Induction versus noninduction in renal transplant recipients with tacrolimus-based immunosuppression

BACKGROUND

The aim of this study was to compare the efficacy and safety of induction treatment with antithymocyte globulins (ATG) followed by tacrolimus therapy with immediate tacrolimus therapy in renal transplant recipients.

METHODS

This 12-month, open, prospective study was conducted in 15 centers in France and 1 center in Belgium; 309 patients were randomized to receive either induction therapy with ATG (n=151) followed by initiation of tacrolimus on day 9 or immediate tacrolimus-based triple therapy (n=158). In both study arms, the initial daily tacrolimus dose was 0.2 mg/kg. Steroid boluses were given in the first 2 days and tapered thereafter from 20 mg/day to 5 mg/day. Azathioprine was administered at 1-2 mg/kg per day.

RESULTS

At month 12, biopsy-confirmed acute rejections were reported for 15.2% (induction) and 30.4% (noninduction) of patients (P=0.001). The incidence of steroid-sensitive acute rejections was 7.9% (induction) and 22.2% (noninduction)(P=0.001). Steroid-resistant acute rejections were reported for 8.6% (induction) and 8.9% (noninduction) of patients. A total of nine patients died. Patient survival and graft survival at month 12 was similar in both treatment groups (97.4% vs. 96.8% and 92.1% vs. 91.1%, respectively). Statistically significant differences in the incidence of adverse events were found for cytomegalovirus (CMV) infection (induction, 32.5% vs. noninduction, 19.0%, P=0.009), leukopenia (37.3% vs. 9.5%, P<0.001), fever (25.2% vs. 10.1%, P=0.001), herpes simplex (17.9% vs. 5.7%, P=0.001), and thrombocytopenia (11.3% vs. 3.2%, P=0.007). In the induction group, serum sickness was observed in 10.6% of patients. The incidence of new onset diabetes mellitus was 3.4% (induction) and 4.5% (noninduction).

CONCLUSION

Low incidences of acute rejection were found in both treatment arms. Induction treatment with ATG has the advantage of a lower incidence of acute rejection, but it significantly increases adverse events, particularly CMV infection.

Multicenter trial of one HLA-DR-matched or mismatched blood transfusion prior to cadaveric renal transplantation

BACKGROUND

The beneficial effect of blood transfusions before cadaveric renal transplantation on allograft survival, although previously well documented, has become controversial in light of their adverse effects. Recently, it has been suggested that their clinical benefits are due to HLA-DR sharing between the blood donor and recipient.

METHODS

In this prospective study, 144 naive patients were randomly assigned to receive one unit of blood matched for one-HLA-DR antigen (N = 49), or one unit of mismatched blood (N = 48), or to remain untransfused (N = 47). Graft survival and acute rejection rate were analyzed in 106 cadaveric renal allograft recipients receiving the same immunosuppressive protocol.

RESULTS

Graft survival was similar in the three groups at one and five years: 91.7 and 80% in untransfused patients, 90.3 and 79.3% in patients transfused with one DR-antigen-matched unit, and 92.3 and 83.7% in patients transfused with HLA-mismatched blood. The difference in the incidence of six-month post-transplant acute rejections was not statistically significant in the three groups: 12 out of 36, 33.3% in nontransfused patients; 6 out of 31, 19.4% in patients transfused with one DR-matched blood; and 13 out of 39, 33.3% in patients transfused with mismatched blood.

CONCLUSION

The results of our prospective randomized trial showed that in a population of naive patients, one transfusion mismatched or matched for one HLA-DR antigen given prior to renal transplantation had no significant effect on the incidence and severity of acute rejection, and did not influence overall long-term graft outcome. Considering the potentially deleterious adverse effects of blood transfusions, the costs, and the considerable logistical efforts required to select and type blood donors, such a procedure cannot be recommended in a routine practice for patients awaiting cadaveric kidney transplantation.

[Hand-assisted laparoscopic bi-nephrectomy for refractory arterial hypertension in kidney transplantation]

OBJECTIVE

The authors report their preliminary experience of a manually assisted laparoscopic bilateral nephrectomy technique for refractory hypertension in renal transplant recipients.

