Evolution of immunoglobulin and mannose binding protein levels after renal transplantation: association with infectious complications

Hypogammaglobulinemia (hypo-Ig) and low mannose binding protein (MBP) levels might be involved in the infectious risk in renal transplantation. In 152 kidney transplant recipients treated with calcineurin inhibitors (CNI) and mycophenolate mofetil (MMF), during the first year, we prospectively recorded the incidence of hypogammaglobulinemia, and low MBP levels. Their influence on infectious complications was evaluated in 92 patients at 3 and 12 months (T3 and T12). The proportion of deficiency increased significantly: hypo-IgG: 6% (T0), 45% (T3), and 30% (T12) (P < 0.001); hypo-MBP: 5%, 11%, and 12% (P = 0.035). Hypo-IgG at T3 was not associated with an increased incidence of first-year infections. A significantly higher proportion of patients with combined hypogammaglobulinemia [IgG+ (IgA and/or IgM)] at T3 and with isolated hypo-IgG at T0 developed infections until T3 compared with patients free of these deficits (P < 0.05). Low MBP levels at T3 were associated with more sepsis and viral infections. Hypogammaglobulinemia is frequent during the first year after renal transplantation in patients treated with a CNI and MMF. Hypo-IgG at T0 and combined Igs deficts at T3 were associated with more infections. MBP deficiency might emerge as an important determinant of the post-transplant infectious risk.

Less-than-subtotal parathyroidectomy increases the risk of persistent/recurrent hyperparathyroidism after parathyroidectomy in tertiary hyperparathyroidism after renal transplantation

BACKGROUND

The optimal surgical approach for tertiary hyperparathyroidism (HPT) after kidney transplantation is unknown. Existing studies are limited by small sample size, lack of adjustment for kidney function, and no long-term follow-up.

METHODS

We retrospectively analyzed 74 patients with tertiary HPT who underwent parathyroidectomy at two centers since 1978. Persistent HPT was defined as parathyroid hormone (PTH) concentrations in excess of the K/DOQI target range for the corresponding estimated creatinine clearance (eCrCl).

RESULTS

Seventy-four patients had 83 operations (72 subtotal and 11 less-than-subtotal parathyroidectomies). Mean follow-up time was 5.4 +/- 4.7 years. Calcium concentrations decreased significantly after parathyroidectomy (2.83 vs 2.28 mmol/L, P < 0.001), as did eCrCl (54.5 vs 44.9 mL/min, P < 0.001) and PTH (382 vs 132 pg/mL, P < 0.001). In the multivariable regression analysis, only the type of operation and postoperative eCrCl were significantly correlated with PTH at follow-up. A limited parathyroidectomy was associated with a fivefold increase in risk of persistent or recurrent hyperparathyroidism.

CONCLUSIONS

The use of limited parathyroidectomy for tertiary HPT after kidney transplantation has a higher risk of persistent/recurrent HPT. Subtotal parathyroidectomy is recommended for patients with tertiary HPT.

Very early steroid withdrawal in simultaneous pancreas-kidney transplants

BACKGROUND

Simultaneous pancreas-kidney (SPK) transplantation is an effective treatment for patients suffering from type 1 diabetes mellitus. Conventional immunosuppressive treatments include steroids that may induce insulin resistance and are responsible for many side effects. In de novo SPK, early withdrawal of corticosteroids may be an important issue.

METHODS

A total of 24 consecutive patients with type 1 diabetes mellitus had been treated by SPK transplantation. All of them had a short induction therapy with anti-thymoglobulin (ATG) and steroids for only 4 days, association with CellCept and tacrolimus. The rate of acute rejection, graft and patient survival and side effects have been analysed.

RESULTS

Patient and kidney survival was 100% and the pancreas survival was 95.6% at 1 year. The rate of acute rejection of kidney and pancreas was 4.2% and 8.3% at 6 months, respectively. The mean serum creatinine was 98.9+/-19.6 micromol/l and the mean HbA1c concentration was 5.1%+/-0.5% at 6 months. Only four patients developed a cytomegalovirus primo-infection, associated in one case with pneumonia, whereas 75% of patients developed a bacterial infection. Because of the occurrence of leucopenia and/or diarrhoea, CellCept has been dramatically decreased in 33% of cases and required the re-introduction of steroids.

CONCLUSION

A short induction with ATG and steroids associated with a chronic therapy with CellCept and tacrolimus is safe and efficient in preventing acute renal rejection in SPK.

Assessment of the risk of chronic allograft dysfunction after renal transplantation in a randomized cyclosporine withdrawal trial

BACKGROUND

We report the two-year follow-up of a trial comparing the three-month postgraft discontinuation of either cyclosporine (CsA) or mycophenolate mofetil (MMF) from a triple-drug regimen after de novo renal transplantation.

METHODS

One hundred and eight patients were enrolled in this study and randomized to be withdrawn from CsA (MMF group, n=54) or MMF (CsA group, n=54).

RESULTS

Despite an increased risk of acute rejection and a lower, but nonsignificant, two-year graft survival, CsA withdrawal induced a sustained improvement of the renal function. At one year, the chronic allograft damage index was similar in both the MMF and CsA groups. However, CsA elimination resulted in a higher incidence of C4d deposits, irrespective of the occurrence of a prior acute rejection. While this finding could suggest a risk of chronic rejection in the MMF group, the outcome did not appear to be related to the C4d status. Moreover, logistic regression analysis showed that only two factors, acute rejection and the one-year glomerular filtration rate level, were predictive of a significant decline of the renal function at two years.

CONCLUSIONS

These results point out the need to secure the minimization of the calcineurin inhibitors after renal transplantation, in order to reduce the risk of acute rejection in these patients, because this strategy allows the improvement of the one-year renal function which is predictive of a chronic allograft dysfunction.

