Comparison of endoscopic ultrasound-guided fine-needle aspiration and fine-needle biopsy to generate pancreatic cancer organoids: Randomized trial

Background and study aims The prognosis for pancreatic cancer remains poor. Molecular diagnostics and customized therapies are becoming increasingly important in clinical routine. Patient-derived, predictive model systems such as organoids have the potential to substantially increase the depth of information from biopsy material by functional and molecular characterization. We compared the extent to which the use of fine-needle aspiration needles (FNA, 22G) or fine-needle biopsy needles (FNB, 22G) influences the generation of pancreatic cancer patient-derived organoids (PDOs) to establish endoscopic standards of organoid technology. Patients and methods Endoscopic ultrasound (EUS)-guided punctures by EUS-FNA and EUS-FNB of pancreatic masses highly suspicious for adenocarcinoma (detected by computed tomography and/or magnetic resonance imaging) were prospectively evaluated. Consecutive patients received EUS-FNA and EUS-FNB in a randomized order without the need to exchange the needle shaft (only the inner needle type (FNA/-B) was exchanged) between the passes. With each needle type, the specimens for histological analysis and for PDOs were obtained separately. Results Fifty patients were enrolled in the study. Histology revealed malignancy in 42 of 50 cases (84%). In total PDOs were generated from 17 patients (34%). Of these, nine were established by FNB only, two by FNA only, and six by both FNA and FNB. Histology revealed malignancy in 13 of 17 PDO cases (76%). In two histologically false-negative cases, PDOs could be established. Conclusions EUS-FNB was superior to EUS-FNA in terms of successful generation of PDOs, although it failed to show statistical significance.

Genetic Architecture of Ischaemic Strokes after COVID-19 Shows Similarities with Large Vessel Strokes

We aimed to analyse whether patients with ischaemic stroke (IS) occurring within eight days after the onset of COVID-19 (IS-COV) are associated with a specific aetiology of IS. We used SUPERGNOVA to identify genome regions that correlate between the IS-COV cohort (73 IS-COV cases vs. 701 population controls) and different aetiological subtypes. Polygenic risk scores (PRSs) for each subtype were generated and tested in the IS-COV cohort using PRSice-2 and PLINK to find genetic associations. Both analyses used the IS-COV cohort and GWAS from MEGASTROKE (67,162 stroke patients vs. 454,450 population controls), GIGASTROKE (110,182 vs. 1,503,898), and the NINDS Stroke Genetics Network (16,851 vs. 32,473). Three genomic regions were associated (p-value < 0.05) with large artery atherosclerosis (LAA) and cardioembolic stroke (CES). We found four loci targeting the genes PITX2 (rs10033464, IS-COV beta = 0.04, p-value = 2.3 × 10-2, se = 0.02), previously associated with CES, HS6ST1 (rs4662630, IS-COV beta = -0.04, p-value = 1.3 × 10-3, se = 0.01), TMEM132E (rs12941838 IS-COV beta = 0.05, p-value = 3.6 × 10-4, se = 0.01), and RFFL (rs797989 IS-COV beta = 0.03, p-value = 1.0 × 10-2, se = 0.01). A statistically significant PRS was observed for LAA. Our results suggest that IS-COV cases are genetically similar to LAA and CES subtypes. Larger cohorts are needed to assess if the genetic factors in IS-COV cases are shared with the general population or specific to viral infection.

Histological evaluation of PAXgene tissue fixation in Barrett’s esophagus and esophageal adenocarcinoma diagnostics

The dysplasia grading of Barrett’s esophagus (BE), based on the histomorphological assessment of formalin-fixed, paraffin-embedded (FFPE) tissue, suffers from high interobserver variability leading to an unsatisfactory prediction of cancer risk. Thus, pre-analytic preservation of biological molecules, which could improve risk prediction in BE enabling molecular and genetic analysis, is needed. We aimed to evaluate such a molecular pre-analytic fixation tool, PAXgene-fixed paraffin-embedded (PFPE) biopsies, and their suitability for histomorphological BE diagnostics in comparison to FFPE. In a ring trial, 9 GI pathologists evaluated 116 digital BE slides of non-dysplastic BE (NDBE), low-grade dysplasia (LGD), high-grade dysplasia (HGD), and esophageal adenocarcinomas (EAC) using virtual microscopy. Overall quality, cytological and histomorphological parameters, dysplasia criteria, and diagnosis were analyzed. PFPE showed better preservation of nuclear details as chromatin and nucleoli, whereas overall quality and histomorphologic parameters as visibility of basal lamina, goblet cells, and presence of artifacts were scored as equal to FFPE. The interobserver reproducibility with regard to the diagnosis was best for NDBE and EAC (κF = 0.72–0.75) and poor for LGD and HGD (κF = 0.13–0.3) in both. In conclusion, our data suggest that PFPE allows equally confident histomorphological diagnosis of BE and EAC, introducing a novel tool for molecular analysis and parallel histomorphological evaluation.

Gut bacterial dysbiosis and instability is associated with the onset of complications and mortality in COVID-19

There is a growing debate about the involvement of the gut microbiome in COVID-19, although it is not conclusively understood whether the microbiome has an impact on COVID-19, or vice versa, especially as analysis of amplicon data in hospitalized patients requires sophisticated cohort recruitment and integration of clinical parameters. Here, we analyzed fecal and saliva samples from SARS-CoV-2 infected and post COVID-19 patients and controls considering multiple influencing factors during hospitalization. 16S rRNA gene sequencing was performed on fecal and saliva samples from 108 COVID-19 and 22 post COVID-19 patients, 20 pneumonia controls and 26 asymptomatic controls. Patients were recruited over the first and second corona wave in Germany and detailed clinical parameters were considered. Serial samples per individual allowed intra-individual analysis. We found the gut and oral microbiota to be altered depending on number and type of COVID-19-associated complications and disease severity. The occurrence of individual complications was correlated with low-risk (e.g., Faecalibacterium prausznitzii) and high-risk bacteria (e.g., Parabacteroides ssp.). We demonstrated that a stable gut bacterial composition was associated with a favorable disease progression. Based on gut microbial profiles, we identified a model to estimate mortality in COVID-19. Gut microbiota are associated with the occurrence of complications in COVID-19 and may thereby influencing disease severity. A stable gut microbial composition may contribute to a favorable disease progression and using bacterial signatures to estimate mortality could contribute to diagnostic approaches. Importantly, we highlight challenges in the analysis of microbial data in the context of hospitalization.

