Absence of CD4CD25 regulatory T cell expansion in renal transplanted patients treated in vivo with Belatacept mediated CD28–CD80/86 blockade

AIMS

Belatacept is a new recombinant molecule (CTLA4-Ig) that interferes with the second activation signal of T lymphocytes. CTLA4-Ig induced T cell allograft tolerance in rodents but not in primates. We examined the changes in peripheral lymphocyte subsets, including regulatory T cells, in renal transplant patients treated with Belatacept.

METHODS

A cross-sectional immunological study was carried out 6 months after transplantation in 28 patients enrolled in the Belatacept phase II study. Eighteen patients received Belatacept, mycophenolate mofetil and steroids (Belatacept group), while the control group of 10 patients received cyclosporine, mycophenolate mofetil and steroids (CsA group). Lymphocyte subsets were examined by flow cytometry. Foxp3 mRNA expression was measured by quantitative PCR.

RESULTS

The number of T lymphocytes and the percentage of CD3+ T cells were similar in both groups. However, the percentage of CD3+ CD4+ T cells was lower in the Belatacept group than in the control CsA group (B=42.5%+/-13.7 vs CsA=52.9%+/-9, p<0.005), and the percentage of CD3+ CD8+ cells was higher in the Belatacept group than in the control (B=32.9%+/-6.7 vs CsA=19.5%+/-8.2, p<0.0002). The percentage of CD19+ cells was similar in both groups. Among CD56+cells, only the percentage of CD16+ cells was significantly higher in the Belatacept group than in the control (B=82%+/-12 vs CsA=59.7%+/-25, p=0.01). Among CD4 and CD8 T cells the percentage of activated lymphocytes expressing CTLA4, HLA-DR or CD40L was similar in both groups. The percentage of CD4+CD25+ T cells was higher in the CsA group. The percentage of regulatory CD4+CD25+ cells with bright CD25 staining was similar in both groups (B=3.6+/-2.3% vs CsA=4.7+/-1.9%, ns) as was the expression of FoxP3.

CONCLUSION

Our results indicated that Belatacept did not induce regulatory T cell expansion in vivo. We suggest that Belatacept treatment should be maintained after transplantation to allow graft acceptance.

Long-term results (10 years) of a prospective trial comparing Lo-tact-1 monoclonal antibody and anti-thymocyte globulin induction therapy in kidney transplantation

To evaluate long-term patient and graft survival, and the incidence of acute and chronic rejection, infectious diseases and malignancies following induction therapy with a rat monoclonal interleukin 2 receptor antibody, Lo-Tact-1, or anti-thymocyte globulin (ATG). Forty first-time kidney transplant patients were prospectively randomized to two groups between May 1990 and June 1991. Twenty recipients were treated with Lo-Tact-1 (group 1) and the other 20, with ATG (group 2) during the first 14 days of the transplantation protocol. All patients were treated with azathioprine, steroids and cyclosporin A. Data were collected over 10 years. Median age was 42.1 years in group 1 and 39.3 years in group 2. Six recipients died during the 10 years of follow-up. All had functioning grafts. Death-censored graft survival was 35% in group 1 and 45% in group 2 after 10 years (P = NS). The number of acute rejection was similar in the two groups. Chronic allograft rejection was significantly more frequent in group 2 (n = 9) than in group 1 (n = 3), P < 0.05. Viral and bacterial infections were more frequent in group 2 than in group 1 (respectively 8 vs. 2 and 16 vs. 10, P < 0.05). Three patients had cancer. Although both Lo-tact-1 and ATG effectively prevented acute renal rejection, fewer bacterial and viral infections and cases of chronic allograft rejection were observed in Lo-tact-1-treated patients after 10 years of follow-up, demonstrating the potential value of this treatment for kidney transplantation.

