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Biomedical subjects

J W de Fijter

Publications and source records attributed to J W de Fijter.

At least 19 recordsLinked to original sources
PubMed2006

Maturation-resistant dendritic cells induce hyporesponsiveness in alloreactive CD45RA+ and CD45RO+ T-cell populations.

Dendritic cells (DCs) play a crucial role in the induction of antigen-specific immunity and tolerance. Considering in vivo application of DCs prior to human organ transplantation, a protocol to develop tolerogenic DCs that not only induce unresponsiveness in naive (CD45RA+) T cells, but also in alloreactive memory (CD45RO+) T cells is required. The present study shows that dexamethasone (Dex) alters the differentiation of human monocyte-derived DCs. DexDCs cocultured with allogeneic CD4+ T cells induced low proliferating and low IFNgamma producing T cells. This is caused by lack of both costimulation via CD28 and hampered production of a soluble factor, as well as additional active suppression via B7-H1 and IL-10. T cells primed by DexDCs demonstrated hyporesponsiveness upon restimulation with mature DCs seemingly via the induction of anergy, since these cells showed no enhanced apoptosis and only a limited suppressive capacity. Interestingly, not only cocultures of allogeneic CD45RA+, but also of CD45RO+ T cells with DexDCs rendered T-cell populations hyporesponsive to restimulation with mature DCs. The finding that also alloreactive memory T cells can be regulated supports the rationale of cell-based therapies to obtain allograft-specific tolerance in transplant recipients.

Antigens, CD↗
PubMed2006

Successful treatment of fungus balls due to fluconazole-resistant Candida sake obstructing ureter stents in a renal transplant patient.

Reported here is the case of a 72-year-old renal transplant recipient with stenosis of the neo-ureter requiring stents, who was admitted to hospital with pyonephrosis caused by fungus balls. Fluconazole-resistant Candida sake was grown. Treatment with external drainage of the renal pelvis and intravenous and local administration of caspofungin resulted in relief of the obstruction. Eradication of the infection was achieved by surgical removal of the ureter with all stents and construction of a cysto-pyelostomy.

Aged↗
PubMed2006

A pathogenic role for secretory IgA in IgA nephropathy.

IgA nephropathy (IgAN) is characterized by deposits of IgA in the renal mesangium. It is thought that deposits of IgA mainly involve high molecular weight (HMW) IgA1. However, there is limited information on the exact composition of HMW IgA in these deposits. In this study, we investigated the presence of secretory IgA (SIgA) in human serum and in the glomerular deposits of a patient with IgAN. Furthermore, we analyzed the interaction of SIgA with mesangial cells. With enzyme-linked immunosorbent assay, SIgA concentrations in the serum of IgAN patients and healthy controls were measured. Both patients and controls had circulating SIgA that was restricted to the HMW fractions. Patients tended to have higher levels of SIgA, but this difference was not significant. However, in patients with IgAN, high serum SIgA concentrations were associated with hematuria. Binding of size-fractionated purified serum IgA and SIgA to mesangial cells was investigated with flow cytometry. These studies showed stronger binding of SIgA to primary mesangial cells compared to binding of serum IgA. Importantly, after isolation and elution of glomeruli from a nephrectomized transplanted kidney from a patient with recurrent IgAN, we demonstrated a 120-fold accumulation of SIgA compared to IgA1 in the eluate. In conclusion, we have demonstrated that SIgA strongly binds to human mesangial cells, and is present in significant amounts in serum. Furthermore, we showed that SIgA is accumulated in the glomeruli of an IgAN patient. These data suggest an important role for SIgA in the pathogenesis of IgAN.

Enzyme-Linked Immunosorbent Assay↗
PubMed2005

[Skin cancer and other skin disorders in patients following solid organ transplantation].