Mucosal-Associated Invariant T (MAIT) Cells Are Highly Activated and Functionally Impaired in COVID-19 Patients

Coronavirus disease 2019 (COVID-19), caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), comprises mild courses of disease as well as progression to severe disease, characterised by lung and other organ failure. The immune system is considered to play a crucial role for the pathogenesis of COVID-19, although especially the contribution of innate-like T cells remains poorly understood. Here, we analysed the phenotype and function of mucosal-associated invariant T (MAIT) cells, innate-like T cells with potent antimicrobial effector function, in patients with mild and severe COVID-19 by multicolour flow cytometry. Our data indicate that MAIT cells are highly activated in patients with COVID-19, irrespective of the course of disease, and express high levels of proinflammatory cytokines such as IL-17A and TNFα ex vivo. Of note, expression of the activation marker HLA-DR positively correlated with SAPS II score, a measure of disease severity. Upon MAIT cell-specific in vitro stimulation, MAIT cells however failed to upregulate expression of the cytokines IL-17A and TNFα, as well as cytolytic proteins, that is, granzyme B and perforin. Thus, our data point towards an altered cytokine expression profile alongside an impaired antibacterial and antiviral function of MAIT cells in COVID-19 and thereby contribute to the understanding of COVID-19 immunopathogenesis.

Does dysfunction of the autonomic nervous system affect success of renal denervation in reducing blood pressure?

Objectives:

Renal denervation is an interventional approach aiming to reduce high blood pressure. Its efficacy is subject of controversial debate. We analyzed autonomic function in patients undergoing renal denervation to identify responders.

Methods:

A total of 21 patients with treatment-resistant hypertension scheduled for renal denervation were included. Heart rate variability, pupillary function and sympathetic skin response were examined prior to intervention. Before and 1 or 3 months after intervention, 24-h ambulatory blood pressure readings were taken.

Results:

Patients were stratified according to sympathetic nervous system function. Sympathetic activity was reduced in 12 participants (group 1) and normal or enhanced in nine patients (group 2). The mean of daytime systolic blood pressure decreased in groups 1 and 2 from 168 to 157 mmHg (95% confidence interval for difference, 1–21 mmHg, p = 0.035) and from 166 to 145 mmHg (8–34 mmHg, p = 0.005), respectively. In a linear model, blood pressure reduction was 11.3 mmHg (0.3–22 mmHg) greater in group 2 than in group 1 (p = 0.045).

Conclusion:

Patients with preexisting reduced activity of the sympathetic nervous system benefited less from renal denervation.

Semiconductor quantized voltage source

We realize and investigate an all-semiconductor quantized voltage source which generates quantized output voltages V(out) = f(h/e) linked only to two fundamental constants, the electron's charge e and Planck's constant h, and to an applied excitation frequency f. The device is based on an integrated quantized circuit of a single-electron pump operated at pumping frequency f and a quantum Hall device monolithically integrated in series. Robust output voltages up to several μV are generated, which are expected to be scalable by orders of magnitude using present technology. The device might open a new route towards the closure of the quantum metrology triangle.

Improvement in long-term renal graft survival due to CMV prophylaxis with oral ganciclovir: results of a randomized clinical trial

Oral ganciclovir prophylaxis and intravenous preemptive therapy are competitive approaches to prevent cytomegalovirus (CMV) disease after renal transplantation. This trial compared efficacy, safety and long-term graft outcome in 148 renal graft recipients randomized to ganciclovir prophylaxis (N = 74) or preemptive therapy (N = 74). Hierarchical testing revealed (i) patients with CMV infection had more severe periods of impaired graft function (creatinine clearance(max-min) 25.0 +/- 14.2 mL/min vs. 18.1 +/- 12.5 mL/min for patients without CMV infection; p = 0.02),(ii) prophylaxis reduced CMV infection by 65% (13 vs. 33 patients; p < 0.0001) but (iii) creatinine clearance at 12 months was comparable for both regimes (54.0 +/- 24.9 vs. 53.1 +/- 23.7 mL/min; p = 0.92). No major safety issues were observed, and patient survival at 12 months was similar in both groups (5 deaths [6.8%] vs. 4 [5.4%], p = 1.0000). Prophylaxis significantly increased long-term graft survival 4 years posttransplant (92.2% vs. 78.3%; p = 0.0425) with a number needed to treat of 7.19. Patients with donor +/recipient + CMV serostatus had the lowest rate of graft loss following prophylaxis (0.0% vs. 26.8%; p = 0.0035). In conclusion, it appears that routine oral prophylaxis may improve long-term graft survival for most renal transplant patients. Preemptive therapy can be considered in low risk patients in combination with adequate CMV monitoring.

Prospective age-matching in elderly kidney transplant recipients--a 5-year analysis of the Eurotransplant Senior Program

Renal transplantation faces challenges: the organ shortage resulting in extended waiting times and an aging population resulting in death with a functioning graft. The Eurotransplant Senior Program (ESP) allocates kidneys within a narrow geographic area from donors aged >/=65 years to recipients >/=65 years regardless of HLA. This analysis investigates the impact of the ESP on waiting time, graft and patient survival. The ESP group (n = 1406, old to old) was compared to two groups allocated via the Eurotransplant Kidney Allocation System (ETKAS) with either similar donor age (old to any [O/A], donor age >/=65, n = 446) or recipient age (any to old, [A/O], recipient age 60-64, n = 1687). All patients were transplanted between 1999 and 2004. Since initiation of the ESP (1999), availability of elderly donors doubled and waiting time for ESP patients decreased. Local allocation led to shorter cold ischemia time (11.9 vs. >17.0 h, p < 0.001) and less delayed graft function (DGF, ESP 29.7% vs. O/A 36.2%, p = 0.047) but 5-10% higher rejection rates. Graft and patient survival were not negatively affected by the ESP allocation when compared to the standard allocation. The ESP age matching of elderly donors and recipients is an effective allocation system for organs from elderly donors.