Single-Center experience with cyclosporine therapy for kidney transplantation: analysis of a Twenty-Year period in 1200 patients

Since the introduction of cyclosporine (CyA) in our center in February 1983, 1267 kidney transplant patients have received an immunosuppressive regimen based on CyA, usually in association with azathioprine and steroids and following an induction therapy in three quarters of patients. The aim of this study was to retrospectively analyze our 20-year experience with CyA and examine the evolution of therapy during this period. Induction treatment has been less commonly used during the past 5 years. Even in the early years of our experience, CyA doses were low (under 6 mg/kg per day at 3 months after transplantation). Acute tubular necrosis was observed in 39.4% of patients. The incidence of acute rejection episodes has dramatically decreased since 1984, but the frequency of steroid-resistant rejection has remained constant (around 20%). The first year of transplantation, 32.7% of patients had arterial hypertension. De novo diabetes mellitus occurred in 2.5% of patients. An incidence of 11.8% of malignancies was observed. Skin cancer and lymphomas accounted for 50% and 12% of neoplasms. Five-year graft and patient survivals were 70% and 87%, respectively. Renal function remained remarkably constant during the first 10 years of follow-up with a mean creatinine of 150 micromol/L. Chronic allograft nephropathy resulted in 43% graft losses. In conclusion, CyA has been well tolerated in our patients. However, the occurrence of chronic allograft nephropathy was a major concern in our cohort.

Prophylactic use of the IL-2 receptor-specific monoclonal antibody LO-Tact-1 with cyclosporin A and steroids in renal transplantation

LO-Tact-1 is a rat anti-human monoclonal antibody which is directed to the 55-kDa alpha-chain of the interleukin 2 (IL2) receptor. We conducted a pilot trial in 15 first-time cadaveric renal transplant patients undergoing for immunosuppression a 14-day course of LO-Tact-1 (10 mg i.v. daily) together with cyclosporine, low dose steroids (0.5 mg/kg) and azathioprine. Results showed a good immunosuppressive effect, as measured by the similar incidence of acute rejection episodes (0.6 per patient) when compared with 20 patients treated during the same period with our standard quadruple prophylactic combination with higher initial doses of steroids (2 mg/kg) and antilymphocyte globulin (ALG) instead of LO-Tact-1 (0.4 per patient). At 2 years post-transplant, graft survival was 93%, and only 1 patient lost his kidney by rejection. No local or general adverse effect of antibody administration was encountered, and haematological changes remained of minor importance. Local bacterial infection was observed in 3 patients, but viral diseases (including cytomegalovirus, CMV) remained exceptional. In contrast, severe clinical CMV infections occurred in 3 patients (15%) treated by ALG. Nine of 15 patients developed rat-specific antibodies, but only 4 before the completion of LO-Tact-1 treatment, without any correlation with the further development of acute rejection. Patients who suffered rejection had lower LO-Tact-1 levels and higher soluble IL2 receptor levels during the period of infusion, suggesting the crucial importance of pharmacokinetic monitoring to adjust individual doses.

The long-term effect of switching from cyclosporin A to mycophenolate mofetil in chronic renal graft dysfunction compared with conventional management

BACKGROUND

To overcome toxicity of calcineurin inhibitors, recent trials have proposed substituting cyclosporin (CysA) with mycophenolate mofetil (MMF). No data concerning the long-term side effects and long-term renal outcome of this strategy have been published.

METHODS

We retrospectively compared 39 renal transplant patients with chronic graft dysfunction who were subjected to CysA to MMF substitution (group 1) with 39 matched renal transplant patients who were continued on conventional management (group 2). The mean serum creatinine and the slope of deterioration of renal function before the date of the therapeutic intervention (T(0)) were similar in both groups. Follow-up in both groups was 76 +/- 42 months before T(0) and 44 +/- 11 months after T(0).

