Histology for nephrology, from pre-implantation to post-transplant kidney biopsy. Lesson learned from ReBIrth (Renal BIopsy for Kidney Transplantation Therapy)

A meeting entitled Renal BIopsy for Kidney Transplantation Therapy (ReBIrth) took place on May 31st, 2022 in Bologna, Italy. The meeting drew together nephrologists, surgeons, and pathologists and recognized as experts in the field of kidney transplantation in Italy. In this paper, we present our experience working with kidney transplants in the current era of immunosuppression therapy. The primary aim is to report the histopathological characteristics of failed kidney allografts after a consensus of experts reviewed the cases on a wholeslide imaging digital platform. Regardless of the cases discussed, digital pathology was reliable in identifying all the morphological and immunohistochemical features required to improve the correct use of immunosuppressive therapy to prevent graft failure and optimize patient management.

BNT162b2 Elicited an Efficient Cell-Mediated Response against SARS-CoV-2 in Kidney Transplant Recipients and Common Variable Immunodeficiency Patients

SARS-CoV-2 vaccination is the standard of care for the prevention of COVID-19 disease. Although vaccination triggers both humoral and cellular immune response, COVID-19 vaccination efficacy is currently evaluated by measuring antibodies only, whereas adaptative cellular immunity is unexplored. Our aim is to test humoral and cell-mediated response after three doses of BNT162b vaccine in two cohorts of fragile patients: Common Variable Immunodeficiency (CVID) patients and Kidney Transplant Recipients (KTR) patients compared to healthy donors. We enrolled 10 healthy controls (HCs), 19 CVID patients and 17 KTR patients. HC BNT162b third dose had successfully mounted humoral immune response. A positive correlation between Anti-Spike Trimeric IgG concentration and neutralizing antibody titer was also observed. CVID and KTR groups showed a lower humoral immune response compared to HCs. IFN-γ release induced by epitopes of the Spike protein in stimulated CD4+ and CD8+ T cells was similar among vaccinated HC, CVID and KTR. Patients vaccinated and infected showed a more efficient humoral and cell-mediated response compared to only vaccinated patients. In conclusion, CVID and KTR patients had an efficient cell-mediated but not humoral response to SARS-CoV-2 vaccine, suggesting that the evaluation of T cell responses could be a more sensitive marker of immunization in these subjects.

Risk of end-stage kidney disease in kidney transplant recipients versus patients with native chronic kidney disease: multicentre unmatched and propensity-score matched analyses

BACKGROUND

In kidney transplant recipients (KTR), the end-stage kidney disease (ESKD) risk dependent on the risk factors acting in native chronic kidney disease (CKD) remains undefined.

METHODS

We compared risk and determinants of ESKD between 757 adult KTR and 1940 patients with native CKD before and after propensity-score (PS) analysis matched for unmodifiable risk factors [(age, sex, diabetes, cardiovascular disease and estimated glomerular filtration rate (eGFR)].

RESULTS

In unmatched cohorts, eGFR was lower in CKD versus KTR (45.9 ± 11.3 versus 59.2 ± 13.4 mL/min/1.73 m2, P < 0.001). During a median follow-up of 5.4 years, the unadjusted cumulative incidence of ESKD was consistently lower in unmatched KTR versus CKD. Conversely, in PS-matched analysis, the risk of ESKD in KTR was 78% lower versus CKD at 1 year of follow-up while progressively increased over time resulting similar to that of native CKD patients after 5 years and 2.3-fold higher than that observed in CKD at 10 years. R2 analysis in unmatched patients showed that the proportion of the outcome variance explained by traditional ESKD determinants was smaller in KTR versus native CKD (31% versus 70%). After PS matching, the risk of ESKD [hazard ratio (HR), 95% confidence interval (95% CI)] was significantly associated with systolic blood pressure (1.02, 1.01-1.02), phosphorus (1.31, 1.05-1.64), 24-h proteinuria (1.11, 1.05-1.17) and haemoglobin (0.85, 0.78-0.93) irrespective of KTR status. Similar data were obtained after matching also for modifiable risk factors.

CONCLUSIONS

In KTR, when compared with matched native CKD patients, the risk of ESKD is lower in the first 5 years and higher later on. Traditional determinants of ESKD account for one-third of the variability of time-to-graft failure.

mTOR Inhibitor Use Is Associated With a Favorable Outcome of COVID-19 in Patients of Kidney Transplant: Results of a Retrospective Study

Introduction

In solid organ transplant recipients, COVID-19 is associated with a poor prognosis because of immunosuppression. Some studies suggest a potential therapeutic role of mammalian Target of Rapamycin (mTOR) inhibitors in SARS-CoV-2 infection. This study aimed to assess the impact of mTOR employment on the evolution and outcome of SARS-CoV-2 infection in solid organ transplant recipients.

