FK 506 in steroid-resistant focal sclerosing glomerulonephritis of childhood

Immunosuppression for adult steroid-dependent or frequently relapsing nephrotic syndrome: A systematic review and meta-analysis

OBJECTIVE

There is limited evidence on which immunosuppressive agents produce the best outcomes for adult patients with steroid-dependent or frequently relapsing nephrotic syndrome (SDNS/FRNS). This review compares the remission rate and adverse effects of various immunosuppressants used.

METHODS

Studies of adult patients with biopsy-proven SDNS/FRNS, administered any immunosuppressive agents and reported complete remission results as one of the clinical outcomes were included. Articles were independently screened by two researchers. ROBINS-I was used for risk of bias assessment. Random-effects model was used for statistical analysis and corresponding 95% confidence intervals (CIs) were calculated.

RESULTS

574 patients across 28 studies were included in the analysis. Patients receiving rituximab have a complete remission rate of 89% (95% CI = 83% to 94%; τ2 = 0.0070; I2 = 62%; overall p < 0.01, low certainty) and adverse event rate of 0.26, cyclosporine (CR 40%; 95% CI = 21% to 59%; τ2 = 0.0205; I2 = 55%; overall p = 0.08, low certainty), tacrolimus (CR 84%; 95% CI = 70% to 98%; τ2 = 0.0060; I2 = 33%; overall p = 0.21, moderate certainty), mycophenolate mofetil (CR 82%; 95% CI = 74% to 90%; τ2 < 0.0001; I2 = 15%; overall p = 0.32, moderate certainty) and cyclophosphamide (CR 79%; 95% CI = 69% to 89%; τ2 = 0; I2 = 0%; overall p = 0.52, moderate certainty).

CONCLUSION

Among the commonly used immunosuppressive agents, only rituximab has a statistically significant effect in achieving complete remission among patients with SDNS/FRNS and has a relatively good safety profile, but this is limited by low quality of evidence with high degree of heterogeneity causing a lack of statistical power.

Efficacy and safety of tacrolimus vs cyclophosphamide in the therapy of patients with idiopathic membranous nephropathy: a meta-analysis

BACKGROUND

As one of the therapeutic drugs for idiopathic membranous nephropathy (IMN), tacrolimus (TAC) has not been fully vindicated for its efficacy and tolerability. A meta-analysis was performed to detect the efficacy and safety of TAC plus glucocorticoid vs cyclophosphamide (CTX) plus glucocorticoid in therapy of patients with IMN.

METHODS

A literature search with a pre-defined search strategy was conducted using English databases (PubMed, EMBASE, ClinicalKey and the Cochrane Library) and Chinese databases (China National Knowledge International, Wanfang, Chinese Scientific Journal Database (VIP)) from inception to Nov 19, 2018. Any high-quality randomized controlled trials (RCTs) comparing the effectiveness or safety of TAC with CTX in IMN patients were included. Data were extracted by two authors independently and analyzed using RevMan 5.3.

RESULTS

Four randomized controlled studies were included. In this analysis, we did not find that the statistically significant difference between TAC and CTX groups on 6-month and 12-month treatment complete remission (CR) was evident (6-month: OR=1.53, 95% CI: 0.85-2.76, P=0.15; 12-month: OR=2.17, 95% CI: 0.56-8.44, P=0.27). But TAC had better 6-month total remission (TR; total CR plus partial remission [PR]) than CTX (6-month: OR=2.62, 95% CI: 1.38-4.96, P=0.003; 12-month: OR=1.74, 95% CI: 0.29-10.48, P=0.54), and got a lower proteinuria after 6-month treatment (OR=-0.80, 95% CI: -1.53 to -0.07, P=0.03). TAC had a lower incidence rate on leucopenia than CTX, but had a tendency towards higher blood creatinine. In the meantime, tremor in TAC group was higher than that in CTX group. The differences on other adverse effects such as gastrointestinal syndrome, infection, herpes zoster, hypertension, liver function disorder and hyperglycemia were also analyzed. However, none of them were statistically significant.