RESULTS

In group 1, conversion was associated with a decrease of mean serum creatinine concentrations from 192 to 172 micro mol/l at 1 year (P = 0.004) and 159 micro mol/l at 3 years (P < 0.003) after T(0), whereas it remained unchanged in group 2. The systolic blood pressure decreased in group 1 from 155 mmHg before T(0) to 145 mmHg at 1 year (P < 0.01) and 133 mmHg at 3 years (P < 0.001) without any increase of the antihypertensive drug, whereas it did not change in group 2. Lipid profile tended to improve in group 1 after T(0) and was unchanged in group 2. None of the patients in group 1 developed acute rejection after T(0), whereas two acute rejections occurred in group 2. Graft survival, however, was similar in both groups. In group 1, several side effects occurred related to MMF treatment, and led to its discontinuation in two cases and the reduction of its dose for 18 patients (64%).

CONCLUSION

CysA/MMF substitution improves renal function and blood pressure in chronic allograft dysfunction when compared with conventional management. However, CysA/MMF substitution is associated with a high rate of MMF-related side effects, requiring modulation of its dose.

Long-term results of renal transplantation using kidneys harvested from non-heartbeating donors: a 15-year experience

PURPOSE

To expand the pool of suitable organ donors we developed an organ procurement program of non-heartbeating donors during the last 15 years. We compare graft survival in patients receiving renal transplants procured from non-heartbeating with recipients of kidneys from heartbeating donors.

MATERIALS AND METHODS

From 1986 to 1999, 60 renal transplantations were performed with kidneys harvested from non-heartbeating donors (Mastrich category IV). Kidneys were procured using a double balloon triple lumen catheter inserted into the femoral artery. The 60 kidneys were selected from 70 non-heartbeating donors based on age younger than 50 years, warm ischemia less than 30 minutes, creatinine less than 200 micromol./l., and no hypertension or major histological lesions. Long-term results of graft survival and complications were compared with a series of 1,065 renal transplantations performed during the same period with kidneys procured from heartbeating donors.

RESULTS

Mean age of the recipients was statistically different as non-heartbeating donors were older. However, the 10-year graft survival rates were similar in both groups (50% versus 53%). Incidence of ureteral stenosis and fistula, arterial stenosis and thrombosis was not statistically different in both groups. On the other hand, delay graft function was more frequent in non-heartbeating donors (60% versus 40%, p = 0.01).

CONCLUSIONS

Despite a high rate of acute tubular necrosis, kidneys harvested from non-heartbeating donors had the same graft survival rates as those procured from heartbeating donors. Surgical complications were not different. Transplantation of selected kidneys procured from non-heartbeating donors should be promoted as a response to organ shortage.

Long-term results of renal transplantation using kidneys harvested from non-heartbeating donors: a 15-year experience

PURPOSE

To expand the pool of suitable organ donors we developed an organ procurement program of non-heartbeating donors during the last 15 years. We compare graft survival in patients receiving renal transplants procured from non-heartbeating with recipients of kidneys from heartbeating donors.

MATERIALS AND METHODS

From 1986 to 1999, 60 renal transplantations were performed with kidneys harvested from non-heartbeating donors (Mastrich category IV). Kidneys were procured using a double balloon triple lumen catheter inserted into the femoral artery. The 60 kidneys were selected from 70 non-heartbeating donors based on age younger than 50 years, warm ischemia less than 30 minutes, creatinine less than 200 micromol./l., and no hypertension or major histological lesions. Long-term results of graft survival and complications were compared with a series of 1,065 renal transplantations performed during the same period with kidneys procured from heartbeating donors.

RESULTS

Mean age of the recipients was statistically different as non-heartbeating donors were older. However, the 10-year graft survival rates were similar in both groups (50% versus 53%). Incidence of ureteral stenosis and fistula, arterial stenosis and thrombosis was not statistically different in both groups. On the other hand, delay graft function was more frequent in non-heartbeating donors (60% versus 40%, p = 0.01).

CONCLUSIONS

Despite a high rate of acute tubular necrosis, kidneys harvested from non-heartbeating donors had the same graft survival rates as those procured from heartbeating donors. Surgical complications were not different. Transplantation of selected kidneys procured from non-heartbeating donors should be promoted as a response to organ shortage.