Accuracy of intra-operative PTH measurement during subtotal parathyroidectomy for tertiary hyperparathyroidism after renal transplantation

BACKGROUND AND AIMS

Intra-operative parathyroid hormone (IOPTH) results are not known in the setting of tertiary hyperparathyroidism (HPT) after renal transplantation.

MATERIALS AND METHODS

A retrospective analysis of 35 tertiary HPT patients who all underwent subtotal parathyroidectomy and IOPTH monitoring was conducted.

RESULTS

The mean follow-up time was 2.2+/-1.4 years. Thirty-four patients were cured; one patient (2.8%) had a persistent disease and was cured after reoperation. Median parathyroid hormone (PTH) (median percent decrease from highest) at baseline and at 5, 10, 20, and 30 min were 244, 78 (69%), 63 (75%), 53 (79%), and 49 pg/ml (83%), respectively. Four patients who were cured had a decrease of <50% at 5 min and two of them had a decrease of <50% at 10 min. The patient with persistent disease had a decrease of >50% at 10 min. The sensitivity of the test was 94% at 10 min using the Miami criteria.

CONCLUSION

This study shows that IOPTH in tertiary hyperparathyroidism has a high sensitivity. However, because of the low risk of persistent hyperparathyroidism when a subtotal parathyroidectomy is performed, its potential impact on the overall success rate is very small. We therefore do not recommend the routine use of IOPTH in tertiary hyperparathyroidism.

Renal artery aneurysm secondary to Candida albicans in four kidney allograft recipients

INTRODUCTION

Infection is a frequent cause of morbidity and mortality in solid organ transplant recipients. It may occur at different periods after transplantation. We report four cases of mycotic aneurysms due to Candida albicans (CA) in renal transplant recipients occurring early after kidney transplantation.

CASE REPORTS

Four patients (three men, one woman) aged from 24 to 55 years who underwent cadaveric renal transplantation from three different donors developed a mycotic aneurysm at 9 to 90 days after transplantation. In all cases aneurysms were located at the anastomosis between the renal graft artery and the iliac axis. The clinical presentations were fever in three cases, including endocarditis in one patient or deterioration of graft function in two cases and hemorrhagic shock secondary to a ruptured renal artery in the fourth case, which led to death. The arterial aneurysm was discovered at autopsy. The diagnosis of a mycotic aneurysm was based on morphological investigations: echotomography, spiral computed tomography, and arteriography. In all cases bacteriological studies (blood culture, culture of the aneurysmal wall and content) isolated CA. In three patients CA was isolated from the preservation solution; it was of the same phenotype as the one isolated from the aneurysm in one recipient. Antifungal therapy was started in patients who lived, but all kidney transplants had to be removed. Anatomical results of arterial reconstructions were satisfactory in all cases and remained so during the follow-up.

CONCLUSION

The insidious presentation and clinical course of mycotic aneurysms due to CA require a high degree of suspicion to make the correct diagnosis.

[Results of systematic subtotal parathyroidectomy with thymectomy for tertiary hyperparathyroidism after renal transplantation - 70 patients]

BACKGROUND

Due to the relatively small number of patients involved, there is currently no consensus on what operation should be performed in patients with tertiary hyperparathyroidism after renal transplantation.

METHOD

Retrospective analysis of the 70 patients with tertiary hyperparathyroidism who all underwent subtotal parathyroidectomy with transcervical thymectomy in the same institution between 1978 and 2003.

RESULTS

The delay between transplantation and parathyroidectomy was 4,1+/-4,3 years. Follow up was available for all patients. Mean follow-up was 5,6+/-5 years. Glomerular filtration rate (GFR) was 53+/-21 ml/min at parathyroidectomy and 42+/-29 ml/min at follow-up [<30 ml/min in 26 patients (37%), 30 - 60 ml/min in 25 patients (36%) et>60 ml/min in 19 patients (27%)]. One patient was successfully reoperated for persistent tertiary hyperparathyroidism during follow-up. No patient was hypercalcemic at follow-up. Four patients with a GFR<30 ml/min had a PTH level>fourfold normal values (6%) without signs or symptoms of hyperparathyroidism. One patient was hypocalcemic (1,5%) and two patients were normocalcemic with undetectable or infranormal PTH level (3%) under oral vitamin D and calcium medication.

CONCLUSION

This approach permits not only to cure the majority of patients with tertiary hyperparathyroidism but also to avoid recurrence when the renal function declines. When medical management has failed, we recommend systematic subtotal parathyroidectomy with thymectomy for patients with tertiary hyperparathyroidism and this should usually be performed during the second year after transplantation.

L'imagerie préopératoire des hyperparathyroïdies des insuffisants rénaux a-t-elle un intérêt en pratique clinique ?

AIM OF THE STUDY

To evaluate the efficiency of preoperative parathyroid ultrasonography and scintigraphy in the management of renal hyperparathyroidism.

PATIENTS AND METHODS

The charts of the last consecutive 200 patients who underwent surgery for renal hyperparathyroidism from 1998 to 2003 were retrospectively reviewed to collect data concerning parathyroid gland function, results of preoperative ultrasonography and scintigraphy, as well as modalities and results of surgical exploration.

RESULTS

Ultrasonography and scintigraphy sensibilities were 36.4% and 49.3%, respectively. Efficiency of both examinations was improved when they were combined (sensibility of 64.7%) and in those patients managed for recurrent hyperparathyroidism. Were more often detected by preoperative examinations glands with high weight and/or greatest diameter, orthotopic and inferior glands as well as glands exhibiting nodular hyperplasia content upon pathological examination.

