Glomerular Diseases and Renal Transplantation: Pathogenic Pathways and Evolution of Therapeutic Interventions

Glomerular diseases and renal transplantation are the main fields of nephrology in which the immune system plays a prevalent role. Glomerular diseases have traditionally been attributed to auto-immune conditions, whereas allograft rejection has been considered an allo-immune response. However, common immunopathologic mechanisms that include Toll-like receptors, complement and B-cell activation, as well as genetic and infectious factors appear to be involved in the pathogenesis of both entities. Novel therapeutic regimens directed against specific targets of the immune system show promising results in glomerulopathies as well as in renal transplantation.

Exploring associations between anthropometric indices and graft function in patients receiving renal transplant

BACKGROUND

The aim of the present study was to identify indicators of malnutrition, as obtained by anthropometric measurements, that might be potential predictors of transplant outcomes.

METHODS

One hundred and three patients receiving a graft from a living or a deceased donor were included in this prospective study. Body mass index (BMI) based on pretransplant dry body weight, triceps skinfold, mid-arm muscle circumference and corrected mid-arm muscle area were measured. Post-transplant data on delayed graft function (DGF) and glomerular filtration rate (GFR) at discharge were collected until patient discharge.

RESULTS

Delayed graft function developed in 36.9% of the patients. BMI was the only anthropometric variable associated with a higher likelihood of DGF (odds ratio = 1.25, 95% confidence interval = 1.07-1.47) after adjusting for age, gender, donor group, donor age and years of dialysis before transplantation. Obesity was associated with a higher frequency of DGF (83.3% versus 31.1%, P = 0.001) compared to normal weight. GFR at discharge was negatively associated with BMI [β = -0.014 (0.005), P = 0.004], being overweight [β = -0.151 (0.041), P < 0.001] and obesity [β = -0.188 (0.053), P = 0.001], after adjusting for age, gender, donor group, donor age and years of dialysis, but was not associated with indices of muscle reserves.

CONCLUSIONS

The likelihood of DGF was higher among obese patients, whereas GFR at discharge was negatively associated with being overweight and obesity.

Lupus nephritis and non-Hodgkin lymphoma simultaneously diagnosed in a patient on methimazole

A 78 year old white male on methimazole due to Grave’s thyroiditis presented with acute renal failure after a short term history of progressive shortness of breath, malaise, myalgias, arthralgias, and bilateral lower limb swelling. The abdomen was remarkable for splenomegaly and lower extremities for erythema nodosum. No peripheral lymphadenopathy was detected. Serum albumin was 1.7 g/dl and very high erythrocyte sedimentation rate. Urine sediment was very active with dysmorphic red blood cells and casts and significant proteinuria (6.6 grams/day). Serum complements were abnormally low and antinuclear and anti-DNA antibodies were positive. Renal histopathology revealed membranoproliferative glomerulonephritis, along with a full house pattern on IFF consistent with lupus nephritis. Bone marrow aspiration revealed a 40% infiltration by a lymphocyte population of small cells consistent with a B cell non-Hodgkin lymphoma.

The patient was treated with methylprednisolone, cyclophosphamide and rituximab and acute dialysis. Over the following weeks the patient became dialysis independent and returned to his baseline GFR.

The value of transcranial Doppler sonography with a transorbital approach in the confirmation of cerebral circulatory arrest

OBJECTIVE

Transcranial Doppler sonography (TCD) provides accurate confirmation of cerebral circulatory arrest (CCA) in brain death (BD), but is not feasible in patients with absent temporal bone windows. We added the transorbital approach in the TCD protocol for the diagnosis of CCA and compared findings with angiography. Furthermore, we evaluated whether reporting the angiographic and sonographic confirmation of CCA to relatives of brain-dead patients improves their comprehension and satisfaction with the medical information.

PATIENTS AND METHODS

Eighty-two clinically brain-dead patients underwent 4-vessel angiography, TCD of the basilar and middle cerebral arteries, and transorbital Doppler sonography (TOD) of the internal carotid arteries. Relatives were randomly allocated to 41 in whom BD was presented as a clinical diagnosis (group A) and to 41 in whom BD was presented as a clinical diagnosis confirmed by TCD and angiography (group B). Comprehension and satisfaction of the relatives were assessed using an interview and a questionnaire.

RESULTS

Both angiography and TCD verified CCA in all cases (k = 1). In 11 patients with failure of the transtemporal approach, CCA was confirmed by the transorbital recordings. The addition of TOD enabled 15.5% more cases of CCA to be diagnosed by TCD. Group B exhibited improved comprehension and satisfaction rates (P < .05).

CONCLUSIONS

The addition of TOD increases the efficacy of TCD in confirming CCA in BD. Reporting confirmation of CCA to families of brain-dead patients may improve their comprehension and satisfaction with the provided medical information.

Urological complications: analysis and management of 1525 consecutive renal transplantations

Urological complications after renal transplantation increase morbidity, delay graft function, and occasionally lead to graft and/or patient loss. The aim of this study was to analyze the causes of and therapeutic approaches to urological complications in renal transplantation as they related to patient outcomes. A series of 1525 consecutive renal transplantations were performed over a 24-year period. Renal grafts were obtained in 814 cases from living-related and in 711 from cadaveric donors. A Lich-Gregoire ureterovesical reimplantation technique with minimal bladder wall dissection was employed in all cases. Ureteral stents were routinely used in cadaveric transplants and exceptionally among living-related grafts. Urological complications were classified according to the mechanism and site of urinary tract involvement: graft ureteropelvic junction obstruction/stenosis (A), ureteral obstruction/stenosis (B), ureterovesical anastomosis obstruction/stenosis (C), urinary leakage (D), and other (E). Overall, we encountered 96 urological complications (6.3%). Group C complications occurred in 29 cases (30.2%), followed by 27 cases (28.1%) for group B patients, 25 cases (26.0%) for group D, 12 cases (12.5%) for group A, and 3 cases (3.1%) for group E patients. Surgical intervention was required in 49 (51.0%) of all urological complications. The others (n = 47, 49.0%) were treated either conservatively or by minimally invasive procedures. A rapid diagnosis of urological complications, assisted by early posttransplant DTPA scans, routine ultrasonography, and especially prompt treatment, resulted in compensation of renal graft dysfunction in the vast majority (n = 90, 93.8%) of cases. Surgical techniques of graft retrieval and reimplantation are of utmost importance to minimize the incidence of urological complications.