Solid organ transplant patients have an increased risk of cutaneous squamous cell carcinomas compared to the immunocompetent population, and often develop multiple and sometimes aggressive tumours. There are few published studies or reviews, which provide guidance to the clinician in the management of these patients. In the prevention of skin cancer in organ transplant patients, patient education about the harmful effects of ultraviolet radiation, sun protection, and the early recognition of (pre)malignant skin lesions should be emphasised. Furthermore, close follow-up by a dermatologist and treatment of (pre)malignant lesions in an early stage are necessary. Chemoprevention of skin cancer can be achieved through systemic retinoids. Reduction of the dose of immunosuppressive agents can be considered. Excision is the first treatment of choice for squamous cell and basal cell carcinomas. In selected rumours curettage and electrodessication can be performed.

Basal Cell Carcinoma↗
PubMed2004

Diabetic nephropathy and beta-cell replacement therapy.

Whole pancreas transplantation can effectively restore endogenous insulin secretion in type 1 diabetes mellitus, and prevent, retard, or reverse diabetic complications. The effect of a simultaneous pancreas and kidney transplantation (SPKT) on diabetic complications is variable. These reports must be interpreted in the light of the fact that most recipients received a pancreas in combination with a kidney graft after having already had diabetes for over two decades. Nevertheless, the potential benefits should also be balanced against the risk of peroperative morbidity and the requirement of long-term immunosuppressive medication. Transplantation of a whole pancreas is currently the only reliable option to achieve long-term normoglycaemia. The success of pancreatic islets transplantation will ultimately depend on the longevity of pancreatic islets, requiring further development of immunosuppressive regimens which are not toxic to the islets and prevent recurrent autoimmune destruction of transplanted pancreatic beta-cells.

Diabetes Mellitus, Type 1↗
PubMed2003

Skin infections in renal transplant recipients and the relation with solar ultraviolet radiation.

BACKGROUND: Ultraviolet radiation (UVR) is an important risk factor for skin cancer in transplant recipients. In view of the potential suppressive effect of UVR on host resistance it was examined whether exposure to UVR was also associated with the occurrence of various skin infections. METHODS: In a cohort of renal transplant recipients (n = 137), lifetime exposure was assessed by means of a retrospective questionnaire on cumulative sunlight exposure. Diagnosed skin infections since renal transplantation were extracted from the patient's medical charts. Season of diagnosis was regarded as indicative of short-term exposure. RESULTS: In comparison with winter a high rate of herpes simplex infections was found in spring [rate ratio (RR) = 4.09, 95% confidence interval (CI) 1.2-14.5], and high rates of herpes zoster infections (RR = 1.6, 95% CI: 0.8-3.5) and fungal/yeast infections in summer (RR = 2.1, 95% CI: 1.3-3.4). A higher lifetime exposure (RR = 2.31, 95% CI: 1.04-5.1) and a greater cumulative number of reported sunburns (RR = 2.3, 95% CI: 1.1-5.1) were independently associated with a higher risk of bacterial infections. CONCLUSIONS: The seasonal association with the occurrence of clinical herpes infections indicates an effect of short-term UVR. Our data suggest that the number of sunburn episodes in the past is also relevant for the susceptibility to certain skin infections.

Candidiasis, Cutaneous↗
PubMed2002

Pharmacotherapeutic approach to prevent or treat chronic allograft nephropathy.

In the current paper we will review the evidence that drug therapy may be of value to prevent or treat chronic allograft nephropathy. We will review the immunosuppressive therapy and non-immune therapies in use to treat risk factors associated with chronic allograft nephropathy and evaluate their efficacy with respect to long term outcome as well as their effect on markers of long-term survival. In the last part of this review, we will indicate possible benefits of new approaches being explored but most of these data are obtained in in vitro test systems and rodent models.

Animals↗
PubMed2001

Rapamycin induces apoptosis in monocyte- and CD34-derived dendritic cells but not in monocytes and macrophages.