CONCLUSION

Parathyroid ultrasonography and scintigraphy are of poor interest in the management of renal hyperparathyroidism. In a preoperative setting, they should be performed only in patients with recurrent disease.

Subtotal parathyroidectomy with thymectomy for autonomous hyperparathyroidism after renal transplantation

Background

There is currently no consensus on the operation that should be performed in patients with tertiary hyperparathyroidism (HPT) after renal transplantation.

Methods

A retrospective analysis of 70 patients with tertiary HPT who underwent subtotal parathyroidectomy with transcervical thymectomy was performed.

Results

Mean(s.d.) follow-up was 5·6(5·0) years. Mean(s.d.) glomerular filtration rate (GFR) at follow-up was 42(29) ml/min and was less than 30 ml/min in 26 patients (37 per cent), 30–60 ml/min in 25 (36 per cent) and more than 60 ml/min in 19 (27 per cent). One patient had persistent disease and was cured after reoperation. No patient was hypercalcaemic. Four patients (6 per cent) with a GFR below 30 ml/min had a parathyroid hormone (PTH) level more than four times the normal value without any signs or symptoms of secondary HPT. One patient (1 per cent) was hypocalcaemic and two (3 per cent) were normocalcaemic, with undetectable or below-normal PTH levels while receiving oral vitamin D and calcium medication.

Conclusion

Systematic subtotal parathyroidectomy associated with thymectomy is effective in treating most renal transplant recipients with tertiary HPT and also minimizes the recurrence of HPT in patients with declining renal function.

Selection of diabetic patients for islet transplantation. A single-center experience

OBJECTIVE

Since the Edmonton protocol, islet transplantation (IT) offers the prospect of adequate glycemic control with no major surgical risk. In our single-center experience of IT, we studied the recruitment of eligible diabetic patients.

METHODS

Between 1998 and 2002, we screened 79 diabetic patients that were divided into 2 groups according to their renal status: 41 were not receiving dialysis (ND) while 38 were receiving ongoing dialysis (D).

RESULTS

In the ND group, 20 patients initiated the contact with our team, 8 patients were recruited during hospitalization for very poor glycemic imbalance, and 13 were referred by their diabetologist. 14/41 (34%) patients were ineligible for IT either because of very good glycemic balance, detectable C-peptide (C-p), kidney or liver problems, or plans for future pregnancy. 16/41 (39%) did not wish to proceed, 7 of whom were more interested by a pump. 11/41 (27%) were eligible, among which 8 are currently being assessed, 1 is on the waiting list and 2 have been transplanted. In the D group, 17/38 (45%) had a detectable C-p and received a kidney graft alone. Among the remaining 21 C-p negative diabetic patients, 3 were not eligible for kidney transplantation mainly for psychological reasons, and 4 were enlisted for kidney+pancreas transplantation. The remaining 14 C-p negative patients were kidney-transplanted. Among them, 6 were not eligible for IT, mainly for lack of motivation, slightly positive C-p stimulation tests, obesity, cancer, or increased creatininemia. The remaining 8/14 C-p negative kidney-engrafted patients were enlisted for IT. 3 had secondary failure with the pre-Edmonton immunosuppressive (IS) protocol. Five have been transplanted with the Edmonton-like IS regimen.

CONCLUSION

Twenty-five per cent of the 79 patients for whom islet transplantation was considered underwent pregraft assessment and 12% (10 patients, 8 kidney-transplanted and 2 islet alone) of the 79 have been transplanted. The main eligibility criteria were undetectable Cpeptide, normal kidney function, average weight, glycemic imbalance, hypoglycemia unawareness, and glycemic brittleness.

Improvement in long-term graft survival in cadaveric renal transplant recipients treated with mycophenolate mofetil

Though mycophenolate mofetil has markedly reduced the incidence of acute rejection in renal transplantation, a significant improvement in graft survival has been more difficult to demonstrate. This retrospective study compares an historical control group of 210 consecutive renal transplant patients, who had received ATG induction associated with cyclosporin, prednisolone and azathioprine, with 187 patients receiving mycophenolate instead of azathioprine. The incidence of acute rejection was decreased with mycophenolate. In rejection-free patients, the 3-year graft survival rates were equivalent. In contrast, graft survival at 3 years improved significantly for patients who experienced a rejection crisis and remained under the initial triple drug regimen with mycophenolate compared to the patients of the historical group who were kept on azathioprine after a rejection episode. In conclusion, mycophenolate mofetil is not only able to reduce the incidence of acute rejection but could also improve the prognostic significance of acute rejection crises.

Eligibility of diabetic patients receiving dialysis for islet after kidney transplantation

INTRODUCTION

The aim of this study was to assess the selection of candidates among 38 dialyzed diabetic patients referred between January 1, 1998 and December 31 2002 for kidney followed by islet transplantation (IAK). The main criteria of eligibility for possible IAK were as follows: (1) plasma C-peptide negative; (2) need for a kidney graft; (3) kidney plus whole pancreas transplantation not desired by the patient; and (4) acceptable results of postkidney graft preislet transplantation evaluation.

RESULTS

Seventeen of 38 patients with positive C-p diabetes received a kidney graft alone. Among the 21 C-p-negative diabetic patients, 3 were not eligible for kidney transplantation mainly for psychological reasons and 4 were eligible for kidney plus pancreas transplantation. The remaining 14 C-p-negative patients underwent kidney transplantation or had previously undergone kidney transplantation. Among them, 1 had moved away, 1 refused IAK, one had slightly positive stimulation tests, 1 was overweight, 1 had breast cancer, and 1 had postkidney graft complications. Among the remaining 8 of 14 C-p-negative, kidney-engrafted patients listed for IAK, 5 have undergone transplantation, 3 with a pre-Edmonton and 2 with the Edmonton protocol.