MATERIAL AND METHODS

Between April and May 1999, 2 laparoscopic bilateral nephrectomies were performed with manual assistance using the Hand-Port. One patient was operated 4 months before renal transplantation and the other was operated 13 months after renal transplantation. Both patients presented severe hypertension refractory to several antihypertensive drugs. An 8 cm midline supra-umbilical incision and 3 trocars were necessary. One hand was introduced into the abdominal cavity via the Hand-Port at the beginning of the operation. The intra-abdominal hand assisted all phases of dissection of the kidney and control of vessels. The renal vessels and ureter were clipped. The kidneys were removed by the intra-abdominal hand through the supra-umbilical incision.

RESULTS

Operating times were 200 min and 130 min. Blood loss was 220 ml. No conversion was performed. The duration of major postoperative analgesics was 3 days. Length of hospital stay was 6 days and 7 days. There were no complications. Blood pressure was controlled by bilateral nephrectomy in both cases, with significant reduction of antihypertensive therapy. One year after the operation, both patients were satisfied with the aesthetic result.

CONCLUSIONS

Laparoscopic bilateral nephrectomy manually assisted by the Hand-Port is an alternative to open bilateral nephrectomy. Larger series are necessary to evaluate the morbidity of this technique.

Hand-assisted laparoscopic live donor nephrectomy in a patient with renal artery aneurysm

Among the transplantation teams there is an increasing interest in laparoscopic live donor nephrectomy. For technical reasons, the use of the left kidney is recommended. However, considering the shortage of organ donors, it is likely that right-side laparoscopic live donor nephrectomy will need to be considered in selected donors, even those with vascular anomalies. Here we report the first case of right-side live donor laparoscopic nephrectomy in a patient with a renal artery aneurysm. Arteriography showed a 3-cm saccular aneurysm of the main right renal artery located at the bifurcation of the secondary branches and associated with an inferior polar artery coming directly from the aorta. The patient was placed in the lumbotomy position. An 8-cm midline incision was made above the umbilicus to insert the HandPort system (Smith & Nephew S.A., 72019 Le Mans Cedex2, France). Four additional trocars were introduced. Dissection of the renal artery was carried out beyond the level of relieving the aneurysm behind the vena cava. The main and polar arteries were clipped, and the renal vein was stapled. The kidney was removed through the HandPort and perfused cold ex vivo. The warm ischemia time for the kidney was 1 min, and the total operative time was 280 min. Vascular abnomalies were corrected ex vivo. The postoperative course of the donor was uneventful. At 6 months after transplantation, the graft function was normal. The hand-assisted approach is of particular value on the right side where the dissection must be carried out behind the vena cava. The HandPort may save few precious minutes over the sac extraction technique of the standard laparoscopic procedure.

Cyclosporine withdrawal in stable renal transplant recipients after azathioprine-mycophenolate mofetil conversion

BACKGROUND

Cyclosporine A (CsA) nephrotoxicity is a nonimmunologic factor of chronic allograft dysfunction (CAD) in kidney transplant recipients. Mycophenolate mofetil (MMF) may allow CsA dosage reduction or even complete withdrawal in selected populations with CsA nephrotoxicity or CAD. The aim of the present study was to evaluate the efficacy and safety of CsA withdrawal after azathioprine (AZA)-MMF conversion in a population of stable renal transplant recipients.

METHODS

Twenty-eight first cadaver kidney recipients were included. AZA was then discontinued, MMF was introduced and after 4 months CsA was completely withdrawn. All patients underwent inuline clearance measurement and renal biopsy at inclusion and at the end of the follow-up (40 wk).

RESULTS

CsA was completely discontinued in 20 patients. No patient lost his graft during the study period, but 1 patient experienced a reversible acute rejection episode. Inuline clearance improved significantly in the whole series. At the end of follow-up, histological worsening was observed in 50% of patients without any specific risk factor. In these patients, inuline clearance did not improve. Systolic blood pressure, the need for anti-hypertensive drugs and HDL cholesterol improved.

CONCLUSION

In stable kidney transplant recipients, CsA withdrawal after AZA replacement by MMF switch was safe with regard to acute rejection. It improved blood pressure and the lipid profile, but, in 50% of patients was associated with histologic deterioration.

[Kidney harvesting in living donors with manually assisted laparoscopy: technique and results]

OBJECTIVE

To evaluate the feasibility and complications of manually assisted laparoscopic live donor kidney harvesting.

