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Nephropathic subjects with impaired immune responses show dramatically high infection rates of coronavirus disease 2019 (COVID-19). This work evaluated the ability to acquire and maintain protective antibodies over time in 26 hemodialysis patients and 21 kidney transplant recipients. The subjects were followed-up through quantitative determination of circulating SARS-CoV-2 S1/S2 IgG and neutralizing antibodies in the 6-month period after clinical and laboratory recovery. A group of 143 healthcare workers with no underlying chronic pathologies or renal diseases recovered from COVID was also evaluated. In both dialysis and transplanted patients, antibody titers reached a zenith around the 3rd month, and then a decline occurred on average between the 270th and 300th day. Immunocompromised patients who lost antibodies around the 6th month were more common than non-renal subjects, although the difference was not significant (38.5% vs. 26.6%). Considering the decay of antibody levels below the positivity threshold (15 AU/mL) as “failure”, a progressive loss of immunisation was found in the overall population starting 6 months after recovery. A longer overall antibody persistence was observed in severe forms of COVID-19 (p = 0.0183), but within each group, given the small number of patients, the difference was not significant (dialysis: p = 0.0702, transplant: p = 0.1899). These data suggest that immunocompromised renal patients recovered from COVID-19 have weakened and heterogeneous humoral responses that tend to decay over time. Despite interindividual variability, an association emerged between antibody persistence and clinical severity, similar to the subjects with preserved immune function.

Background and Aims Many studies are available that reported a higher risk of COVID-19 disease among patients on dialysis or with kidney transplantation, and the poor outcome of COVID-19 in these patients. Patients in conservative therapy for chronic kidney disease (CKD) have received lower attention, therefore little is known about how COVID-19 may affect this population. The aim of this study was to analyse the COVID-19 incidence and mortality in CKD patients followed up in an integrated healthcare program, living in a small area of Northern Italy. Method The study population included CKD patients from the Emilia-Romagna Prevention of Progressive Renal Insufficiency (PIRP) project, followed up in the 4 nephrology units (Ravenna, Forlì, Cesena and Rimini) of AUSL Romagna (Italy) and alive at 1.01.2020. All patients were in conservative therapy and none of them had initiated dialysis or received kidney transplantation. The hospital discharge database was used to identify patients hospitalized with COVID-19 up to 31.07.2020, and the mortality database was used to assess mortality among patients with COVID-19 at the same date. Multivariable logistic regression was used to identify predictors of COVID-19 disease, and Kaplan-Meier survival analysis to identify predictors of COVID-19 mortality. Excess mortality of 2020 compared to mortality in 2015-19 in the PIRP cohort was also estimated. Results COVID-19 incidence among CKD patients was 4.09% (193/4716 patients), while in the general population it was 0.46% (5,195/1,125,574). COVID-19 was more likely in CKD patients with older age (Odds Ratio=1.038), cardiovascular comorbidities (OR=2.217), COPD (OR=1.559) and less likely in patients living in the province of Ravenna (OR=0.468), that was hit later by the first wave of pandemic compared to the other areas of AUSL Romagna. Baseline eGFR was lower in CKD patients with COVID-19 (31.7 vs. 35.8 ml/min/1.73 m2), but this difference did not reach statistical significance (p=0.066). As of 31.07.2020, the crude mortality rate among CKD patients with COVID-19 was 44.6% (86/193), compared to 4.7% (215/4523) in CKD patients without COVID-19 and to 14.5% (4289/29670) in the general population with COVID-19 of the Emilia-Romagna region. Factors associated with mortality of CKD patients with COVID-19 were older age (p=0.034) and the period of COVID-19 onset (p=0.003). The highest crude mortality rate (71.4%) was found in CKD patients for whom COVID-19 onset occurred between 8 and 21 March. The excess mortality of January-July 2020 with respect to the average mortality of January-July 2015-19 in the PIRP cohort was +17.7%, corresponding to 77 excess deaths. March-April was the period with the highest excess mortality (+69.8%), while in January-February a 15.9% lower mortality was observed with respect to the corresponding months of the five previous years. Conclusion In our study, including a cohort of regularly followed up CKD patients, the risk of COVID-19 disease and of COVID-19 related mortality was comparable, or even somewhat higher, to that observed in patients on dialysis and those who received kidney transplantation. The incidence of COVID-19 in CKD patients was higher in the areas of AUSL Romagna earlier affected by the pandemic wave, whereas mortality rates were similar across all areas. CKD patients represent a population very vulnerable to COVID-19 disease, and their protection should be highly prioritized in the models of care and prevention measures.