CONCLUSION

In conclusion among this series of 38 diabetic patients undergoing dialysis, more than 90% were kidney-grafted. Approximately 50% were ineligible for pancreas transplantation or IAK because of a positive C-p, and 20% were enlisted for IAK. These results highlight the importance of C-p determinations in diabetic dialysis patients to identify eligible patients for pancreas transplantation or IAK.

Kinetics of diabetes-associated autoantibodies after sequential intraportal islet allograft associated with kidney transplantation in type 1 diabetes

OBJECTIVE

Presence or occurrence of pancreas auto-antibodies (aAb) has been shown to be of poor prognosis for islet cell transplantation. The aim of the study was to monitor the kinetics of these aAb after sequential intra-portal islet plus kidney transplantation with pre-Edmonton immunosuppressive regimen in order to determine whether the sequential protocol of transplantation was involved in the occurrence of the immune response.

PATIENTS AND METHODS

Three patients with IDDM and a previous (IAK) or simultaneous (SIK) kidney transplantation received 3 or 4 ABO compatible islet preparations. Islets (> 8 000 IEQ/kg post culture) were sequentially transplanted within a 12 day period via a per-cutaneous catheter. Immunosuppressive treatment included cyclosporine, steroïds and mycophenolate. Plasma ICAs, GAD 65, IA2 and C peptide (C-p) levels were monitored. Type II HLA phenotype was determined in donors and recipients.

RESULTS

Patient #1 had high anti-GAD levels (26.5 UI/l) before the IAK, while anti-IA2 and ICA levels were low. After the transplantation, C-p levels increased to 4.9 ng/ml at one month before becoming undetectable at 2 months. GAD levels remained high, ICA and IA2 aAb were undetectable. Patients #2 and #3 did not have significant levels of aAb before the islet transplantation. A slight increase in GAD was observed with each islet transplantation, followed by an overt but transient increase in ICA. IA2 levels remained undetectable. Three months after the transplantation and 2 weeks after the increase of ICA, C-p levels, that were >3.4 ng/ml at one month, fell below 0.2 (N: 0.5-2).

CONCLUSION

The immunosuppressive regimen used in kidney transplantation is unable to control perfectly anti-pancreas aAb production. Moreover, these results seem to indicate that the benefits of sequential islet transplantation lie more in the increased islet mass they provide than in potential immune benefit.

Primary brain lymphomas after kidney transplantation: presentation and outcome

BACKGROUND

Non-Hodgkin's lymphoma is the second most frequent neoplasia following solid-organ transplantation. The objective of this study is to describe the clinical, histologic, and radiologic features of primary posttransplantation brain lymphomas (PTBL) in addition to their outcome.

METHODS

Twenty-five kidney transplant patients with histologically proven PTBL from 11 French centers were retrospectively investigated.

RESULTS

Immunosuppressive regimen included induction with antithymocyte globulins (ATG) in 20 patients. Median overall delay between transplantation and lymphoma was 18 months (4-264). Six of 10 patients with late posttransplantation brain lymphomas (PTBL) occurrence (>3 years) had been recently switched from azathioprine to mycophenolate mofetil (median switch lymphoma delay 14 months). Cerebral computed tomography (CT) scans and magnetic resonance imaging (MRI) revealed multifocal lesions (n=18), with a ring contrast enhancement (n=20) similar to cerebral abscesses, as observed in HIV-related brain lymphomas. Histology showed large B-cell non-Hodgkin's lymphoma in 87.5% of cases; Epstein-Barr virus (EBV) was detected in 95%. After lymphoma diagnosis, immunosuppressive treatment was reduced in all patients, and all but one received complementary treatment by surgery (n=2), anti-CD21 antibodies (n=2), chemotherapy including high-dose intravenous methotrexate (n=7), encephalic radiotherapy (n=5), or chemotherapy plus radiotherapy (n=8). Median overall survival was 26 months. Patients with a radiotherapy-based regimen seemed to have a longer survival (36 vs. 7 months, P<0.005).

CONCLUSIONS

Our study showed that PTBL are EBV-induced large B-cell lymphomas, which mimic cerebral abscesses on imaging and whose occurrence may be influenced by immunosuppression modifications. Treatment by radiotherapy is associated with better survival.

[Evaluation of verification of brain death and coordination with hospital organ procurement at the University Hospital at Lille]

OBJECTIVES

To determine the incidence of brain death (BD) and to evaluate the registration of potential organ donors (PD) by the organ procurement team (OPT).

STUDY DESIGN

Two-year prospective audit in the French university hospital of Lille.

PATIENTS AND METHODS

All deaths occurring in the intensive care units or the emergency department were studied. If death was consecutive to brain damage, on-site review of medical records and charts was performed. Death cause, presence of criteria for brain death and reference to the OPT were recorded for each death. A medical expert staff evaluated the incidence of and reasons for unsuitability for organ donation. After 12 months of observation, a protocol for "systematic alert of the OPT when brain death is suspected" was broadcast and evaluated during the next 12 months.

RESULTS

During the first period, 277 BD occurred and 119 PD were suitable for organ donation. The OPT recorded 80 PD (67.2% of all PD) and 45 multi-organ procurements (MOP) were performed. Physicians opposed two major reasons for not calling OPT: anticipation of a non-validated medical contraindication in 18 cases and approach of the family without the OPT team in 21 cases. After broadcast of the protocol, 110 PD were identified and the OPT was called in 93 cases (84.5% of all PD, p < 0.004 versus first period). Fifty-three MOP were performed.

CONCLUSION

The OPT was not called to manage one-third of the PD. The protocol for "systematic alert of the OPT when brain death is suspected" improves the call of the OPT and increases MOP.

