Cytomegalovirus Infection in Kidney Transplant Recipients: Evolution of Approach Through Three Eras

Cytomegalovirus (CMV) prophylaxis is recommended for high-risk patients, while preemptive therapy is considered acceptable for patients at moderate/low risk. After reviewing kidney transplant patients from 1992-1995 and 1996-1999, we decided to replace prophylaxis by preemptive therapy. Herein we have presented our data. From 1996-1999 we treated 129 patients with ganciclovir prophylaxis for 3 months if D+/R- or if they received depleting antibodies. The incidence of CMV was 13.2% versus 3.7% in the 1992-1995 cohort. The increase was associated with mycophenolate mofetil (MMF) use (P = .002). Forty-two percent of the D+/R- developed an infection with 89% of bouts occurring in the first month after cessation of prophylaxis. From 2002-2004, we never gave prophylaxis to 129 patients except when they received thymoglobulin. High-risk D+/R- patients were monitored by polymerase chain reaction (PCR) CMV for 3 months. The incidence of CMV was 17.1% with 54% of the D+/R- developing CMV. CMV infection occurred mostly during the first trimester posttransplantation. Creatinine at 1 year posttransplantation was worse in the presence of CMV infection (154.3 mumol/L-1.75 mg % versus 130.2 mumol/L-1.47 mg %, P = .03). Time to cure CMV infection was longer when MMF was discontinued: 36.7 days versus 69.9 days (P = .026). Our results indicated that CMV incidence is increasing: 3.7% (1992-1995) --> 13.2% (1996-1999) -->17.1% (2002-2004) and that it impairs 1 year graft function. Recovery was faster among patients still receiving MMF compared with those discontinuing MMF. Although MMF inhibits synthesis of anti-CMV IgM, it increases the anti-herpes virus effect of ganciclovir and may protect against chronic allograft nephropathy. Based on our experience, we plan to reintroduce prophylaxis in high-risk patients and to continue MMF when treating CMV infection.

Trichosporon beigelii funguria in renal transplant recipients

Trichosporon beigelii funguria in renal transplant recipients is usually benign and is seldom associated with invasive or deep-seated infections.

Safety and tolerability of cyclosporine and cyclosporine microemulsion during 18 months of follow-up in stable renal transplant recipients: a report of the Canadian Neoral Renal Study Group

BACKGROUND

There has been concern that the increased drug exposure associated with treatment with cyclosporine microemulsion (CsA-ME) would lead to an increase in adverse events.

METHODS

The long-term safety and tolerability of conventional cyclosporine (CsA) and CsA-ME were compared in a randomized, multicenter, pharmacoepidemiologic study involving 1097 stable renal transplant patients after 18 months of follow-up.

RESULTS

No significant difference was seen in change in serum creatinine or calculated creatinine clearance between the two groups. Episodes of deterioration in renal function (change in serum creatinine > or = 20%) were categorized with the following results for CsA-ME versus CsA, respectively: acute rejection, 4.5% vs. 4.5%; chronic rejection, 8% vs. 11%; CsA nephrotoxicity, 12% vs. 7% (P=0.008); transient changes, 17% vs. 12%; other causes, 4% vs. 6%. During the first 6 months of the study, a transient increase in the incidence of gastrointestinal and neurological adverse events was seen in the CsA-ME group compared with the CsA group. Up to 18 months, patients in the CsA group reported significantly fewer hearing and vestibular disorders, but more cardiovascular problems than those in the CsA-ME group (P=0.035).

CONCLUSIONS

Tolerance to CsA and CsA-ME was similar. Renal function over 18 months was not adversely affected by the increased drug exposure with CsA-ME, although there was a transient increase in nephrotoxicity. The frequency of acute and chronic rejection did not change.

Economic analysis of Neoral in de novo renal transplant patients in Canada

This pilot economic evaluation was performed as part of the Canadian arm of an international randomized, controlled, double-blind safety and tolerability trial (OLM-105/NOF-2). The clinical study compared the safety and tolerability of a new microemulsion oral formulation of cyclosporine A (Neoral) with the oral cyclosporine. A preparation currently in use (Sandimmune SGC)/(SGC). To assess the economic impact of Neoral in newly grafted renal transplant patients, primary cost data were collected at the five participating Canadian centers and evaluated from the Ministry of Health (MOH) and hospital perspectives. The results of this cost analysis are presented in this paper. Since the new formulation has shown more consistent absorption and a more predictable pharmacokinetic profile, medical resource utilization and, consequently, cost of treatment could be expected to be lower for those renal transplant recipients treated with Neoral than for those receiving standard SGC. The findings of this study support this hypothesis. Robustness of the conclusion was confirmed with sensitivity analyses. Reduced health care costs for patients treated with Neoral were primarily a result of fewer hospitalization days and lower physician costs for inpatient and outpatient procedures.

