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Biomedical subjects

Anke Schwarz

Publications and source records attributed to Anke Schwarz.

At least 19 recordsLinked to original sources
PubMed2006

Decreased renal transplant function after parathyroidectomy.

BACKGROUND: Persistent secondary hyperparathyroidism after renal transplantation may require parathyroidectomy (PTX). Clinical experience suggests that these patients commonly develop decreased renal function thereafter. METHODS: To test this notion, we evaluated 76 transplant patients who underwent pararhyroidectomy between 1997 and 2003. RESULTS: In half the patients (47%), creatinine clearance decreased >20% (before vs after PTX, 57 +/- 21 vs 38 +/- 17 ml/min, P = 0.001). The patients with decreased creatinine clearance had higher parathyroid hormone (PTH) concentrations before and lower values after PTX compared with those who did not (594 +/- 392 vs 447 +/- 234 pg/ml before PTX, P = 0.03; 35 vs 123 pg/ml thereafter, P = 0.002). They also had lower serum calcium concentrations after PTX (2.0 vs 2.2 mmol/l, P = 0.005) and they required more calcium and vitamin D analogues. These patients also more commonly underwent total PTX with autotransplantation, compared with subtotal (75 vs 50%, P = 0.03). However, in multivariate analysis, only the delta PTH decline (%) after PTX was a significant predictor of deteriorating renal function (P = 0.005) and was correlated with the creatinine clearance decrease (R = 0.369, P = 0.001). Prospectively measured inulin and para-amino-hippuric acid (PAH) clearance decreased significantly after PTX in a subgroup of 19 patients (inulin before vs after PTX 67 vs 55 ml/min/1.73 m(2), P = 0.001; PAH 360 vs 289 ml/min/1.73 m(2), P = 0.001). Transplant biopsies revealed calcification in 70% of biopsied cases. CONCLUSION: Since PTH has a known positive regulatory effect on renal perfusion and glomerular filtration rate, we conclude that relative hypoparathyroidism after PTX is the main mechanism contributing to decreased renal function in these patients. There was no difference in 10-year-graft survival between the deteriorating and the non-deteriorating group.

Biopsy↗
PubMed2006

Quality of life in adult transplant recipients more than 15 years after kidney transplantation.

BACKGROUND: With continuously rising survival rates following renal transplantation, health-related quality of life (HQOL) of long-term transplant survivors becomes increasingly important. METHODS: Recipients more than 15 years after successful renal transplantation were studied retrospectively. HQOL in 139 long-term transplant recipients was assessed using the SF-36 and the disease-specific kidney transplant questionnaire (KTQ-25). RESULTS: Long-term transplant recipients revealed satisfactory HQOL that was comparable to the healthy population in four of eight SF-36 categories (role physical, social functioning, role emotional and mental health). Other SF-36 categories such as physical functioning, physical pain, general health, and vitality were reduced. Among the study population, disease-specific HQOL was comparable or even improved to that of patients awaiting transplantation. In contrast to retired or unemployed patients, employed recipients revealed a highly significant improved HQOL in numerous SF-36 categories such as physical functioning (P<0.001), physical pain (P<0.001), general health (P<0.001), vitality (P<0.001), social functioning (P<0.005), and mental health (P<0.001), as well as for the KTQ-dimensions physical symptoms (P<0.001), fatigue (P>0.001), uncertainty/fear (P<0.01), and emotions (P<0.05). Other factors positively correlating with improved HQOL in certain dimensions were living situation, systolic blood pressure, and recipient age. CONCLUSIONS: More than 15 years after renal transplantation, recipients present satisfactory HQOL comparable to the general healthy population or at least to pretransplant patients. Vocational rehabilitation following renal transplantation is of highest importance among long-term survivors and is associated with improved HQOL.

Aging↗
PubMed2006

ABO-incompatible kidney transplantation of an 8-yr-old girl with donor/recipient-constellation A1B/B.