Methods

We enrolled kidney transplant patients attending the Azienda Ospedaliera Universitaria Federico II in Naples and followed up on these patients from March 2020 to June 2021. We evaluated the risk of acquiring the SARS-CoV-2 infection, the clinical presentation of the disease, and its outcome together with the type of immunosuppressive therapy. Finally, we assessed the impact of mTOR inhibitors on relevant clinical metrics of SARS-CoV-2 infection.

Results

We enrolled 371 patients, of whom 56 (15.1%) contracted SARS-CoV-2 infection during the period of the study. There were no differences observed among the different immunosuppressive therapies concerning the risk of acquiring SARS-CoV-2 infection. In contrast, the type of immunosuppressive therapy had a significant impact on the outcome of the disease. In detail, patients who received mTOR inhibitors, as part of their immunosuppressive therapy, compared to other regimens had a lower chance of developing a moderate or severe form of the disease (OR = 0.8, 95, CI: (0.21-0.92), P = 0.041).

Conclusion

In kidney transplant patients, the use of mTOR inhibitors as part of an immunosuppressive regimen is associated with a better prognosis in the case of COVID-19.

SARS-CoV-2 in Kidney Transplant Patients: A Real-Life Experience

Background

The COVID-19 pandemic has significantly impacted the management of solid organ transplant recipients and on clinical evolution in post-transplantation. Little is known on the impact of SARS-CoV-2 infection in these patients. The severity and lethality of this disease in solid organ transplant patients are higher thanin the general population. This study aims to describe clinical characteristics of SARS-CoV-2 infection in solid organ transplant recipients followed in our center.

Methods

In this observational study, we enrolled all kidney transplant recipientsattending the A.O.U. Federico II of Naples from March 2020 to January 2021. For each patient we evaluated the epidemiological and clinical characteristics as well as outcome.

Results

We enrolled 369 kidney transplant patients (229, male, 62%). Of these, 51 (13.8%) acquired SARS-CoV-2 infection and 29 showed symptomatic disease. Of the 51 patients with the infection, 48 (94.11%) had at least one comorbidity and such comorbidities did not constitute a risk factor for a more severe disease. Hospitalization was necessary for 7 (13.7%) patients. Of these, 2 required low-flow oxygen supplementation, 3 non-invasive/high flow ventilation and 2 invasive ventilation. Finally, 2 patients died.

Conclusions

Our study shows a lower mortality and hospitalization rate compared to figures available in the literature (4% vs. 13–30% and 14% vs. 32–100%, respectively). Furthermore, the comorbidities examined (hypertension, dyslipidemia, and diabetes) did not constitute a risk factor for a more severe disease condition in this patient category. Further studies with larger sample size are necessary to confirm these data.

Effects of Sugammadex Plus Rocuronium vs Neostigmine Plus Cisatracurium During Renal Transplantation on Graft Function: A Retrospective, Case-Control Study

BACKGROUND

Rocuronium can be used in patients with severe renal failure (creatinine clearance <30 mL/min), but the duration of muscle relaxation is longer and results in an increased risk of postoperative residual neuromuscular block. Rocuronium can be antagonized by sugammadex, but the elimination of the complex they make (rocuronium-sugammadex complex) varies according to the renal function. Two case reports/series have reported the use of rocuronium-sugammadex complex during renal transplantation. A recently published retrospective study showed no differences in postoperative creatinine levels in patients receiving kidney transplantation. This retrospective case-control study aims to investigate the effects of rocuronium-sugammadex, used during renal transplantation, on transplanted kidney function.

METHODS

We analyzed 113 medical records of patients undergoing kidney transplantation from January 2015 to December 2018. Forty-seven medical records were excluded because they did not report the administration of one of the following drugs during the transplantation: rocuronium, sugammadex, cisatracurium, neostigmine. The demographics of patients and donors were collected along with the following data: blood urea and creatinine, serum and urinary electrolytes, and diuresis. Marginal, single, or double kidney transplantations; Karpinski scores; and histologic evaluations of transplanted kidney were collected.