CONCLUSION

TAC treatment could get high value of TR and had low value of proteinuria level when compared with those in CTX on 6-month treatment in therapy of patients with IMN.

Tacrolimus for children with refractory nephrotic syndrome: a one-year prospective, multicenter, and open-label study of Tacrobell®, a generic formula

BACKGROUND

Cyclosporine A and tacrolimus (TAC) are often used as a second-line treatment for children with refractory nephrotic syndrome (NS). This study was undertaken to investigate the efficacy and safety of Tacrobell®, a locally produced generic form of TAC.

METHODS

This study was a one-year prospective, open-label, single-arm, multicenter trial. Fourty-four children with steroid-dependent NS (SDNS) and 33 children with steroid-resistant NS (SRNS) were enrolled. The primary endpoints were defined as the remission rates, whereas the secondary endpoints were recognized as the duration of remission and adverse effects of TAC.

RESULTS

After one-year treatment, 34 (77.3%) of the 44 patients with SDNS were in complete remission, and 6 (13.6%) were in partial remission. Nineteen (43.2%) patients did not relapse during the study; for those who did relapse, the mean duration of remission was 4.6±2.9 months. The number of relapse episodes during the study period (0.90 per patient-year) was significantly lower than that in the preceding year (2.8 per patient-year). After treatment for 3 and 6 months, 12 (36.4%) of the 33 patients with SRNS were in remission, and after treatment for 12 months, the number of patients had increased to 13 (39.4%). The mean time to achieve remission was 4.0±3.2 months. After remission (duration, 3.7±2.7 months), 12 (54.5%) of 22 patients relapsed. The fasting blood glucose and blood pressure levels during the therapy were similar to those at the time of study entry.

CONCLUSIONS

Treatment with Tacrobell® was effective and safe for children with refractory NS. The efficacy of this generic form of TAC was better than that of the original TAC formula.

History of Nephrotic Syndrome and Evolution of its Treatment

The recognition, evaluation, and early treatment of nephrotic syndrome in infants and children originate from physicians dating back to Hippocrates. It took nearly another 1000 years before the condition was described for its massive edema requiring treatment with herbs and other remedies. A rich history of observations and interpretations followed over the course of centuries until the recognition of the combination of clinical findings of foamy urine and swelling of the body, and measurements of urinary protein and blood analyses showed the phenotypic characteristics of the syndrome that were eventually linked to the early anatomic descriptions from first kidney autopsies and then renal biopsy analyses. Coincident with these findings were a series of treatment modalities involving the use of natural compounds to a host of immunosuppressive agents that are applied today. With the advent of molecular and precision medicine, the field is poised to make major advances in our understanding and effective treatment of nephrotic syndrome and prevent its long-term sequelae.

Outcomes of tacrolimus therapy in adults with refractory membranous nephrotic syndrome: a prospective, multicenter clinical trial

INTRODUCTION

The treatment of adult refractory idiopathic membranous nephropathy with steroid and other immunosuppressant-resistant nephrotic syndrome can be a significant challenge. The authors investigated the efficacy and safety of tacrolimus (TAC) as a promising regimen.

METHODS

A prospective, multicenter trial was conducted in 9 nephrology centers from 2006 to 2008. Fourteen patients were enrolled. In conjunction with prednisone, TAC was started at 0.05 mg/kg/d, titrated to achieve a trough blood level of 5 to 10 ng/mL for the first 6 months, then reduced to 4 to 6 ng/mL for the subsequent 6 months. The primary endpoints included complete or partial remission. Secondary endpoints included relapse, change of clinical parameters and adverse events.