Background/Aims: The coronavirus disease 2019 (CO­VID-19) pandemic is the major current health emergency worldwide, adding a significant burden also to the community of nephrologists for the management of their patients. Here, we analyzed the impact of COVID-19 infection in renal patients to assess the time to viral clearance, together with the production and persistence of IgG and IgM antibody response, in consideration of the altered immune capacity of this fragile population. Methods: Viral clearance and antibody kinetics were investigated in 49 renal patients recovered from COVID-19 infection: 7 of them with chronic decompensated renal failure, 31 under dialysis treatment, and 11 kidney transplant recipients. Results: The time span between the diagnosis of infection and recovery based on laboratory testing (2 negative nasopharyngeal swabs in consecutive days) was 31.7 ± 13.3 days. Three new positive cases were detected from 8 to 13 days following recovery. At the first serological determination after swab negativization, all the patients developed IgG and IgM antibodies. The semiquantitative analysis showed a progressive increase in IgG and a slow reduction in IgM. Discussion/Conclusion: In subjects with decompensated chronic kidney disease, under dialysis and in transplant recipients, viral clearance is lengthened compared to the general population. However, in spite of their common status of immunodepression, all of them were able to produce specific antibodies. These data might provide useful insights for monitoring and planning health-care activities in the weak category of patients with compromised renal function recovered from COVID-19.

Many studies reported a higher risk of COVID-19 disease among patients on dialysis or with kidney transplantation, and the poor outcome of COVID-19 in these patients. Patients in conservative management for chronic kidney disease (CKD) have received attention only recently, therefore less is known about how COVID-19 affects this population. The aim of this study was to provide evidence on COVID-19 incidence and mortality in CKD patients followed up in an integrated healthcare program and in the population living in the same catchment area. The study population included CKD patients in conservative management recruited in the Emilia-Romagna Prevention of Progressive Renal Insufficiency (PIRP) project, followed up in the 4 nephrology units (Ravenna, Forli, Cesena and Rimini) of the Romagna Local Health Authority (Italy) and alive at 1.01.2020. We estimated the incidence of COVID-19, its related mortality and the excess mortality within the PIRP cohort as of 31.07.2020. COVID-19 incidence in CKD patients was 4.09% (193/4,716 patients), while in the general population it was 0.46% (5,195/1,125,574). The crude mortality rate among CKD patients with COVID-19 was 44.6% (86/193), compared to 4.7% (215/4,523) in CKD patients without COVID-19. The excess mortality of March-April 2020 was +69.8% than the average mortality of March-April 2015-19 in the PIRP cohort. In a cohort mostly including regularly followed up CKD patients, the incidence of COVID-19 disease and COVID-19 related mortality were about ten times higher than those of the general population. The incidence of COVID-19 among CKD patients was strongly related to the spread of the infection in the community, while its lethality is associated with the underlying kidney condition and comorbidities. For this reason, it is urgent to offer a direct protection to CKD patients by prioritizing their vaccination.