Acute hantavirus infection or renal transplant rejection

Hantaviruses belong to the so-called emerging pathogens that are transmitted to humans by infected rodents and their excreta. In Central Europe, hantavirus infections usually occur in a mild to moderate form of hemorrhagic fever with renal syndrome. In contrast to the mostly benign or even asymptomatic course of hantavirus infections in previously healthy individuals, the acute hantavirus infection in kidney transplant recipients represents an exceptional situation regarding diagnosis and therapy. We describe the case of a 44-year-old kidney transplant recipient with acute renal transplant failure associated with acute hantavirus infection.

Relationship between donor factors, immunogenic up-regulation, and outcome after kidney transplantation

Epidemiological data show that the cause of brain death as well as the condition of the organ donor have considerable influence on the outcome of kidney transplantation. An early immunogenic up-regulation, which already exists at the time of organ removal seems to be primarily responsible. So far it has remained unclear which donor factors cause this effect. In a prospective study of 37 organ donors a 0-hour biopsy was performed at the time of explantation to measure the expression of HLA-DR and endothelin-1 (ET-1) immunohistologically using the alkaline phosphatase anti-alkaline phosphatase (APAAP) method. The transplant outcome and the immunohistological results were correlated with various donor factors. Statistically significant correlations were seen with the following parameters: the donor serum creatinine prior to explantation correlated with the incidence of delayed graft function (DGF: 104 +/- 39 vs 78 +/- 35 micromol/L versus no DGF n = 37; P = .043). Early graft loss after transplantation correlated significantly with increased numbers of leukocytes as well as with decreased O2 saturation in the donor immediately before explantation (leucocytes: 16.7 +/- 6.8 vs 12.6 +/- 4.6/nL, n = 37; P = .036; O2 saturation: 94.1% +/- 6.9%, vs 97.7% +/- 2.3%, n = 37; P = .026). Further, donor-independent factors that correlated with acute rejections included cold ischemic time (P = .031), HLA mismatches (P = .028), and occurrence of DGF (P = .033). The degree of HLA-DR expression (range 0 to 2) correlated significantly with early graft loss (2.0 +/- 0.2 vs 1.33 +/- 0.9 for graft function, n = 37; P = .01) as well as the ET-1 expression with DGF (2.0 +/- 0.3 vs 1.5 +/- 0.7 versus no DGF, n = 37; P = .016). In summary, marginal donors should be seen as high immunological risk situations that need careful conditioning.

Cyclosporine C2 levels in de novo renal allograft recipients: a German multicenter prospective observational study

This ongoing multicenter prospective observational study was undertaken in de novo renal allograft recipients managed with cyclosporine (CsA) trough (C0) and 2-hour postdose (C2) level monitoring at defined times so as to assess the risk for an acute rejection episode or allograft dysfunction. The renal transplant recipients (n = 159) were enrolled at 11 German centers. The 6-month posttransplant data from 138 patients were evaluable for this interim analysis. Mean C2 levels (ng/mL), which were measured by liquid chromatography-tandem mass spectrometry at a central laboratory, were: days 3 to 5: 873.1 +/- 391.9; days 7 to 10: 939.1 +/- 422.8; days 14 to 28: 1116.3 +/- 497.6; 3 months: 905.0 +/- 316.8; and after 6 months: 787.0 +/- 276.5. To identify patients at higher risk for acute rejection or allograft dysfunction, we calculated the relative CsA absorption capacity (C2 [ng/mL]/morning dose [mg/kg]; CsA-Abs), yielding mean values on days 3 to 5: 284.4 +/- 115.1; days 7 to 10: 306.7 +/- 134.8; days 14 to 28: 382.5 +/- 164.7; month 3: 501.5 +/- 168.8; month 6: 512.7 +/- 176.5. Three groups were distinguished by CsA-Abs at days 7 to 10: low absorbers (CsA-Abs < 200), normal absorbers (CsA-Abs 200 to 350), and high absorbers (CsA-Abs > 350). A between-group comparison of absorption level at 6 months posttransplant revealed the incidences of biopsy-proven acute rejection and Cockcroft-Gault formula-based mean glomerular filtration rates of 23.8% and 54.7 +/- 19.0 mL/min, 22.6% and 59.5 +/- 20.7 mL/min, and 17.6% and 67.7 +/- 23.5, respectively. In conclusion, mean C2 levels >1000 ng/mL are attained within 2 to 4 weeks, with CsA-Abs increasing continuously over the first 6 posttransplant months. High CsA absorbers show a propensity toward good allograft function and lower acute rejection rates at 6 months after renal transplantation.

Laparoscopic fenestration of posttransplant lymphoceles

BACKGROUND

A lymphocele is a common finding after renal transplantation and occurs in up to 20% of patients. The majority of patients are asymptomatic. However, once a lymphocele has become symptomatic (e.g., through transplant dysfunction) this condition has to be treated. We report our 9-year experience with laparoscopic lymphocele fenestration and discuss the current management options for posttransplant lymphoceles.

METHODS

Since 1993, 19 patients (11 males and 8 females; median age 56 years, range 22-68 years) of a total of 31 patients with a symptomatic posttransplant lymphocele have undergone laparoscopic fenestration of their lymphocele at a median of 66 days (range, 19-111 days) following successful renal transplantation in our department. As a first-line treatment, a percutaneous pigtail drainage catheter was inserted in all patients. In case of failure in resolving the fluid collection, the next step included sclerotherapy by instillation of tetracycline or ethanol into the lymphocele cavity in some cases. In patients with a persistent lymphocele, a laparoscopic lymphocele fenestration via a transabdominal approach was undertaken to achieve adequate drainage.

RESULTS

Primary laparoscopic lymphocele fenestration was successful in all except two patients, who required a conversion. The median operating time was 36 min (range, 20-70 min). Following the procedure, renal transplant function remained stable or returned to individually normal levels in all patients. Median duration of hospital stay was 4 days (range, 1-13 days). At median follow-up of 27 months, all patients were alive with a functioning transplant.

CONCLUSIONS

Laparoscopic lymphocele fenestration is reserved for patients in whom temporary drainage with or without sclerotherapy failed to resolve the fluid collection. In these cases the laparoscopic approach offers obvious technical and clinical advantages compared to open operative techniques.