RESULTS

After 12 months, complete remission was achieved in 35.7% of patients and partial remission in 42.9%, yielding a response rate of 78.6%. Proteinuria, serum albumin, cholesterol, triglyceride and low-density lipoprotein were improved significantly (P < 0.001, P < 0.001, P = 0.002, P = 0.01, P = 0.004, respectively). Proteinuria and serum albumin were significantly improved (42.0% ± 13.2%, P = 0.02; 15.2% ± 4.5%, P = 0.01, respectively) even after the first month of treatment. One patient relapsed during the subsequent 6 months of follow-up. Adverse events included 2 cases of infection and 1 case each of hyperglycemia, hand tremor, sudden death (nondrug related) and diarrhea.

CONCLUSIONS

TAC plus prednisone may be an alternative therapeutic option for steroid and general immunosuppressant-resistant membranous nephrotic syndrome patients, with a favorable safety profile. However, given the limitation of a small number of patients in this trial, further study with a larger number and longer follow-up is needed.

Tacrolimus is an alternative therapy option for the treatment of adult steroid-resistant nephrotic syndrome: a prospective, multicenter clinical trial

BACKGROUND

The optimal therapy for adult steroid-resistant nephrotic syndrome (SRNS) remains a therapeutic challenge. We investigated the efficacy and safety of tacrolimus as a promising regimen in Chinese adult patients.

METHODS

A prospective, multicenter trial was conducted in 9 nephrology centers from 2006 to 2008, in patients with SRNS (defined as failure to respond to 1 mg/kg/day of prednisone for 8, and 16 weeks, in focal segmental glomerulosclerosis). Patients were treated with tacrolimus (TAC) plus prednisone for 12 months. TAC dose was titrated to achieve a target trough blood concentration of 5-10 ng/ml for the first 6 months and 4-6 ng/ml for the subsequent 6 months. The primary outcomes included complete or partial remission [complete remission (CR): proteinuria <0.3 g/24 h, with serum albumin ≥ 3.5 g/dl and stable renal function; partial remission (PR): proteinuria between 0.3 and 3.5 g/24 h and a decrease of at least 50 % from the baseline level, with serum albumin ≥ 3.0 g/dl and stable renal function]. Secondary end-points included relapse rate, changes of clinical parameters (proteinuria, serum albumin, and lipid profile) and adverse events.

RESULTS

Twenty-four patients with SRNS were enrolled. After 6 months of therapy, CR was achieved in 58.3 % of patients and PR in 16.7 %, yielding a final response rate of 75.0 %. The decrease in proteinuria was 43.1 ± 17.5 % after the first month of treatment (P < 0.001). Complete or PR was achieved in 6 of 8 patients with minimal change disease, 4 of 6 patients with mesangioproliferative glomerulonephritis (MsPGN), 6 of 7 patients with focal segmental glomerulosclerosis (FSGS), and all 2 patients with IgA nephropathy. Two patients (1 with MsPGN and 1 with FSGS) experienced relapses during the subsequent 6 months of follow-up. Adverse events included infection, hand tremor, diarrhea, acute reversible or persistent nephrotoxicity.

CONCLUSIONS

In conjunction with prednisone, TAC may be an alternative therapeutic regimen for adult SRNS patients. However, adverse events in these patients should be carefully monitored, especially at the beginning of treatment. Randomized controlled trials with longer follow-up are warranted.

Tacrolimus in the treatment of idiopathic nephrotic syndrome

The immunosuppressant tacrolimus (FK-506) is a calcineurin inhibitor with a widespread use for the prevention of graft rejection in transplantation medicine. Tacrolimus inhibits the activation of an essential transcription factor for the transcription of cytokine genes in T cells leading to a decreased production of cytokines such as IL-2 and IFN-gamma. As T-cell activation plays a crucial role in the pathogenesis of inflammatory glomerular diseases, there is an increasing number of reports on the use of tacrolimus in nephrotic syndrome. In idiopathic nephrotic syndrome, corticosteroid treatment constitutes the first-line therapy to achieve remission. In the case of steroid resistance or steroid dependence, alternative immunosuppressive strategies are needed. Cyclophosphamide and ciclosporin are well-established drugs in this condition. The present article reviews the pharmacodynamics, pharmacokinetics, safety and clinical efficacy of tacrolimus in steroid-resistant and steroid-dependent nephrotic syndrome.