EULAR points to consider for conducting clinical trials in systemic lupus erythematosus: literature based evidence for the selection of endpoints: Table 1

Objective:

To assess available evidence on the use of end-points (outcome measures) in clinical trials in systemic lupus erythematosus (SLE), as a part of the development of evidence-based recommendations for points to consider in clinical trials in SLE.

Methods:

The European League Against Rheumatism (EULAR) Task Force on SLE comprised 19 specialists, a clinical epidemiologist and a research fellow. Key questions addressing the evidence for clinical trial end-points in SLE were compiled using the Delphi technique. A systematic search of the PubMed and Cochrane Library databases was performed using McMaster/Hedges clinical query strategies and an array of relevant terms. Evidence was categorised based on sample size and type of design, and the categories of available evidence were identified for each recommendation. The strength of recommendation was assessed based on the category of available evidence and agreement on the statements was measured across the 19 specialists.

Results:

Eight questions were generated regarding end-points for clinical trials. The evidence to support each proposition was evaluated. The literature review revealed that most outcome measures used in phase 2/3 trials in SLE have not been formally validated in clinical trials, although some indirect validation has been undertaken.

Conclusion:

This systematic literature review forms the evidence base considered in the development of the EULAR recommendations for end-points in clinical trials in SLE.

EULAR points to consider for conducting clinical trials in systemic lupus erythematosus

OBJECTIVE

Systemic lupus erythematosus (SLE) is a complex multi-organ disease, characterised by relapses and remissions.

DESIGN

ng a high-quality randomised controlled trial poses many challenges. We have developed evidenced-based recommendations for points to consider in conducting clinical trials in patients with SLE.

METHODS

The EULAR Task Force on SLE comprised 19 specialists and a clinical epidemiologist. Initially, the evidence for clinical trial end-points in SLE was evaluated and this has been reported separately. A consensus approach was developed by the SLE Task Force in formulating recommendations for points to consider when conducting clinical trials in SLE.

RESULTS

The literature review revealed that most outcome measures used in phase 2/3 trials in SLE have not actually been validated in clinical trials, although other forms of validation have been undertaken. The final recommendations for points to consider for conducting clinical trials in SLE address the following areas: study design, eligibility criteria, outcome measures including adverse events, concomitant therapies for SLE and its complications.

CONCLUSIONS

Recommendations for points to consider when conducting clinical trials in SLE were developed using an evidence-based approach followed by expert consensus. The recommendations should be disseminated, implemented and then reviewed in detail and revised using an evidence-based approach in about 5 years, by which time there will be further evidence to consider from current clinical trials.

EULAR recommendations for the management of systemic lupus erythematosus. Report of a Task Force of the EULAR Standing Committee for International Clinical Studies Including Therapeutics

OBJECTIVE

Systemic lupus erythematosus (SLE) is a complex disease with variable presentations, course and prognosis. We sought to develop evidence-based recommendations addressing the major issues in the management of SLE.

METHODS

The EULAR Task Force on SLE comprised 19 specialists and a clinical epidemiologist. Key questions for the management of SLE were compiled using the Delphi technique. A systematic search of PubMed and Cochrane Library Reports was performed using McMaster/Hedges clinical queries' strategies for questions related to the diagnosis, prognosis, monitoring and treatment of SLE. For neuropsychiatric, pregnancy and antiphospholipid syndrome questions, the search was conducted using an array of relevant terms. Evidence was categorised based on sample size and type of design, and the categories of available evidence were identified for each recommendation. The strength of recommendation was assessed based on the category of available evidence, and agreement on the statements was measured across the 19 specialists.

RESULTS

Twelve questions were generated regarding the prognosis, diagnosis, monitoring and treatment of SLE, including neuropsychiatric SLE, pregnancy, the antiphospholipid syndrome and lupus nephritis. The evidence to support each proposition was evaluated and scored. After discussion and votes, the final recommendations were presented using brief statements. The average agreement among experts was 8.8 out of 10.

CONCLUSION

Recommendations for the management of SLE were developed using an evidence-based approach followed by expert consensus with high level of agreement among the experts.

Transorbital sonographic monitoring of optic nerve diameter in patients with severe brain injury

OBJECTIVE

We investigated whether alterations in the optic nerve diameter (OND) correlated with brain computed tomography (CT) imaging results among patients with brain injury and whether monitoring of OND could predict brain death.

PATIENTS AND METHODS

We enrolled 54 patients with brain injury (Glasgow Coma Scale < 8) and 53 controls. OND measurements were performed 3 mm posterior to the papillae by means of transorbital sonography. The severity of the injury was classified according to a semiquantitative CT neuroimaging scale (1 to 4). All patients underwent 3 repeated evaluations of OND combined with synchronous CT scans.

RESULTS

Twenty-two patients progressed to brain death, while 32 patients showed gradual clinical improvement. Upon admission, the patients showed significantly increased OND (4.84 +/- 1.2 mm) compared with the controls (3.49 +/- 1.1 mm; P < .001). The median intraobserver variation of OND was 0.2 mm (95% confidence intervals [CI]: 0.1-0.7). The median interobserver variation of OND was 0.3 mm (95% CI: 0.1-0.9). Alterations in the OND were significantly correlated with the neuroimaging scale on 3 repeated evaluations: r = .65, r = .70, and r = .73 (all P < .001). An OND greater than 5.9 mm (specificity = 65% and sensitivity = 74%; P < .01) and a 2.5 mm increased OND between repeated measurements (specificity = 70% and sensitivity = 81%; P < .01) were associated with a poor prognosis.

CONCLUSIONS

Alterations in OND strongly correlated with neuroimaging results among patients with brain injury. However, monitoring of OND exhibited a low predictive value for brain death.