RESULTS

We included data from 66 medical reports from January 2015 to December 2018. Blood creatinine levels at 6, 12, and 24 hours were significantly lower in the rocuronium + sugammadex group than in the cisatracurium + neostigmine group (creatinine 6 hours P = .05, creatinine 12 hours P = .038, creatinine 24 hours P = .049). Blood urea levels for 24 hours after transplantation were significantly lower in the rocuronium + sugammadex group than in the cisatracurium + neostigmine group (urea 0 hours P = .025, urea 6 hours P = .011, urea 12 hours P = .03, urea 24 hours P = .011). We found no statistically significant differences in blood sodium, blood potassium, blood calcium, diuresis, urinary sodium, or urinary potassium levels before and after transplantation.

CONCLUSIONS

In this retrospective case-control study, the use of rocuronium and sugammadex during renal transplant surgery did not affect relevant kidney recovery outcomes in the first week after transplantation.

Impact of Kidney Transplantation on Male Sexual Function: Results from a Ten-Year Retrospective Study

BACKGROUND

The effects of kidney transplantation on male sexual function are controversial.

AIM

To evaluate the impact of kidney transplantation on erectile and ejaculatory function and to assess a possible correlation between some selected characteristics of patients and their erectile and ejaculatory function after renal transplantation.

METHODS

An observational retrospective analysis was conducted on male patients who had undergone kidney transplantation from January 2009 to April 2019. A prospectively maintained database was used to collect all data. Patients were evaluated before kidney transplant and 6 and 12 months after kidney transplant. Male patients undergoing renal transplantation for any cause who were sexually active with a stable partner were included in the study.

OUTCOMES

The main outcome measures included the International Index of Erectile Function (IIEF-15) and the 4-item version of Male Sexual Health Quality-Ejaculation Disorders (MSHQ-EjD Short Form) questionnaires. The first 3 questions of the MSHQ-EjD Short Form were used to assess the ejaculatory function, whereas the fourth question was used to evaluate the ejaculation bother.

RESULTS

A total of 95 patients were eligible in the study. The evaluation of sexual function was available in 56 patients (58.9%). Mean IIEF-15 significantly decreased at 6 months (P < .001) remaining unchanged at 12 months (P = .228). Mean MSHQ-EjD Short Form (1-3) significantly decreased at 6-month follow-up (P < .001) and at 12-month follow-up (P = .024). Mean MSHQ-EjD Short Form (4) was significantly increased compared with the baseline at both 6 and 12 months (P < .05). IIEF-15 was significantly related to the MSHQ-EjD Short Form at 6-month and 12-month follow-up (P < .001). Age, diabetes, hypertension, smoking, pretransplantation testosterone, time for transplantation, baseline IIEF-15, and baseline MSHQ-EjD Short Form (1-3) were significantly associated (P < .05) with both IIEF-15 and the MSHQ-EjD Short Form (1-3) at 6-month and 12-month follow-up after kidney transplantation.

CLINICAL IMPLICATIONS

Improvement of knowledge regarding the effects of kidney transplantation on sexual function and about the patient characteristics related to sexual health after transplantation.

STRENGTH & LIMITATIONS

This is the first article that analyzes in depth the ejaculatory function in patients who had undergone kidney transplantation assessing ejaculation with a validated questionnaire. The main limitation is the retrospective design of the study.

CONCLUSION

Kidney transplantation appears to have a negative impact on sexual health, significantly worsening both erectile and ejaculatory functions. Age, diabetes, hypertension, smoking, pretransplantation testosterone levels, time for transplantation, as well as erectile and ejaculatory function before transplant were significantly related to erectile and ejaculatory functions after renal transplantation. Spirito L, Manfredi C, Carrano R, et al. Impact of Kidney Transplantation on Male Sexual Function: Results from a Ten-Year Retrospective Study. J Sex Med 2020;17:2191-2197.

Gastroenterological complications in kidney transplant patients

Kidney transplantation is the surgical operation by which one of the two original kidneys is replaced with another healthy one donated by a compatible individual. In most cases, donors are recently deceased. There is the possibility of withdrawing a kidney from a consenting living subject. Usually, living donors are direct family members, but they could be volunteers completely unrelated to the recipient. A much-feared complication in case of kidney transplantation is the appearance of infections. These tend to arise due to immune-suppressor drugs administered as anti-rejection therapy. In this review, we describe the gastrointestinal complications that can occur in subjects undergoing renal transplantation associated with secondary pathogenic microorganisms or due to mechanical injury during surgery or to metabolic or organic toxicity correlated to anti-rejection therapy. Some of these complications may compromise the quality of life or pose a significant risk of mortality; fortunately, many of them can be prevented and treated without the stopping the immunosuppression, thus avoiding the patient being exposed to the risk of rejection episodes.