Management of steroid-resistant focal segmental glomerulosclerosis in children using tacrolimus

BACKGROUND

The use of tacrolimus in steroid-resistant (SR) focal segmental glomerulosclerosis (FSGS) has been reported in single and small series case reports.

AIM

To determine the efficacy of tacrolimus in the management of SR FSGS in children.

STUDY DESIGN

This was a prospective study of 20 children with SR FSGS treated with tacrolimus (0.2-0.4 mg/kg/day in two divided doses over 12 h adjusted to a trough level between 7 and 15 ng/ml) for 12 months in combination with low-dose steroids. Other therapies included angiotensin-converting enzyme inhibitors, folic acid, multivitamins and lipid-lowering agents.

RESULTS

The mean age at study entry was 11.1 years (range 5.6-16.8). The mean duration of nephrotic syndrome before initiation of tacrolimus therapy was 4.7 years (range 2.1-7.6). At the end of the treatment period, 8 (40%) children were in complete remission, 9 (45%) were in partial remission, and 3 (15%) failed to respond. The average follow-up period following cessation of tacrolimus treatment was 27.5 months (range 13.7-43.7). At last hospital follow-up, 5 (25%) children were in complete remission, 10 (50%) in partial remission, and 2 (10%) in relapse. Three children died from dialysis-related complications following cessation of tacrolimus treatment. Adverse events included sepsis (2), nausea (2), diarrhea (2), anemia (4) and worsening of hypertension (4).

CONCLUSION

Tacrolimus is a safe and effective treatment for SR FSGS. However, like cyclosporine, some children tend to relapse following cessation of treatment.

Treatment of severe steroid-dependent nephrotic syndrome (SDNS) in children with tacrolimus

BACKGROUND

Severe steroid-dependent nephrotic syndrome (SDNS) is a common type of nephrotic syndrome (NS) observed in childhood. Steroid-sparing agents such as calcineurin inhibitors (CNIs) are used to avoid steroid toxicity in SDNS. Tacrolimus (TAC) has been prescribed for maintaining remission of NS in patients who have developed treatment resistance or adverse effects with cyclosporin A (CYA) at our institution since 1995. The aim of this study was to compare the efficacy and complications of TAC with CYA in the management of severe SDNS.

METHODS

We report a retrospective longitudinal clinical series of patients with SDNS, all of whom have been treated with TAC.

RESULTS

Ten SDNS children (eight males) were reviewed quarterly from time of initial referral to the present day during 93 completed treatment patient years. Nine patients had minimal change disease and one had focal segmental glomerulosclerosis on their first biopsy. The median age at diagnosis was 2.9 years (range 1.6-12.9). The median age at initial referral was 3.9 years (range 2.2-12.9). All patients initially responded to prednisolone at 60 mg/m2/day, and subsequent frequent relapses were treated sequentially with oral cyclophosphamide 168 mg/kg over 8-12 weeks (n = 10), CYA (n = 10), intravenous mustine or a second course of cyclophosphamide (n = 7) and then TAC (n = 10). The initial daily treatment of CYA and TAC in two divided doses was 5 and 0.1 mg/kg/day, respectively; targeted 12 h blood drug levels were of 50-100 microg/l for CYA and 5-10 microg/l for TAC. Patients underwent renal biopsy and the formal glomerular filtration rate (GFR) was measured using plasma clearance of the Inutest method every 2-3 years while receiving CNIs. Six patients continued with TAC; in four patients, TAC was discontinued because of poor response (n = 2), hypertension (n = 1) and glucose intolerance (n = 1). For CYA and TAC treatment periods, the median NS relapse rate was two and one relapses per year, respectively, and cumulative steroid dosage was 73.9 and 105.2 mg/kg/day, respectively (P = 0.54). The reduction in GFR was 5.8 and 11.7 ml/min/1.73 m2 during these periods. Three of the 10 patients showed histological evidence of mild CNI nephrotoxicity over the whole of the CNI treatment period despite achieving target therapeutic drug levels; no significant change in measured or calculated GFR over this prolonged CNI therapy was observed. Antihypertensive medication was prescribed for 11 of 31 CYA and 22 of 40 TAC treatment years. Growth was maintained during the entire CNI therapy period with median change in height SD scores (SDS) of +0.37 and -0.03 over CYA and TAC, respectively (P = 0.13).