Many studies reported a higher risk of COVID-19 disease among patients on dialysis or with kidney transplantation, and the poor outcome of COVID-19 in these patients. Patients in conservative management for chronic kidney disease (CKD) have received attention only recently, therefore less is known about how COVID-19 affects this population. The aim of this study was to provide evidence on COVID-19 incidence and mortality in CKD patients followed up in an integrated healthcare program and in the population living in the same catchment area. The study population included CKD patients recruited in the Emilia-Romagna Prevention of Progressive Renal Insufficiency (PIRP) project, followed up in the 4 nephrology units (Ravenna, Forlì, Cesena and Rimini) of the Romagna Local Health Authority (Italy) and alive at 1.01.2020. We estimated the incidence of COVID-19, its related mortality and the excess mortality within this PIRP cohort as of 31.07.2020. COVID-19 incidence in CKD patients was 4.09% (193/4,716 patients), while in the general population it was 0.46% (5,195/1,125,574). The crude mortality rate among CKD patients with COVID-19 was 44.6% (86/193), compared to 4.7% (215/4,523) in CKD patients without COVID-19. The excess mortality of March-April 2020 was +69.8% than the average mortality of March-April 2015–19 in the PIRP cohort. In a cohort mostly including regularly followed up CKD patients, the incidence of COVID-19 among CKD patients was strongly related to the spread of the infection in the community, while its lethality is associated with the underlying kidney condition and comorbidities. COVID-19 related mortality was about ten times higher than that of CKD patients without COVID. For this reason, it is urgent to offer a direct protection to CKD patients by prioritizing their vaccination.

From its introduction in 1943 and until the late 1970s, hemodialysis (HD) has been a lengthy and cumbersome treatment administered by a few skilled physicians and technicians to a very limited number of terminal kidney patients. The technological innovations introduced over the years made HD a treatment administered and supervised by nursing personnel to a very large numbers of kidney patients, hopefully until recovery of kidney functions or kidney transplantation. In 2013, it is estimated that 2.250.00 kidney patients were treated worldwide, and their number is steadily increasing. Shortage of transplant kidneys and quality of current treatments has contributed to increasing the survival of HD patients. Today, it is not unusual to find patients who have been on HD for longer than twenty years. All this generated the feeling that performance of membranes and dialysis technology has reached its limit. Recently, the increasing economic burden of healthcare caused by people ageing and the increasing incidence of degenerative diseases (e.g. diabetes and cardiovascular diseases), and the economic crisis has pushed many governments and health insurances to cut resources for healthcare. The main consequence is that investments in research and development in HD have been significantly reduced. The question is whether there is indeed no need for innovation in HD.In this paper, it is discussed how the paradigm of HD has changed and what possibly are now the drivers for innovation in HD. A few ideas are proposed that could be developed by adapting existing technologies to the future needs of HD.

Pretransplant donor biopsy (PTDB)-based marginal donor allocation systems to single or dual renal transplantation could increase the use of organs with Kidney Donor Profile Index (KDPI) in the highest range (e.g. >80 or >90), whose discard rate approximates 50% in the United States. To test this hypothesis, we retrospectively calculated the KDPI and analyzed the outcomes of 442 marginal kidney transplants (340 single transplants: 278 with a PTDB Remuzzi score

On all kidney waiting lists the 10% to 20% of patients who have antibodies against more than 80% of a panel of HLA antigens (panel reactive antibody [PRA] >80%) are difficult to transplant. The best solution for these patients is to find a compatible donor, ideally a full match, who yields a negative crossmatch test (CMX). If this is not possible, desensitization treatment (high-dose) intravenous immunoglobulin (IVIG) or plasmapheresis (PP) + low-dose IVIG is possible with good results in living donor kidney transplantation mainly if the antibody titer is low. It may also be offered to patients awaiting cadaveric donors too after a long waiting time; however, when applied for several months, it has the obvious disadvantage of giving the patient the risk for long-lasting immunologic weakness without the certitude of finding a kidney. In one of our recent cases of combined liver plus kidney transplantation, a positive CMX became negative 8 hours after the liver operation; the kidney was transplanted with a good result which lasted over 3 years. This observation suggested the possibility of a quick desensitization protocol in selected patients with a large (but not strong) immunization who probably are the majority. Patients sensitized to IVIG and with low titer PRA could be given a single PP + low-dose IVIG (what can be done within the time limit of cadaveric donor kidney transplantation) with good probability of turning an initial positive CMX to negative with the possibility of performing the operation and the advantage of giving the immunosuppression only when the kidney is present.