MATERIAL AND METHOD

Since June 1999, all related live donor kidney harvests have been performed by manually assisted laparoscopy. The patient is placed in the lumbotomy position and an 8 cm midline periumbilical incision is made. The assistant's hand is introduced through a watertight port (HandPort). Three trocars are used. The assistant presents the structures to be dissected and controls the ureter. The artery is clipped and the vein is stapled or clipped, depending on its diameter. The kidney is extracted via the midline incision and washed.

RESULTS

Five kidney harvests were performed (three right kidneys and two left kidneys) with a mean operating time of 220 +/- 30 minutes. Conversion was necessary in one case following the intraoperative discovery of two right renal veins. Warm ischaemia lasted 5 minutes for the first patient and one to two minutes for the other four non-converted patients. Blood losses were minimal. The mean duration of major analgesia was 2.4 days and the mean length of hospital stay was 7.2 days. Complications were: bacteriuria in 2 cases and prolonged lymphorrhoea in 1 case. One transplanted kidney had to be removed because of immediate thrombosis of the recipient iliac artery. With a mean follow-up of 6 months (1 to 12 months), no ureteric or venous complications have been observed in the 4 evaluable transplanted kidneys.

CONCLUSION

An intra-abdominal hand during laparoscopic live donor kidney harvesting simplifies dissection, ensures intraoperative security and allows rapid extraction of the kidney.

Focal segmental glomerulosclerosis associated with mitochondrial cytopathy

BACKGROUND

The nonspecific lesion of focal segmental glomerulosclerosis (FSGS) can occur as a primary disease or in a variety of secondary settings. In mitochondrial cytopathies (MCs), the phenotypic expression of the disease depends on the degree of cellular dysfunction, and this correlates with the proportion of abnormal mitochondrial DNA in the cells and the dependence of tissues on oxidative metabolism. The most common renal manifestation in MCs is tubular dysfunction; little has been reported about glomerular diseases.

METHODS

Cases of four adult patients with FSGS and MC are reported. Routine histology and mitochondrial DNA analysis were carried out on renal biopsies.

RESULTS

Family history and clinical manifestations in the four patients with FSGS suggested a diagnosis of MC. An A3243G transition in the mitochondrial DNA tRNA(leu(UUR)) was found in lymphocytes and kidney. Glomerular lesions of FSGS were associated with unusual hyaline lesions, which appeared to represent individual myocyte necrosis in afferent arterioles and small arteries.

CONCLUSION

FSGS is a renal manifestation of MCs. The renal lesion can precede other manifestations of the genetic disease by many years. The striking arteriolar lesions in these cases may have resulted in glomerular hypertension and hyperperfusion, leading to secondary epithelial cell abnormalities and, ultimately, FSGS. However, primary epithelial cell dysfunction caused by mitochondrial defects could not be ruled out on morphological grounds. MCs should be considered in cases of so-called primary FSGS, particularly if there is a familial history of diabetes, neuromuscular disorders, or deafness.

Hemolytic uremic syndrome. Recurrence after renal transplantation. Groupe Coopératif de l'Ile-de-France (GCIF)

Hemolytic uremic syndrome (HUS) is an uncommon cause of end-stage renal failure in adults, and few data are available concerning the outcome of renal transplantation in these patients. We conducted this retrospective multicentric study to appreciate the outcome of adult renal transplant recipients whose primary disease was HUS. Sixteen patients, transplanted between 1975 and 1995, were included in the study. In each case, initial diagnosis of HUS was documented by a kidney biopsy. These 16 patients received a total of 25 allografts: 1 graft for 9 patients, 2 grafts for 5 patients, and 3 grafts for 2 patients. Nine patients (56%) developed definite clinical and pathologic evidence of recurrence on at least 1 graft. Four additional patients (25%) demonstrated only some clinical or pathologic evidence of recurrence which could not be distinguished from acute vascular rejection. Three patients had no sign of recurrence of the initial disease. The 1-year graft survival rate was 63% and the 5-year graft survival rate was 18.5%. In the group of patients with proven or possible recurrence (n = 13), the 1-year and 5-year graft survival rates were 49% and less than 10%, respectively. The recurrence was an early event, occurring before the end of the first month after transplantation in half the cases. The recurrence rate was 92% in non-nephrectomized patients and 50% in patients with bilateral nephrectomy. In the literature, 71 adult patients with primary HUS had received a total of 90 kidney grafts. Among them, 54% had a recurrence on their graft, which was diagnosed in 52% of the kidney transplants. It is note-worthy that when data from the literature are pooled with our results, the rate of recurrence appears to be significantly lower in binephrectomized patients than in patients with their native kidneys at the time of transplantation (5 of 14 versus 27 of 35 patients, respectively, p = 0.0155). By univariate analysis, no other risk factor for recurrence could be identified. Treatment with cyclosporine A did not influence the recurrence rate. We conclude that recurrence of HUS after renal transplantation is a frequent, early, and severe complication, leading rapidly to graft loss. Prospective studies are needed to confirm that bilateral nephrectomy prior to transplantation decreases the rate of recurrence.