Successive emergence of two CD8 subsets in primary CMV infection of allograft recipients

Allograft recipients with cytomegalovirus (CMV) infection develop increased proportions of circulating CD8+ lymphocytes. A longitudinal study of 11 kidney and 5 liver allograft recipients with primary CMV infection but no other aetiological factor to explain graft dysfunction revealed selective imbalances in peripheral blood CD8+ T cell subsets. Initially, CMV viraemia was associated with elevated CD8+bright T cell numbers and T cell activation. Activation markers fell to normal when viral cultures became negative (before the end of the 1st month). During the 2nd-6th months, most (12/16) patients continued to have high CD8+ T cell counts (1050-2900 CD8+ cells/mm3), comprising an uncommon CD8+ T cell subset, as 45-73% of CD8+bright lymphocytes were CD3+ and TCRalphabeta+ but were not stained by anti-CD28, CD11b, CD16, CD56 and CD57 antibody. Unexpectedly, CD8+ CD57+ T cells, a hallmark of CMV infection, did not appear until the 2nd-6th months of primary CMV infection, and their numbers increased progressively thereafter. They became the predominant CD8+ T cell subset after about 6 months of infection and their persistence for several (up to 4) years was strongly correlated (r = 0.87) with expansion of CD8+ cells. Persistence of CD8 lymphocytosis was, thus, directly related to the rate of expansion of an uncommon CD8+ CD57- subset and its progressive replacement by CD8+ CD57+ T cells that were chronically elicited by CMV.

Intraoperative decay profile of intact (1-84) parathyroid hormone in surgery for renal hyperparathyroidism--a consecutive series of 80 patients

BACKGROUND

The utility of intraoperative parathyroid hormone (PTH) monitoring is unclear in the surgical management of renal hyperparathyroidism. Our goal was to define the normal pattern of decay during operation for renal hyperparathyroidism by using the rapid intact (1-84) parathyroid hormone (PTH) assay.

METHODS

Eighty consecutive patients underwent neck exploration for renal hyperparathyroidism. Intact PTH levels were monitored with a rapid immunochemiluminometric assay. Samples were assayed at the induction of anesthesia, after dissection before resection, and 20 and 40 minutes after resection. Follow-up ranged from 3 to 24 months.

RESULTS

Twenty minutes after resection, PTH levels remained many-fold supranormal. Seventy-seven patients (96%) were cured. Of these, 75 patients (94%) had PTH decay of more than 50% from the preoperative level; 74 (99%) were cured. Only 1 of 3 patients (33%) in whom the PTH level decreased less than 40% from the preoperative level was cured. Two patients had intermediate values and both were cured.

CONCLUSIONS

The intraoperative decay of PTH during operation for renal hyperparathyroidism is slower than for patients with normal renal function. However, 20 minutes after resection, a decline to less than 50% of the preoperative level predicts cure, while a level greater than 60% predicts failure.

Negative immunohistochemical detection of CD103 (alphaEbeta7 integrin) in the infiltrates of acute rejection in liver and kidney transplantation

BACKGROUND

The infiltration of epithelium by CD8+ T lymphocytes in human renal or liver allografts is a critical feature of acute rejection. CD103 expression can be acquired in vitro by CD8+ cytotoxic T lymphocytes in response to allogeneic renal epithelial cells and promotes their adhesion to epithelium and subsequent lysis of epithelial cells. We investigated the expression of CD103 in T-cell infiltrates during acute renal or liver rejection (grade < III).

METHODS

Immunohistochemical detection of CD103 in 11 liver and 10 kidney transplant biopsies with histopathological diagnosis of acute rejection.

RESULTS

None of the infiltrates expressed detectable CD103, although positive controls were stained under our conditions.

CONCLUSIONS

Failure to detect CD103 in renal biopsies can be related to the early posttransplantation interval (<6 months) corresponding to a first rejection episode. In our hands, immunohistological detection of CD103 was not possible in the infiltrates of acute rejection in liver or kidney transplantation.

Immunomodulatory effect of pentoxifylline during human allograft rejection: involvement of tumor necrosis factor-alpha and adhesion molecules

BACKGROUND

Pentoxifylline (PTX), a methylxanthine phosphodiesterase inhibitor, is poorly active as an immunosuppressant but prevents the synthesis of proinflammatory cytokines. In a randomized double-blind study comparing PTX versus placebo in 140 patients receiving cadaveric kidney grafts under cyclosporine and prednisone, we have shown that PTX weakened the consequences of rejection on graft survival. To assess the mechanism underlying the beneficial effect recorded during this trial, we analyzed the impact of PTX on tumor necrosis factor (TNF-alpha) production and expression of cell adhesion molecules.

METHODS

Plasma levels of TNF-alpha and its soluble receptors (sTNF-RI, sTNF-RII) and of soluble vascular cell adhesion molecule 1 (sVCAM-1) were monitored over the 6 months postgraft period when PTX or placebo were administered. Expression of VCAM-1 and intercellular cell adhesion molecule 1 was scored by immunohistochemical staining of biopsy specimens from patients who underwent rejection crisis. Lymphocyte subset composition was analyzed longitudinally during cytomegalovirus (CMV) infections.

RESULTS

Plasma TNF-alpha levels were significantly reduced in the PTX-treated group over the 6 months of administration, and specifically during isolated rejection episodes and during CMV infections. Plasma levels of sTNFR-I, sTNFR-II, and sVCAM-1 did not differ between the two groups of patients, but a decrease in renal tubular VCAM-1 expression was observed in the PTX group. During CMV infections, CD8 lymphocytosis and expansion of CD57+ (CD28-) CD8+ T cells were similar in the two groups.

CONCLUSION

The data collected during this double-blind study point to an immunomodulatory role of PTX, the beneficial effect on graft survival resulting from a restraining effect of the drug on the inflammatory conditions involved in acute graft rejection.