Sublingual administration improves systemic exposure of tacrolimus in kidney transplant recipients: comparison with oral administration

BACKGROUND

Tacrolimus (TCR) is an immunosuppressive drug used by oral administration. Intravenous (IV) TCR administration is required under conditions of gastrointestinal diseases or abdominal surgery at the onset of paralytic ileus. The infusion formulation needs a large dilution and therefore a careful technical management during continuous infusion by 24 h and may determine anaphylaxis, cardiac arrhythmia, QT prolongation and torsades de pointes. Sublingual (SL) TCR administration was suggested as an alternative route.

DESIGN

The aim of this study was to compare in the same kidney transplanted patients the TCR pharmacokinetic profiles by both the routes coupled with the pharmacoeconomic analysis. The study enrolled eight subjects undergoing renal transplantation and treated with TCR and methylprednisolone. TCR was administered by oral route at the scheduled dosage while the 50% of oral dosage was used by SL route, taking into account the absence of liver first pass.

RESULTS

Except for AUC, which resulted significantly increased after oral administration, all exposure parameters were not significantly different between the two routes of administration. Analysis of dose-adjusted exposure parameters showed significant increases in AUC and Cmin after SL administration confirming a better bioavailability of the SL route compared with oral route. Cost saving was obtained using the SL rather than the IV route of TCR delivery.

CONCLUSION

When oral administration of TCR is not advised, SL delivery represents an attractive option to IV administration.

Complicated diverticulitis in kidney transplanted patients: analysis of 717 cases

INTRODUCTION

This study aims to investigate possible risk factors for diverticulitis in kidney transplant recipients affected by colonic diverticulosis.

METHODS AND RESULTS

We investigated 717 patients transplanted between 2000 and 2010. Diverticular disease was endoscopically diagnosed in 17 of 717 examined patients. Eight patients were diagnosed with autosomal dominant polycystic kidney disease (ADPKD); 9 of 17 patients underwent emergency surgery. We performed Hartmann's procedure on all patients, with a second stage performed at least 6 months later.

DISCUSSION

Although the incidence of colonic diverticular perforation in kidney transplanted patients is similar to that observed in the general population, perforation in immunosuppressed patients is associated with a higher morbidity/mortality rate. In our study, the incidence of perforation is 1.25% (9 of 717), with almost half of the cases observed in patients with ADPKD (4 of 9). Such an observation is consistent with published data, in which patients with ADPKD are reported to more frequently develop colonic diverticulosis and its complications. One possible explanation might be related to a belated diagnosis of diverticulitis, which could initially simulate an inflammatory disease as a consequence of renal cysts. Also, steroids seem to be a predisposing factor for colonic perforation in these patients.

CONCLUSIONS

A timely surgery can significantly reduce mortality. In cases of elective surgery, mortality and morbidity are similar to those of immunocompetent patients; accordingly, this is the goal to be pursued. Early signs and symptoms are often masked by immunosuppressive therapy. In these patients, surgeons should always perform (1) abdominal computed tomography scanning and, in the presence of diverticulitis, reduce or withdraw immunosuppressive therapy; and (2) early surgery, with Hartmann's procedure being, in our opinion, the best choice. Before transplantation, elective surgery for colonic resection should be considered in patients with ADPKD or with a history of 1 or more episodes of acute diverticulitis who then regressed with medical therapy.

[Lipocalin and kidney transplant]

INTRODUCTION

Kidney transplantation is frequently complicated by delayed graft function (DGF). DGF is associated with more frequent rejection episodes, increased need of post-transplantation biopsies, dialysis sessions and prolonged hospitalization. These complications may have negative impact on long-term survival of transplanted kidney.Urinary neutrophil gelatinase-associated lipocalin (uNGAL) is regarded as acute kidney injury marker.This preliminary study aimed at evaluating whether uNGAL may be early predictor of DGF in kidney transplanted patients.

SUBJECTS AND METHODS

Urine samples were collected from renal transplant recipients on day 1 post-transplantation to determine 24/h urinary NGAL and creatinine excretion. On same day, routine blood chemistry was assessed.

RESULTS

N. 20 renal transplant recipients were evaluated. DGF was observed in n. 6 patients (DGF-patients). In DGF-patients compared to NO-DGF-patients, mean age was higher (586 Vs 5111, p=0.001), while 24/h urine output (5735 Vs 4150 2230 ml/24h; p=0.001) and urinary creatinine excretion (191184 Vs 683660 mg/24h; p=0.001) were lower. No difference was found between DGF- and NO-DGF-patients in 24/h urinary NGAL excretion (1,202,20 Vs 2,444,0 mg/24h; p<0.20). In univariate analysis, DGF was inversely associated to 24/h urine output (r2=-0.795, p=0.001) and urinary creatinine excretion (r2=-0.480, p=0.037) and positively to age (r2=0.446, p=0.049). In multivariate analysis 24/h urine output (p=0.014) and 24/h urinary creatinine excretion (p=0.039) were associated to DGF.