Rapamycin (Rapa), a recently introduced immunosuppressive drug, seems to be effective in preventing acute allograft rejection. Although its antiproliferative effect on T lymphocytes has been investigated extensively, its effect on the initiators of the immune response, the dendritic cells (DCs), is not known. Therefore, the effect of Rapa on monocyte- (mo-DCs) and CD34(+)-derived DCs in vitro but also on other myeloid cell types, including monocytes and macrophages, was examined. The present study shows that Rapa does not affect phenotypic differentiation and CD40L-induced maturation of mo-DCs. However, Rapa dramatically reduced cell recovery (40%-50%). Relatively low concentrations of Rapa (10(-9) M) induced apoptosis in both mo-DCs and CD34(+)-derived DCs, as visualized by phosphatidylserine exposure, nuclear condensation and fragmentation, and DNA degradation. In contrast, Rapa did not affect freshly isolated monocytes, macrophages, or myeloid cell lines. The sensitivity to Rapa-induced apoptosis was acquired from day 2 onward of mo-DC differentiation. Rapa exerts its apoptotic effect via a reversible binding to the cytosolic receptor protein FKBP-12, as demonstrated in competition experiments with FK506, which is structurally related to Rapa. Partial inhibition of Rapa-induced apoptosis was obtained by addition of ZVAD-fmk, which implies caspase-dependent and caspase-independent processes. The fact that Rapa exerts a specific effect on DCs but not on monocytes and macrophages might contribute to the unique actions of Rapa in the prevention of allograft rejection and other immune responses.

Antigen-Presenting Cells↗
PubMed2001

Successful outcome with a "quintuple approach" of posttransplant lymphoproliferative disorder.

BACKGROUND: The treatment of posttransplant lymphoproliferative disorder (PTLD) remains empirical. We review our treatment of seven cases of PTLD consisting of five interventions: 1) reduction of immunosuppression; 2) antiviral drugs; 3) interferon-alpha; 4) gamma-globulins; and 5) anti-CD19 monoclonal antibodies. METHODS AND RESULTS; Seven consecutive patients who had undergone a simultaneous pancreas-kidney, liver, heart, or kidney transplantation were treated. One patient acquired a primary EBV infection with an oligoclonal immunoblastic lymphoma early after pancreas-kidney transplantation; all others developed a monoclonal polymorphic or immunoblastic lymphoma 2 to 123 months after transplantation. In all patients extranodal sites were involved, in three the graft was also involved. Five patients received the full quintuple approach and all rapidly obtained a complete remission (CR) with a median follow-up of 31 months (7-74 months). Of the two patients who did not receive interferon-alpha for fear of graft rejection one responded slowly with a CR after 7 months, and the other obtained a rapid CR followed by a relapse at 4 months. All three patients with a liver or heart transplant could keep their graft. All patients are still alive with a median follow-up of 31 months (7-74 months). CONCLUSION: This combined approach resulted in a favorable outcome in patients with high risk monoclonal PTLD after solid organ transplantation.

Acyclovir↗
PubMed2001

Skin infections in renal transplant recipients.

BACKGROUND: Skin infection is a frequent complication in renal transplant recipients. The purpose of the study was to acquire long-term, period-specific incidence data on the most commonly occurring skin infections in renal transplant recipients. METHODS: A retrospective analysis was performed using medical records of 134 patients, covering a period between 10 and 29 yr. Cumulative incidences of the skin infections were calculated by counting the infections per patient for different time periods and were expressed as a percentage of the total group of patients. The incidence of the skin infections was determined for different post-transplant time periods. RESULTS: A total of 340 skin infections in 105 out of 134 patients were recorded. Some infections, such as candidal infection, herpes simplex infection, and impetigo were most prominent during the first post-transplant year and did not affect many new patients after the first year. Other infections, such as dermatomycoses, herpes zoster, and folliculitis were also affecting a substantial number of new patients after the first post-transplant year. CONCLUSIONS: This study confirms that skin infections among renal transplant recipients are very common and that the spectrum of skin infections differs according to the post-transplant time period.

Adult↗
PubMed2001

Risk factors of cyclosporine nephrotoxicity after conversion from Sandimmune to Neoral.