A randomized, prospective multicenter pharmacoepidemiologic study of cyclosporine microemulsion in stable renal graft recipients. Report of the Canadian Neoral Renal Transplantation Study Group

BACKGROUND

The safety, tolerability, and pharmacokinetics of conventional cyclosporine (ConCsA) and cyclosporine microemulsion (MeCsA) were compared under conditions of normal clinical practice in a prospective, randomized, concentration-controlled, pharmacoepidemiologic study.

METHODS

Between September 1994 and March 1995, 1097 stable renal transplant recipients in 14 Canadian centers were randomized 2:1 to treatment with MeCsA or ConCsA. Patients were commenced on each study drug at a dose equal to their previous therapy with ConCsA, and the dose was adjusted to maintain predose whole blood cyclosporine concentrations within the therapeutic range established for each center. Prednisone and azathioprine were continued unless dose adjustment was required for clinical reasons.

RESULTS

The mean cyclosporine concentration was comparable in both treatment groups at all time points throughout the 6 months of follow-up. The mean dose of cyclosporine was 3.6 mg/kg/day in both treatment groups at entry to the study, and declined by 0.3% and by 2.8% in patients receiving ConCsA and MeCsA, respectively. The nature and severity of adverse events were similar in both treatment groups, but there was a transient increase in neurological and gastrointestinal complications in the group receiving MeCsA within the first month after conversion (P<0.05). Serum creatinine and creatinine clearance did not change in either treatment group throughout the study. Biopsy-proven acute rejection occurred in three patients (0.8%) receiving ConCsA and in seven patients (0.9%) receiving MeCsA, with non-histologically proven acute rejection in an additional three patients (0.8%) receiving ConCsA and five patients (0.6%) receiving MeCsA (P=NS). Serum creatinine rose transiently in 35 patients (9.8%) receiving ConCsA and 138 patients (18.7%) receiving MeCsA (P<0.05) and resolved either spontaneously or after a reduction in the cyclosporine dose. One graft was lost in the MeCsA group due to irreversible rejection, and seven patients died, three in the group receiving ConCsA and four of those receiving MeCsA (P=NS). Absorption of cyclosporine was more rapid and complete from MeCsA than from ConCsA during the first 4 hr of the dosing interval, resulting in almost 40% greater exposure to the drug (P<0.001). There was close correlation between area under the time-concentration curve (AUC) over the first 4 hr of the 12-hr dosage interval and AUC over the entire 12-hr dosage interval for both formulations, making AUC over the first 4 hr a good predictor of total cyclosporine exposure. Using this parameter, patients with low absorption randomized to receive MeCsA showed a marked increase in drug exposure by months 3 and 6, whereas there was no change in those who continued on ConCsA. A limited sampling strategy utilizing samples at the predose and postdose trough levels provided an excellent correlation with drug exposure, particularly for patients receiving MeCsA (r2=0.94 MeCsA vs. r2=0.89 ConCsA).

CONCLUSIONS

MeCsA appears to be a safe and effective therapy in stable renal transplant patients and provides superior and more consistent absorption of cyclosporine when compared with ConCsA. Transient toxicity after conversion to MeCsA occurs in some patients, and may reflect the increased exposure to cyclosporine. Use of a limited sampling approach combining trough and 2-hr postdose concentrations may provide an effective way to monitor this exposure.