BACKGROUND: Antigen-specific immunoadsorption combined with rituximab offers the possibility for ABO-incompatible kidney transplantation without splenectomy. PATIENT AND METHOD: An 8-year-old mentally retarded girl with steroid-resistant nephrotic syndrome and focal segmental glomerulosclerosis due to mitochondriopathy poorly tolerated hemodialysis. Paternal blood group A1B was incompatible with blood group B of the child. Therefore, we decided to perform the first ABO-incompatible renal transplantation in a child in Germany using antigen-specific immunoadsorption. Rituximab (1 x 375 mg/m2) was administered 2 weeks before the first immunoadsorption (Glycosorb) ABO A-column). Triple-drug immunosuppression (tacrolimus, mycophenolate mofetil and prednisolone) was simultaneously started with immunoadsorption. Initial tacrolimus levels were targeted between 15 and 20 ng/ml. Before transplantation, six immunoadsorptions were applied on days -9, -7, -4, -3, -2 and -1. Intravenous immunoglobulin (0.5 g/kg) was administered preoperatively. After transplantation, three immunoadsorptions were performed on days +4, +6 and +8. RESULTS: Before transplantation, antibody (Ab) titers against paternal erythrocytes (20 degrees C) were reduced from 1 : 64 to 1 : 4 by six antigen-specific immunoadsorptions. After transplantation, we performed three more immunoadsorptions and the Ab titers were stable between 1 : 1 and 1 : 8. One, 2 and 8 months later we observed increases in the Ab titer up to 1 : 32 requiring no change in immunosuppressive therapy. No side effects of immunoadsorption were observed. The girl had excellent initial graft function with a serum creatinine of 55 to 70 micromol/l. Two weeks after transplantation, graft biopsy showed no signs of rejection; there was focal positivity for C4d only. Twelve months after transplantation, renal function was stable, with a serum creatinine of 117 micromol/l. Episodes of rejection or severe infections were absent. CONCLUSION: ABO-incompatible transplantation using antigen-specific immunoadsorption and rituximab may serve as a suitable alternative for children urgently needing renal transplantation and missing a blood group-compatible donor.

ABO Blood-Group System↗
PubMed2006

Living kidney donors >60 years of age: is it acceptable for the donor and the recipient?

Donors >60 years are now frequently accepted for living kidney transplantation (LKT). We asked whether a donor age >60 years may result in a higher risk for donor and recipient. All adult LKT from May 1996 to June 2005 were included. Long-term outcome was analysed, and results were compared for donors >60 and 60 (group A) and 158 from donors 60 years, we suggest that age should no longer be considered as a contra-indication for living donation.

Age Factors↗
PubMed2005

Quality of life following living donor nephrectomy comparing classical flank incision and anterior vertical mini-incision.

In this study we focused on the quality of life and satisfaction of living kidney donors comparing traditional lumbar (LDN) and mini-incision donor nephrectomy (MIDN). From May 1996 to December 2002, 174 donor nephrectomies including 127 cases of LDN and 47 cases of MIDN were performed. Donors were evaluated using the SF-36 quality-of-life survey as well as a questionnaire dealing with donors' attitude towards kidney donation, financial burdens, pain, cosmetic satisfaction and duration of sick leave. Our donors achieved comparable or even higher scores in all the SF-36 categories in comparison to the general US population. Following MIDN, quality of life tended to be superior compared to that of LDN donors; however, statistical significance was reached only in one of the eight categories. Duration of sick leave following surgery was in favor of MIDN compared to LDN donors. Statistically significant differences favoring MIDN were observed regarding postoperative hospital stay and cosmetic satisfaction. The procedure would be again undergone by 94 of LDN and 97% of MIDN donors. Open-donor nephrectomy is a safe and cost-effective procedure. Introduction of the here-described MIDN has led to comparable or even improved results compared to LDN.

Female↗
PubMed2005

Risk factors for chronic allograft nephropathy after renal transplantation: a protocol biopsy study.

