randomized control trials. Several strategies are required to maximize the potential benefit of this treatment in the renal population including provision of adequate nutrition intake, following bone parameters with appropriate interventions, and strategies to reduce steroid therapy including utilization of alternate day steroid treatment. Studies are required to further assess the impact of rhGH on renal allograft function, rejection risk, and allograft ultrastructural changes.     

过敏性紫癜外周血单个核细胞CD40 L表达及其干预研究

目的 观察过敏性紫癜患儿外周血单个细胞表达ＣＤ４０配体及其干预因素,以期探讨在过敏性紫癜发病机制中的作用并指导临床治疗。方法 用流工细胞技术,ＥＬＩＳＡ法及单向免疫扩散法检测观察组３３例患儿ＣＤ４０ Ｌ阳性细胞率,ＩＬ－４,ＩＬ－５及ＩｇＥ,Ａ,Ｇ,Ｍ,并与对照组比较。     

Results and specific problems in unrestricted indications for kidney transplantation in children

In Hamburg 22 children had 33 renal transplantations in the time from 1976 till 1982. 58% of all children in this area with end-stage renal disease have now a functioning graft compared to only 11% of the adult patients. This is the result of preferred transplantation in children whenever possible. Retransplantation was more frequent in children (32%) than in adults (19%). 5 years function rate of renal allografts is significantly worse in children than in adults. Growth and degree of rehabilitation are described in 12 pediatric renal allograft recipients who survived with a functioning graft for at least 3 years. Good rehabilitation as indicated by attendance of school and employment was reached in 83% of these patients. Different growth patterns occurred. Clinical factors associated with growth performance include graft function and age at the time of transplantation.     

Successful renal transplantation following prior bone marrow transplantation in pediatric patients

Improving survival rates following pediatric bone marrow transplantation (BMT) will likely result in greater numbers of children progressing to end-stage renal disease (ESRD) because of prior chemotherapy, irradiation, sepsis, and exposure to nephrotoxic agents. Renal transplantation remains the treatment of choice for ESRD; however, the safety of renal transplantation in this unique population is not well established. We report our experience with living related renal transplantation in three pediatric patients with ESRD following prior BMT. Two patients with neuroblastoma and ESRD because of BMT nephropathy, and one patient with Schimke immuno-osseous dysplasia and ESRD because of immune complex mediated glomerulonephritis and nephrotic syndrome. Age at time of BMT ranged from 2 to 7 yr. All patients had stable bone marrow function prior to renal transplantation. Age at renal transplant ranged from 8 to 14 yr. All three patients have been managed with conventional immunosuppression, as no patient received a kidney and BMT from the same donor source. These patients are currently 7 months to 6 yr status post-living related transplant. All have functioning bone marrow and kidney transplants, with serum creatinine levels ranging 0.6-1.2 mg/dL. There have been no episodes of rejection. One patient with a history of grade III skin and grade IV gastrointestinal-graft-vs.-host disease (GI-GVHD) prior to transplantation, had a mild flare of GI-GVHD (grade I) post-renal transplant and is currently asymptomatic. The incidence of opportunistic infection has been comparable with our pediatric renal transplant population without prior BMT. One patient was treated for basal cell carcinoma via wide local excision. Renal transplantation is an excellent option for the treatment of pediatric patients with ESRD following BMT. Short-term results in this small population show promising patient and graft survival, however long-term follow-up is needed. Pre-existing immune system impairment and bone marrow function should be taken into consideration when weighing different immunosuppressive agents for renal transplantation. Patients who have undergone renal transplantation following BMT are at high risk for opportunistic infections and malignancy, and need life-long medical surveillance.     

Pediatric obesity at renal transplantation: a single center experience

Obesity is a major issue affecting health care delivery. While studies have been done in adults with end-stage renal disease, similar studies are lacking in pediatric patients with this disease. We retrospectively analyzed our renal transplant database from 1978 to 2002, to identify prevalence and predisposing factors to obesity in a pediatric end-stage renal disease population. Obesity, particularly in younger individuals, was found to be prevalent at transplantation.     

Effect of donor-specific transfusions on renal transplantation in children

Most family members who are evaluated as kidney donors for children have high reactivity in a mixed lymphocyte culture test and are thus excluded from donation. Fifty children, most of whom had highly reactive mixed lymphocyte cultures with their donors, were challenged with three blood transfusions from their donors before transplantation and were tested for the development of lymphocytotoxic antibodies. Ten children (20%) became sensitized and had a positive T-cell or B-cell crossmatch. Sensitization occurred less frequently in children treated with azathioprine during donor-specific transfusions (11%) than in those not treated (26%), but the difference was not significant. Thirty-seven children received renal transplants from their blood donors after the donor-specific transfusions. There were no deaths, and only two patients had kidney failure. Actuarial kidney survival was 93% after 6 years. The use of donor-specific transfusion has increased the number of related-donor transplants performed and the results have been highly successful.