CONCLUSION

This preliminary study suggests that 24/h urinary NGAL excretion, measured 1 day after kidney transplantation, is not a reliable predictor of DGF. Larger study with longer observation period is mandatory.

Efficacy of subcutaneous epoetin-zeta on anemia in renal transplant recipients: a single-center experience

BACKGROUND

Persistent or "de novo" anemia (plasma hemoglobin<11 g/dL) may complicate the graft outcome in a significant number of renal transplant recipients. We describe a single-center experience with epoetin-zeta (EPO-Z), the biosimilar form for epoetin-alfa.

METHODS

Twenty patients were included in the study, 10 in treatment with different erythropoiesis-stimulating agents (ESA) and shifted to EPO-Z (shift group) and 10 who started EPO-Z treatment for anemia (naive group). All the patients had stable renal function and normal values of main inflammation markers and were prospectively followed up for 12 months. Iron supplements were administered during the study, as needed.

RESULTS

In the shift group, mean plasma hemoglobin levels>11 g/dL were maintained for the entire 1-year follow-up period, with average EPO-Z doses 3.4% higher than the corresponding doses of previous ESA; in the naive group, the target value was reached between the first and third months and remained stable throughout the study. Mean corpuscular volume did not vary in either group. No change was observed in glomerular filtration rate, nor in proteinuria or in main laboratory data. No drug-related side effect was reported.

CONCLUSIONS

EPO-Z may be considered a valid alternative to different ESAs in renal transplant recipients, with an interesting pharmaco-economic profile, considering its lower cost.

Efficacy of a reduced pill burden on therapeutic adherence to calcineurin inhibitors in renal transplant recipients: an observational study

PURPOSE

The aim of this study was to determine the prevalence of nonadherence in a cohort of renal transplant recipients (RTRs) and to evaluate prospectively whether more intense clinical surveillance and reduced pill number enhanced adherence.

PATIENTS AND METHODS

The study was carried out in 310 stable RTRs in whom adherence, life satisfaction, and transplant care were evaluated by specific questionnaires (time 0). The patients under tacrolimus (TAC; bis in die [BID]) were then shifted to once-daily TAC (D-TAC) to reduce their pill burden (Shift group) and were followed up for 6 months to reevaluate the same parameters. Patients on cyclosporin or still on BID-TAC constituted a time-control group.

RESULTS

The prevalence of nonadherence was 23.5% and was associated with previous rejection episodes (P<0.002), and was inversely related to Life Satisfaction Index, anxiety, and low glomerular filtration rate (minimum P<0.03). Nonadherent patients were significantly less satisfied with their medical care and their relationships with the medical staff. A shift from BID-TAC to D-TAC was performed in 121 patients, and the questionnaires were repeated after 3 and 6 months. In the Shift group, a reduction in pill number was observed (P<0.01), associated with improved adherence after 3 and 6 months (+36%, P<0.05 versus basal), with no change in controls. Decreased TAC trough levels after 3 and 6 months (-9%), despite a slight increase in drug dosage (+6.5%), were observed in the Shift group, with no clinical side effects.

CONCLUSION

The reduced pill burden improves patients' compliance to calcineurin-inhibitors, but major efforts in preventing nonadherence are needed.

Absence of pharmacokinetic interference of moxifloxacin on cyclosporine and tacrolimus in kidney transplant recipients

This study investigates the potential pharmacokinetic interactions between an antimicrobial agent, moxifloxacin, and 2 immunosuppressant drugs, cyclosporine and tacrolimus, in kidney transplant recipients. Twenty-two kidney transplant patients needing antibiotic therapy for urinary tract infections are enrolled. Eleven patients are under cyclosporine treatment and the other 11 patients are under tacrolimus treatment. Because the urinary tract infections are caused by gram-negative aerobes sensitive to moxifloxacin, this antibiotic is administered by oral route at a dose of 400 mg/d for 1 week; in each patient pharmacokinetic studies are carried out before and at the seventh day of therapy. For both immunosuppressors, none of the pharmacokinetic parameters investigated show statistically significant differences between values obtained before and during treatment with moxifloxacin. In fact, the concentration-time profiles of monoclonal cyclosporine, polyclonal cyclosporine, and tacrolimus are not significantly different before and during the antimicrobial therapy. The results of the present study rule out interference of moxifloxacin with both cyclosporine and tacrolimus kinetics and indicate that the concomitant administration of the fluoroquinolone and cyclosporine or tacrolimus does not require modifications of the dosages of 2 immunosuppressant drugs.