Protein A Sepharose immunoadsorption can restore the efficacy of platelet concentrates in patients with Glanzmann's thrombasthenia and anti-glycoprotein IIb-IIIa antibodies

Type I Glanzmann's thrombasthenia is a rare congenital platelet function disorder, characterized by undetectable platelet membrane glycoprotein IIb-IIIa (GPIIb-IIIa). Severe bleeding is controlled by transfusion of normal platelets, leading in some cases to the occurrence of anti-GPIIb-IIIa isoantibodies, which induces a loss of transfused platelet efficacy. We used immunoadsorption on protein A Sepharose (IA-PA), which has been shown to be efficient in decreasing the titre of antibodies in several immune diseases, in three patients with Glanzmann's thrombasthenia and anti-GPIIb-IIIa isoantibodies on five different occasions. IA-PA was well tolerated with no deleterious side-effects reported. It induced a dramatic decrease of total immunoglobulin (Ig)G, including anti-GPIIb-IIIa isoantibody levels, as assessed by the monoclonal antibody-specific immobilization of platelet antigens test and the ex vivo inhibition of normal platelet aggregation induced by the patient's platelet-rich or platelet-poor plasma. Elimination of the antibody was associated with a correction of the bleeding time following platelet transfusion. IA-PA combined with platelet transfusion made it possible to control two life-threatening haemorrhages, and allowed two surgical procedures and one bone marrow transplantation to be performed safely. Our experience suggests that IA-PA, which restores the haemostatic efficacy of platelet transfusion, is a valuable therapeutic strategy in patients with Glanzmann's thrombasthenia and anti-GPIIb-IIIa isoantibodies.

Protein A sepharose immunoadsorption: immunological and haemostatic effects in two cases of acquired haemophilia

Acquired haemophilia is a life-threatening disorder caused by circulating auto-antibodies that inhibit factor VIII coagulant activity (FBIII:C). Immunoadsorption on protein A sepharose (IA-PA) was performed in two bleeding patients with acquired haemophilia: we observed a dramatic and quick decrease in the anti-FVIII:C inhibitor titre leading to a normal, albeit transient, haemostatic status. In one case, IA-PA was the only procedure which succeeded in stopping massive haemorrhage. In the second case, IA-PA reinforced the haemostatic effect of recombinant activated factor VII by increasing the endogenous plasma factor VIII level. The efficacy of IA-PA was sustained with immunosuppressive treatment introduced, respectively, 10 and 15 d before the IA-PA procedures. Our experience with IA-PA suggests that this extracorporeal anti-FVIII:C removal procedure is a valuable therapeutic tool for acquired haemophilia and can alleviate life-threatening haemorrhages.

[Diffuse colitis associated with mycophenolate mofetil treatment: apropos of 1 case]

Mycophénolate mofétil (MMF) or Cellcept is a potent immunosuppressor that inhibits purin synthesis used to prevent human allograft rejection. The most important secondary effects include haematological and intestinal disorders. Among them, diarrhea is the most common. It is dose-dependant and appears commonly during the first 2 months of treatment. Its physiopathology remains unclear. We reported a case of colitis, 6 months after a kidney transplantation. The patient was treated since day 2 with 2 grams per day of MMF. Morphological analysis showed a diffuse colitis from the coecum to the rectum. Histological samples confirmed a colitis with atrophic crypts but with mucosal secretions and some cryptic abscesses. No granuloma or CMV inclusion was founded. Histochemical immunostaining for CMV was negative. Finally, symptoms regressed within 5 days after tapering down MMF dose in association with metronidazole treatment. The role of MMF in inducing colitis is discussed.

[Which urologic treatment alternatives are there for the hemophiliac patient?]

OBJECTIVE

Urological procedures are hazardous for hemophilic patients. The aim of this work is to report the treatment of 22 hemophilic patients in order to define prognosis factors and treatment options.