Genotypic and phenotypic analysis of the polymorphic thiopurine S-methyltransferase gene (TPMT) in a European population

1. Characterization of allelic variants of the TPMT gene (TPMT) responsible for changes in TPMT activity, and elucidation of the mechanism by which these alleles act, are required because of the clinical importance of this polymorphism for patients receiving thiopurine drugs. 2. We defined the mutational and allelic spectrum of TPMT in a group of 191 Europeans. Using PCR-SSCP, we screened for mutation the entire coding sequence, the exon-intron boundaries, the promoter region and the 3'-flanking region of the gene. Six mutations were detected throughout the ten exons and seven TPMT alleles were characterized. Four of them, TPMT*2, *3A, *3C and *7, harbouring the known mutations, G238C, G460A, A719G or T681G, were nonfunctional and accounted for 0.5, 5.7, 0.8 and 0.3% of the allele totality, respectively. 3. Within the promoter region, six alleles corresponding to a variable number of tandem repeats (VNTR), were identified. VNTR*V4 and *V5a which harbour four or five repeats of a 17-18 bp unit, were the most frequent (55% and 34%, respectively). The other VNTR alleles, having from five to eight repeats, were rarer. 4. The TPMT phenotype was correctly predicted by genotyping for 87% of individuals. A clear negative correlation between the total number of repeats from both alleles and the TPMT activity level was observed, indicating that VNTRs contribute to interindividual variations of TPMT activity. Therefore, additional analysis of the promoter region of TPMT can improve the phenotype prediction rate by genotyping.

Improvement in the outcome of rejection with pentoxifylline in renal transplantation: a randomized controlled trial

BACKGROUND

Pentoxifylline (PTX), a methylxantine phosphodiesterase inhibitor commonly used to treat peripheral vascular disease, has been shown to decrease the production of proinflammatory cytokines and reactive oxygen species and to reduce the toxic effects of cyclosporine. Thus, administration of PTX to transplant patients, as an adjunct to immunosuppressive therapy, could prevent numerous posttransplantation complications.

METHODS

One hundred forty consecutive patients receiving cadaveric kidney grafts were registered in a randomized double-blind study comparing PTX at a dose of 800 mg/day, then 1200 mg/day, versus placebo during the first 6 months after transplantation. All patients were followed up for 1 year.

RESULTS

Rejection episodes were validated as the only independent risk factor for graft loss in this study. We compared graft survival rates in each group according to the presence or absence of acute rejection. Acute rejection reduced graft survival in the control group (graft survival rate at 1 year, 59% vs. 97%, P < 0.001), but this adverse effect was blunted in the PTX group (72% vs. 89%, NS). This improvement was confirmed by multivariate analysis for risk factors, with graft survival rates being described at best as the interaction between rejection and treatment (PTX vs. placebo, P = 0.045).

CONCLUSION

Although PTX does not modify the incidence of any posttransplant complications, it weakens the consequences of rejection on graft survival.

Recall response to cytomegalovirus in allograft recipients: mobilization of CD57+, CD28+ cells before expansion of CD57+, CD28- cells within the CD8+ T lymphocyte compartment

BACKGROUND

Strong correlations have been described between persistently elevated proportions of CD57+ (CD28-) CD8+high T lymphocytes and cytomegalovirus (CMV) infection, in healthy individuals as well as in transplant patients. We investigated whether secondary exposure to CMV triggers recall responses within the CD8 T cell compartment.

METHODS

In a longitudinal study in 123 kidney recipients, we compared 17 primary CMV infections with 27 secondary CMV infections. Subset composition of the CD8 compartment was analyzed by flow cytometry.

RESULTS

CD8 lymphocytosis occurred significantly earlier (by 17 days on average) in CMV reactivations than in primary infections. Both in primary and secondary infections, CD28+ CD8+high T lymphocytes were mainly recruited at the start. In formerly CMV-seropositive patients, preexisting CD57+ CD8+high T lymphocytes switched at the start from no expression of CD28 to high expression of CD28 and, concomitantly, from CD45RA to high expression of CD45RO. These cells reverted rapidly to a CD28- and CD45RA+ phenotype. Nevertheless, the accumulation of CD57+ (CD28-) CD8+high T cells was delayed similarly in primary and secondary CMV infection, progressing over a period between 2 and 8 weeks after the onset of CD8 lymphocytosis to plateau at 366 CD57+ CD8+high cells/ mm3 on average.

CONCLUSIONS

The faster kinetics of CD8 lymphocytosis in secondary CMV infection suggests that a recall response triggers cycling "memory" cells within the CD28+ CD8+high subset, while preexistent CD57+ CD8+high T cells with a long-lived cell phenotype can also be mobilized, possibly through the transient acquisition of CD28 expression. The protracted accumulation of CD57+ (and CD28-) lymphocytes might then reflect an end-stage differentiation.

Consecutive successful pregnancies in a combined liver and kidney transplant recipient with type 1 primary hyperoxaluria

Pregnancy is now a common, but high-risk event, in young women who have received transplants. Consequences to the fetus are known, but pregnancy may also interfere with graft function. We report the outcome of two successive and successful pregnancies in a 29-year-old woman with type 1 hyperoxaluria, who received a combined liver and kidney transplant. Two healthy children were born at 35 and 37 weeks of gestation, with low birth weight. Liver function remained normal before, during, and after pregnancies up to 52 months after transplantation. Renal function was impaired before the first conception, worsened during both pregnancies, and returned to the previous level in both immediate postpartum periods. However, renal function has declined 17 months after the last delivery. This report shows the feasibility of successive pregnancies in multiple organ transplant recipients, but raises the question of long-term maternal kidney graft survival.