Ureteral obstruction with impaired urine flow is the most common urological complication following renal transplantation. From December 1976 to December 1997, 869 kidney grafts were performed by our kidney transplantation group, 96 from living related donors and 773 from cadaver donors (736 first grafts and 37 regrafts). A stricture of the ureter (SU) was observed in 27 cases with a follow-up ranging from 18 months to 18 years after the graft and 11 months to 11 years after the treatment of the SU. In six patients, SU was immediately apparent and limited to the anastomosis: they were obviously technical flaws. In all the other patients, there was a free interval ranging from 2 months to 11 years after surgery; the SU usually involved the entire ureter, suggesting multiple etiologies. Repeated urinary infections could be a cause but immunological problems might be more determinant. In our series, acute rejection was more common than chronic so that the correction of SU was followed in many cases by a good and long lasting result (up to 11 years). In our experience, SU was not a dangerous complication even in patients in whom for different reasons (mainly refusal of treatment) the therapy was delayed – even if anuria occurred, no case of graft loss or serious damage were observed. At the beginning of our experience, the diagnosis of SU was based on urography, and therapy has always been re-operation. For 15 years, the diagnosis of SU has been based on routine echographic surveillance, which was intensified after each rejection, and the first treatment of SU in the last 8 years was re-operation in early technical SU and interventional radiology (balloon dilatation with or without temporary stent) in other cases. When it failed or in case of recurrence, surgical correction was performed utilizing the native ipsilateral or contralateral ureter for a uretero-ureterostomy.

Ureteral obstruction with impaired urine flow is the most common urological complication following renal transplantation. From December 1976 to December 1997, 869 kidney grafts were performed by our kidney transplantation group, 96 from living related donors and 773 from cadaver donors (736 first grafts and 37 regrafts). A stricture of the ureter (SU) was observed in 27 cases with a follow-up ranging from 18 months to 18 years after the graft and 11 months to 11 years after the treatment of the SU. In six patients, SU was immediately apparent and limited to the anastomosis: they were obviously technical flaws. In all the other patients, there was a free interval ranging from 2 months to 11 years after surgery; the SU usually involved the entire ureter, suggesting multiple etiologies. Repeated urinary infections could be a cause but immunological problems might be more determinant. In our series, acute rejection was more common than chronic so that the correction of SU was followed in many cases by a good and long lasting result (up to 11 years). In our experience, SU was not a dangerous complication even in patients in whom for different reasons (mainly refusal of treatment) the therapy was delayed - even if anuria occurred, no case of graft loss or serious damage were observed. At the beginning of our experience, the diagnosis of SU was based on urography, and therapy has always been re-operation. For 15 years, the diagnosis of SU has been based on routine echographic surveillance, which was intensified after each rejection, and the first treatment of SU in the last 8 years was re-operation in early technical SU and interventional radiology (balloon dilatation with or without temporary stent) in other cases. When it failed or in case of recurrence, surgical correction was performed utilizing the native ipsilateral or contralateral ureter for a uretero-ureterostomy.

We report on a kidney transplant recipient experiencing an unexpected early acute vascular graft rejection. Retrospective analysis of patient serum samples, utilizing a new ELISA HLA screening technique, revealed that the rejection crisis and the subsequent graft loss were due to a pretransplant donor-specific pre-sensitization caused by a non-complement-fixing antibody of IgG2 class. The case illustrates the clinical significance of non-complement-fixing anti-HLA antibodies. In addition it is shown that ELISA methods are suitable for detecting potentially harmful donor pre-sensitization in waiting-list patients not detectable by standard lymphocytotoxicity techniques. Hence ELISA could be an alternative to flow cytometry for this purpose. It is concluded that screening and cross-matching techniques which detect non-complement-fixing anti-HLA antibodies could improve graft outcome, and should form part of the immunological monitoring of kidney transplant waiting-list patients.