CONCLUSION

In conclusion, we observed that the replacement of CYA by TAC does not lead to a better management of severe SDNS.

Tacrolimus therapy in pediatric patients with treatment-resistant nephrotic syndrome

This is a retrospective analysis of 16 children started on tacrolimus with various types of treatment-resistant nephrotic syndrome. There are 13 patients with focal glomerulosclerosis, 1 minimal change disease, and 2 IgA nephropathy with nephrosis. The mean age of the children was 11.4 years (range 3.5-18.1 years) with a mean age at diagnosis of 5.6 years (range 1.6-13.3 years). All patients initially received prednisone 2 mg/kg per day. Other therapies for 15 of 16 included cyclosporine (n=15), chlorambucil (n=5), mycophenolate mofetil (n=5), levamisole (n=3), i.v. methylprednisolone (n=3), and cyclophosphamide (n=2). The major indication for the initiation of tacrolimus included treatment resistance/dependence (n=15) and intolerable side effects from other therapies (n=1). The average time from the diagnosis to initiation of tacrolimus was 5.3 years (range 0.3-13.3 years, median 6 years). The initial dosage of tacrolimus utilized was 0.1 mg/kg per day divided into two doses. The mean follow-up period was 6.5 months (range 2.5-18 months). Thirteen patients (81%) went into a complete remission within an average of 2 months (range 0.5-5.5 months), with 3 patients relapsing while on treatment. Three patients did not respond. Of these, 2 had partial remissions (13%) and 1 failed to respond. Adverse events included anemia (n=1), seizure (n=1), worsening or new-onset hypertension (n=5), and sepsis (n=1). All patients remain on tacrolimus. Tacrolimus is an effective, well-tolerated medication for treatment-resistant forms of nephrotic syndrome in children, with a complete remission rate of 81% and a partial remission rate of 13% (totaling 94%).

Combined therapy of tacrolimus and corticosteroids in cyclosporin-resistant or -dependent idiopathic focal glomerulosclerosis: a preliminary uncontrolled study with prospective follow-up

BACKGROUND

Cyclosporin has improved the outcome for steroid-resistant patients with focal glomerulosclerosis, but there is a proportion of patients that are either cyclosporin-resistant or suffer relapses, needing long-term therapy to sustain the remission. In these cases, preliminary reports suggest that tacrolimus could be an alternative therapy, but to date the evidence is limited to small series of patients with no long-term follow-up.

METHODS

In this study we analysed the efficacy and safety of a combined therapy of tacrolimus and steroids in 25 patients (mean serum creatinine= 1.24+/-0.49 mg/dl; mean proteinuria=10.2+/-9.5 g/day; mean serum albumin=2.4+/-0.58 g/dl) with idiopathic primary focal glomerulosclerosis and proven resistance to or dependence on cyclosporin A.