MATERIAL AND METHODS

22 patients have been treated: 8 had severe hemophilia, 5 A (FVIII < 1%), 3 B (F IX < 1%), 2 had moderate hemophilia A (FVIII 2 to 6%) and 10 minor hemophilia A (F VIII 7 to 30%). Two had acquired hemophilia with auto-anti-FVIII antibodies (ab). Four patients were HIV+. Eighteen patients were first referred to our hospital, and 3 were transferred from an other institution for persistent hematuria: one with anuria, one after bladder neck incision, and the other following suprapubic prostatectomy.

RESULTS

For patients without FVIII ab, a sufficient level of FVIII or IX (> 60%), could be achieved pre-operatively and maintained post operatively (4 to 20 days, according to the surgical procedure) by injections of FVIII, FIX or by injections of desmopressin. For one haemophilia A patient with anti-F VIII ab, transferred for uncontrollable bleeding after bladder neck incision, selective arterial embolization was successful. But for 2 patients with acquired haemophilia, improvement of the coagulation was insufficient, with human or porcine FVIII, activated prothombic complex concentrates or recombinant activated FVII. In spite of surgical procedures and arterial embolizations the 2 patients died.

CONCLUSION

The urological treatment of haemophilic patients needs to be performed in specialised centers. For patients without FVIII ab, classical urological procedures can be performed. But for patients with FVIII ab when alternative treatments (radiotherapy, LHRH agonists) can be used, the surgical procedures must be delayed; in emergency if hemostasis cannot be achieved arterial embolization could be useful.

Low levels of lymphocyte MDR1 gene expression during early renal transplantation in patients treated with tacrolimus

P-glycoprotein (P-gp) is a membrane efflux pump increasing the transport of drugs such as tacrolimus out of the cells. The aim of the study was to determine the kinetics of lymphocyte P-gp expression in patients treated with tacrolimus during the first 3 months following renal transplantation. Lymphocyte MDR1 gene expression was measured by semi-quantitative RT-PCR a few hours before transplantation, 3 weeks and 3 months after the graft. Lymphocyte MDR1 gene expression was low in all the 10 patients compared to 10 healthy volunteers: 0.30 +/- 0.07 arbitrary units (patients) vs. 1.74 +/- 0. 55 (healthy volunteers) (P = 0.0002). MDR1 gene expression decreased among the patients during the study: 0.28 +/- 0.12 (3 weeks later) and 0.12 +/- 0.09 (3 months later) (P = 0.006). We can conclude that lymphocyte MDR1 gene expression among patients before renal transplantation is low and remains low during the first 3 months following the graft.

Severe hemolytic uremic syndrome in an advanced ovarian cancer patient treated with carboplatin and gemcitabine

Hemolytic uremic syndrome (HUS) is a rare clinical and biological entity. HUS has been reported after several anticancer chemotherapies and most often after mitomycin C-based chemotherapy regimens. Little information is available concerning the occurrence and outcome of this syndrome after administration of more recent chemotherapeutic agents. We present a case of HUS in an advanced ovarian cancer patient treated with carboplatin and gemcitabine, and described its favorable outcome after chemotherapy interruption and supportive care with a 1 year follow-up.

Human parvovirus B19 infection in organ transplant recipients

We report a 61-yr-old kidney transplant recipient with human Parvovirus B19 (HPV B19) infection presenting as a severe pancytopenia 1 month after transplantation. Bone marrow aspiration revealed severe erythroid hypoplasia with giant and dystrophic proerythroblasts. Bone marrow cells were positive for HPV B19 DNA detected by polymerase chain reaction (PCR). Pancytopenia resolved shortly after administration of intravenous immunoglobulins. Nineteen cases of HPV B19 infection in organ transplant recipients have been so far reported in the literature. Immunocompromised patients should be considered at risk from developing symptomatic HPV B19 infections. In such patients, specific anti-HPV B19 IgM and IgG antibodies may be absent or transient and therefore their negativity cannot rule out the diagnosis of HPV B19 infestation. Bone marrow smear morphological findings may suggest the diagnosis but testing for viral DNA by PCR is mandatory. Patients may spontaneously recover. However, since specific anti-viral therapy is not currently available, intravenous immunoglobulin administration appears to be the more efficacious treatment.