Thyroid function and morphology after a successful kidney transplantation

Although thyroid disorders related to the end-stage renal disease (ESRD) are well known, there are discordant data on the function and morphology of the thyroid gland after renal transplantation (RT). The objective of this cross-sectional, case-control study was to investigate the prevalence and risk factors for disorders in the thyroid function and morphology after a successful RT. Fifty consecutive patients (25 females, 25 males) with fully functioning allograft were enrolled. Their age at transplant ranged from 23 to 44 yr (median, 38) and their post-RT follow-up lasted 15-86 months (median, 23). One hundred healthy subjects matched for sex, age and body mass index (BMI) were included as controls. Serum free thyroid hormones, TSH, thyroglobulin, thyroid hormone-binding globulin (TBG) and iodine urinary excretion were determined; ultrasonographic exam of the thyroid gland was performed in all subjects. Age, gender, time elapsed from RT, dialysis duration, kidney function, type of immunosuppression and corticosteroid dose were considered as possible influencing factors for the thyroid function. Hypothyroidism was found in 6% of patients, "low T3 syndrome" in 52%, while another 26% had free T3 (FT3), free T4 (FT4) and TSH in the lowest third of the normal range, suggesting inhibition of the whole hypothalamic-pituitary-thyroid (HPT) axis. Iodine excretion and prevalence of anti-thyroid antibodies were similar in both patients and controls. There was no significant difference in the thyroid function according to different immunosuppressive regimens. In patients, an ultrasonographic exam revealed a very variable thyroid volume ranging from 7.2 to 24.8 ml. Solid nodules were detected in 12 (24%) cases and cystic lesions in another four (8%); they were proven negative at cytological examination. Dialysis duration was longer in patients with thyroid nodules than in those without (p<0.05). Inhomogeneous hypoechoic pattern typical for chronic thyroiditis was more frequent than its biochemical expression. In conclusion, a high prevalence of abnormal thyroid morphology was found in patients after a successful RT, being partly related to a previous uremia. Abnormalities in the thyroid function are likely an expression of the post-transplant general and immunological conditions. Endocrinological follow-up is advisable in patients after RT, in order to discriminate thyroid dysfunctions which need specific treatments from those that can only be followed-up, avoiding inappropriate treatments of biochemical abnormalities.

Pharmacokinetic interaction between levofloxacin and ciclosporin or tacrolimus in kidney transplant recipients: ciclosporin, tacrolimus and levofloxacin in renal transplantation

BACKGROUND AND OBJECTIVE

Bacterial infections are common complications after organ transplantation. Fluoroquinolones are frequently used for treatment because of their broad spectrum of activity; but some of them, such as ciprofloxacin and norfloxacin, are reported to increase blood concentration of ciclosporin because they are metabolised by the liver through the same enzymatic pathway, the cytochrome P450 system. This study was performed to establish whether levofloxacin, a more recent fluoroquinolone that undergoes limited hepatic metabolism, interferes with metabolism and excretion of either ciclosporin microemulsion or tacrolimus.

METHODS

Pharmacokinetic studies were carried out in two groups of renal transplant patients, on either ciclosporin or tacrolimus treatment, before and at the sixth day of treatment with levofloxacin.

RESULTS

Levofloxacin significantly increased the mean area under the blood concentration-time curve (AUC) and the other pharmacokinetic parameters of ciclosporin and tacrolimus by about 25%. The interference of levofloxacin on the hepatic metabolism of these drugs was demonstrated by the concomitant decrease by 5% of polyclonal ciclosporin concentration, which is the expression of parent drug and its metabolites. Both before and during levofloxacin treatment we observed trough concentrations of monoclonal and polyclonal ciclosporin significantly lower in the evening (C(12)) than in the morning (C(0)); this observation suggests a circadian variation in the metabolism of this drug. However, no difference between C(0) and C(12) was observed with tacrolimus, confirming its more predictable bioavailability.

CONCLUSION

Our data demonstrate that levofloxacin partially inhibits the metabolism of both ciclosporin microemulsion and tacrolimus, and therefore close therapeutic monitoring of these two drugs should be recommended during levofloxacin therapy.