Comparison between transcranial color Doppler ultrasonography and angiography in the confirmation of brain death

OBJECTIVE

Cerebral blood flow tests have increasingly been advocated for the confirmation of brain death (BD). Angiography has been considered the gold standard in the diagnosis of BD but is invasive. We validated transcranial color Doppler ultrasonography (TCD) to confirm BD by comparing it to angiography.

PATIENTS AND METHODS

Forty patients experienced the clinical diagnosis of brain death due to head injury in 19 cases (47.5%), cerebral hemorrhage in 11 (27.5%), subarachnoid hemorrhage in 7 (17.5%), and cerebral infarction in 3 (7.5%). Blood pressure, heart rate, SPO2, and PCO2 were monitored throughout the study. Patients were excluded if episodes of hypoxia, arrhythmia, and hypotension occurred during examinations, or if the TCD was not technically feasible.

RESULTS

Both angiography and TCD confirmed BD in all patients. The agreement between the above methods to confirm BD was 100%. Angiography showed the absence of filling of intracranial arteries, while TCD revealed: (1) brief systolic forward flow or systolic spikes and diastolic reversed flow (50%); (2) brief systolic forward flow or systolic spikes and no diastolic flow (25%); (3) no demonstrable flow in a patient in whom flow had been clearly documented on a previous TCD examination (12.5%). Five patients required repeated TCD examinations, because of initial detection of a diastolic to-and-fro flow pattern. BD was confirmed by TCD in the above patients after 30 hours of clinical BD.

CONCLUSION

TCD was a sensitive tool to diagnose BD, affording a reliable alternative examination to standard angiography.

Biopsy-related hemorrhage of renal allografts treated by percutaneous superselective segmental renal artery embolization

INTRODUCTION

Biopsy-related vascular injuries in renal transplants are rare, but they can lead to dramatic clinical symptoms prompting immediate treatment. Transcatheter embolization is a minimally invasive technique used to treat some forms of arterial bleeding. This study evaluated the efficacy of this technique in iatrogenic biopsy-related vascular lesions in renal allografts.

MATERIALS AND METHODS

Over the last eight years, six patients with severe renal hemorrhage were admitted to the angiography department of our hospital for evaluation and possible further treatment. All of them had a history of previous biopsy of a transplanted kidney. They all presented with clinical signs of hemodynamic instability. Angiographic investigation of the kidneys preceded further intervention in all cases. All underwent hyperselective embolization of the specific bleeding vessel with the use of microcoils and/or gelfoam particles.

RESULTS

Successful embolization of the feeding artery could be performed in all patients. Superselective segmental renal artery embolization had a successful outcome concerning a steady renal function and a stable clinical course. No complications occurred.

CONCLUSION

Transcatheter embolization is a safe and efficient endovascular technique to treat biopsy-related vascular injuries in renal transplants. Immediate clinical success and significant benefit in renal function can be obtained, and the longevity of the allograft after successful embolization mainly depends on the natural outcome.

Molecular epidemiology of hepatitis C virus (HCV) in Greece: temporal trends in HCV genotype-specific incidence and molecular characterization of genotype 4 isolates

This study aimed to estimate the overall HCV genotype distribution and to reconstruct the HCV genotype-specific incidence in Greece during the recent decades. It also focused at the identification of genotype 4 subtype variability in Greek isolates. A total of 1686 chronically infected HCV patients with detectable serum HCV RNA by RT-PCR, belonging to different risk groups were studied. Amplified products from the 5'-noncoding region were typed using a commercially available assay based on the reverse hybridization principle. The HCV genotype-specific incidence was estimated using a previously described back calculation method. HCV genotype 1 was the most prevalent (46.9%) followed by genotype 3 (28.1%), 4 (13.2%), 2 (6.9%) and 5 (0.4%). A high prevalence of genotype 1 (66.3%) in haemophilia patients was recorded whereas HCV genotype 3 was found mainly among patients infected by I.V. drug use (58.2%). Data on the temporal patterns of HCV genotype-specific incidence in Greece revealed a moderate increase (1.3-1.6 times) for genotypes 1 and 4, and a decrease (1.5 times) for genotype 2 from 1970 to 1990, whereas there was a sharp (13-fold) increase for genotype 3. The molecular characterization of 41 genotype 4 HCV isolates belonging to various risk groups revealed that, subtype 4a was the most frequently detected (78%). Phylogenetic comparison of the Greek 4a isolates with all HCV-4a isolates reported worldwide so far revealed a topology which does not discriminate Greek isolates from the others. HCV-4 does not represent a recent introduction in Greece.

Delayed renal graft function: the influence of immunosuppression

INTRODUCTION

We evaluated the influence of different immunosuppressive regimens on delayed renal graft function and progression of renal function in the first year after transplantation.

PATIENTS AND METHODS

Patients were divided into four groups according to the immunosuppressive regimen received: (1) rapamycin (Rap) + mycophenolate mofetil (MMF) + methylprednisolone (MP) + daclizumab (Dmab); (n = 44); (2) tacrolimus (Tac) + MMF + MP + Dmab (n = 39); (3) cyclosporine (CsA) + MMF + MP + basiliximab (Bmab); (n = 30); (4) antithymocyte globulin (ATG) + MMF + MP and CsA after ATG withdrawal (n = 40). Data were analyzed using ANOVA and linear regression. Delayed graft function was defined as the need for hemodialysis posttransplantation.

RESULTS

There were no statistically significant differences between the four groups in terms of gender, time on dialysis before transplantation, histocompatibility, donor age, and cold ischemia time. However, age (49.8, 50.4, 49.8, and 43.5 years, P < .05), panel reactive antibodies (22%, 39%, 27%, 34%, P < .05) and time of delayed graft function (12, 7, 3, 6 days, P < .05) were significantly different between the four groups. The time of delayed graft function depended on the immunosuppressive regimen, as well as donor and recipient age (P < .05). The creatinine clearance demonstrated a statistically significant difference between the four groups in the first month after transplantation (45, 46, 61, 53 mL/min, P < .05), though no further difference was observed at the month 12th.