INTRODUCTION: Delayed graft function (DGF) is a common complication in kidney transplantation. We sought to evaluate possible correlates for DGF including intraoperative parameters, focusing on fluid replacement and central venous pressure (CVP) values among patients undergoing kidney transplantation at our center. METHODS: One hundred fifty-five cadaveric donor transplantations performed at our center between 2001 and 2005 were selected for the study. We compared intraoperative parameters together with 15 other clinical and socio-demographic recipient and donor variables among patients experiencing DGF (n = 58) versus those with immediate graft function (IGF; n = 97). All significant variables at P < .05 upon univariate analysis were entered into a multivariate logistic regression model to identify risk factors for DGF. RESULTS: CVP at awakening of ≤8 mm Hg (odds ratio [OR] = 3.53; 95% confidence interval [CI], 1.63-7.63), fluid input during surgery ≤2.250 mL (OR = 2.12; 95% CI, 1.00-4.51), and recipient age ≥50 years (OR = 2.72; 95% CI, 1.11-6.68) were the strongest correlates of DGF. CONCLUSIONS: Our data suggested that reduced intraoperative perfusion as measured using CVP monitoring might increase DGF risk. This study provides the rationale to further investigate the optimal CVP target during this surgery.

Immunological evaluation by panel-reactive antibody (PRA) and determination of anti-HLA specificity are important phases in the evaluation of patients awaiting kidney transplantation. The main causes of immunization are previous solid organ transplantation, hemotransfusion, and pregnancy. It is also possible that immunogenicity can be triggered by vascularized tissue grafts. Immune induction by cryopreserved bone prostheses is not yet understood. A 19-year-old patient with osteosarcoma had undergone resection of the left proximal tibia with reconstruction using human bone in 1997. The donor HLA typing was as follows: A3, A29 (19); B44 (12), Bw4; DR13 (6), DR7, DR52, DR53. The patient was subsequently enrolled onto the waiting list for cadaveric donor kidney transplantation due to chronic kidney failure caused by cisplatin toxicity. Pretransplantation immunological screening using the complement-dependent cytotoxicity (CDC) technique revealed a PRA of 63%. IgG antibody specificities were detected against class I and class II donor antigens, specifically anti-A3, B44, DR7 antibodies, using flow cytometry (Tepnel Luminex). Further immunological studies using single HLA specificity analysis (LSA Class I degrees -II degrees , Tepnel-Luminex) showed direct antibodies against all donor antigen specificities. This case showed immune induction after the implantation of bone prosthesis in a kidney transplant candidate, underlining the importance of the availability of HLA typing data of donors of a human prosthesis.

This paper reports a 2-year experience of more than 5,000 cross-match tests for renal transplantation. Tests were performed by means of both standard light microscopy and an innovatory method based on flow cytometry, an up-to-date investigative technique for computerized analysis of individual cell characteristics. Flow cytometry allowed a better detection of weak positive reactions (false-negative cross-matches) than light microscopy, thus reducing the risk of selecting candidates with donor presensitization. Transplant clinical outcome supported the value of this original and advanced technological method.

Serum C-reactive protein (CRP) levels were measured by nephelometry in 30 healthy subjects (controls) and in 99 patients with uncomplicated terminal uremia on conservative therapy (group 1, n = 30) or chronic hemodialysis (group 2, n = 69). Whereas there was no difference between controls and group 1, both the mean concentration of CRP and the incidence of elevated levels were significantly higher in group 2 in comparison with both controls and group 1. Moreover, the degree of increase in these patients was directly correlated with the duration of hemodialysis. The abnormality, therefore, is somehow related to chronic hemodialysis per se. From a practical standpoint, we concluded that this test cannot be recommended as an acute-phase reactant in this clinical setting.