RESULTS

After a 6 months trial of tacrolimus and steroids, proteinuria decreased in 17 patients (68%) (complete remission in 10 patients (40%), partial remission in two patients (8%) and a moderate reduction in proteinuria to levels <3 g/day was seen in five additional patients (20%)). The only predictor of response to tacrolimus was a previous response to cyclosporin and prednisone, either as a complete or partial remission (remission rate 75% vs 15.3; P=0.036). Mean time to remission was 112+/-24 days. After tacrolimus discontinuation, 13/17 patients (76%) relapsed and were treated with a second trial of tacrolimus for 1 year, achieving complete remission in five patients (38.4%), partial remission in four patients (30.7%) and reduction of proteinuria <3 g/day in four patients (30.7%). After 2 years of follow-up, 12 patients (48%) were on sustained remission. The main side effect was acute reversible nephrotoxicity (40%). Predictors of renal toxicity were age (P=0.037), baseline creatinine (P=0.046) and tacrolimus trough level (P=0.001).

CONCLUSIONS

We conclude that combined therapy of tacrolimus and steroids induce sustained remission of proteinuria in a significant number of patients with idiopathic focal glomerulosclerosis whose disease was not controlled by the standard therapy of steroids and cyclosporin A.

Plasmapheresis reduces proteinuria and serum capacity to injure glomeruli in patients with recurrent focal glomerulosclerosis

To test the hypothesis that a circulating mediator is associated with recurrent idiopathic focal glomerulosclerosis (FGS), we studied the effect of plasmapheresis on reducing proteinuria in patients with the disease. An in vitro assay measured the capacity of sera before and after plasmapheresis to cause increased albumin permeability (P(albumin)++) in isolated rat glomeruli. Nine patients (five males aged 2 to 66 years) who underwent plasmapheresis for recurrent FGS were identified. Study variables included age, sex, time from diagnosis of recurrence to first pheresis, glomerular hyalinosis, complications, outcome, and proteinuria before and after plasmapheresis. Rat glomeruli were isolated in medium containing 4 g/dL bovine serum albumin, and P(albumin) was determined from the change in glomerular volume in response to an albumin gradient after incubation of the glomeruli in a 1:50 dilution of patient serum. Plasmapheresis reduced proteinuria from a mean of 12 +/- 7.46 g/24 hr to 5.1 +/- 7.39 g/24 hr (P = 0.03). Six patients in whom the diagnosis was made early in the course of the disease and in whom plasmapheresis was initiated immediately had lasting remissions. Preplasmapheresis biopsies in the patients who did not achieve remissions showed both epithelial foot process effacement and glomerular sclerosis. Serum samples were available from four patients for albumin testing in vitro. P(albumin)++ was reduced from a mean of 0.76 +/- 0.17 before pheresis to 0.18 +/- 0.31 after (P = 0.07). Therefore, the mechanism by which plasmapheresis reduces proteinuria in patients with recurrent FGS involves the decreased capacity of sera from these patients to injure the glomerular permeability barrier.(ABSTRACT TRUNCATED AT 250 WORDS)

Tacrolimus, a new immunosuppressant--a review of the literature

OBJECTIVE

To review the clinical pharmacology, pharmacokinetics, adverse effects, therapeutic uses, and current status of tacrolimus.

DATA SOURCES

Data from scientific literature were identified by a MEDLINE search. The data were extracted, evaluated, and summarized for presentation. Experiences from studies evaluating tacrolimus in the form of articles, abstracts, letters to the editor, or proceedings were considered for inclusion.

STUDY SELECTION

Open and controlled clinical and animal trials were reviewed in evaluating the pharmacology, pharmacokinetics, and adverse effects of tacrolimus.

DATA EXTRACTION

Data from animal and human studies published in the English literature were evaluated.

DATA SYNTHESIS

Tacrolimus is an 822-kDa macrolide antibiotic that has potent immunosuppressive properties. The mechanism of action is similar to that of cyclosporine in that it ultimately blocks the production of interleukin 2, thereby inhibiting further T-lymphocyte proliferation. Tacrolimus is metabolized solely in the liver and the metabolites are primarily excreted in the bile. The elimination half-life of tacrolimus is approximately 8.5 h, and is prolonged in hepatic dysfunction. Tacrolimus has shown efficacy in the prophylaxis of allograft rejection in both animals and human clinical trials, and has been used effectively to rescue patients who have exhibited refractory rejection failing cyclosporine prophylaxis. Adverse effects requiring tacrolimus dosage adjustment include nephrotoxicity, neurotoxicity, alterations in glucose metabolism, and infection or susceptibility to malignancy.