CONCLUSIONS

The type of immunosuppressive therapy seems to substantially influence the time of recovery from delayed renal graft function, even though it does not seem to affect future graft function. Especially Rap, probably due to its potent antiproliferative effects, seems to prolong the length of graft recovery after renal transplantation.

Polyomavirus BK infection in Greek renal transplant recipients

BK polyoma virus associated nephropathy is increasingly recognized as an important cause of allograft dysfunction among renal transplant recipients. Herein we present the cases of two renal transplant recipients who developed progressive functional deterioration suspicious for BK polyoma virus involvement. One patient had been treated with mycophenolate mofetil (MMF), cyclosporine (CsA), and prednisolone (P), and the second patient with tacrolimus (Tac), MMF, and (P). Using quantitative real-time polymerase chain reactions for BK virus DNA, we monitored the content of BK virus in the blood to evaluate disease progression. The high BK virus load initially detected in the blood samples from these patients decreased in the patient who received MMF, CsA, and P after the reduction of immunosuppression, but not in the patient who was treated with Tac, MMF and P. In contrast to previous reports, our patients had not received treatment with anti-lymphocyte globulin (ALG) or monoclonal anti-CD3 antibody (OKT3) after transplantation. It is concluded that even in the absence of vigorous antirejection treatment, immunosuppressive therapy based on Tac and MMF may carry the risk of BK virus-associated nephropathy. Because BK virus specific antiviral therapy is not available, its course may be monitored by measuring the viral load in blood.

Human herpesvirus type 8 genotypes in iatrogenic, classic and AIDS-associated Kaposi's sarcoma from Greece

BACKGROUND

Kaposi's sarcoma-associated herpesvirus (KSHV)/human herpesvirus 8 (HHV-8) is consistently found in almost all observed Kaposi's sarcomas (KS), whether AIDS-associated, iatrogenic or classic. To our knowledge no data are available on the genetic polymorphism of HHV-8 from Greece. We report the study of 15 renal transplant recipients with KS, 5 with AIDS-associated KS, 11 with classic KS and 60 healthy individuals from Greece.

MATERIALS AND METHODS

Polymerase chain reaction (PCR) was carried out on DNA extracted from peripheral-blood mononuclear cells (PBMC) or KS cutaneous biopsies, using specific primers for the HHV-8, KS330 fragment from ORF-26 (233 bp) and the highly variable region (VR1) from ORF-K1 (363 bp).

RESULTS

HHV-8 DNA was detected in 30 out of 31 (97%) KS cases, regardless of their clinico-pathological subtype and in 10 out of 60 (16.7%) healthy individuals. Sequencing of the ORF26 fragment demonstrated that the 40 HHV-8 strains were of the A and C sub-types. Furthermore, sequencing of the ORF-K1 showed that these HHV-8 strains of Greek origin were of the A1, A4, C1 or C3 sub-type.

CONCLUSION

Our findings imply a possible link of the C3 subtype of HHV-8 in renal transplant-related KS cases (iatrogenic KS) in Greece, a link of the A4 subtype in AIDS-associated KS cases and a potential involvement of the A1 subtype in Greek classic KS incidences, as HHV-8 strains among healthy individual tested belong to the C1, C3 or A1 subtypes.

Study of "de novo" malignancies among greek renal transplant recipients

The incidence of malignancy was estimated in 1055 renal transplant recipients, engrafted between 1983 and 2001 including 611 grafts from living and 444 from cadaveric donors. The meoplasms were 22 skin cancers, 18 Kaposi's sarcomas, 10 lymphomas nine non-Hodgkin's and one Hodgkin's lymphoma) and 24 visceral carcinomas. Skin cancers were completely excised. Patients with Kaposi sarcoma were treated by tapering the immunosuppression with cessation of cyclosporine. In addition, four patients received chemotherapy, and one of them received local radiotherapy. All patients with lymphomas were treated by cessation of calcineurin inhibitors with modulation of the immunosuppression to levels that were safe for the graft. Furthermore, five patients underwent first line chemotherapy, two patients radiotherapy and two patients, surgical removal of the tumor. The patients with visceral tumors were treated surgically with excision of the lesions when possible, without severe modification of the immunosuppressive regimen. Chemotherapy or radiotherapy was added accordingly. Disease-related mortality rate in patients with skin cancer was 4.5%; in Kaposi's Sarcoma cases 11.11%; in lymphomas 50%; and in all the other instances, 45.8%. This study shows the increased incidence of certain malignancies in transplant recipients, illustrating the importance of cancer surveillance following kidney transplantation. A substantial reduction or even cessation of immunosuppressive therapy may be necessary to achieve patient survival.

Definition of permissible and immunogenic HLA antigens based on epitope analysis of the HLA specific antibodies produced in sensitized patients

The goal of this study was to develop an accurate protocol whereby detection of acceptable HLA-A and -B mismatches is based on epitope analysis of HLA class I specific antibodies detected in the serum of highly sensitized patients awaiting a kidney retransplant. A total of 400 serum samples from 44 highly sensitized patients with panel reactive antibodies (PRA) of > or = 60% were collected during a 3-year follow-up period. All patients had been sensitized from a previous graft. In order to define the specificities of the HLA class I specific antibodies, two techniques were used in parallel: the antihuman globulin augmented complement-dependent cytotoxicity (CDC) technique and an enzyme-linked immunoabsorbent assay (ELISA) technique. Epitope identification was based on class I HLA antigen sequencing, where the unique epitope configuration on one HLA antigen represented the private epitope of the specific HLA antigen, and epitopes shared by more than one HLA antigen represented public determinants. The epitope prediction for the immunogenic HLA epitopes was based on an MHC database. For each highly sensitized patient, antibody specificities against actual and 'at risk' epitopes were defined. Following epitope analysis, all HLA antigens that did not express the actual and/or 'at risk' immunogenic epitopes were considered as acceptable mismatches of epitope analysis. The cytotoxicity of highly sensitized patients was determined using two different panels of selected, separated T lymphocytes. HLA class I specific IgG antibodies against 69 actual and 86 'at risk' epitopes were detected. In all patients, a large number of acceptable mismatches were defined. These included a large number of HLA antigens, corresponding to both HLA-A and -B loci. Our study introduces an accurate protocol for the detection of acceptable mismatches in highly sensitized patients. According to this protocol, the detailed description of immunogenic HLA specific epitope targets, against which HLA class I specific antibodies are directed, is a useful tool for the detection of acceptable mismatches in highly sensitized patients. This may lead to reduced production of HLA class I specific antibodies and, consequently, improved graft survival.