Hemolytic anemia after kidney transplantation: case report and differential diagnosis

A 58-year-old woman presented with hemolysis and thrombocytopenia 2 weeks after receiving a kidney graft. Hemolytic uremic syndrome was initially suspected, because in addition to hematological changes the graft function was missing. Unexpectedly, the results of the direct antiglobulin test became positive (4+), which is not normally observed in the hemolytic uremic syndrome. Differentiation of the eluted antibodies revealed anti-rhesus D specificity, which had to be interpreted either as an autoantibody of patient's origin or, hypothetically, as a "graft versus host" antibody of donor origin. Gm- and Km allotyping of these antibodies demonstrated a pattern which differed from the patient's but was identical to that of the kidney donor. Therefore hemolysis could be explained unambiguously by "graft versus host" antibodies. Whether the thrombocytopenia was also due to an immune process was not clear, although some evidence favors this hypothesis. Immunosuppressive treatment remained unchanged and several red blood cell transfusions were necessary before reactivity of the direct antiglobulin test diminished and became negative 7 weeks after kidney transplantation. The occurrence of hemolysis in the early posttransplantation period should thus draw attention to the possibility of "graft versus host" antibodies directed against red cells. Concomitant thrombocytopenia may occur. Donor screening for irregular erythrocyte antibodies should be performed whenever solid organ transplantation is intended.

A randomized, double-blind trial of basiliximab immunoprophylaxis plus triple therapy in kidney transplant recipients

BACKGROUND

A double-blind, placebo-controlled, randomized study was performed to assess whether immunoprophylaxis with basiliximab (Simulect) could reduce the incidence of acute rejection in kidney transplant recipients treated with cyclosporine (Neoral), steroids, and azathioprine.

METHODS

Three hundred forty patients received either placebo or basiliximab at a dose of 20 mg, given intravenously on days 0 and 4. All patients received cyclosporine, steroids, and azathioprine. The primary endpoint was the incidence of acute rejection at 6 months. Secondary endpoints included the safety and tolerability of basiliximab and placebo, 1-year patient and graft survival, and significant medical events up to 12 months.

RESULTS

During the first 6 months posttransplantation, acute rejection occurred in 20.8% of patients given basiliximab versus 34.9% of patients administered placebo (P=0.005). Similarly, there was a reduction in biopsy-proven acute rejection at 6 months in the patients receiving basiliximab (P=0.023). One-year patient survival was 97.6% with basiliximab and 97.1% with placebo, graft survival was 91.5% versus 88.4%, respectively (NS). The adverse-events profile of patients treated with basiliximab was indistinguishable from that of patients treated with placebo. The number of patients with infections was similar (65.5% for basiliximab vs. 65.7% for placebo), including cytomegalovirus infections (17.3% vs. 14.5%, P=0.245). Nine neoplasms (three in the basiliximab group, six in the placebo arm) were recorded up to 1 year from transplantation.

CONCLUSIONS

Basiliximab in combination with cyclosporine, steroids, and azathioprine triple therapy was highly effective in reducing the incidence of acute renal allograft rejection without increasing the incidence of infections and other side effects.

Laparoscopic nephroureterectomy to exclude upper urinary tract malignancy associated with analgesic nephropathy

BACKGROUND AND PURPOSE

Analgesic abuse is a potential cause of end-stage renal disease. Such patients bear an elevated risk of developing malignancies, predominantly transitional-cell carcinoma. We report our experience with laparoscopic nephroureterectomy carried out in patients with analgesic nephropathy to exclude upper urinary tract malignancy. All patients were scheduled to be put on the waiting list for cadaveric renal transplantation.

PATIENTS AND METHODS

Since 1996, nine women and two men with a long-term history of analgesic abuse have undergone laparoscopic nephroureterectomy at our hospital. The median age was 63 years (range 51-70 years). All patients had developed end-stage renal failure secondary to heavy analgesic abuse with a median duration of 14 years (range 7-40 years). The median interval from the beginning of hemodialysis to laparoscopic nephroureterectomy was 36 months (range 6-76 months).

RESULTS

The median operative time was 99 minutes (range 55-170 minutes). There were no conversions to open surgery. Two complications occurred, and three patients required blood transfusions. The median hospital stay lasted 5 days (range 2-12 days), and the median convalescence was 20 days (range 6-44 days). In seven patients, histopathologic examination of the kidney revealed changes attributable to analgesic abuse. None of the patients had a transitional-cell carcinoma, but in two patients, a renal-cell carcinoma stage pT1cN0cM0 grade 2 was detected.

CONCLUSION

Patients with analgesic nephropathy bear an elevated risk for the development of transitional-cell or renal-cell carcinoma. In these patients, laparoscopic nephroureterectomy combines minimally operative invasiveness with a maximum of diagnostic safety.

Human thiopurine S-methyltransferase activity in uremia and after renal transplantation

In addition to cyclosporin and steroids, azathioprine is frequently used for immunosuppression after renal transplantation. Thiopurine S-methyltransferase (TPMT) catalyses the S-methylation of thiopurine drugs. A genetic polymorphism was shown with 1 in 300 homozygous for a TPMT deficiency. These subjects carry the risk of severe myelosuppression when treated with azathioprine.

OBJECTIVE

To investigate the influence of hemodialysis on TPMP activity in uremic patients and the effect of azathioprine treatment on enzyme activity.

METHODS

The assay for measurement of TPMT activity in packed red blood cells is based on a non-radioactive conversion of 6-thioguanine to 6-methylthioguanine. In 251 patients, TPMT activity was determined before and after a 4-h period of hemodialysis. In 49 patients (26 on azathioprine, 23 on mycophenolate mofetil as control group), TPMT activity was regularly determined during the first 120 days after renal transplantation.

RESULTS

TPMT activity is elevated in red blood cells of uremic patients before hemodialysis when compared with TPMT activity after hemodialysis. The latter is comparable to the activity in healthy subjects. In patients treated with azathioprine, the TPMT activity showed a slow increase that declined to pre-treatment values when azathioprine was withdrawn. This could not be observed in patients treated with mycophenolate mofetil.