Development of cytomegalovirus resistance to ganciclovir after oral maintenance treatment in a renal transplant recipient

The emergence of a resistant strain is a theoretical threat after extensive use of antiviral drugs. We report the emergence of a ganciclovir-resistant cytomegalovirus (CMV) strain in a kidney transplant recipient during oral ganciclovir maintenance treatment. The patient was treated by oral ganciclovir for 2 months after successful treatment of CMV primary infection by intravenous ganciclovir. He developed a new episode of CMV infection with no clinical response to intravenous ganciclovir. The CMV isolate exhibited both phenotypic and genotypic resistance to ganciclovir. The CMV isolate was constituted of a mixture of strains, with and without a mutation at codon 460 of the UL97 gene. The clinical condition improved when mycophenolate mofetil (MMF) was discontinued, and a short course of intravenous globulin was added to ganciclovir. The emergence of the CMV strain could be secondary to more potent immunosuppression provide by MMF or subtherapeutic level obtained during oral ganciclovir treatment. We believe that ganciclovir resistance must be part of the differential diagnosis when a patient relapses or fails to respond to ganciclovir treatment.

Human herpes virus-8 and other risk factors for Kaposi's sarcoma in kidney transplant recipients. Groupe Cooperatif de Transplantation d' Ile de France (GCIF)

BACKGROUND

The exact reasons for the high incidence of Kaposi's sarcoma (KS) after kidney transplantation are still unknown. Immunosuppression is classically considered as the main risk factor, but the relative risk contributed by the patient's geographic origin and by human herpes virus (HHV)-8 infection still has to be determined.

METHODS

We carried out a retrospective and a prospective study among kidney transplant recipients (TP) to identify the risk factors for posttransplantation KS. Each of 30 KS patients was matched with two controls to investigate the association with geographic origin, immunosuppressive regimen, HHV-8 antibodies before and after transplantation, and other infections. Among TP with new onset of KS, we prospectively evaluated HHV-8 serology and viremia in response to decreased immunosuppression.

RESULTS

African and Middle East origins, past infection with hepatitis B, hemoglobin level <12 g/dl, lymphocyte count <750/mm3 at the time of diagnosis and initial use of polyclonal antilymphocyte sera were risk factors for KS. After multivariate analysis, origin in Africa or Middle East and use of antilymphocyte sera for induction remained as independent risk factors. Sixty-eight percent (17/25) of TP with HHV-8 antibodies before or after transplantation developed KS compared with 3% (1/33) of seronegative TP (P<0.00001). HHV-8 DNA was detectable in seven of nine peripheral blood mononuclear cells (PBMC) and in six of six KS lesions at diagnosis; it became negative in PBMC in three of five patients in parallel with tumor regression.

CONCLUSION

African and Middle East geographic origins, HHV-8 infection before and after kidney transplantation, and initial use of polyclonal antilymphocyte sera were independent risk factors for KS. The presence of HHV-8 antibodies before or after transplantation was highly predictive of the emergence of posttransplantation KS and conferred a 28-fold increased risk of KS (odds ratio=28.4; 95% confidence interval: 4.9-279). Detection of HHV-8 DNA within PBMC and KS lesions seems related to tumor burden and evolution.

Long-term outcome of kidney transplantation in patients with systemic lupus erythematosus: a multicenter study. Groupe Cooperatif de Transplantation d'île de France

BACKGROUND

The outcome of 60 renal transplantations in 53 patients with end-stage renal disease (ESRD) because of lupus nephritis was studied retrospectively and compared with 106 controls matched for age, sex, maximum panel-reactive antibody (PRA) level, and date of transplantation.