Extragonadal seminoma after renal transplantation and immunosuppression; treatment in the presence of renal dysfunction: a case report and literature review

A 37-yr-old man who had undergone renal transplantation for end-stage renal failure presented with a large right pelvic mass obstructing the transplanted kidney. Initially, this was diagnosed as an anaplastic tumor while he had been on immunosuppressive treatment for kidney allograft rejection after transplantation. Despite difficulties of classic histopathology to reveal the origin of his tumor, FISH analysis revealed the presence of chromosome 12p abnormalities, strongly indicative of a germ-cell tumor-more likely seminoma-with extragonadal presentation. Because of renal dysfunction, he was treated with carboplatin (dose adjusted according to renal clearance) and etoposide, and when he experienced a rather atypical progression with bone metastases, he was treated with single-agent paclitaxel, and died almost 13 mo after initial presentation. The case adds further to the existing small list of seminoma/GCTs developing in transplant recipients, points to the unusual presentation patterns and diagnostic histopathology challenges, and presents the difficulty in therapeutic options, as a result of frequent renal dysfunction and intercurrent immunosuppressive therapy. All of these issues together with an extensive literature review are discussed in detail.

Prevalence and genotypic distribution of TT virus in Athens, Greece

The prevalence of TT virus (TTV) infection in various population groups from Athens, Greece, was assessed by the polymerase chain reaction (PCR) using two primer sets from distinct regions of the genome: the conventional set derived from the open reading frame-1 (ORF-1) and the new, highly sensitive set targeting the region that includes the TATA signal localized upstream of ORF-2. Based on both primer sets, TTV DNA was detected in 42/50 (84.0%) healthy individuals, 42/50 (84.0%) chronic hepatitis C patients, 31/39 (79.5%) acute non-A-E hepatitis patients (group I), 14/16 (87.5%) renal failure patients with acute non-A-E hepatitis (group II), 47/50 (94.0%) intravenous drug users (IVDU), 36/50 (72.0%) hemophiliacs, and 21/31 (67.7%) hemodialysis patients. The presence of TTV was not associated with any particular risk group, and no differences were observed in relation to demographic, biochemical and virological characteristics between TTV DNA-positive and -negative patients. TTV did not seem to have a profound effect on the course of chronic C or acute non-A-E hepatitis either. Phylogenetic analysis revealed that TTV strains circulating in the greater metropolitan area of Athens belong not only to the G1 and G2 genotypes that are encountered worldwide, but also to G3 and to G5 that are found mainly in Europe and Asia, respectively. Further studies will shed light on the role of this highly prevalent virus.

Obstructive uropathy in the transplanted kidney: definitive management with percutaneous nephrostomy and prolonged ureteral stenting

BACKGROUND AND PURPOSE

Renal transplantation is an effective treatment for end-stage renal disease. Ureteral stenosis is the most frequent urologic complication. We report our experience with percutaneous nephrostomy and antegrade ureteral stenting, which may offer a primary and definitive alternative to open surgery.

PATIENTS AND METHODS

Fifteen patients with renal allograft obstructive uropathy were managed with percutaneous nephrostomy and prolonged ureteral stenting.

RESULTS

Percutaneous nephrostomies were successfully performed in all 15 kidneys: In 13 patients, antegrade ureteral stenting was attempted, this being successful in 11 (85%). After prolonged ureteral stenting (mean duration 15 months), the stent was removed in eight patients, and six of them (75%) did not have recurrences. During follow-up, urea, creatinine, sodium, and potassium determinations and ultrasound scans were performed, and success was confirmed by the decline of creatinine and reduction in hydronephrosis. No major complication was observed.

CONCLUSION

Percutaneous nephrostomy and ureteral stenting is a safe and effective treatment for renal allograft obstructive uropathy. Prolonged ureteral stenting may offer a definitive treatment with low morbidity.

Epitope analysis of HLA class I donor specific antibodies in sensitized renal transplant recipients

OBJECTIVE

The goal of this study was to evaluate the epitope specificity of donor-specific HLA class I antibodies detected in the serum of alloimmunized from a previous renal graft patients.

METHOD

A total of 410 serum samples from 87 patients who had lost a previous graft, were collected every 4 months during a 2-year follow-up period. All recipients and donors were typed for class I HLA-antigens by a standard lymphocytotoxicity technique. To define the specificities of the HLA class I antibodies, two techniques were used in parallel: the antihuman globulin augmented CDC (AHG-CDC) technique and an ELISA technique. The mismatched HLA-antigens and the detected HLA class I antibodies were categorized as intra-cross-reactive group mismatches (intra-CREGs-MMs) and other-CREG-MMs. For each sensitized patient actual and at risk epitope specificities were defined.

RESULTS

Thirty-eight patients (43.7%) had developed IgG HLA class I-specific antibodies with stable specificities against mismatched alloantigens from the previous graft. A total of 60 antibody reactivity patterns and 82 specificities against private and public epitope were recognized. Patients with only intra-CREGs-MMs produced HLA class I-specific antibodies less frequently than patients with only other-CREG-MMs, although the difference was nearly statistically significant (P=0.053). All HLA class I donor-specific antibodies were considered to have specificities against the private epitopes of the mismatched graft HLA-antigens. In the cases where HLA class I alloreactivity was spreading to more than one donor antigens, we considered that the detected antibodies had specificities against the private and the shared between the alloantigens epitope(s). No epitope-specific antibodies were detected against shared epitopes between the mismatched alloantigens and the HLA-antigens of the patients. In 11/38 cases (28.9%) HLA class I alloreactivity spreading to non-graft antigens was detected. These antibodies were directed against HLA-antigens that share epitope(s) and have strong serological reactivity with the immunogenic alloantigens.