CONCLUSIONS

In uremic patients, TPMT activity is activated by some uremic factors that are removed by hemodialysis. In contrast to what has been observed before, dialysis shifted the TPMT activity close to that of a healthy control group. In patients treated with azathioprine after renal transplantation, the observed increase of TPMT activity could possibly be the result of enzyme induction.

The effect of HLA-C matching on acute renal transplant rejection

BACKGROUND

The acute immunological rejection and long time survival of kidney allografts are correlated with the human leukocyte antigen (HLA) match status between donor and recipient. HLA-A, -B and -DR have all turned out to be relevant HLA loci in several studies. The role of HLA-C has not been studied before now.

METHODS

In 104 consecutive patient/donor pairs from our transplantation unit, we retrospectively analysed whether acute graft rejection is influenced by HLA-C match status between donor and recipient. For typing HLA-C alleles, we used an allele-specific PCR protocol in combination with serology.

RESULTS

By analysing groups of donor/recipient pairs with a homogeneous distribution of HLA-B mismatches in order to exclude an effect of the linkage disequilibrium between HLA-B/C, HLA-C mismatch turned out to be significantly correlated with acute transplant rejection in pairs with one additional mismatch on the B locus (P=0.004). Additional parameters that may hypothetically influence acute rejection episodes (HLA-A or DR mismatch, time of cold and warm ischaemia, previous transplantations, pre-existing HLA antibodies) were also analysed but cannot explain this finding.

CONCLUSION

HLA-C matching of all kidney donors and recipients seems to be an option to reduce the probability of acute rejection episodes. Further studies of greater patient cohorts analysing organ rejection and organ survival are warranted.

Primary hyperoxaluria type 1 causing end-stage renal disease in a 45-year-old patient

Primary hyperoxaluria type 1 (PH1) is caused by deficiency of peroxisomal alanine-glyoxylate aminotransferase which is in humans exclusively expressed in liver cells. The disease is inherited as an autosomal recessive trait, and initial symptoms usually occur in early childhood. Up to the age of 25 years, 90% of the patients are symptomatic, and many patients develop end-stage renal failure. Pronounced medical care is necessary in PH1 patients to prevent generalized oxalosis with complications due to bone disease and peripheral gangrene. The rather short survival of patients on hemodialysis is caused by sudden arrhythmias and heart block. As no dialysis procedure is able to remove the daily produced oxalate, early transplantation is mandatory. Our 45-year-old patient is remarkable on the basis of the late manifestations of PH1. The diagnosis was delayed by unspecific symptoms of nephrolithiasis with recurrent pyelonephritis. Clinical course and diagnostic cornerstones of primary hyperoxaluria are outlined. The principles of conservative treatment and experiences with dialysis and transplantation are discussed.

Monitoring of anti-HLA class I and II antibodies by flow cytometry in patients after first cadaveric kidney transplantation

While the relevance of pre-formed anti-human leukocyte antigen (HLA) antibodies has been studied extensively, the role of anti-HLA class I and II antibodies produced after cadaveric kidney transplantation is still a matter of discussion. As it has been proposed that they are involved in a considerable number of cases, it should be investigated whether a post-transplant monitoring is a sensitive parameter for the early diagnosis of acute rejection episodes. Additionally, it has been suggested that antibodies are a major cause for chronic rejection; thus, it would be of interest to correlate antibody detection and graft survival. We retrospectively investigated 59 patients after a first cadaveric kidney transplantation without known anti-HLA antibodies (complement-dependent cytotoxicity [CDC] testing). The panel reactivity was determined with a new highly sensitive and specific flow-cytometric technique (Flow-PRA Screening Test, One Lambda, Canoga Park, USA) in sequentially collected serum samples pre- and post-transplant. In patients with acute rejection episodes during the clinical course, the last sample prior to rejection, and in patients without rejection, the last sample prior to discharge, was analyzed. Furthermore, we analyzed 3-yr graft survival and several clinical parameters such as cold ischemia time (CIT). Twenty-four of 59 patients (41%) experienced acute rejections during the clinical course. Five of 59 died with a functioning graft within the first 3 yr. Seven of 54 patients, still alive after 3 yr, lost their graft. Anti-HLA antibodies were detectable in only 7/59 patients and a correlation between antibody positivity and acute rejections (p = 0.32 and 0.54 for anti-HLA class I and II, respectively) could not be identified (sensitivity 12.5 and 8.3%). However, we found a significant correlation between the detection of anti-HLA class II and graft loss within 3 yr (p = 0.005, specificity 97.9%). Additionally, anti-HLA class II positive patients had significantly longer CIT (p = 0.003). Whether the detection of anti-HLA class II antibodies in the early post-transplant phase is of great value for the identification of patients at high risk for early graft loss needs additional investigation. However, we found that anti-HLA antibodies are detectable only in a minority of unsensitized patients and we conclude that flow-cytometric monitoring with Flow PRA is not a sensitive parameter for the early diagnosis of acute rejection episodes in patients after first cadaveric kidney transplantation.

The IL-4 receptor alpha-chain variant Q576R is strongly associated with decreased kidney allograft survival

The involvement of the interleukin-4 (IL-4) pathway in B-lymphocyte activation and induction of a T helper 2 (Th2) cell response prompted us to investigate the influence of a recently described gain-of function mutation in the IL-4 receptor alpha-chain gene (IL-4R alpha; CD 124) on renal allograft survival. We developed a genotyping assay for the IL-4R alpha variant Q576R and investigated 203 renal transplant patients, all of whom underwent transplantation surgery at a single institution. The overall frequency of the IL-4R alpha variant Q576R in this group was 38.9% (79/203). The Kaplan-Meier method was used to estimate the graft survival of 156 patients with complete follow-up time of 24 months. Significantly higher graft survival rates (P=0.012, log-rank test) were found in patients with the wild-type IL-4 receptor (2-year graft survival 78.8%) as compared to patients with the IL-4R alpha variant Q576R (2-year graft survival 60.6%). Multifactorial cox regression analysis showed that this effect was independent of HLA matching, sex of donor and recipient, age of recipient, year of transplantation and preformed antibodies (P=0.017). These results indicate a strong association of the IL-4R alpha variant Q576R with kidney allograft loss. Genotyping of kidney allograft recipients for the IL-4R alpha variant may offer a simple method to identify high-risk patients in the post-transplantation period.