A pretransplant positive cross-match is a contraindication for kidney transplantation, unlike in liver transplantation (OLT). In combined liver kidney transplantation (LKT) it is hypothesized that liver can protect kidney from rejection. We report the case of a 35-year-old woman on renal replacement therapy with gastrointestinal tract compression due to a hematoma following spontaneous liver rupture (May 2004). She was affected by amyloidosis, treated with a bone marrow autotransplantation (2001). The liver rupture was surgically untreatable, so an LKT was proposed. Panel-reactive antibody was 80% to 100% (complement dependent cytotoxicity) with specific anti-HLA antibodies (enzyme-linked immunosorbent assay). A compatible donor was found (July 2004). The cross-match before LKT was positive for B and T cells (score 8): an emergency OLT was performed. Immediately after liver reperfusion the cross-match result was less positive (6) for T cells. After 6 hours it was negative for T and slightly positive for B cells (4): the kidney was transplanted. The immunosuppressive therapy was: alemtuzumab, steroids, and tacrolimus. Renal function immediately recovered. On day 7 a rejection episode was successfully treated by increasing steroids (intravenous bolus). At discharge hepatic and renal function were normal (creatinine 1 mg/dL). They are stable after 1 year. This case showed LKT efficacy even in complex immunological situations. Many immunological mechanisms, still not defined, are hypothesized about the protective role of the liver. This case confirmed experimental data that highlighted that in vivo in humans a cross-match can change from positive to negative after OLT giving highly sensitized patients the possibility for LKT.

Combined liver kidney transplantation (LKT) has the potential to provide a complete recovery of liver and kidney failure; the literature reports an increase in LKT in the last few years and an improvement in patient and graft survival. In our experience 15 patients underwent LKT from 1997 to 2005. The mean age was 50 +/- 9 years (range 34 to 63). The patients were affected by viral (n = 9), alcoholic (n = 1), polycystic (n = 2), cholangitis (n = 1), cholestatic (n = 1), or amyloidotic (n = 1) chronic hepatopathy. Chronic renal failure (CRF) was due to polycystic kidney disease (n = 4), IgA (n = 2), interstitial nephropathy (n = 2), glomerulonephritis (n = 4), amyloidosis (n = 1), vascular nephropathy (n = 1), of unknown end-stage renal disease (n = 1). Twelve of 15 patients were on renal dialysis treatment, three patients had moderate/severe CRF. Two patients had previously been transplanted (kidney). All patients were selected based upon blood group identity and negative cross-match before kidney transplant. Histocompatibility matching (HLA) was not included in the selection criteria. We did not observe delayed graft function. After a mean follow-up was 23 +/- 32 months (range 5 to 99), 12 subjects show, normal hepatic and renal function. At the beginning of our experience two patients in bad clinical condition died within 3 months because of sepsis, and one died because of a malignancy after 7 years. Both organs were functioning well in the deceased patients. Survival analysis confirms LKT efficacy: at 5 years follow-up patient survival is 86%, graft survival censored for death 100%. Only two subjects had an acute rejection episode in the first year; the kidney rejection incidence was lower than that reported for an isolated kidney transplant (13% vs 21%).

URETERAL obstruction with impaired urine flow is the most common urologic complication following kidney transplantation (KT): some authors report a certain amount of graft loss and operative mortality. Ureteral stenosis (US) may appear days or years after KT with an incidence ranging from 2% to 7%. Because the renal graft is denervated, the evolution of a stricture is usually asymptomatic until graft failure sets in. Aware of this fact and of its frequency, today all recipients are submitted to ultrasonographic and clinical monitoring. Moreover, US deserves some attention because it can frequently be corrected with a long-lasting success rate and because the therapy of this condition has changed in the last few years; the recent advances in percutaneous radiologic maneuvers have significantly replaced surgical revision of the implant. The aim of this paper was to evaluate today’s indication for surgery and interventional radiology in correcting the US after KT.