Post-transplantation polyomavirus infections

Increasing attention has been recently accorded to BK and JC viruses (BKV and JCV). Both these human polyomavirus (HPV) are members of the papovavirus family which includes the simian virus SV 40. BKV and JCV infect more than 60% of the population worldwide. After primary infection, they remain harboured in the kidneys and may become reactivated in situations of immune impairment. HPV were first described in 1971. BKV was isolated in a renal transplant patient with ureteral stricture and JCV in a patient with progressive multifocal leukoencephalopathy (PML). BKV was known to be involved in post-bone marrow transplantation (BMT) hemorrhagic cystitis. In renal transplantation, BKV and JCV were initially found in the post-transplant ureteric stricture and PML. They are now recognised as a possible cause of transplant interstitial nephritis, mimicking rejection (satisfying the Banff criteria for acute rejection) or drug toxicity. In HPV nephritis there is a mixed interstitial inflammatory infiltrate with focal tubular injury; the tubular epithelium shows marked anisonucleosis, nuclear atypia and basophilic or amphophilic intranuclear inclusions. Tubulitis is frequent. DNA hybridisation or gene amplification by polymerase chain reaction usually demonstrate HPV. Although histology with viral nucleic acid detection may be helpful in differentiating viral infection and rejection, confusion between these complications may lead to either anti-rejection therapy, with the risk of over-immunosuppression, or reduction of immunosuppression, with the risk of graft loss. Confusion may also arise with inclusions of other viruses, such as cytomegalovirus, herpes virus and adenovirus. Reactivation of BKV and JCV infection was demonstrated in respectively 22.2% and 10.9% of renal transplant recipients and 55% and 6.7% of BMT patients. Unfortunately, no routine screening is available for these viruses, so this complication is probably underestimated. No specific therapy of HPV infection is currently available.

Incidence and consequences of post-transplantation lymphoproliferative disorders

Post-transplant lymphoproliferative disorder (PTLD) is a recognized severe complication arising in allograft recipients treated with immunosuppressive drugs. Although not common, PTLD is one of the most frequent tumours among graft recipients, comprising 15-25% of neoplasms, compared with 5% in the general population. The introduction of cyclosporin A (CyA) in the early 1980's and the very potent new immunosuppressants such as anti-CD3 monoclonal OKT3 and FK506 have been associated with a significant rise in the incidence of PTLD and with their earlier presentation. The incidence of this malignancy varies with the organ transplanted (1-2% of renal transplant recipients) and with the nature and severity of the accompanying immunosuppressive regimen. While the precise etiology of PTLD is still unclear, significant advances have been made recently in the understanding of its pathogenesis. Most PTLD tumour cells present an activated B-cell phenotype and an unrestricted pattern of latent EBV gene products. It is generally accepted that Epstein-Barr virus (EBV) infection or reactivation and intensive anti-T lymphocyte regimens play a major role in the genesis of PTLD. They include a spectrum of EBV-related disorders ranging from lymphoid hyperplasia to frank malignant non-Hodgkin's lymphoma. Although different therapeutic attempts have been proposed, optimal treatment remains elusive. The mortality rate for monoclonal lymphomas was reported to be as high as 80%. Infusion of anti-B monoclonal antibodies seems to be a promising modality. Different preventive approaches have been proposed, including EBV sero-negative donor/recipient matching and careful monitoring of EBV infection. Cautious use of anti-rejection treatment in combination with prophylactic antiviral therapy is recommended.