Treatment of posttransplant hypertension by laparoscopic bilateral nephrectomy?

BACKGROUND

Hypertension is an important risk factor for the development of chronic graft failure and decreased graft and patient survival after renal transplantation.

METHODS

Between September 1994 and August 1996, 14 patients underwent laparoscopic bilateral nephrectomy for treatment of drug-resistant hypertension after successful renal transplantation. Common causes of hypertension were largely excluded before bilateral nephrectomy. A scoring system was developed for comparison of different antihypertensive regimes. In this system, points were given according to type and dosage of each antihypertensive drug.

RESULTS

At 6-month follow-up, all patients showed well-controlled blood pressure (median of mean arterial pressure: 104 vs. 130 mmHg preoperatively, P<0.001, n=14), and significantly fewer antihypertensive drugs were needed according to the scoring system (48.9+/-20.9 points vs. 105.9+/-23.5 points preoperatively, P<0.001, n=14). During laparoscopy, three conversions to open surgery were necessary. Postoperatively, four complications occurred. After laparoscopy, immunosuppression and other oral medication were given continuously. The hospital stay ranged between 3 and 6 days (median: 5 days).

CONCLUSIONS

The results indicate that bilateral nephrectomy using the laparoscopic technique can be an effective alternative method for a selected group of patients with severe hypertension, which is unresponsive to conservative management after successful renal transplantation with regard to improving the long-term graft survival.

Laparoscopic nephrectomy: comparison of dialysis and non-dialysis patients

BACKGROUND

Laparoscopy is believed to result in possible clinical benefits for the patient. We report our experience with renal laparoscopy in dialysis patients and compare the results with those from non-dialysis patients.

METHODS

Between December 1994 and April 1997, 19 dialysis patients underwent laparoscopic nephrectomy or nephroureterectomy at our hospital. The group consisted of 11 female and eight male patients (mean age 45 years). In nine patients the indication for nephrectomy was chronic pyelonephritis. Nephroureterectomy for vesicoureteral reflux with recurrent episodes of pyelonephritis or analgesic nephropathy for exclusion of transitional cell carcinoma of the upper urinary tract was considered in nine other patients. Laparoscopic bilateral nephrectomy for drug-resistant hypertension was performed in one patient. In comparison, a consecutive group of non-dialysis patients who had undergone renal laparoscopy was reviewed.

RESULTS

In the dialysis group, one patient had to be converted to open nephrectomy due to bleeding. Six dialysis patients required blood transfusions compared with none in the non-dialysis group. There were four complications in the dialysis group and two in the non-dialysis group. Both groups had comparable results for operative times, analgesic consumption, postoperative start of oral intake and mobilization, and duration of hospitalization and convalescence.

CONCLUSIONS

Laparoscopic nephrectomy in dialysis patients has acceptable results. The higher transfusion rate is probably due to a lower preoperative haemoglobin and is not aggravated by possible affects of the clotting system in patients with chronic uraemia.

Comparison of laparoscopic and open nephroureterectomy for benign disease

PURPOSE

We report our experience with laparoscopic nephroureterectomy for benign disease and compare the results to a contemporary group of patients undergoing open nephroureterectomy.

MATERIALS AND METHODS

Between October 1994 and March 1997, 12 women and 4 men with a mean age of 50 years (range 22 to 70) underwent laparoscopic nephroureterectomy at our hospital. Indications for operation were nonfunctioning kidneys due to vesicoureteral reflux with recurrent episodes of pyelonephritis or analgesic nephropathy before a planned renal transplantation. In comparison 11 women and 4 men with a mean age of 40 years (range 18 to 64) underwent open nephroureterectomy for various benign diseases.

RESULTS

Laparoscopic and open nephroureterectomy had no significant differences regarding operative times (100 versus 124 minutes) and complication rates (25 versus 20%). In the laparoscopy group conversion to open surgery was not necessary. Patients who underwent laparoscopic nephroureterectomy had significantly less consumption of morphine equivalent for postoperative pain control (12 versus 40 mg.), shorter time to achieve mobilization and oral intake (11 versus 39 hours), shorter hospital stay (6 versus 12.7 days) and faster return to normal activities (21 versus 39 days).

CONCLUSIONS

Laparoscopic nephroureterectomy in patients with benign disease has similar operative results but obvious postoperative advantages compared to the open approach.

[The angiography of kidney transplant arteries using carbon dioxide]

BACKGROUND AND OBJECTIVE

After renal transplantation hypertension occurs in 60-80% of patients, in 3-23% of them due to renal artery stenosis in the transplanted kidney. Angiographic assessment of the severity of the stenosis would best be done with a non-nephrotoxic contrast medium. We investigated the use of carbon dioxide, a bubble-forming contrast medium excreted via the lung, for its suitability in the angiography of the arterial system in the renal transplant.

PATIENTS AND METHODS

In an uncontrolled series of observations on six patients with renal transplants and hypertension who were being treated with three or four antihypertensive drugs, the transplant's arteries were demonstrated with carbon dioxide, injected by Seldinger technique into the ipsilateral femoral artery, and the results recorded by subtraction angiography.

RESULTS

The angiograms demonstrated postoperative kinked renal artery, a plaque in the external iliac artery, and a sharply angled origin of the external iliac artery in one case each, and three normal cases.

CONCLUSIONS

Carbon dioxide is a suitable medium for demonstrating renal arteries in a transplanted kidney and is preferable to conventional contrast media for the angiographic diagnosis of possible renal artery stenosis.