Three hundred sixty-five patients who underwent cadaver donor kidney transplantation between 1993 and 1998 were divided into four groups: 40 immunized patients with at least one peak panel-reactive antibody (PRA) value more than 50 %, 11 hyperimmunized patients with more than three peak PRA values over 50 %, 10 retransplanted patients and 304 control patients. Before transplantation, we ascertained the antibody specificities against individual HLA antigens (Prastat Sangstat ELISA method for HLA typing of first donor, husbands of multiparous women and potential donors against whom candidates gave positive cross-matches); thus, patients underwent transplantation excluding the presence of the HLA antigens previously detected and looking for high HLA (class I and II) compatibility. Actuarial graft survival after 12 months was satisfactory in all groups: 87 % immunized, 81 % hyperimmunized and 80 % retransplanted vs 92 % controls. Renal function at the end of the first year was similar and the number of rejection episodes in the first 3 months did not significantly differ.

Introduction: this prospective study defines the immune response to fresh arterial homograft replacement for graft infection. Materials and methods: ten patients who underwent ABO-compatible homograft transplantation were studied for anti-HLA antibody production, and CD3–CD4–CD8-positive lymphocytes subset. Immunological studies were performed preoperatively, and at early (1, 3, 7 days) and late (1, 3, 6, 12, 18, 24 months) follow-up. All patients received immunosuppressive treatment with cyclosporine (1–3 mg/kg/day). Abdominal CT scans were performed postoperatively at the 1, 6, 12, 18, 24 months follow-up. Results: preoperatively, antibodies could not be detected. Postoperatively, as from 1st month post-transplant, a progressive increase in % PRA was observed in all patients, up to the 12th month of follow-up. Subsequently, at 18 and 36 months, a progressive decrease in % PRA was detected. Data showed that the recipient antibodies were directed against donor-specific antigens. During the immediate postoperative period (1, 3, 7 days) CD3- and CD4-positive T lymphocytes slightly increased, whereas CD8 simultaneously decreased. Later, CD3 and CD4 progressively decreased and CD8 increased. Clinically, all patients were cured of infection at late follow-up. CT scans showed thickening of the aortic wall (range: 2.5–4.5 mm), with no signs of aneurysmal degeneration. Conclusions: fresh arterial homografts are immunogenic. Implanted homografts induce a strong anti-HLA antibody response, similar to chronic rejection, in spite of immunosuppressive treatment.

The solute removal characteristics and haemocompatibility of low-flux dialysers containing Cuprophan, cellulose acetate, polymethylmethacrylate (PMMA), and polycarbonate-polyether (Gambrane) membranes were compared in a multicentre cross-over clinical trial. While all four dialysers provided comparable removal of urea and creatinine, the dialyser containing PMMA membrane showed a reduced ability to remove phosphate compared to that containing Cuprophan membrane. Significant beta 2-microglobulin removal was obtained with the dialyser containing Gambrane membrane, whereas the other three dialysers had no impact on plasma beta 2-microglobulin concentrations. The ability to activate complement, measured as changes in the plasma concentrations of C3a des Arg and the terminal complement complex, and to produce leukopenia was greater for the dialyser containing Cuprophan membrane than for the other three. The ability to activate complement and cause leukopenia was not consistent among the remaining three dialysers and the degree of leukopenia could not be predicted from the level of complement activation. Neutrophil degranulation, as indicated by the release of elastase-alpha 1-proteinase inhibitor, occurred to a greater extent with the dialysers containing Cuprophan and Gambrane membranes. None of the dialysers was overtly thrombogenic as judged by changes in platelet count and plasma concentrations of the thrombin-antithrombin III complex. Our results demonstrate that although there are many similarities between dialysers containing low-flux membranes, there are also significant differences. These differences may enable improvements in therapy, while allowing continued use of low-flux dialysers.