Opinions on renal transplantation and organ donation in high school students in two large northern (Torino) and southern (Napoli) Italian cities

Organ shortage for transplantation has focused attention on educational interventions. Italy is a nonhomogenous country whose cultural and economic differences are reflected in the health-care system: dialysis is mainly public in the north versus private in the south; and transplantation rates display a wide range from 3.4 to 37.8 per million people in 2002. The aim of the present study was to analyze the opinions of population of high school students (last two years) in two large cities: northern (Torino) and southern (Napoli) Italy, as a knowledge base for a randomized controlled trial on the efficacy of educational interventions on renal replacement therapy and organ donation, targeted to high school students.

METHODS

This preliminary study included eight public high schools that completed a first and anonymous semistructured questionnaire. Five hundred and eighty nine questionnaires were retrieved in Torino and 539 in Napoli. In both cities most students answered that they would give a kidney to a brother, sister, or partner needing dialysis (Torino: yes 80.6%; no 2.2%, uncertain-blank 17.2%; Napoli: yes 86.1%, no 1.1%; uncertain-blank 12.8%). Only 36.3% of the students in Torino and 37.7% in Napoli answered that they would consent to organ donation, if they had to choose for a strict relative with brain death. Opposition was 28% in Torino and 23.7% in Napoli; 35.7% in Torino and 38.6% in Napoli were blank-uncertain. These data underline the need for detailed information on the opinions of the overall population as basis for tailored educational campaigns.

Hypothalamic-pituitary-gonadal axis function after successful kidney transplantation in men and women

BACKGROUND

Renal transplantation (RT) is the most common solid organ transplant procedure. Several studies have reported on gonadal function in male and female RT recipients with controversial results.

METHODS

Forty consecutive patients (20 male, 20 female) with a fully functioning allograft (serum creatinine 0.8-1.3 mg/dl) for at least 15 months after RT were included in the study. Their ages ranged from 23 to 44 years (median 38) and their post-RT follow-up lasted 15-86 months (median 23). FSH, LH, prolactin, 17-beta-estradiol, testosterone, androstenedione and dehydroepiandrostrone were determined in all patients and compared with a group of 80 healthy subjects. Pelvic ultrasonography was performed in all participants.

RESULTS

Testosterone was below the normal range in 70% of male patients and within the lowest third in the remainder; a lack of LH increase indicated an inhibition of the reproductive axis. Male testosterone values were negatively influenced by calcineurine inhibitors treatment (P < 0.005), but positively influenced by a better graft function (P < 0.0001). Testicular and prostate volumes were reduced with respect to controls, with the latter related to circulating testosterone levels. Ten of the women (50%) had menstrual cycle disorders after RT, three being affected by transient, and three by persistent, amenorrhea. Another two patients had had transient polymenorrhea. In four women (20%), a premature ovarian failure was diagnosed. No relationship was found between female reproductive function and age, graft function or duration of the post-transplant period. Prolactin was lower in patients on calcineurin inhibitors (P < 0.01).

CONCLUSIONS

Abnormalities of the reproductive system were frequent after successful RT in both genders.

Safety and immunogenicity of HIV-1 DNA constructs in chimpanzees

A global effort to control the HIV epidemic is likely to rely heavily on immunization strategies. As our closest genetic relative, the chimpanzee provides the most important model for preclinical safety and immunogenicity studies. We have immunized adult, pregnant and infant chimpanzees with our plasmid vaccines. We have found these vaccines to be safe and well tolerated in all of these groups. The same vaccines have induced both humoral and cellular immunity in each instance.

DNA vaccination as anti-human immunodeficiency virus immunotherapy in infected chimpanzees

The role of the immune response in controlling human immunodeficiency virus type 1 (HIV-1) replication is controversial. Immunotherapeutic strategies that have the ability to broaden immune responses might play a role in slowing disease progression. DNA immunization was studied as immunotherapy in infected chimpanzees. Two HIV-1-infected chimpanzees were vaccinated with DNA plasmid vaccines, one with plasmid pCMN160, which expresses the envelope glycoprotein of HIV-1MN and rev, and the other with a control plasmid. The chimpanzee immunized with pCMN160 demonstrated enhanced humoral responses. Virus load was monitored. Virus load in the chimpanzee receiving pCMN160 decreased at week 20 and has remained at background levels. The control chimpanzee was subsequently vaccinated with pCMN160. After immunization, the antibody responses increased and, as in the first animal, the virus load decreased. These results indicate the potential of the immune response to have a direct impact on HIV-1 replication in chimpanzees.