Five years' experience at one centre with protein A immunoadsorption in patients with deleterious allo/autoantibodies (anti-HLA antibodies, autoimmune bleeding disorders) and post-transplant patients relapsing with focal glomerular sclerosis

Protein A is extracted from a strain of Staphylococcus aureus and binds specifically to the constant domains of immunoglobulins and possibly to fibronectin. It has already been shown that concentrations of all IgG isotypes (except IgG3) are efficiently decreased by immunoadsorption (IA) on protein A linked to sepharose beads. This system has been developed by Cobe-Excorim Co. to either remove IgG in some instances where they wil be harmful, i.e. allo- and autoantibodies inducing pathological conditions (autoimmune diseases, haematological disorders with allo/autoantibodies, anti-HLA antibodies in sensitized patients awaiting organ transplantation) or treat several immunological diseases with unknown pathogenesis. In our unit, 20 patients with high titres of anti-HLA panel-reactive antibodies, four patients with haematological disorders (haemophilia with anti-VIII antibodies and Glanzmann diseases) and three patients with post-transplant focal glomerular sclerosis (FGS) underwent IA over the past 5 years. Infectious complications were not observed after IA and the procedure was always well tolerated. In spite of the use of adjunctive immunosuppressive therapy with prednisone and cyclophosphamide, and although the reduction in serum IgG was close to 90%, the de novo synthesis of allo- and autoantibodies was important after IA procedures. In the cases of removal of anti-HLA antibodies, patients with a pre-IA antibody titre which was > 1:128 clearly did not benefit from the technique and other immunological criteria were not predictive of efficacy. Fourteen patients were transplanted, four with a well-matched kidney with both pre- and post-IA negative cross-matching, and 10 with a positive historical cross-match with the donor.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of plasma protein adsorption on protein excretion in kidney-transplant recipients with recurrent nephrotic syndrome

BACKGROUND

Among patients with the idiopathic nephrotic syndrome who have focal and segmental glomerulosclerosis and undergo renal transplantation, 15 to 55 percent have recurrent nephrotic syndrome. The recurrence may be caused by a plasma factor or factors that increase glomerular permeability, because plasma exchange transiently decreases or abolishes proteinuria in some patients. We studied the effect on proteinuria of the removal of protein (mostly immunoglobulins) by adsorption onto protein A from the plasma of patients with recurrent nephrotic syndrome.

METHODS

Eight patients were treated with one to three cycles of two to seven 1-day sessions of protein adsorption, and the patients' urinary protein excretion was measured repeatedly. Their immunosuppressive regimens were not changed during the treatment. The adsorbed proteins were eluted from the protein A and injected into rats, and the urinary albumin excretion of the rats was measured.

RESULTS

The protein-adsorption treatment consistently decreased urinary protein excretion by an average of 82 percent at the end of a cycle (P < 0.001). In one patient proteinuria disappeared, and in another urinary protein excretion remained below 2.5 g per day with repeated cycles of protein adsorption. In all but one patient the effect of adsorption was limited in time, with a return to the preadsorption level of protein excretion within a maximum of two months. The administration to rats of material eluted from the protein A increased urinary albumin excretion 2.9- to 4.6-fold (P < 0.001 and P = 0.005, respectively). Although protein A primarily binds immunoglobulins, the active fraction of the eluted proteins had a molecular weight below 100,000, indicating that immunoglobulin was not directly involved.

CONCLUSIONS

Adsorption of plasma protein decreases urinary protein excretion in patients with recurrence of the nephrotic syndrome after renal transplantation. Studies of the adsorbed proteins should provide information about the mechanism of this disease.