CONCLUSION

Our data show that a small number of private and public alloepitopes seem to be responsible for antibody production in patients sensitized from a previous graft. A detailed description of these HLA-epitopes, in the context of clinical graft complications, may lead to an improved organ allocation strategy.

A limited number of HLA epitopes are recognized from HLA class I-specific antibodies detected in the serum of sensitized patients

The goal of this study was to evaluate the epitope specificity of HLA class I-specific antibodies detected in the serum of sensitized patients awaiting retransplantation. The study group consisted of 22 sensitized from previous graft patients, who produced stable IgG HLA class I-specific antibodies. A total of 60 serum samples were screened and analyzed by two techniques in parallel: the antihuman globulin augmented CDC (AHG-CDC) technique and an ELISA technique. All recipients and donors were typed for class I HLA antigens by a standard lymphocytotoxicity technique. The epitope identification was based on class I HLA antigens sequencing, where the multiple immunogenic epitopes are differentially shared among various HLA antigens. The unique epitope configuration on one HLA antigen represents the private epitope of the specific HLA antigen while epitopes shared by more than one HLA antigen represent public determinants. In some HLA antigens (HLA-A1), more than one private epitope has been defined, while in others (HLA-B35, -B51), the private epitopes are not yet known. In a total of 36 antibody reactivity patterns, the majority of the definable IgG HLA class I-specific antibodies corresponded to the A-locus (75%), and only 25% had specificities against the B-locus antigens, although the number of incompatibilities concerning both loci were almost identical (29 for the HLA antigens of the A-locus and 26 for those of B-locus). All patients produced HLA class I-specific antibodies with specificities against the private epitopes of the immunogenic mismatched HLA antigen(s). In 6/21 cases (28.6%), HLA class I alloreactivity spreading to nongraft HLA antigens was detected and 9 public (shared) immunogenic alloepitopes were recognized. In conclusion, appling the epitope analysis of HLA class I-specific antibodies produced by sensitized from previous graft patients, we were able to define the immunogenic alloepitopes. We consider that the immunogenic alloepitopes, during transplantation course, are mainly private epitopes of mismatched HLA antigens and, in certain cases, shared epitopes between the donor alloantigens and other HLA antigens. This knowledge may offer the potential of transplanting sensitized patients through improved donor selection.

Molecular epidemiology of GB virus C/hepatitis G virus in Athens, Greece

The relevance of GB virus C/hepatitis G virus (GBV-C/HGV) infections in liver pathology remains unclear. To investigate the epidemiology of GBV-C/HGV in Athens, Greece, sera from 512 subjects were screened for present and past markers of GBV-C/HGV infection using a reverse transcription-polymerase chain reaction (RT-PCR) and a serological assay, respectively. GBV-C/HGV RNA was detected in 18/56 (32.1%), 12/42 (28.6%), and 16/55 (29.1%) patients with acute hepatitis B, C, or non-A-E, and in 5/58 (8.6%) and 18/68 (26.5%) patients with chronic hepatitis B or C, respectively, as well as in 50/133 (37.6%) hemodialysis patients and 10/100 (10%) healthy individuals. The data indicated that GBV-C/HGV seroprevalence is age-dependent; thus, GBV-C/HGV RNA and anti-E2 positivity were shown to be associated with younger age [odds ratio 0.98, 95% confidence interval (CI) 0. 97-1.00, P = 0.017] and older age (odds ratio 1.03, 95% CI 1.01-1.05, P = 0.002), respectively. No significant associations were identified between GBV-C/HGV RNA status and alanine aminotransferase (ALT) levels in either hepatitis or hemodialysis patients. Nevertheless, GBV-C/HGV RNA-positive acute non-A-E hepatitis patients were more likely to manifest a more severe clinical form of acute hepatitis (P = 0.024). Phylogenetic analysis of partial 5'-untranslated region sequences isolated from 18 viremic individuals showed that most GBV-C/HGV strains circulating in the greater metropolitan area of Athens belong to the 2a subgroup. A genetically diverse type 2 sequence that may represent a novel subtype within group 2 was also characterized.

Assignment of HLA-antigens in CREGs facilitates the detection of acceptable mismatches in highly sensitized patients

The purpose of this study was to investigate whether in highly sensitized patients (HSPs) the acceptable HLA-A and -B mismatches (AMs) can be predicted on the basis of patients' HLA-phenotype. To this affect, 1000 historical serum samples obtained from 50 HSPs (PRA > 60%), panel reactive antibodies (PRA) value and the specificity of class I anti-HLA-antibodies were detected by two techniques in parallel: An anti-human globulin augmented cytotoxicity (AHG-CDC) and an Elisa technique. Thereafter, class I HLA-antigens of the nonreactive cells in the screening panel and class I HLA-antigens of the patients were assigned to CREGs. The AMs for each one of the patients were detected using a separate cell panel, which was prepared in a way to include almost all the HLA-antigens belonging to the CREGs of the patients as well as to those of the nonreactive cells in the screening panel. It was found that the AMs in HSPs, detected with this protocol were more, compared to those we usually detect using only the HLA-antigens of the nonreactive cells in the screening panel (up to 8 versus 2-5). Both, the definitively detected AMs, and the HLA-specificities of the nonreactive cells of the screening panel belonged to the same CREGs. These CREGs were equivalent to the CREGs of class I HLA-phenotypes of each patient. The data presented in this paper introduce a new, rapid and easier way for the detection of AMs in HSPs. According to this proposed protocol, the assignment of patients' standard class I private HLA-phenotypes in CREGs, not only greatly facilitates the detection of AMs, but the detected AMs are also in fact significantly more than those determined by the conventional methodology. We have also confirmed that the majority of antibodies induced by HLA alloimmunization are directed against mismatched shared or public group epitopes CREGs. Moreover, we have confirmed that prospective matching for major CREGs would be feasible on a national level and would not significantly prolong waiting time, which could result in a significant augmentation of the potential donor pool.