METHODS

The patients received their transplants over a 260-month period (21.5 years) between October 1971 and August 1993. The population was predominantly women (90%), and the mean age at the time of the transplantation was 33.2 years (range: 21-54 years). Fifty-six transplants (93%) were from cadaveric donors, and 4 (7%) were from living-related donors; 46 patients (86%) had primary allografts, and 7 (14%) received a second allograft. The duration of disease before transplantation was 93.6+/-6.2 months, and the duration of dialysis before transplantation was 48+/-6 months.

RESULTS

No patient had clinically active systemic lupus erythematosus (SLE) at the time of transplantation. The 1-year graft and patient survival rates were 83% and 98%, and the 5-year graft and patient survival rates were 69% and 96%. Actuarial graft and patient survival rates in SLE patients were not significantly different from those of the matched control group. Chronic rejection was the major risk factor for graft loss. Lupus nephritis recurred in the graft of one patient 3 months after transplantation, and there were extrarenal manifestations of SLE in four others.

CONCLUSIONS

The present study confirms that patients with SLE can receive transplants with excellent graft and patient survival rates and a low rate of clinical recurrent lupus nephritis.

A randomized multicenter trial comparing leukocyte function-associated antigen-1 monoclonal antibody with rabbit antithymocyte globulin as induction treatment in first kidney transplantations

Adhesion molecules are involved in several steps in the immune response: leukocyte adhesion to the endothelium, transendothelial migration, cooperation between immunocompetent cells, and cytotoxicity. Leukocyte function-associated antigen-1 plays a central role among adhesion molecules. In a multicenter randomized open trial, we compared a monoclonal antibody directed against the alpha chain of LFA-1 (Oduli-momab; IMTIX/Pasteur Mérieux Sérums et Vaccins) with rabbit antithymocyte globulin (rATG; IMTIX/Pasteur Mérieux Sérums et Vaccins), as part of a quadruple sequential protocol in 101 patients receiving a first kidney transplant. Clinical tolerance of anti-LFA-1 mAb was better than that of rATG. Short-term rejection rates (< 15 days) were not significantly different (15% and 16% for anti-LFA-1 mAb and rATG, respectively). However, 11% of the anti-LFA-1 mAb patients experienced rejection during the first 10 days of the treatment course compared with none of the patients treated with rATG. The incidence and severity of acute rejection in the first 3 months was not significantly different between groups. Of the LFA-1 and rATG patients, 96% and 92% of the grafts, respectively, were functioning at 12 months. The incidence and severity of infection, whatever the origin, were comparable in both groups. In addition, it was observed that fewer patients required posttransplantation dialysis in the anti-LFA-1 mAb group (19%, vs. 35% for rATG), although the difference was not statistically significant. Altogether, the beneficial action of this monoclonal antibody on short-term renal function recovery makes it a useful tool in the management of renal patients undergoing kidney transplantation.

Diabetes mellitus after renal transplantation: characteristics, outcome, and risk factors

The incidence and risk factors of posttransplant diabetes mellitus were evaluated in 1325 consecutive renal transplant recipients. Thirty-three (2.5%) patients developed diabetes mellitus requiring insulin therapy. Onset occurred a mean of 5.7 +/- 1.5 months following transplantation. The patients were compared with 33 paired-control kidney recipients. The patients were significantly older than the controls (46.8 +/- 1.9 vs. 40.6 +/- 2.1 years) (P<0.05), and chronic renal failure was more often related to interstitial nephritis (P<0.05). A family history of diabetes mellitus, the body mass index, ethnic origin, HLA phenotype, and the total doses of steroids and cyclosporine were similar in the two groups. The number of patients with at least one rejection episode was significantly higher among the diabetic patients (21 versus 9) but the number of episodes was similar. Diabetes occurred a mean of 1.1 +/- 0.3 months following rejection treatment. Intravenous pulsed prednisolone was always used for anti-rejection therapy. Insulin was withdrawn in 16 cases after a mean of 4 +/- 1 months, independently of steroid dosage reductions. Actuarial patient and graft survival rates were not significantly different, although 6-year outcome tended to be better in the controls (86% versus 93% for patient survival and 67% versus 93% for graft survival). This study suggests that pulsed steroid therapy might be the critical factor in the onset of posttransplant diabetes and that the risk is increased in older patients with chronic interstitial nephrititis.