ICAM-1, soluble-CD23, and interleukin-10 concentrations in serum in renal-transplant recipients with Epstein-Barr virus reactivation

Primary and reactivated Epstein-Barr virus (EBV) infections after organ transplantation are associated with the development of posttransplant lymphoproliferative malignancies. Since viral reactivation frequently stays asymptomatic, early diagnosis and treatment are challenges during posttransplant patient monitoring. Both soluble-CD23 (sCD23) and intercellular adhesion molecule 1 (ICAM-1) cell surface expression as well as interleukin-10 (IL-10) production are closely associated with viral gene expression. Therefore, immunoglobulin M (IgM), IgG, IgA, sCD23, ICAM-1, and IL-10 concentrations were measured in serum samples from patients during EBV reactivation (n = 14) and were compared with those in samples from patients without EBV reactivation (n = 10) following renal transplantation. In addition, serum sCD23, ICAM-1, and IL-10 concentrations were measured longitudinally in weekly to biweekly samples from 10 patients with EBV reactivation for at least 20 weeks following transplantation. A significant elevation of sCD23 was found during viral reactivation (P < 0.05), whereas ICAM-1 levels showed a nonsignificant increase. The finding of a highly significant elevation of the serum IL-10 concentration during EBV reactivation (P < 0.001) may support speculations about its role in EBV-induced lymphoproliferation and in the development of opportunistic infections and secondary malignancies. Maximum serum IL-10 levels at the time of EBV reactivation were found in 7 of 10 patients. Well-defined ICAM-1 and sCD23 concentration peaks were found in 9 of 10 and 8 of 10 patients, respectively. Although both markers are not specific for EBV reactivation and therefore may not be useful for primary diagnosis, sCD23 and ICAM-1 might be potent tools for the clinical monitoring of EBV activity and virus-induced lymphoproliferation.

Renal graft rejection or urinary tract infection? The value of myeloperoxidase, C-reactive protein, and alpha2-macroglobulin in the urine

Previous investigations have shown that the determination of two acute-phase proteins in the urine, C-reactive protein (CRPu) and alpha2-macroglobulin (alpha2-MGu), allows a noninvasive diagnosis of acute renal graft dysfunction. A reliable differentiation between rejection and urinary tract infection can be made only when considering the C-reactive protein in serum and urine at the same time (CRPs:CRPu ratio). Therefore, a diagnostic procedure independent of parameters other than urinary proteins is needed. As granulocytes play only a minor role in graft rejection but are a common feature in urinary tract infection, we determined a marker of granulocytes (myeloperoxidase) in urine (MPOu). Eighty-nine renal transplant recipients were included in the study. In normal courses, CRPu, alpha2-MGu, and MPOu were within the normal range. In 15 cases of acute interstitial rejection, an increased excretion of CRPu and alpha2-MGu could be confirmed, but MPOu could not be detected. On the occasion of acute vascular rejection (n=6), with the exception of one case, MPOu could not be observed. The pattern of the three urinary proteins differed in urinary tract infections (n=40): MPOu could be detected in all cases, CRPu in 50% of cases, and alpha2-MGu in 73% of cases. In patients with cytomegalovirus infection (n=7), no MPOu, CRPu, or alpha2-MGu was found. In conclusion, the simultaneous measurement of the three proteins allows a complete, noninvasive, differential diagnostic procedure of renal graft dysfunction.

[The significance of risk-adapted antiviral prophylaxis and modern virus diagnosis for organ survival after kidney transplantation]

BASIC PROBLEM AND OBJECTIVE

Viral, especially cytomegalovirus (CMV), infections are after rejection reaction the most serious problem following organ transplantation. The risk of disease correlates with the CMV donor/recipient constellation and the degree of immunosuppression. The importance of antiviral prophylaxis remains unresolved. Whether drug prophylaxis adapted to the individual risk is of clinical value was investigated in a prospective study.

PATIENTS AND METHODS

A risk-adapted stepwise antiviral prophylactic regimen was given to 62 patients with renal transplants. All patients at risk of CMV infection were given acyclovir, 200 mg four times daily for 3 months. Patients with rejection reaction for which they were receiving i.v. immunosuppressive treatment additionally received CMV hyperimmunoglobulin (2 ml/kg body weight on days 1 and 14). High-risk patients (donor CMV positive and recipient CMV negative) were given as basic prophylaxis CMV hyperimmunoglobulin i.v. on days 1 and 14 after transplantation, and additionally i.v. ganciclovir during any rejection treatment. The results were compared with those of a retrospectively selected patient cohort (n = 52) who had received only acyclovir as basic prophylaxis. The diagnosis of CMV infection was made by demonstrating CMVpp65 antigen in blood. In the prospectively studied patients measurement of beta 2 microglobulin concentration was used to determine viruria in 24-hour urine.

RESULTS

Among the high-risk group (donor CMV positive/recipient CMV negative) the additional prophylactic regimen significantly reduced the proportion of CMV-associated cases of rejection (14% compared with 42%, P < 0.05) in the basic prophylaxis only group. Similar results were obtained for CMV-caused transplant loss within the first 3 years (19% vs 50%, P < 0.05). The additional prophylaxis had no influence on the incidence of CMV infection. In case of active infection an isolated rise of beta 2-microglobulin in urine occurred in active infection at a mean of 6 days before CMVpp65 antigenaemia (sensitivity of 89%).

CONCLUSIONS

These results indicate that risk-adapted antiviral prophylaxis can decisively influence the long-term prognosis for a renal transplant, but not the incidence of CMV infection. The early and reliable diagnosis of active CMV infection is made possible by the combined use of beta 2-microglobulinuria and pp65 antigenaemia.

Laparoscopy in renal transplant patients

OBJECTIVES

To evaluate the use of laparoscopic techniques in patients with a renal transplant.

METHODS

Since 1992, 358 patients have undergone urologic laparoscopy at our hospital. Among these, 37 procedures (10.4%) were performed in patients with a renal transplant: 14 bilateral nephrectomies for severe drug-resistant hypertension, 9 marsupializations of symptomatic lymphoceles, 6 renal allograft biopsies in patients with clotting abnormalities, 6 unilateral nephrectomies, and 2 nephroureterectomies for recurrent episodes of pyelonephritis and symptomatic vesicoureteral reflux, respectively.

RESULTS

Five complications (14%) and three conversions (8%) occurred. Patients who underwent successful laparoscopic operations began mobilization and oral intake on the day after the operation. The hospital stay ranged from 1 to 6 days. In the nephrectomy groups, perioperative urine outputs remained stable and post-operative urine outputs were increased as compared with those in the perioperative period (P < 0.05). Post-operatively, serum creatinine remained stable or improved in patients who underwent nephrectomy or marsupialization of lymphocele.