BACKGROUND: Chronic allograft nephropathy (CAN) leads to chronic allograft dysfunction and loss. Regular renal transplant biopsies may be useful to find risk factors for CAN. METHODS: We carried out 688 protocol biopsies in 258 patients at 6, 12, and 26 weeks after renal transplantation. Patients with signs of CAN in the biopsy 3 (N= 70, CAN group), and those without (N= 120, non-CAN group), were compared. RESULTS: Chronic tubulointerstitial changes increased from biopsy 1 to 3 (5% vs. 37%, P < 0.0001). Fifty-six of 190 patients had acute rejection within 6 months (30%), 33 of which were found in protocol biopsies (17%). On univariate analysis, the CAN group had CAN more often at biopsy 2 than the non-CAN group (23% vs. 4%, P < 0.0001), had a lower calculated creatinine clearance at biopsy 1 and 2 (49.4 +/- 25.8 vs. 57 +/- 20.2 mL/min, P= 0.01; 47.3 +/- 21.2 vs. 57.9 +/- 19.5 mL/min, P= 0.001, respectively), had a living donor less often than a brain dead donor (7% vs. 18%, P= 0.045), had a longer cold ischemia time (17.4 +/- 7 vs. 14.9 +/- 8.1 hours, P= 0.04), and had arterionephrosclerosis more often (24% vs. 12%, P= 0.02). On multivariate analysis, the differences in CAN at biopsy 2 (P= 0.001) and lower GFR at biopsy 2 (P= 0.002) were confirmed; in addition, nephrocalcinosis (P= 0.006) and acute rejection (P= 0.046) were found to occur more often. CONCLUSION: Chronic tubulointerstitial changes develop early after renal transplantation and are associated with reduced kidney function. Risk factors for CAN are arterionephrosclerosis (donor-related), nephrocalcinosis (related to preexisting hyperparathyroidism), a long cold-ischemia time (ischemia-perfusion-related), and acute rejection. Renal functional decline precedes morphologic changes of CAN, expressed as tubular atrophy and interstitial fibrosis.

Atrophy↗
PubMed2005

Incidence of C4d stain in protocol biopsies from renal allografts: results from a multicenter trial.

C4d staining of renal allografts is regarded as an in situ marker of active humoral rejection. Few data are available about the incidence of C4d deposition in protocol biopsies compared to indication biopsies. To evaluate whether center-specific factors influence the incidence of C4d detection, we performed a multicenter study. From three European centers, 551 protocol and 377 indication biopsies were reclassified according to the updated Banff criteria and stained for C4d. C4d results were recorded as diffuse or focal positive and statistically correlated to clinical parameters, morphology and graft survival. In the protocol biopsies, a diffuse C4d stain was found in 2.0%, and a focal stain in 2.4%. In indication biopsies, 12.2% were diffusely and 8.5% focally C4d positive (protocol:indication p < 0.0001). The incidence of C4d deposition varied significantly between centers, attributable to variable numbers of presensitized patients with more C4d positive indication and protocol biopsies. Diffuse and focal C4d stain correlated with morphology of humoral rejection in protocol as well as in indication biopsies. Protocol biopsies show a significantly lower incidence of C4d deposition than indication biopsies. Subclinical C4d detection in protocol biopsies had no significant impact on allograft survival in our series.

Biopsy↗
PubMed2005

Local complement C3 expression is upregulated in humoral and cellular rejection of renal allografts.

Evidence on the role of the complement system in transplantation pathology has been accelerated by the discovery of C4d as an in situ marker of antibody-mediated rejection. However, a local or systemic source of complement expression during acute rejection is under discussion. Thus, we quantitatively analyzed local RNA expression of complement component C3 as a pivotal molecule in active humoral and cellular rejection of renal allografts. After laser microdissection, real-time RT-PCR was performed for C3 using RNA extracted from tubuli and glomeruli of 68 paraffin-embedded renal allograft biopsies. Protocol and indication biopsies with signs of humoral and/or cellular rejection were investigated. Quantitative expression analysis of cytokines (IFN gamma, MCP-1, IL2, IL8) potentially influencing local C3 expression was performed. We observed a significant increase in median expression level of C3 mRNA in tubuli of C4d-positive indication biopsies, and in tubuli from indication biopsies with signs of T-cell-mediated cellular rejection. Highest expression levels were found in C4d-positive indication biopsies with signs of cellular rejection. Biopsies with upregulated C3 showed increased IFN gamma expression, suggesting allograft-infiltrating T-cells as potential stimulus for local C3 expression. Therefore, locally synthesized complement component C3 contributes to both humoral and cellular rejection, with tubular epithelial cells being a major source.