Determinants of late allograft nephrectomy

When loss of graft function occurs more than six months after transplantation, allograft nephrectomy is not routinely performed at the time of graft failure. It is usually performed only on those patients who subsequently develop specific complications. However, little is known about the characteristics that make patients more likely to require allograft nephrectomy. The purpose of our study was to identify risk factors for the subsequent need for allograft nephrectomy in patients with graft failure occurring more than 6 months after transplantation. Forty-one patients were studied. Inclusion criteria were: loss of graft function > or = 6 months after transplantation, resumption of dialysis and initiation of weaning from immunosuppression. Thirty patients were treated with cyclosporine + prednisone +/- azathioprine and 11 with azathioprine + prednisone. Mean follow-up time was 17.8 months, ranging from 6 months to 6.1 years. Recipient age, sex and race, original renal disease, donor, donor source (cadaveric vs living related), HLA compatibility, levels of panel reactive antibodies, occurrence of initial delayed graft function, causes of graft failure and tapering of immunosuppression were similar in patients with and without allograft nephrectomy. Using univariate analysis, allograft nephrectomy was found to be significantly more frequent in patients with a history of 2 or more episodes of acute rejection than in patients with no rejection episode: 83% vs 30% (p = 0.03). In addition, allograft nephrectomy was found to be significantly more frequent if the immunosuppressive regimen included cyclosporine (62% vs 27.3%; p = 0.04). Using multivariate analysis however, the number of previous episodes of rejection was found to be the only significant predictor for allograft nephrectomy. None of the other variables considered in the multivariate analysis, including the type of immunosuppressive therapy, was identified as a significant predictor for the need to perform allograft nephrectomy. In summary, the need for late allograft nephrectomy was correlated with the number of previous episodes of acute rejection. Patients with a history of numerous rejection episodes should thus be considered more likely to require allograft nephrectomy once immunosuppression is withdrawn. Possible interventions to reduce or prevent the need for nephrectomy include more gradual tapering of immunosuppression at the time of graft failure or indefinite low-dose immunosuppressive therapy.

A randomized study of cyclosporine with and without prednisone in renal allograft recipients. Canadian Transplant Group

Sixty-nine patients receiving Cs after cadaveric or LRD renal transplants were randomly allocated to receive prednisone or no prednisone beginning on the day of transplant. There were 36 in the prednisone group and 33 in the group assigned to no prednisone. Of these latter, only seven (21%) never received prednisone and an additional four had one short course for rejection episodes (11%). Of the remaining 22 who were placed on continuous steroids, only 12 met rejection criteria and either some or all of the remainder probably had Cs nephrotoxicity. The patient and graft survival were better but not statistically so in the no-prednisone group (97% v 89%) and (88% v 78%), and the number of infections was only half that of the prednisone-treated group (22% v 42%). A policy of withholding steroids except for rejection episodes does not prejudice graft or patient survival in Cs-treated patients.

Reduction of azathioprine in renal transplant patients with chronic hepatitis

To determine whether prolonged reduction of azathioprine in renal transplant recipients with chronic hepatitis affected the progression of liver disease without an adverse effect on graft survival we studied all transplant patients with a raised serum glutamic oxaloacetic transaminase level greater than normal for more than 1 year who had azathioprine reduced below 100 mg/day for longer than 1 year. Six HBsAg-positive patients had chronic hepatitis for 67 +/- 7 (SE) months before reduction of azathioprine and were followed for a further 49 +/- 14 months. None of the six patients remitted, 3 patients died from liver disease, and none returned to dialysis. In the group of 12 patients who did not have azathioprine reduced, none remitted, 4 died from liver disease, and none returned to dialysis during a follow-up of 115 +/- 9 months. Seven HBsAG-negative patients had chronic hepatitis for 32 +/- 11 months before reduction of azathioprine and were followed for a further 46 +/- 8 months. One of the seven remitted, none died from liver disease and one returned to dialysis. In the group of 15 patients who did not have azathioprine reduced 5 patients remitted, none died from liver disease, and none returned to dialysis. We conclude that prolonged reduction of azathioprine does not slow the progression of liver disease in renal transplant recipients with HBsAg-positive or HBsAg-negative chronic hepatitis, nor does it predispose to graft failure. However reduction of immunosuppression early in the course of hepatitis B disease may be necessary to prevent adverse long-term sequelae.

Chronic hepatitis in end-stage renal disease: comparison of HBsAg-negative and HBsAg-positive patients

To determine the outcome of chronic hepatitis in ESRD we studied all 358 renal transplant recipients and 295 hemodialysis patients treated for greater than 1 year since 1970. The incidence of chronic hepatitis (elevated SGOT for greater than 1 year) was 15% (N = 54) in transplanted and 3.4% (N = 10) in dialysis patients. Forty-eight percent (26) of transplanted and 50% (5) of dialysis patients were HBsAg positive. In the transplanted group, the clinical outcome of chronic hepatitis was significantly better in HBsAg-negative compared to HBsAg-positive patients; 11% died, none from liver disease, and 32% remitted after a mean follow-up from start of liver disease of 77.3 +/- 8.2 months, whereas in the HBsAg-positive group 54% (14) died, nine from liver disease, and one remitted after a follow-up of 90.2 +/- 8.9 months. Adverse prognostic factors (age, duration of diabetes, and heart disease) present before ESRD treatment began were similar in both groups, as was duration of follow-up. Only 14% (2/14) of HBsAg-negative patients progressed to chronic active hepatitis on liver biopsy compared to 71% (15/21) of HBsAg-positive patients. Histological stability in those with serial biopsies occurred in 66% (4/6) of HBsAg-negative patients, but in only 18% (13/16) of HBsAg-positive patients with a similar duration of follow-up. No dialysis patients died from liver disease. We conclude that chronic hepatitis occurs more frequently in transplanted than dialyzed patients, and that HBsAg-negative chronic hepatitis has a more benign, clinical, and histological outcome than chronic HBsAg-positive hepatitis in renal transplant recipients.