Patient presensitization represents a considerable problem in candidacy for renal transplantation. While it is well known that hyperimmunized patients-panel reactive antibody (PRA) higher than 60% — create difficulties in donor matching and have a worse outcome than non-hyperimmunized patients, less information is available on patients with an intermediate degree of sensitization (30–60%). In order to evaluate how graft outcome relates to such degrees of sensitization, 241 consecutive transplanted patients were divided into two groups on the basis of their previous year’s PRA peak: group A, PRA 0–29%; group B, PRA 30–60%. Group A showed a significantly better survival both in the first year (90% vs 79%, P

Flow cytometry (FC) may be considered as a fundamental technique in studying cell biology and pathology. It combines the quantitative character of biochemical methods with the multiparametric capacities of microscope analysis in a high-precision process for rapid analysis of individual cell characteristics. Three original FC techniques routinely applied in the field of renal transplantation are reported in the present study. They concern the donor—recipient cross-match test, the morphological analysis of urinary sediment and the modulation of the density of various membrane antigens on the lymphocyte surface. A common factor underlies all these methods: they aim to provide the physician with a reliable diagnostic tool in clinical renal transplantation.

The value of exfoliative urinary cytology for the diagnosis of different pathological conditions in renal transplantation is widely recognized. The method, however, has not yet gained full acceptance, mainly because identification of the different cells is not always possible by means of standard staining techniques. In view of its characteristics, flow cytometry (FC) seems to represent a consistently reliable, rapid and innovative approach for differentiating the various cells present in the urinary sediment and assessing their number. This study gives the examination result of 223 urinary specimens from 127 transplanted patients selected according to pathology. Sediment cells, collected from fresh urine samples, were washed, treated with a lysing solution, resuspended in saline solution and directly analysed in a FACSCAN cy-tometer. Morphological evaluation showed: a small number of cells in patients with stable renal function; a larger number of cells, with predominance of lymphocytes, during acute rejection episodes; an absolute predominance of neutrophils during bacterial infection; large-sized cellular debris in cases of post-transplant tubular necrosis; and small cell debris in cases of cyclosporine cytotoxicity. Lymphocyte surface-marker evaluation made it possible to differentiate lymphocyte populations observed during acute rejection episodes (cytotoxic T-cell, CD8 and HLA class II and NK cells) from those detected during bacterial infection (T-cell CD4 positive). These results suggest that urinary FC may be a reliable diagnostic tool in clinical renal transplantation.

Because of increasing incidence of diabetes and longer survival of most patients a growing number of diabetics are today affected by end stage of renal failure (ESRF) and diabetes will become in the 90s the single most frequent cause of nephropathy leading to dialysis or renal transplantation in the Western world ([1]). The impact of this problem in terms of clinical and socio-economic implications is therefore becoming more and more huge ([2]).

The pathogenesis of the renal artery stenosis in renal transplantation is not yet completely clear. A possible role may be played by the impaired progression of the sphigmic wave and of the blood pulse at the point of the vascular anastomosis, caused by an anastomosis between two artery segments with different straining characteristics (1).

With the recovery of the excretory and endocrine renal functions after successful Renal Transplantation (RT), renal bone disease also tends to disappear. Nonetheless, several new biochemical changes to the calcium-phosphorus metabolism (e.g. hypercalcemia, hypophosphatemia) may appear while bone histology may remain altered or show new lesions. Apart from scattered reports in the literature, the new bone remodelling that invariably occurs after RT has not been sufficiently investigated, above all as a possible source of overt clinical bone disease.

The number and the in vitro and in vivo affinity of digitalis receptors for digoxin were measured in patients with normal renal function and in uraemics. In uraemic patients the number of receptors was decreased. Although their in vitro affinity for digoxin was unchanged the in vivo affinity was decreased, probably due to hyperkalaemia. These findings provide a possible pharmacodynamic explanation for decreased activity of cardiac glycosides in chronic renal failure.