BACKGROUND: In 1995 - 1996, we switched from a once-daily Sandimmune dose to a twice-daily dose regimen of Neoral. Concurrent with the switch we changed our target trough level from 100 microg/l at 24 hours to the generally accepted 12-hour level of 150 microg/l. We performed a retrospective cohort study to assess cyclosporine toxicity following this switch and to identify risk factors for nephrotoxicity. PATIENTS AND METHODS: Of 212 patients with a stable graft function pre-conversion clinical parameters at 1 and 12 months post-conversion were compared with those at time of conversion. Cyclosporine nephrotoxicity was defined as a significant decline of the reciprocal of the serum creatinine concentration over time post-conversion in the absence of other obvious causes for declining graft function. Risk factors of cyclosporine nephrotoxicity were assessed using logistic regression analysis. RESULTS: The mean cyclosporine trough level rose from 87 microg/l at the time of conversion to 139 microg/l at 12 months post-conversion whereas the daily drug dose increased over the same period from 233 mg to 252 mg. Mean serum creatinine increased by 10% from 135 to 148 micromol/l (p < 0.001). Cyclosporine nephrotoxicity was present in 42 patients (20%). Cyclosporine dose and trough level did not predict nephrotoxicity but beta-blockers (OR 0.35, 95% CI 0.17-0.72) and calcium channel blockers (OR 0.35, 95% CI 0.19-0.82) reduced the risk of nephrotoxicity, independent from an effect on blood pressure. CONCLUSION: 20% of stable renal transplant patients experienced chronic cyclosporine nephrotoxicity after conversion from a once-daily Sandimmune regimen to a twice-daily Neoral regimen with dose adjustments to a trough level of 150 microg/l. beta-blockers and calcium channel blockers reduced the risk of nephrotoxicity.

Adrenergic beta-Antagonists↗
PubMed2001

Morbidity and mortality during renal replacement therapy: dialysis versus transplantation.

AIM: Many patients with end-stage renal disease are eligible for renal transplantation. To enable a patient to choose between transplantation or to remain on dialysis comparable data on morbidity and mortality should be available. METHODS: Data were collected retrospectively from the medical records of all patients on the waiting list for renal transplantation and of transplanted patients during the period January 1, 1990, to January 1, 1997. All patients were dialyzed in the Kennemer Gasthuis and renal transplantation was performed in the Leiden University Medical Center (LUMC). Morbidity and mortality in both groups were compared. Morbidity was assessed by studying number, length and cause of hospital admissions. RESULTS: During the study period 102 patients had been on the waiting list and 54 patients had been transplanted in the LUMC. Mean length of stay on the waiting list before transplantation was 37 months. During the follow-up period 11 patients (10.8%) died on the waiting list and 6 patients (11.1%) died after renal transplantation. The mean length of stay on the waiting list of these two groups was much longer, being 55 months and 62 months, respectively. Length of hospitalization was significantly different between both patient groups during the first 6 months of treatment (13.24 days for those on the waiting list versus 40.75 days transplanted patients) and after 6 months (32.4 days for those on the waiting list versus 13.1 days transplanted patients). The number of hospital admissions did not differ significantly. Dialysis-related admissions constituted 47% of the total of admissions in the waiting list group and transplantation-related admissions were 43% in the transplanted group. CONCLUSION: In the present study we revealed no difference in overall mortality. However, mortality was influenced by length of stay on the waiting list. Morbidity was increased during the first 6 months after transplantation. Therapy modality greatly influenced the specific cause of morbidity.

Female↗
PubMed2000

Addition of isradipine (Lomir) results in a better renal function after kidney transplantation: a double-blind, randomized, placebo-controlled, multi-center study.

BACKGROUND: After successful kidney transplantation patients may suffer from the adverse effects due to the use of calcineurin inhibitors. Calcium channel blockers are effective in the treatment of hypertension and may ameliorate cyclosporine- (CsA) induced impairment of renal function after kidney transplantation. Calcium channel blockers may also modulate the immune-system which may result in reduction of acute rejection episodes. PATIENTS AND METHODS: From June 1995 till 1997 the effect of isradipine (Lomir) on renal function, incidence and severity of delayed graft function (DGF), and acute rejection after kidney transplantation, was studied in 210 renal transplant recipients, who were randomized to receive isradipine (n=98) or placebo (n=112) after renal transplantation in a double-blind fashion. RESULTS: In the isradipine group renal function was significantly better at 3 and 12 months (P=0.002 and P=0.021) compared with the placebo group. DGF was present in both groups: isradipine: (28+6)/98 (35%); placebo: (35+9)/112 (40%), P=0.57. Severity of DGF was comparable in both groups (isradipine: 9.1+/-8.7 vs. placebo: 9.3+/-8.1 days). No statistical difference was found in incidence or severity of biopsy-proven acute rejection [isradipine: (42+6)/98 (49%) versus placebo: (46+9)/112 (49%), P=1.00]. Renal vein thrombosis was observed in eight patients. This proved to be associated with the route of administration of the study medication [6/45 (13%) on i.v. medication versus 2/165 (1%) on oral medication, P<0.001]. CONCLUSIONS: Addition of isradipine results in a better renal function after kidney transplantation, without effect on incidence or severity of DGF or acute rejection.