DNA inoculation induces neutralizing immune responses against human immunodeficiency virus type 1 in mice and nonhuman primates

DNA, or genetic, inoculation mimics aspects of attenuated vaccines in that synthesis of specific foreign proteins is accomplished in the host. These proteins can be processed and presented on the relevant major histocompatibility complex (MHC) antigens and ultimately become the subject of immune surveillance. Very recently, we have described the use of the new technology to generate immune responses in mice against the human immunodeficiency virus type 1 (HIV-1) envelope using a gp160 DNA construct. Further analysis of this technology specifically in regard to HIV vaccine design is clearly important. In this report, we describe the analysis of additional HIV constructs as immunogens in both mice and report the use of this genetic immunization technology in nonhuman primates. In these studies, successful seroconversion occurs in more than 70% of the mice following the second immunization with 100 micrograms of construct DNA; three and four immunizations result in routinely 100% seroconversion of the mice. Furthermore, the same strategy has successfully seroconverted primates following their second inoculation, resulting in the generation of both antiviral and neutralizing antibodies in this animal species. These studies are the first report of which we are aware that demonstrate successful immunization of nonhuman primates through genetic vaccination technology and the first to describe genetic immunization of primates against HIV antigens. This technology has relevance for the development of safe and efficacious immunization strategies against HIV because it provides for relevant antigen production in vivo without the use of infectious agents.

Phase I trial of multiple large doses of murine monoclonal antibody CO17-1A. I. Clinical aspects

Twenty-five patients with metastatic gastrointestinal adenocarcinoma received one to four infusions (400 mg) of murine monoclonal antibody CO17-1A. Eleven patients had mild gastrointestinal symptoms, and one had a transient flushing episode. Two of five who received three weekly infusions had readily reversible anaphylactic reactions at the time of the third infusion (day 15). There were no other toxic effects. One patient had a complete remission and is surviving at greater than 104 weeks, and four had stable disease. The median survival for the whole group was 57 weeks. In general, the antibody infusions were well tolerated but had modest antitumor effects.

Phase I trial of multiple large doses of murine monoclonal antibody CO17-1A. II. Pharmacokinetics and immune response

Twenty-five patients with metastatic gastrointestinal adenocarcinoma received one to four infusions of large doses (400 mg) of murine monoclonal antibody CO17-1A (17-1A). The pharmacokinetics of 17-1A at the time of first, second, third, or fourth infusion were not statistically different; plasma half-lives were 15.0 +/- 1.7 hours (n = 5), 15.1 +/- 1.8 (n = 10), 25.3 +/- 6.2 (n = 3), and 14.4 +/- 1.8 (n = 5), respectively. Most patients had an antibody response to 17-1A, with peak levels occurring 15-22 days after infusion. The presence of serum antibody to 17-1A at the time of the second or third infusion did not significantly alter the pharmacokinetics of this large dose of antibody. Four of 25 patients failed to develop an antibody response, but this did not correlate with the amount of 17-1A administered. The administration of four doses of 400 mg over 1 week provided continuously circulating 17-1A for 10 days.

Phase I clinical trial of CO17-1A monoclonal antibody

Twenty patients with metastatic gastrointestinal cancer received one or more weekly infusions of 400 mg CO17-1A monoclonal antibody. The most common side effect was mild gastrointestinal symptoms in 9/20 patients. Two of five patients receiving three weekly infusions had reversible anaphylactic reactions at the time of their third infusion. The pharmacokinetics of the antibody were similar at the first, second or third infusion. Human antibody to 17-1A occurred in 17/20 patients with 11/20 having antibody detectable by 8 days following initial infusion. Thus, one or two infusions (weekly) of large doses of 17-1A were well tolerated but allergic responses limit ability to administer therapy by 15 days post-initial infusion.

Comparison of the relative mutagenic activity for eight antineoplastic drugs in the Ames Salmonella/microsome and TK+/- mouse lymphoma assays

Eight antineoplastic drugs were evaluated for their ability to induce mutation in the Ames Salmonella/microsome and the TK+/- mouse lymphoma assay. Dose response data were utilized to determine the relative potency of each of these drugs. They were then ranked based on this information. Vincristine, the most potent compound tested in the mouse lymphoma assay, was not active in the Salmonella assay, nor were DTIC and Methotrexate. Excluding these compounds from the comparison ranking, we found that the only difference in the order between the Ames and lymphoma assays was between Daunomycin and Adriamycin. Daunomycin was most potent in the Ames assay, compounds was reversed in the mouse lymphoma assay. This observation of relative activity is of interest because it underscores the ability to extrapolate between microbial and mammalian test systems, provided one keeps in mind the differences associated with chromosome structure and modes of segregation in these two cell types. Furthermore, it is suggested that relative potency ranking may provide prospective insight into expectations of risk for human populations exposed to these drugs.