The 10 years single center experience of using elderly donors for living related kidney transplantation

The use of elderly donors has been advocated to expand the organ donor pool because of increased needs and organ shortage. The aim of the study was to analyse whether old age of donors affects the outcome of renal transplantation and the long term safety of retrieval for the donors. We present data of 335 consecutive living related kidney transplants, performed in our centre the last 10 years, where in 174 patients the donor was less than 60 years of age, while in the rest 161 patients the donor was more than 60 years of age. No statistical difference was noted in either group at the incidence of irreversible acute rejections, early acute tubular necrosis, vascular complications and patient deaths. The graft survival was 86.7%, 80.4% and 78.1% for the 3rd, the 5th and the 8th year for the younger group of donors, while it was 83.6%, 78.2% and 67.8% for the older group (p = 0.13). Patient survival of the younger group was 95.9%, 94.7% and 94.7%, while for the older was 94.4%, 92.0% and 89.2% for the 3rd, the 5th, and the 8th year post transplantation (p = 0.24). Functional rehabilitation and quality of life were good in donors and recipients of both groups. These results suggest that renal transplantation from elderly donors offers comparable results from those obtained from younger donors.

The value of proliferating cell nuclear antigen (PCNA)/cyclin in the assessment of cell proliferation in glomerulonephritis

Proliferating cell nuclear antigen (PCNA)/cyclin is an acidic nuclear protein increasing from the late G1 to S phases of the cell cycle and whose detection parallels other standard methods for assessing cell proliferation. The aim of this study was to investigate PCNA expression in normal and diseased human kidneys, in order to clarify cell proliferation in renal tissue and to define a possible correlation of its expression with various types of glomerulonephritis (GN). The immunohistochemical avidin-biotin complex (ABC) method was used for the demonstration of PCNA applying the monoclonal antibody PC-10 to paraffin sections from: 10 normal kidneys, 55 renal biopsies with various types of proliferative GN (PGN), 44 renal biopsies with various types of non proliferative GN (NPGN). In PCNA-positive renal biopsies with GN the antigen showed a heterogenous nuclear expression in occasional or few mesangial and glomerular epithelial cells as well as in a greater number of tubular epithelial cells. PCNA was expressed in 20% of normal kidneys and in 38% of renal biopsies with GN. The frequency of PCNA expression was significantly increased in the cases of PGN (47%) compared to that observed in the cases of NPGN (27%) (p = 0.03). PCNA was detected in 10/24 cases of IgA nephropathy, in 3/4 cases of IgM nephropathy, in 5/14 of other types of primary PGN and in 8/13 of secondary PGN. PCNA expression was not correlated with the degree of mesangial cellularity in PGN. Moreover, there was no significant difference in PCNA expression between primary and secondary PGN. PCNA demonstrated an intense expression in the majority of epithelial cells forming cellular crescents in 8/11 cases of PGN. In conclusion, PCNA was observed more frequently in diseased than in normal kidneys. The significant increase in the frequency of PCNA intraglomerular expression in PGN suggests that PCNA has a certain value in the assessment of mesangial proliferation. Moreover, the increased PCNA expression in tubular epithelial cells especially in PGN, indicates their proliferative state and may be correlated with their proposed activation and role in the progression of renal injury.

Hepatitis E virus (HEV) infection in haemodialysis patients. The Multicentre Haemodialysis Cohort Study on Viral Hepatitis

BACKGROUND

The aim of this study was to determine the prevalence of hepatitis E virus (HEV) infection among patients undergoing haemodialysis (HD) and to evaluate whether chronic haemodialysis is associated with an increased risk of HEV infection.

METHODS

Serum samples from 420 HD patients and 316 healthy volunteers were tested for IgG and IgM antibodies to HEV (anti-HEV). Anti-HEV IgG positive sera were confirmed using synthetic peptides.

RESULTS

Anti-HEV IgG was confirmed in 27/420 (6.4%) of the HD patients and in 7/316 (2. 2%) of the reference group (P=0.07). However, multiple logistic regression analysis showed that the prevalence of anti-HEV IgG was not significantly higher in HD patients compared with the reference group, after controlling for age and sex. No patient was found positive for anti-HEV IgM. The presence of anti-HEV was associated with sex in HD patients (P=0.04). No significant association was found between anti-HEV and underlying renal disease, anti-HCV, anti-HBc, blood transfusions, history of elevated transaminases, history of clinical hepatitis and renal transplantation. A marginal association, which was observed with the duration of haemodialysis in univariate analysis (P=0.07), was not confirmed in multivariate analysis.

CONCLUSIONS

Chronic haemodialysis is not associated with an increased risk of exposure to HEV, and the high prevalence of anti-HEV IgG in HD patients reported in uncontrolled studies is possibly due to the confounding effect of age and sex.

Expression of bcl-2 oncoprotein in various types of glomerulonephritis and renal allografts

BACKGROUND

Bcl-2 oncogene was identified as a transcript associated with the t (14;18) and exhibits the unique functional role of blocking apoptosis. Apoptosis as a remodelling mechanism has been reported to embryonic and adult kidney. The aim of this study was to investigate the expression of bcl-2 protein in normal and diseased renal tissue and to define any correlation with the type of renal injury.

MATERIALS AND METHODS

Our material comprised of 10 normal adult kidneys, 31 renal allografts with acute (22) and chronic (9) rejection, and 70 renal biopsies with various types of primary (49) (31 proliferative and 18 non-proliferative) and secondary (21) glomerulonephritis. The immunohistochemical strept.ABC method was performed on paraffin sections for the detection of bcl-2 protein with a monoclonal antibody after microwave pretreatment.