Adult↗
PubMed2000

Insulin secretion and sensitivity after simultaneous pancreas-kidney transplantation estimated by continuous infusion of glucose with model assessment.

BACKGROUND: Monitoring of insulin secretion and sensitivity after pancreas transplantation remains a practical problem. METHODS: We introduced the simple structural model, continuous infusion of glucose with model assessment (CIGMA), to obtain insulin secretion and insulin sensitivity estimations after 35 successful simultaneous pancreas-kidney transplantations. Eighteen non-diabetic kidney transplant recipients were used as control group. RESULTS: The baseline characteristics were equal between the two groups except for higher fasting insulin levels in the pancreas transplant group. After the 1-hr CIGMA glucose load, the pancreas transplant group reached a mean +/- SD blood glucose of 8.2+/-1.7 mmol/L compared with 7.3+/-1.0 mmol/L in the control group (P = 0.05). Concurrent stimulated insulin and C-peptide levels were 48+/-28 mU/L and 2.3+/-0.9 nmol/L in the pancreas transplant group compared with 36+/-21 mU/L and 2.9+/-1.1 nmol/L in the control group (P = 0.1 and P = 0.03, respectively). Both the CIGMA estimation for secretion as well as the CIGMA estimation for sensitivity were lower in pancreas transplant group (P = 0.003 and P = 0.01, respectively). Mean +/- SE coefficients of variation for the model estimations were 15+/-4% for secretion and 17+/-6% for sensitivity. CONCLUSIONS: We conclude that CIGMA can be used clinically to evaluate carbohydrate metabolism in pancreas-kidney transplant recipients. These patients have a reduction in insulin secretory capacity and evidence of more insulin resistance than non-diabetic kidney transplant recipients.

Adult↗
PubMed2000

The prevalence of human papillomavirus DNA in benign keratotic skin lesions of renal transplant recipients with and without a history of skin cancer is equally high: a clinical study to assess risk factors for keratotic skin lesions and skin cancer.

UNLABELLED: DNA of the epidermodysplasia-verruciformis associated subgroup of HPV (EV-HPV) is frequently detected in biopsies of premalignant lesions and nonmelanoma skin cancers of renal transplant recipients. The prevalence of EV-HPVs, however, has never been systematically studied in benign keratotic skin lesions of patients with or without a history of skin cancer. This study included 42 renal transplant recipients with and 36 without a history of skin cancer. A total of 176 skin biopsies were tested for the presence of EV-HPV DNA, using a nested polymerase chain reaction (PCR). METHOD: EV-HPV typing was done by comparison of the sequence of the amplified PCR products with the sequence of all known EV-HPVs. The natural history of the development of keratotic skin lesions was studied. The number of keratotic skin lesions rapidly increased after transplantation. This increase was most pronounced in patients who developed skin cancer. The prevalence of EV-HPV DNA in benign keratotic skin lesions was equally high in patients with and without a history of skin cancer, i.e., 55 and 53% in the two groups, respectively. A large variety of EV-HPV types was found, but of these none were predominantly present in either patient groups. A higher prevalence of EV-HPV DNA was found in benign skin lesions from sun-exposed sites, but only in patients with a history of skin cancer. The association between the number of keratotic skin lesions and the development of skin cancer strongly supports the hypothesis that EV-HPVs play a role in cutaneous oncogenesis. The equally high prevalence of EV-HPV infection in patients with and without a history of skin cancer, however, may indicate that besides EV-HPV infection, other factors, such as sun exposure may also be important.