Biopsy↗
PubMed2005

Early calcification of renal allografts detected by protocol biopsies: causes and clinical implications.

Interstitial calcification has been described in renal allografts, however, the etiology and significance of this finding for the graft are unclear. The aim of this study was to examine calcification in serial protocol biopsies, to test the hypothesis that calcification is related to parameters of calcium homeostasis in these patients and to analyze a possible relation between calcification and graft function at 1 year. We studied 213 patients with 586 protocol biopsies obtained 6 weeks, 3 and 6 months after transplantation. Calcifications increased over time, from 6.1% at 6 weeks to 17.8% at 6 months. Out of the 213 patients, 56 had calcification in one or more biopsies. Patients age and gender, underlying renal disease, dialysis mode and duration, previous transplantations, donor type, age and gender, HLA matches and ischemia time had no influence on calcification. Calcification was not related to rejection episodes, acute tubular lesions, calcineurin inhibitor toxicity or tubulointerstitial fibrosis and tubular atrophy. Patients with calcification had significantly higher serum parathormone and calcium levels. In patients with calcification, high PTH levels correlated with an inferior outcome of graft function at 1 year after transplantation (p<0.05). Therefore, treatment of hyperparathyroidism should be considered earlier and more often in these patients.

Adult↗
PubMed2005

Safety and adequacy of renal transplant protocol biopsies.

The protocol biopsy strategy has been criticized because of risks and marginal utility. We tested the risk. We performed 1171 protocol biopsies in 508 patients at 6, 12 and 26 weeks after renal transplantation, as well as 499 biopsies as indicated in 429 transplant patients. Biopsies were done as an outpatient procedure using an 18- or 16-gauge automated biopsy needle followed by 4 h bed rest. Complications were: gross hematuria 3.5%, perirenal hematomas 2.5%, arterio-venous fistulas 7.3% and vasovagal reactions 0.5%. Major complications requiring invasive procedures such as blood transfusions or urinary catheter were seen in 1% of cases. The hospitalization rate for observation was 1.9%. According to the Banff criteria of specimen adequacy, biopsies with 18-gauge needles yielded >7 glomeruli and at least one artery in 53% of cases. Changing the needle size in October 2003, those biopsies done with 16-gauge needles yielded >7 glomeruli and at least one artery in 76% of cases, while the rate of major complications did not change. In conclusion, transplant protocol biopsies with 16-gauge needles provide better utility and similar risk as biopsies with 18-gauge needles. A 4-h recovery after biopsy appears adequate for discharge.

Biopsy, Needle↗
PubMed2005

Polyoma virus nephropathy in native kidneys after lung transplantation.

Polyoma virus nephropathy is recognized as an emerging clinical problem in renal transplantation; however, polyoma in native kidneys is unusual. We report a patient who developed polyoma nephropathy in his native kidneys 15 months after successful lung transplantation. His immunosuppression consisted of tacrolimus, mycophenolate mofetil, and large doses of steroids because of three rejection episodes. When the condition was recognized, cidofovir was an effective treatment (3 doses of 2-3mg/kg); however, his renal function deteriorated nonetheless. Tubulitis and interstitial cell infiltration in his native kidneys were evidence that the changes were in response to viral injury. Polyoma nephropathy of native kidneys is unusual. An earlier course of cisplatin treatment because of metastatic seminoma prior to lung transplantation may have been contributory to pre-existing renal injury. After cidofovir was begun, the polyoma viral load in serum and urine decreased substantially; however, after high-dose steroid treatment of two rejection episodes, each time a significant increase in viral load was seen. We stained biopsies of native kidneys from 30 recipients of other organs. The biopsies were done for various reasons but not because polymoma virus was suspected. We found no additional cases.

Adult↗
PubMed2005

Detection of acute tubulointerstitial rejection by proteomic analysis of urinary samples in renal transplant recipients.