How to deal with the hyperimmunized potential recipients

End-stage renal disease (ESRD) patients with high levels of anti-HLA panel reactive antibodies (PRA) represent an increasing group in which sensitization, induced by pregnancies, previous transplants, and blood transfusions, considerably delay the opportunity to receive a graft. Currently, more than 50% of the 4700 patients awaiting transplantation in France are sensitized, of which 33% are defined as hyperimmunized (PRA greater than = 80%), and only 9.5% of the total number of transplants have been done in highly sensitized recipients. The magnitude of this problem, similar in Europe and North America, explains why more active strategies for managing hyperimmunized patients have been introduced during the past decade. Clearly, the simplest is finding of a well-matched organ that does not carry the HLA antigens against which the recipient has generated antibody, but that is limited by the number of shared grafts. The second is the development of a new cross-matching technique prior to transplantation. Attempts at immunoregulation of secreting B cell clones have been carried out using either hypertransfusions or injection of polyclonal Ig. Finally, removal and prevention of the resynthesis of HLA antibodies is a most attractive approach using immunoadsorption (IA) system with sepharose-bound protein-A columns. In our unit, fifteen ESRD patients with high levels of PRA were treated with IA. Infectious complications were not observed after IA and transplantation, and the procedure was well tolerated. In spite of the use of adjunctive immunosuppressive treatment with cyclophosphamide and prednisolone, this method produced only variable effects in lowering PRA levels, and was hampered by high de novo resynthesis of anti-HLA antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunoadsorption of anti-HLA antibodies for highly sensitized patients awaiting renal transplantation

Fifteen end-stage renal disease patients with high titres of panel reactive (PRA) antibodies were treated with immunoadsorption (IA) on sepharose-bound protein A columns in order to remove anti-HLA antibodies and facilitate transplantation. Infectious complications were not observed after IA and transplantation, and the procedure was well tolerated. In spite of the use of adjunctive immunosuppressive treatment with cyclophosphamide and prednisolone, this method produced only variable effects in lowering panel reaction antibodies, and was hampered by high de novo resynthesis of anti-HLA antibodies. Patients whose pre-IA antibody titre was greater than or equal to 1:64 clearly did not benefit from the procedure, but other immunological criteria were not predictive of efficacy. Twelve patients were transplanted on the basis of a negative cross-match with current serum, historical sera being retrospectively tested. Surprisingly, seven patients received a well-matched graft with both pre- and post-IA negative cross-matching. Graft survival was 86% in this group. Conversely, in the group of five transplants which were performed in recipients having a positive historical cross-match with the donor, graft survival was only 40%. One patient died with a functional graft, and two grafts failed due to hyperacute humoral rejection. Humoral rejection in a third patient was successfully treated by a second IA course and administration of polyclonal IgG. We conclude that IA is a safe procedure for managing hyperimmunized transplant candidates. However, its efficacy remains variable, and a better definition of patients who should benefit from IA needs to be found.

[Treatment with Lo-Tact-1, a monoclonal antibody to the interleukin-2 receptor, in kidney transplantation]

From May to August 1989 15 cadaver-donor renal transplant recipients were treated for 14 days with LO-Tact-1 (10 mg i.v. per day) in combination with cyclosporin (8 mg/kg/day from day-1), low-dose steroids (1/2 mg/kg/day from day 1, then reduced to 0.25 mg/kg at day 26 and 10 mg/day at day 45), and azathioprine (1 mg/kg/day) started at day 45. LO-Tact-1 is a rat monoclonal antibody which is directed to the interleukin-2 receptor. The control group consisted of 20 patients receiving cyclosporin, high-dose steroids (2 mg/day at day 1) and a 14-day course of polyclonal horse antilymphocyte globulins (ALG). Seven patients experienced 9 rejections during the first 3 months post-transplant between day 10 and day 67 (mean 0.6 per patient), comparable to the incidence of rejections in the control group: 8 rejections in 7 patients (mean 0.4 per patient). All rejections were reversed by steroid boluses and ATG. To date, all study patients have functioning grafts, and at 1-year post-transplant, the mean blood creatinine level is 161.2 mumol/l. In the control group, one patient died of CMV infection, and 2 other grafts failed due to rejection. No adverse effect of antibody administration was observed, and hematological changes remained of minor importance. Viral infections were not observed, except one case of herpes simplex. Comparatively, clinical CMV infections occurred in 3 patients receiving ALG (15 percent). Our data suggest that a combination anti-IL-2 monoclonal antibody, cyclosporin and low-dose steroids can safely be administered to allograft recipients, avoid severe viral infections, and, in our early experience, is as potent as the powerful combination ALG, cyclosporin and high-doses steroids in preventing allograft rejection.