CONCLUSIONS

Our results indicate that laparoscopic techniques are safe and effective in the treatment of patients with a renal transplant. Renal allograft function apparently is not affected by laparoscopic procedures.

Laparoscopic bilateral nephrectomy: results in 11 renal transplant patients

PURPOSE

We report our experience with bilateral laparoscopic nephrectomy after renal transplantation.

MATERIALS AND METHODS

Between August 1994 and October 1995, 11 patients who had previously undergone renal transplantation underwent bilateral laparoscopic nephrectomy at our hospital due to poorly controlled hypertension. The records of 10 patients undergoing bilateral open nephrectomy were reviewed for comparison.

RESULTS

Mean operative time in the laparoscopy group was 195 minutes (range 125 to 270). Mean blood loss was 345 ml. and 1 patient required conversion to an open operation. Oral intake and mobilization were begun 1 day postoperatively. Mean postoperative morphine equivalent consumption was 14 mg., mean hospital stay was 4.2 days (range 3 to 6) and mean return to normal activities was 14 days. At a mean followup of 10.4 months blood pressure had improved significantly in 8 patients (73%). Mean operative time in the open surgery group was 145 minutes (range 115 to 170) and mean postoperative morphine equivalent required was 44 mg. Compared to the laparoscopy group the interval to resumption of oral intake (3.5 days), duration of hospital stay (10.7 days) and return to normal activities (36 days) were prolonged in the open surgery group.

CONCLUSIONS

According to our results, bilateral laparoscopic nephrectomy could be an effective alternative for the treatment of severe hypertension after renal transplantation. Compared to open nephrectomy most patients benefit from the laparoscopic approach.

[Does preoperative corticoid administration reduce the incidence of acute rejections after kidney transplantation?]

Primary immunosuppressive therapy in renal transplantation is mediated by glucocorticosteroids with a delay of several hours. Consequence of the common practice of using first dose of steroids intraoperatively is a first contact of antigens with an unaltered immune system. In a prospective study on 111 renal transplant patients, we could show by the parameters of in vitro cytokine generation and acute rejection episodes that immunological responsiveness can be altered by early (5 h) preoperative use of glucocorticosteroids.

Preoperative application of glucocorticosteroids efficaciously reduces the primary immunological response in kidney transplantation

Early acute rejection episodes have a considerable influence on long-term prognosis of renal transplants. Therefore the aim of primary immunosuppressive therapy must be effective suppression of the immunological response following antigen recognition. Owing to their pharmacological properties, intravenously given glucocorticosteroids are suitable for the alteration of the primary immunological response. However, even after intravenous administration, glucocorticosteroids have a latency of hours prior to reaching maximum activity. In a prospective clinical study, 111 patients undergoing renal transplantation were preoperatively treated with 500 mg methylprednisolone for immunosuppressive induction. A historical group of 40 patients who had received the same dose as intraoperative bolus, was used for comparison. Postoperative immunosuppression did not substantially differ between the two groups. The incidence of acute rejections within 30 d after transplantation was a clinical parameter of the study. The mitogenic cytokine induction was measured in blood samples which were collected intraoperatively and on days 1, 2, and 5 after transplantation. Cytokine release served as an in vitro parameter for the immunological responsiveness of the transplant recipient. In the group under study, the incidence of acute rejections was 21% (23/111) and, in contrast, 43% (17/30) in the historical group (p < 0.05). 89% of the patients in the group being studied showed normal renal function after 1 yr, compared to 78% in the reference group (n.s.). Following preoperative (mean 5.09 h) administration of glucocorticosteroids, mitogenic cytokine induction (IL-1 beta, IL-2, sIL-2R and IFN-gamma) was almost completely blocked at the time of transplantation. A prospective, randomized study has just been started to evaluate the effect of preoperative administered glucocorticosteroids on the incidence of acute rejections and long-term allograft survival.

Coincidence of Epstein-Barr virus reactivation, cytomegalovirus infection, and rejection episodes in renal transplant recipients

Reactivation of the Epstein-Barr virus was reported to occur frequently under immunosuppressive therapy following organ transplantation. However, little is known about the clinical significance of these EBV reactivations. Therefore, we searched for correlations among the treatment with various immunosuppressive drugs, the incidence of CMV infections, rejection crises, and serological signs of EBV reactivation. EBV-specific antibodies were measured with novel ELISAs, utilizing the recombinant antigens p72 (for anti-EBV nuclear antigen [EBNA]1-IgG), p54, and p138 (anti-early antigen [EA]-IgM, -IgG, -IgA) in a follow-up study of 79 renal transplant recipients. Patients receiving antithymocyte globulin or antilymphocyte globulin therapy showed increasing anti-EA-IgG and -IgA more often than did patients not receiving antithymocyte globulin or antilymphocyte globulin therapy (P < 0.05). In patients receiving OKT3 antirejection therapy, anti-EA-IgM seroconversion was found more frequently (P < 0.01). A significant correlation was also found between groups of patients who had had at least one rejection episode versus patients without any sign of organ rejection, and the incidence of increasing anti-EA-IgG (P < 0.05). Since in most of these patients signs of EBV reactivation followed the appearance of the rejection episode, this may not be due to viral-induced rejection but may be caused by the reinforced immunosuppression during antirejection therapy. As opposed to patients with no signs of CMV infection and with nonsymptomatic CMV infection, patients undergoing symptomatic CMV infection showed anti-EA-IgM seroconversion (P < 0.01), increasing anti-EA-IgA (P < 0.01), and decreasing anti-EBNA-IgG (P < 0.01) more frequently. Our results confirm the role of immunosuppressive therapy in the pathogenesis of EBV reactivation. We further demonstrate a striking coincidence of EBV reactivation and symptomatic CMV infection.

Generation of high-power subpicosecond pulses at 155 nm

Subpicosecond vacuum-ultraviolet radiation at 155 nm with pulse energies above 0.2 mJ has been obtained by near-resonant four-wave difference-frequency mixing in a Xe gas jet. Laser fields for the mixing process have been generated by a short-pulse KrF dye excimer laser system and a Raman converter. The process permits tuning in a broad vacuum-ultraviolet range and can be scaled up to higher output energies.