Diagnostic and predictive value of an immunohistochemical profile in asymptomatic acute rejection of renal allografts

We have retrospectively studied the diagnostic and predictive value of immunohistochemical characterization of adhesion molecules (ICAM-1, CD54, VCAM-1) and HLA-DR antigen in a homogeneous clinical group of 36 patients. Between 1 January 1991 and 31 January 1993, 130 patients received a kidney transplant in our unit. Biopsies of renal allografts were only performed in asymptomatic patients who had graft dysfunction, revealed by an isolated serum creatinine increase. Available frozen samples were included in this study (n = 44). The 35 cases of acute rejection diagnosed by biopsy corresponded to mild acute rejection according to the Banff classification criteria. First, we compared the expression of HLA-DR, ICAM-1 and VCAM-1 to morphological data to determine if the immunohistochemical data improved the histopathological diagnosis when the interstitial infiltrate was mild with slight tubulitis. We also studied the phenotype of infiltrating cells with monoclonal antibodies directed against T helper cells, T cytotoxic-suppressor cells, activated T cells and macrophages. Expression on tubular epithelium and density of each type of cell was graded semiquantitatively. Expression of HLA-DR, ICAM-1 and VCAM-1 was observed on tubular epithelium and endothelium in both acute rejection and other causes of graft dysfunction, limiting its diagnostic value. Activated T cells expressing CD69-AIM (activation inducer molecule) and/or HLA-DR were frequently observed in acute rejection (24/35 (69%) and 25/35 (71%) respectively) but not in other causes of renal dysfunction. We then studied the prognostic usefulness of the immunohistochemical profile in acute rejection. Of 27 patients, 12 had a progressively decreased renal function or returned to dialysis within one year after transplantation while the other 15 had a stable graft function after at least 18 months of follow-up. In the group of bad prognosis (n = 12), corticosteroid-resistant rejection episodes were significantly more frequent (p < 0.01). In this group, nine patients had an overexpression of HLA-DR on tubular epithelium versus one patient in the group of stable graft function (chi 2c = 10.57, p < 0.002). Seven patients included in the group of bad prognosis showed tubular overexpression of both ICAM-1 and VCAM-1 versus one patient in the other group chi 2c = 6.23, p < 0.02). Moreover, patients of the first group had a significantly higher number of interstitial macrophages as compared with those who had stable graft function (chi 2c = 4.87, p < 0.01). Thus, our data show that the immunohistochemical profile studied is of little value in the diagnosis of renal allograft rejection. However, an intense tubular expression of HLA-DR and/or both ICAM-1 and VCAM-1, and a high number of interstitial macrophages are significantly related to unfavorable graft outcome.

Implication of cyclosporine in up-regulation of Bcl-2 expression and maintenance of CD8 lymphocytosis in cytomegalovirus-infected allograft recipients

T cell homeostasis and CD4/CD8 ratios are normally reestablished by apoptotic clearance of activated T cells after immune stimulation. In allograft recipients with cytomegalovirus infection, CD8 lymphocytosis persists after negativation of viral cultures, contrary to immunocompetent hosts. We investigated the expression of Bcl-2 protein, an intracellular suppressor of apoptosis, and of CD95 (APO-1/Fas), a membrane inducer of apoptosis, in peripheral blood lymphocytes from 45 solid organ recipients. During the viremic phase of CMV infection, we found absence or diminished expression of Bcl-2 protein and increased expression of CD95 antigen in activated CD8+ T cells. Opposite evolution of these molecular regulators of apoptosis was reflected by the presence of 10-25% of apoptotic lymphocytes with fragmented DNA, as shown by both in situ nick translation and electrophoresis. Normalization of Bcl-2 expression was progressive over several months but still lower than in uninfected allograft recipients. These results suggest that the initial evolution of CMV infection in allograft recipients resembles acute viral infection in immunocompetent hosts. Conversely, we showed that overexpression of Bcl-2 protein in lymphocytes from uninfected allograft recipients, and culture of unstimulated normal lymphocytes with 0.5 micrograms/ml cyclosporine led to an increase in the expression of intracellular Bcl-2. This up-regulation of Bcl-2 protein by cyclosporine suggests the acquisition of resistance to apoptosis. Thus, the reversion of balance between T cell death and survival after acute CMV infection might be impeded by cyclosporine. Combination of CMV latent infection and cyclosporine therapy appears therefore critical to shift the homeostatic maintenance of the peripheral lymphocyte compartment toward persistingly high numbers of CD8+ T cells.

Detergent extraction and enzymatic analysis for fecal long-chain fatty acids, triglycerides, and cholesterol

We report a procedure for determining fecal long-chain fatty acids (LCFA), triglycerides, and cholesterol after detergent extraction with 10 mL/L Triton X-100, 6 mL/L Brij 30, and 0.1 mol/L HCl in isotonic saline by enzymatic analysis of the extraction supernates. Mean recoveries of calibrators ranged from 105% to 117%. Assays of fecal extracts were linear with concentration from 0 to 1000 mumol/L for LCFA, from 10 to 90 mumol/L for triglycerides, and from 0 to 300 mumol/L for cholesterol. Within-run CVs were < 3% for medium and high concentrations, and 3%, 14%, and 28% for low concentrations of LCFA, cholesterol, and triglycerides, respectively. Correlation with gravimetric determination resulted in coefficients (r2) of 0.72 for total fat, 0.63 for neutral fat, and 0.66 for nonesterified fat. Assays of extracts and residues prepared for gravimetric determination indicated that approximately 90% of triglycerides, cholesterol, and LCFA were extracted by organic solvents and that the extracts contain a significant amount of other fats. The proposed method appears accurate, precise, specific, and suitable for routine analysis.