Hodgkin's disease after transplantation

Hodgkin's disease (HD) has seldom been reported after transplantation. Epstein-Barr virus (EBV) is present in about 50% of Reed-Sternberg cells in HD developing in immunocompetent individuals, but is more frequently found in HD of acquired immune deficiency syndrome patients. We report 7 cases of HD that occurred in transplant recipients. Clinical and pathological data and studies of EBV reveal specific features of HD after transplantation. Six patients received kidney transplants and 1 patient received combined kidney and pancreas transplantation. Immunosuppressive therapy consisted of cyclosporine, steroids, azathioprine, and antilymphocyte globulins. One patient received, in addition, anti-CD3 mAb therapy and an EBV+ B cell lymphoma developed. Retrospective EBV serological data from patients were collected. Tumors were classified according to pathology. EBV studies were conducted by immunohistochemical methods with monoclonal antibodies to EBV-latent membrane protein (LMP) or EBV-nuclear antigen 2 (EBNA2), and by in situ hybridization for latent nuclear EBV-early RNAs (EBERs). The mean lapse of time between transplantation and HD was 49 months. Six patients presented with enlarged lymph nodes and 1 patient presented with liver involvement. HD was classified as IA in 2 patients, IIA in 3 patients, IIIB in 1 patient, and IVB in 1 patient. Four patients had primary EBV infection after graft, before HD, and the others reactivated latent EBV infection. Histological subtypes were mixed cellularity in 6 cases and lymphocytic depletion in 1 case. Latent EBV infection was detected with EBERs in all tumors. Reed-Sternberg cells expressed LMP, and were negative for EBNA2 expression. Six patients were treated: 2 patients at stage I received radiotherapy, and relapsed within 1 year with a more advanced stage of HD; chemotherapy was indicated as primary therapy in 5 patients, and as salvage therapy in 2 patients; it was associated with radiotherapy in 4 patients. Immunosuppressive therapy was reduced in all patients. Four patients were alive and in complete remission 18, 25, 31, and 67 months after chemotherapy, with a functioning graft in 3 patients. Two patients died of infection. Mixed cellularity is the most frequent histological subtype observed in HD occurring in transplant patients. EBV is present in all Reed-Sternberg cells. Posttransplant HD shows similarities with human immunodeficiency virus-associated HD. These facts argue for a role of EBV infection and immunosuppression in the progression of HD after transplantation.

Proton nuclear magnetic resonance spectroscopy of urine and plasma in renal transplantation follow-up

Urine and plasma samples from 39 patients who underwent renal transplantation were analyzed by proton nuclear magnetic resonance (NMR) spectroscopy. The most relevant resonances for evaluating renal function after transplantation were those arising from citrate, trimethylamine-N-oxide (TMAO), alanine, and lactate when compared to creatinine. A resonance at 3.7 ppm was related to cyclosporine toxicity when associated with elevated levels of TMAO. The respective variations in these metabolites in urine could contribute to prognosis and diagnosis of renal function impairment related to cyclosporine toxicity or overdosage, or to rejection. Thus, NMR spectroscopy should improve the follow-up and management of renal transplantation patients.

False-positive HIV antigens related to emergence of a 25-30 kD protein detected in organ recipients

OBJECTIVE

The routine screening of organ donors for HIV-1 since 1985 has markedly reduced the risk of acquiring infection in organ recipients. However, commercial HIV-1 p24-antigen assays reveal false-positive reactivity in certain recipients. This observation will be discussed here.

METHODS

Post-transplantation sera collected sequentially from different organ recipients were tested for HIV antigen: 79 samples were from 14 kidney recipients, 57 from seven bone-marrow allografts and 18 from two heart recipients. Neutralization assays to determine specificity were performed on reactive samples. Immunoblots prepared from sera containing high levels of antigens were tested by Western blot using polyclonal anti-HIV sera.