CONCLUSIONS

To date, trials comparing tacrolimus with cyclosporine are not available in the literature; however, tacrolimus appears to be useful in rescuing grafts, particularly liver grafts that fail cyclosporine-based immunosuppression. Direct comparisons with cyclosporine are needed to define the role of tacrolimus as primary transplant therapy.

Recurrent focal glomerulosclerosis: natural history and response to therapy

PURPOSE

Recurrent focal glomerulosclerosis (FGS) has been well documented since it was first reported in 1972. However, the course of the disease after transplantation and the optimal treatment regimen have not been well defined since the introduction of newer treatment modalities.

PATIENTS AND METHODS

We reviewed all the charts of patients with biospy-proven FGS who received renal transplants at our institution from January 1980 through December 1990. Case histories consistent with diagnoses other than primary FGS (such as reflux nephropathy or intravenous drug use) were eliminated from the study. During this time period, 78 allografts were received by 71 patients with FGS. Independent variables that were analyzed included sex, race, time in months between the diagnosis of FGS and end-stage disease (dialysis or transplantation), age at time of transplantation, type of dialysis, source of allograft (cadaveric or living related), haplotype matching, donor-specific transfusions, age and sex of the donor, post-transplantation acute tubular necrosis, rejection episodes, immunosuppression regimen, use of plasmapheresis and angiotensin converting enzyme (ACE) inhibitors, and outcome.

RESULTS

FGS recurred in 25 allografts (32%) of 21 patients. Biopsy-proven diagnosis of recurrence was made a mean of 7.5 months (range: 0.5 to 44 months) after transplantation. Patients who had rapid progression to end-stage disease tended to experience more frequent recurrences. Of seven patients who received a second transplant, five patients lost the first graft to recurrent FGS, and four of those patients (80%) had a recurrence in the second allograft. Recurrent disease developed in 34% of patients concurrently treated with cyclosporine and in 28% of those treated with prednisone and azathioprine alone (NS). Patients with recurrent FGS who were treated with ACE inhibitors benefited from a significant reduction of proteinuria. Six patients underwent plasmapheresis after diagnosis of the recurrence. Three of five patients in whom the diagnosis was made early in the course of the disease and in whom plasmapheresis was initiated immediately had reversal of epithelial foot process effacement and remission of proteinuria. End-stage disease eventually developed in 14 allografts (56%) an average of 23.7 months (range: 1 to 65 months) after diagnosis of recurrent disease. The cause of failure was chronic rejection in four allografts and recurrent disease in the remaining 10 allografts.

CONCLUSIONS

FGS recurs in approximately 30% of allografts and causes graft loss in half of these. Patients who have lost a first allograft to recurrent FGS are at high risk for developing recurrent disease in a second allograft. Prolonged allograft survival is possible in patients with recurrent FGS and may best be obtained with a combination of treatment modalities including cyclosporine (perhaps in higher dosages than are routinely used in clinical renal transplantation), ACE inhibitors, and early use of plasmapheresis. The efficacy of these modalities supports the notion that recurrent FGS is caused by a circulating humoral mediator.

FK 506: an immunosuppressant for the 1990s?

The novel macrolide immunosuppressant FK 506 is a powerful and selective anti-T-cell agent which has a similar mode of action to that of cyclosporin. Clinical studies of FK 506 in liver allograft recipients indicate a lower risk/benefit ratio than with cyclosporin, and wider evaluation of FK 506 in transplant recipients is now under way in multicentre, prospective, controlled trials in both Europe and North America.