Use of pluronic micelles to overcome multidrug-resistance

Pluronic P-85 (poly(55)(oxypropylene)dipoly(s)(oxyethylene)) was used to form daunorubicin containing micelles. This new carrier was tested in vitro on sensitive and resistant ovarian cancer cell lines. Drug incorporation was measured by cytofluorometry and the cytotoxicity was measured by the tetrazolium formazan XTT assay. ID50 of 0.16 and 25 mu g/ml were obtained for conjugated and free daunorubicin respectively. The results obtained suggest that this approach may be used in combination with a chemotherapeutic agent to overcome multidrug resistance.

Detergent extraction and enzymatic analysis for fecal long-chain fatty acids, triglycerides, and cholesterol

We report a procedure for determining fecal long-chain fatty acids (LCFA), triglycerides, and cholesterol after detergent extraction with 10 mL/L Triton X-100, 6 mL/L Brij 30, and 0.1 mol/L HCl in isotonic saline by enzymatic analysis of the extraction supernates. Mean recoveries of calibrators ranged from 105% to 117%. Assays of fecal extracts were linear with concentration from 0 to 1000 mumol/L for LCFA, from 10 to 90 mumol/L for triglycerides, and from 0 to 300 mumol/L for cholesterol. Within-run CVs were &lt; 3% for medium and high concentrations, and 3%, 14%, and 28% for low concentrations of LCFA, cholesterol, and triglycerides, respectively. Correlation with gravimetric determination resulted in coefficients (r2) of 0.72 for total fat, 0.63 for neutral fat, and 0.66 for nonesterified fat. Assays of extracts and residues prepared for gravimetric determination indicated that approximately 90% of triglycerides, cholesterol, and LCFA were extracted by organic solvents and that the extracts contain a significant amount of other fats. The proposed method appears accurate, precise, specific, and suitable for routine analysis.

CD8 lymphocytosis in primary cytomegalovirus (CMV) infection of allograft recipients: expansion of an uncommon CD8+ CD57- subset and its progressive replacement by CD8+ CD57+ T cells

Allograft recipients undergoing cytomegalovirus infection present increased proportions of circulating CD8+ lymphocytes. A longitudinal study of 11 kidney and five liver allograft recipients with primary CMV infection but no other etiological factor of graft dysfunction revealed selective imbalances of peripheral blood CD8+ T cell subsets. Initially, CMV viraemia is associated with elevated CD8+bright T cell numbers and T cell activation. Activation markers fall to normal when viral cultures become negative (before the end of the first month). During the second to sixth month, most (12/16) patients keep up high CD8+ T cell counts (1050-2900 CD8+ cells/mm3), comprising an uncommon CD8+ T cell subset, as 45-73% of CD8+bright lymphocytes were CD3+ and TCR alpha beta+, but were not stained by anti-CD28, CD11b, CD16, CD56, and CD57 antibody. Unexpectedly, CD8+CD57+ T cells, a hallmark of CMV infection, do not appear until the second to sixth month of primary CMV infection, and their numbers increase progressively thereafter. They become the predominant CD8+ T cell subset after 6 months of infection and their persistence for several (up to 4) years is strongly correlated (r = 0.87) with expansion of CD8+ cells. By analysis with MoAbs, there was no bias towards the use of particular TCR-V beta gene families at any time of primary CMV infection. Persistence of CD8 lymphocytosis is thus directly related to the rate of expansion of an uncommon CD8+CD57- subset and its progressive replacement by CD8+CD57+ T cells that are chronically elicited by CMV.

A new fluorometric assay for cytotoxicity measurements in-vitro

Cytotoxicity testing of anticancer drugs requires techniques which are sensitive, reproducible and applicable to large scale testing using automated instruments. These assays are presently performed with end point staining of cell proteins with dyes, viability stains or energy dependent of substrates such as MTT or XTT. Although reliable. these assays are not sensitive enough, too expensive for large scale screening or they use reagents that may be harmful for personnel or equipment. We describe, the use of Alamar Blue, a new non fluorescent substrate, which after reduction in living cells, yields a very strong fluorescent product. Using the automated fluorescence plate reader Cytofluor, we have evaluated the various parameters such as substrate concentration, time and volume of incubation with respect to linearity and lower limit of detection. We found that for a two hour assay, this new non toxic substrate could detect as low as 200 cells per well with a useful measurement range up to 20,000 cells per well. The fluorescent assay is more than ten times as sensitive as the colorimetric assay. When the cytotoxicity of daunorubicin was measured with this assay and compared to the XTT formazan assay we found comparable IC50 values but this new assay was more economical and results are obtained in two hours as compared to four hours for the formazan assay. This new economical and versatile assay could be used with advantage for large scale in vitro screening of anticancer drugs and other cytotoxic agents.

[Transplantation for primary hyperoxaluria. Role of oxalate crystal deposits in the occurrence of kidney failure]

We analyzed the records of 3 patients transplanted for end-stage renal failure due to primary hyperoxaluria and evaluated on repeat biopsies the role played by oxalate deposits in the constitution of renal failure after isolated kidney graft, or combined liver and kidney transplantation. Early failure of the renal graft is frequent and often interpreted as the consequence of recurrence because of the presence of oxalate deposits on the graft biopsy. In fact, the decrease in oxalate deposits observed in our 2 cases of combined liver and kidney transplantation despite the progressive renal failure, indicates that crystal deposition is not responsible for the renal lesions. However, we cannot exclude that the oxalate molecule toxicity plays a role in the constitution of the diffuse sclerosis which occurred in these two cases after a primary renal non function, aggravating a hemodynamic process by using cyclosporin. On the other hand, as observed in our isolated kidney graft, renal crystal deposition occurring before the onset of renal failure suggests the true mechanism explaining the slow recurrence of renal oxalosis.