RESULTS

Bcl-2 protein was detected in all the cases of normal and diseased renal tissue, showing an analogous expression. The antigen was expressed in a few parietal epithelial cells, and in the majority of distal and collecting tubular epithelial cells, but not in the glomerular capillary tuft. No difference was found in bcl-2 expression between cases of proliferative and non-proliferative glomerulonephritis as a whole, or between primary and secondary glomerulonephritis. Bcl-2 expression in acute and chronic rejection demonstrated a similar cytoarchitectural expression to the one observed in normal kidneys and glomerulonephritis. Bcl-2 was detected in podocytes near intraglomerular fibrotic lesions and in epithelial cells of early adhesions and cellular crescents, wherever observed in cases of glomerulonephritis. However, bcl-2 expression in proximal tubular epithelial cells was significantly higher in cases of proliferative glomerulonephritis than in non-proliferative glomerulonephritis (P<0.01), while bcl-2 expression in parietal epithelial cells in cases of chronic rejection was higher than in cases of acute rejection (P<0.08).

CONCLUSIONS

The absence of bcl-2 expression in normal and diseased glomeruli suggests and supports the reported notion that the mechanism of apoptosis may be available in the injured glomerulus. Moreover, bcl-2 expression in podocytes near intraglomerular fibrotic lesions and in epithelial cells of early adhesions and cellular crescents indicates the deregulation of apoptosis and its possible role in the progression of glomerular scarring. Key words: apoptosis; bcl-2 oncoprotein; glomerulonephritis; immunohistochemical; renal rejection.

Hepatitis E virus infection in individuals at high risk of transmission of non-A, non-B hepatitis and sexually transmitted diseases

The aim of the study was to determine the prevalence of hepatitis E virus (HEV) infection among individuals at high risk of transmission of non-A, non-B hepatitis or sexually transmitted diseases (STDs), and to evaluate whether they have an increased risk of exposure to HEV. Serum samples from 125 thalassemia patients, 300 intravenous drug users, 420 hemodialysis patients, 263 individuals with STDs, 47 human immunodeficiency virus (HIV) infected homosexual men, and 316 healthy volunteers were tested for immunoglobulin G (IgG) and M (IgM) antibodies to HEV (anti-HEV) by enzyme immunoassays (EIAs) following a predetermined algorithm (Abbott Labs). Anti-HEV IgG was confirmed in 3/125 (2.4%) thalassemia patients, 5/300 (1.7%) intravenous drug users, 27/420 (6.4%) hemodialysis patients, 4/263 (1.5%) STD patients, 1/47 (2.1%) homosexual men, and 7/316 (2.2%) of the reference group. No patient was found positive for anti-HEV IgM. The higher prevalence which was observed in hemodialysis group was due to the confounding effect of age, as multivariate analysis showed. The anti-HEV prevalence increased significantly with age (p = 10(-4)). No significant association was found between anti-HEV, anti-HCV, and anti-HBc. In conclusion, individuals at high risk of non-A, non-B hepatitis and STDs have no increased risk of exposure to HEV and the higher prevalence of anti-HEV IgG among older subjects may be due to an epidemic form of HEV infection which occurred some decades ago, when the sanitary conditions in our country were poor.

The frequency of hepatitis B virus infection in Greek patients with various types of glomerulonephritis

The frequency of hepatitis B surface antigen (HBsAg) was studied in the sera of 622 patients with glomerulonephritis (GN). The prevalence of HBs-antigenemia was 2.8% (18/622; eleven adults and seven children); the difference from 2.6% in the general population of Central and Southern Greece was not statistically significant (chi 2 = 0.01; p > 0.50). Two of the 11 HBsAg-seropositive adult patients with GN suffered from IgA nephropathy, one from IgA and membranous glomerulonephritis (MGN), four from diffuse proliferative GN, two from membranous GN and one each from crescentic GN and focal segmental glomerulosclerosis. Five children out of 12 with membranous glomerulonephritis, one out of 24 with IgA nephropathy and one out of 16 with focal segmental glomerulosclerosis had HBs-antigenemia. The frequency of HBs-antigenemia in children with MGN was 41.7%, which is significantly higher than in children with other types of GN (0.9%). All seropositive patients were asymptomatic HBsAg carriers, while one seropositive HBsAg child with MGN suffered from chronic persistent hepatitis. HBsAg was detected by the immunoperoxidase-antiperoxidase (PAP) method in the glomeruli of only 3 children with MGN and HBs antigenemia, while HBcAg was not detected in any case. Our study suggests that in the Greek population there is no increased prevalence of HBs-antigenemia in patients with glomerulonephritis. Moreover, HBsAg was not found to contribute in the pathogenesis of GN in adults but it may be associated with the pathogenesis of membranous GN in children.

The glomerular distribution of laminin and fibronectin in glomerulonephritis

Laminin (LAM) and fibronectin (FI) are regarded as major components of the glomerular extracellular matrix. The aim of this study was to define the distribution of LAM and FI in primary glomerulonephritis (GN) and GN of systemic lupus erythematosus (SLE) and to correlate the type of glomerular disorders with possible changes in the expression of these components. Normal portions of kidney tissue from 10 patients with renal tumors and sixty-six renal biopsies obtained from patients with GN were studied by the immunoperoxidase-antiperoxidase (PAP) method for the detection of LAM and FI. Twelve patients had membranous GN (MGN), 8 mesangiocapillary GN (MCGN), 21 mesangioproliferative GN (MPGN), including 11 cases of IgA nephropathy, 11 focal segmental glomerulosclerosis (FSGS) and 14 had SLE. In MGN, LAM was detected more intensely than FI along the glomerular basement membranes (GBM), in subepithelial GBM protrusions and in the newly-formed GBM. On the contrary, FI was intensely expressed in the mesangium. LAM and FI expression was pronounced in stages II and III of MGN. In MCGN, LAM and FI were diffusely expressed along the GBM and in the mesangium. The distribution of the two antigens in MPGN and FSGS was similar to that seen in normal glomeruli. However, the FI staining reaction was more intense in severe mesangioproliferative lesions, mainly observed in the cases of IgA-nephropathy. There were no differences in the distribution of LAM and FI between primary and SLE GN. The antigen staining pattern was pronounced in the membranous and mesangiocapillary lesions of SLE GN.(ABSTRACT TRUNCATED AT 250 WORDS)