Nephrogenic adenoma of the bladder after kidney transplantation: spontaneous improvement with azathioprine removal; surgical trauma and cytomegalovirus infection as possible etiologic factors

We report 2 cases of nephrogenic adenoma several years after successful cadaver kidney transplantation. In 1 case the lesion had cytomegalovirus inclusions, and we observed a marked and sustained reduction in the extension of the lesion with cessation of azathioprine. Surgical trauma and cytomegalovirus infections are discussed as etiologic factors. Conservative treatment seemed appropriate.

Malignancies associated with renal transplant: first case report of a nephroblastoma occurring in an adult host kidney

The increased incidence of malignancies after renal transplantation has been well documented. We describe the first reported case of a nephroblastoma (Wilms tumor) occurring in the host kidney of an adult after renal transplantation.

Antithymocyte globulin in cadaver kidney transplantation: a randomized trial based on T-cell monitoring

The influence of horse antihuman thymocyte globulin (ATG) on renal allograft survival was assayed between March 1977 and August 1978. Fifty consecutive patients were randomly assigned to the treatment or the control group. Patients in both groups received azathioprine and prednisolone. ATG was added in the experimental group. The daily dosage was such as to maintain the rosette-forming cell (RFC) level at 10% of baseline values. The number of renal failure episodes (RFE's)was significantly lower in the experimental group during the period (1 month) ATG was given than it was in the control group during that same period of time. Two years after transplantation, kidney survival was 79% in the ATG group and 52% in the control group. The amount of steroids necessary to control RFE's was significantly lower in the ATG group. The dosages of ATG used in the experimental group were relatively small (average daily dose, 3.08 +/- 0.26 mg/kg of body wt), and adverse reactions were mild. Blood tolerance was excellent. T-cell monitoring thus appears to be an effective method in evaluating the daily dosage of ATG.

[Bacterial infections in renal homotransplant recipients. Results of regular bacteriological controls (author's transl)]

Bacterial infections were studied in 51 immunosuppression kidney transplant recipients. Eighty infectious episodes occured in the first six post-transplantation months. Forty percent of these episodes were nonfebrile, detected during the routine bacteriological follow-up examination. Out of these 80 bacterial infections, 59 were localized (47 in the urinary tract, nine in the surgical wound and three in the lungs) and 21 had spread. Neutopenia occured in 13 patients, in association with septicaemia in eight of them. Usually septicaemia appeared before neutropenia. In 12 cases, infectious episodes (10 septicaemias and two localized infections) and transplant failure were closely related. The bacterial strains responsible for these infections were essentially: Staphylococcus spp (39), Streptococcus spp (14), Klebsiella pneumoniae (9), Escherichia coli (9). Most of the localized infections cleared up when treated with a specific antibiotic. Seven failures of antibiotic treatment were observed in 21 cases of generalized infections. The importance of regular post-transplantation bacteriological check-up in detecting and treating infectious complications in graft recipients must be emphasized.

Bumetanide, a new loop diuretic

The effect of bumetanide on renal function has been compared with that of furosemide and a placebo in a double-blind study of 9 healthy young men. The sequence for oral administration of the drug was subjected to a random assignation based upon the Latin-square methodology under three different conditions. (1) Normal hydration: The administration of bumetanide (2 mg) produced within the next 4 hr a diuresis comparable to that induced by 80 mg of furosemide. Urinary excretion of sodium, potassium, chloride, calcium, and uric acid also followed comparable patterns. Phosphaturia occurred only under bumetanide. The effect of bumetanide seemed longer lasting. (2) Water loading: The effects of bumetanide and furosemide were comparable with the exception of the phosphaturic effect induced by bumetanide. The action of both diuretics on the diluting segment of the nephron was well demonstrated by the marked depression of CH2O. (3) Water deprivation: The effects of the two diuretics were comparable, including depression tCH20. In none of these conditions did the placebo produce any significant effect.