This study investigates proteomic analysis of urinary samples as a non-invasive method to detect acute rejection of renal allografts. Capillary electrophoresis coupled to mass spectrometry (CE-MS) was used to analyze urinary samples in 19 patients with different grades of subclinical or clinical acute rejection (BANFF Ia to IIb), 10 patients with urinary tract infection and 29 patients without evidence of rejection or infection. A distinct urinary polypeptide pattern identified 16 out of 17 cases of acute tubolointerstitial rejection, but was absent in two cases of vascular rejection. Urinary tract infection resulted in a different polypeptide pattern that allowed to differentiate between infection and acute rejection in all cases. Potentially confounding variables such as acute tubular lesions, tubular atrophy, tubulointerstitial fibrosis, calcineurin inhibitor toxicity, proteinuria, hematuria, allograft function and different immunosuppressive regimens did not interfere with test results. Blinded analysis of samples with and without rejection showed correct diagnosis by CE-MS in the majority of cases. Detection of acute rejection by CE-MS offers a promising non-invasive tool for the surveillance of renal allograft recipients. Further investigation is needed to establish polypeptide patterns in vascular rejection and to explore whether changes in the urinary proteome occur before the onset of histologically discernible rejection.

Adult↗
PubMed2004

Prognostic value of cytotoxic T-lymphocytes and CD40 in biopsies with early renal allograft rejection.

After renal transplantation, different immunological and non-immunological factors lead to long-term allograft deterioration. Acute rejection episodes are one risk factor for chronic renal allograft dysfunction (CRAD). Following the current Banff classification the histological grade in acute rejection episodes is of limited prognostic value, therefore, additional morphological surrogate markers would be helpful. We investigated the biopsies of 91 patients with early acute rejection episodes for the immunohistochemical expression of key molecules (perforin, granzyme B, TIA-1, CD40) in the T cell-mediated rejection process. Staining results were correlated to long-term allograft outcome. Patients with greater than 2% of granzyme B or greater than 25% of CD40-positive cells in the interstitial infiltrate showed significantly shorter allograft survival. Patients with a CD40-positive vascular rejection or greater than 2% of granzyme B-positive cells in the interstitial infiltrate were significantly correlated with an earlier onset of CRAD. Our findings provide potential morphological surrogate markers in biopsies with early acute rejection episodes after renal transplantation. These could become part of combined clinical and histological algorithms, allowing patient-specific risk estimation and customized therapy options to be made.

Acute Disease↗
PubMed2004

Long-term effects of acute ischemia and reperfusion injury.

Ischemia reperfusion (I/R) injury plays a major role in delayed graft function and long-term changes after kidney transplantation. By using different therapeutic strategies to prevent I/R injury in rat models of kidney transplantation we studied relationships between inflammatory cell arrival and adhesion molecule expression. In other rat models for acute renal failure we investigated the effect of up-regulation of protective genes such as heme oxygenase-1 (HO-1) on infiltrating cells, showing that infiltrating cells also contribute to beneficial effects. In order to gain more insight into the complex mechanisms of long-term changes after kidney transplantation, we started a protocol biopsy program to study histologic changes 6, 12, and 26 weeks after transplantation. The following article clarifies some of the complex mechanisms contributing to long-term changes caused by I/R injury.

Animals↗
PubMed2003

Improvement of Erdheim-Chester disease in two patients by sequential treatment with vinblastine and mycophenolate mofetil.

Erdheim-Chester disease (ECD) is a rare non-Langerhans' form of histiocytosis with a plethora of different clinical manifestations owing to multiple organ involvement. We report two patients who presented initially with different clinical symptoms. The presenting complaint of the first patient was bone pain, predominantly in the legs, whereas in the other patient the initial symptoms were related to obstruction of both ureters, as in idiopathic retroperitoneal fibrosis. Ultimately, ECD was diagnosed in both patients by the occurrence of both pathognomonic manifestations, the histologic presence of non-Langerhans' histiocytes in bone biopsies, and osteosclerotic lesions of the long bones. Because the extraosseous manifestations progressed and a single application of corticosteroids was ineffective, sequential treatment with vinblastine and mycophenolate mofetil, together with prednisolone, was started. At follow-up respectively 15 and 16 months after the start of treatment a beneficial effect was noted in both patients. These cases illustrate the clinical spectrum of ECD, detail the pathognomonic manifestations of this rare disease, emphasize the need to consider ECD as an uncommon but important differential diagnosis in patients with arthralgias or systemic fibrosis, and give the first evidence for a new treatment option.

Antineoplastic Agents, Phytogenic↗