RESULTS

Abbott HIV-1-EIA kits detected non-neutralizable antigens in early post-transplantation sera from 12 kidney, five bone-marrow and two heart recipients. Using in-house immunoblots prepared from positive non-neutralizing antigen sera, a 25-30 kD protein was detected and shown to be the cause of the false HIV antigen cross-reactivity.

CONCLUSION

False-positive HIV antigens related to the emergence of a 25-30 kD protein in early post-transplantation sera are detectable in transplant recipients.

Recurrence of Fabry's disease in a renal allograft eleven years after successful renal transplantation

A case of Fabry's disease in a renal transplant recipient with a follow-up period of 11 years is reported. The patient suffered from renal, skin, peripheral nerve lesions, and asymptomatic cardiomegaly. Fabry's disease symptoms disappeared after transplantation. Improvement of renal function was rapidly observed, and it remained satisfactory during the whole posttransplantation period. The patient died of a severe, uncontrolled infection and of biliary peritonitis. Autopsy showed a polyvisceral accumulation of sphingolipids deposits. The engrafted kidney was histologically free of disease. Ultrastructurally, it revealed numerous sphingolipid inclusions in the endothelial cells of capillaries. The explanation of this complication could be attributed to: (1) high circulating levels of plasma substrates locally overwhelming the enzymatic capability of the graft endothelial cells; and (2) the endothelial cells originated from the recipient but not from the donor, an occurrence that has been described after transplantation. Rejection and the newly formed deposits in the endothelial cells may lead to the loss of the engrafted organ. As a consequence of the increasing possibility of organ transplantation, this complication should be detected by studying the blood vessels ultrastructurally in order to evaluate the condition of the transplant.

Distinct phenotypic composition of diffuse interstitial and perivascular focal infiltrates in renal allografts: a morphometric analysis of cellular infiltration under conventional immunosuppressive therapy and under cyclosporine A

Phenotypic analysis of interstitial mononuclear cell infiltrates was undertaken in 40 transplant renal specimens obtained from 38 patients in order to assess the influence of immunosuppressive therapy. Thirteen patients were given conventional immunosuppressive treatment (azathioprine and prednisone) and the other 25 received cyclosporine. The immunostaining was performed using seven antileucocyte antibodies by alkaline phosphatase-anti-alkaline phosphatase method. Interstitial infiltrates were distributed in two patterns: diffuse infiltrates and periglomerular/perivascular aggregates. The phenotypic composition was distinct in these two patterns: in diffuse infiltrates, monocytes/macrophages (EBM 11) represented the predominant inflammatory cell and were associated with a minor component of T cells (T 11). In contrast, aggregates had a major T lymphocyte phenotype in addition with few foci of B cells. T4 subset of T lymphocytes always predominated over T8 subset. The repartition and the proportion of each cell type were not significantly different in rejecting and not rejecting grafts and were not affected by the immunosuppressive regimen.

[Indirect approach of stenosis of transplanted kidneys by Doppler echography]

Pulsed Doppler ultrasound for the detection of rejection and renal artery stenoses involving transplanted kidneys was evaluated. Using mean velocity curves, the time interval between the ECG R wave and the onset of peak velocity was measured successively on the renal and ipsilateral iliac arteries and divided by the R-R interval. In 27 patients, a Doppler index defined as the ratio of the standardized renal artery and iliac artery time intervals, was determined and compared to angiographic data. The DI index failed to detect stenoses associated with rejection; conversely, in the absence of rejection, clear separation of patients without (n = 14, DI = 1.03 +/- 0.6) and with (n = 6, DI = 1.24 +/- 0.05) stenosis (t = 7.48, p less than 0.001) was achieved. Thus renal artery stenoses in transplant recipients can be detected by the comparative study of time intervals calculated for renal vessels and for the neighbouring iliac artery.

Percutaneous transluminal angioplasty of renal transplant arterial stenoses

Renal artery stenosis is a relatively frequent occurrence after renal transplantation. Forty-three hypertensive patients with such a stenosis underwent percutaneous transluminal angioplasty (PTA). The procedure was successful in 35 patients (81%). One month after a primary successful PTA, 74% of patients were improved. Restenosis occurred in seven patients. It was diagnosed in all seven before the fifth post-PTA month. In six patients, repeat PTA was attempted and was successful. One year after successful PTA, 67% of the patients were improved. No complication causing loss of renal parenchyma or needing surgery occurred. PTA is the procedure of choice for relief of transplant renal artery stenosis in patients with hypertension refractory to medical treatment or decline in renal function. It is effective and appears safer than surgery.