Adult↗
PubMed2000

The effect of calcineurin inhibitors and corticosteroids on the differentiation of human dendritic cells.

Corticosteroids and the calcineurin inhibitors cyclosporin A (CsA) and FK506 have been studied extensively regarding their effects on T lymphocytes, but their effects on dendritic cells (DC) are relatively unknown. Monocytes are one of the precursors of DC that differentiate into CD14-CD1a+ immature DC upon culture with IL-4 and GM-CSF. The presence of CsA or FK506 during differentiation did not affect DC development. In contrast, the presence of corticosteroids, either dexamethasone (Dex) or prednisolone (Pred), for as little as the first 48 h of culture blocked the generation of immature DC. Dex-DC were unresponsive to signals inducing maturation (CD40 ligand, lipopolysaccharide), as demonstrated by the absence of CD83, CD80/CD86 and HLA-DR up-regulation and their strongly reduced T cell stimulatory capacity. Furthermore, Dex-DC showed a decreased CD40 ligand-induced IL-6 and TNF-alpha production, a complete block in IL-12p40 production, while IL-10 production was unaffected. CsA-DC and FK506-DC showed a partial reduction in the production of TNF-alpha, whereas all other functional activities appeared to be similar to control DC. These data show that, when compared to calcineurin inhibitors, corticosteroids have a unique and profound inhibitory effect on the generation and function of DC.

Antigens, CD↗
PubMed2000

Delayed graft function influences renal function, but not survival.

BACKGROUND: In renal transplantation, the impact of delayed graft function (DGF) on prognosis is controversial. We analyzed the risk factors of DGF and its impact on graft function and prognosis. METHODS: Seven hundred thirty-four cadaveric renal transplants performed between 1983 and 1997 were analyzed. DGF was diagnosed when serum creatinine levels increased, remained unchanged, or decreased less than 10% per day in three consecutive days in the first week after transplantation. Creatinine clearances of more or less than 50 or 30 mL/min at one year were used as cut-off points for optimal and suboptimal graft function, respectively. The logistic regression model was used to identify independent risk factor related to DGF and renal function one year after transplantation. The Cox regression model was used to examine the influence of DGF on long-term graft survival. RESULTS: Multivariate analysis revealed the following risk factors for DGF: recipient pretransplantation mean arterial blood pressure of less than 100 mm Hg (OR = 2.08, 95% CI, 1.43 to 3.03), female donor to male recipient combination (OR = 1.55, 95% CI, 1.02 to 2.35), donor age of more than 50 years (OR = 2.21, 95% CI, 1.49 to 3.26), cold ischemia time of more than 28 hours (OR = 1.78, 95% CI, 1.19 to 2.63), and peak panel reactive antibodies of more than 50% (OR = 1.7, 95% CI, 1.15 to 2.55). The incidence of DGF was one of the independent risk factors for suboptimal graft function at one year (OR = 1.68, 95% CI, 1.14 to 2.48), together with donor age of more than 50 years (OR = 2.39, 95% CI, 1.61 to 3.57), female donor gender (OR = 1.99, 95% CI, 1.42 to 2.78), the occurrence of acute rejection episodes (OR = 2.66, 95% CI, 1.87 to 3.78), peak panel-reactive antibodies of more than 50% (OR = 1.67, 95% CI, 1.15 to 2.47), and sharing of 1 to 3 versus 4 to 8 cross-reactive antigens groups (OR = 1.65, 95% CI, 1.09 to 2. 49). Moreover, DGF was one of the two independent risk factors for acute rejection episodes, but it had no independent effect on graft survival. CONCLUSION: Several risk factors for DGF were identified, of which a low recipient pretransplant mean arterial blood pressure, the transplantation of kidneys from female donors to male recipients, and a prolonged cold ischemia time are potentially avoidable. Although DGF is one of the several risk factors of acute rejection and suboptimal function at one year, it is not independently associated with an increased rate of graft loss.

Acute Disease↗