[Allogeneic immune response after blood transfusion in patients awaiting renal transplantation]

To investigate the mechanisms of the beneficial effect of blood transfusions (BT) on subsequent kidney transplant survival, we studied the influence of 3 planned BT on lymphocyte reactivity and on lymphocytotoxic antibody (LT) production in previously non-transfused uremic patients. A sustained and non-specific decrease in mixed lymphocyte reactivity (MLR) was observed in approximately 60% of the cases, whereas other patients had only a transient decrease but otherwise normal or even increased responses. Neither the pre-BT degree of immune responsiveness nor the clinical status of the patients had any influence on this phenomenon. Similarly, hepatitis B seroprophylaxy or vaccination did not interfere with this BT effect. Anti-HLA, LT, which are potentially harmful for the transplant, were noted in 13% of cases, while 13% additional cases displayed "cold" anti-B lymphocyte LT which do not have the same prognostic value. In some instances, suppression of cellular reactivity developed concurrently with LT production, which indicates that there is no interaction between cellular and humoral responses induced by BT.

Demonstration of a passive Heymann nephritis-like mechanism in a human kidney transplant

The underlying mechanism of human extramembranous glomerulonephritis (EMGN) is generally thought to involve circulating immune complexes. Data presented here suggest that "in situ" formation of immune deposits may also be important in the pathogenesis of EMGN. We describe a patient with a "de novo" EMGN in a kidney transplant a few months after the graft placement. Before transplantation, the patient's serum contained antibodies reacting in vitro with rat kidney brush-border, but serum concentration of these antibodies rapidly decreased prior to the onset of proteinuria. No circulating immune complexes were detected on serial serum samples from the patients. Antibodies which were eluted from the kidney transplant biopsy were shown to react with the brush-border of the proximal convoluted tubule of rat kidney. We postulate that "in situ" formation of immune complexes within the glomerular capillary walls, and not circulating immune complexes, is the pathogenic mechanism responsible for the glomerular lesions of this case of EMGN.

Hepatocyte localization of hepatitis B core and surface antigens in renal transplant recipients. An ultrastructural prospective study

A prospective series of 45 liver biopsies taken from 22 renal transplant patients was investigated for the presence of hepatitis B antigen core (HBc) and surface (HBs) components by electron microscopy. At the time of each biopsy serum HBs Ag was sought by radioimmunoassay. Sections were taken for the detection of HBs Ag by immunofluorescence. In seropositive patients, intravesicular tubular structures resembling HBs Ag were found in 61% of biopsies while the intranuclear core HBc was present in 69%. No correlation could be made between the ultrastructural pattern of the viral components and the intensity of the histological liver damage. During the follow up, there was an accumulation of both HBs and HBc Ag even in a period as short as 1 year. The 9 liver specimens examined after three years of transplantation showed a marked accumulation of both antigens. Thus the expression of HB Ag at the hepatocellular level seems to correlate better with the duration of antigenaemia than with the histological pattern. Lastly, on matched semithin and ultrathin sections, the ground glass appearance of cytoplasm appeared to correlate with smooth endoplasmic reticulum distorsion, irrespective of the simultaneous presence or absence of intravesicular tubular structures. The sanded nuclei expressed a rare massive accumulation of core antigen.

[Significance of lymphocytotoxic antibodies in kidney transplantation revisited (author's transl)]

Lymphocytotoxic antibodies against peripheral blood lymphocytes (LT anti-PBL) were investigated in sera obtained before and after 148 kidney transplantations. Reactivity was assayed on a panel of unrelated donor cells and, in 15 cases, on the kidney donor's lymphocytes. Pretransplant LT anti-PBL, whether they persisted or not after grafting, were of no prognostic value. However, they were associated with longer periods of treatment by chronic hemodialysis, due to an increased frequency of positive cross-matches against potential donors. De novo occurrence of LT anti-PBL after transplantation was more frequently observed in mismatched kidney recipients, and they were significantly correlated to graft failure. In this respect, LT specifically directed to the kidney donor are of more avail than those directed to the panel. Anti-B lymphocyte LT do not seem to be more specific or more predictive for the follow-up of these patients.