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Biomedical subjects

D Abramowicz

Publications and source records attributed to D Abramowicz.

At least 55 records · Page 3Linked to original sources
PubMed1997

Absence of deleterious effect on long-term kidney graft survival of rejection episodes with complete functional recovery.

BACKGROUND: Rejection episodes (RE) exert a detrimental influence on long-term kidney graft outcome. However, the impact of the severity of those RE on graft survival and the factors that could predict this impact are ill defined. The present retrospective study was undertaken on adult patients who received 582 cadaver kidney transplants at our center during the last 12 years, to assess the impact on graft survival of RE occurring during the first year after transplantation and to uncover the factors associated with the severity of those RE. METHODS: Three grades of rejection were defined: (1) rejection without loss of graft function (benign rejection); (2) rejection followed by partial loss of graft function (severe rejection); and (3) rejection with return to dialysis (irreversible rejection). The grafts were distributed among four groups: (1) grafts free of rejection; (2) grafts with benign RE (only grade 1 RE); (3) grafts with severe RE (one or more grade 2 RE); and (4) grafts with irreversible (grade 3) RE. RESULTS: Multivariate analyses revealed that (1) the occurrence of RE during the first posttransplant year (group 1 versus groups 2, 3, and 4) was significantly associated with primary immunosuppression with CsA rather than with OKT3 monoclonal antibody, the number of HLA-B + DR mismatches, and the younger recipient's age; (2) in patients with rejection, OKT3 monoclonal antibody prophylaxis was less often used in patients with irreversible RE (group 4) than in those with reversible RE (group 2, benign, and group 3, severe); and (3) no single factor was able to differentiate patients with benign RE (group 2) from those with severe RE (group 3). For grafts still functioning 1 year after transplantation, long-term graft survival was similar in grafts with either no RE or benign RE, but it was significantly lower (P<0.0001) in grafts with severe RE: 8-year survival rates were 89% and 60%, respectively. The decline in graft survival after 1 year was significantly correlated with the serum creatinine value but not with the dose of cyclosporine at 1 year. CONCLUSIONS: Benign RE occurring during the first year after transplantation and resulting in no loss of graft function do not exert a detrimental influence on long-term kidney graft outcome. In contrast, the prognosis of grafts with severe RE during the same period of time is much poorer.

Adult↗
PubMed1997

Disseminated angiosarcoma presenting as a hemophagocytic syndrome in a renal allograft recipient.

A case of angiosarcoma arising in the setting of transplantation is reported. This rare and malignant tumor of the endothelial system is seldom observed in allograft recipients, with only seven cases having been previously reported. What is interesting about the present observation is that the tumor is thought to have developed in the vicinity of a Dacron graft and that it showed prominent erythrophagocyte-like activity. This activity was associated with a particular clinical syndrome that shared some attributes with infection-associated hemophagocytic syndrome.

Diagnosis, Differential↗
PubMed1997

A case of rapidly fatal systemic capillary leak syndrome in a kidney transplant recipient.

Idiopathic Systemic Capillary Leak Syndrome (SCLS) is a rare entity characterised by idiopathic increasing of capillary permeability associated with recurrent attacks of hypovolaemic shock. We report the case of a 39-year-old man with a SCLS fourteen years after a cadaveric renal transplantation. The clinical evolution was rapidly fatal despite treatment with corticoids, aminophylline and terbutaline which are the most efficient drugs known to prevent attacks.

Adult↗
PubMed1996

Renal transplantation exposes patients with previous Kaposi's sarcoma to a high risk of recurrence.

It is currently estimated that about 0.5% of patients will develop Kaposi's sarcoma (KS) after kidney transplantation. Tapering of immunosuppression often leads to KS remission, but also results in graft loss in more than 50% of cases. Whether retransplantation is safe in these patients is unknown. We here report on eight patients who developed KS recurrence after kidney transplantation-(A) Patients with previously treated KS: There were 4 patients who had clinical remission of KS (including three posttransplantation) for periods ranging from 5 months up to 19 years before transplantation. All 4 developed KS recurrence within months after transplantation. In 3 patients, KS regressed only when all immunosuppression was discontinued, at the price of allograft removal. Partial remission occurred in the fourth patient following reduction of immunosuppression and gancyclovir administration; (B) Patients with recurrent KS during a single transplant: 4 patients developed KS after transplantation that regressed following reduction of immunosuppressive therapy. Increased immunosuppression, in the form of steroid pulses in 3 patients was associated with recurrence of KS. Subsequent reduction of immunosuppression caused regression of KS in all 4 patients, but 2 recipients lost their allografts. These data emphasize the high risk of recurrence of KS after renal transplantation. If physicians decide to transplant patients with a history of KS, they should inform the future recipient of the possibility of KS recurrence.

Adult↗
PubMed1996

Monocyte procoagulant activity induced by in vivo administration of the OKT3 monoclonal antibody.

The first injection of OKT3 in kidney transplant recipients activates the common pathway of coagulation. This may result in early thrombosis of graft vessels. To this day, the cells involved in this phenomenon have not been identified. The aim of this study was to investigate whether circulating monocytes participated in this OKT3-induced coagulopathy. The procoagulant activity (PCA) of circulating monocytes rose from (mean +/- SEM) 0.15 +/- 0.02 mU/mL to 0.40 +/- 0.05 mU/mL at 3 hours (P = .002) and 0.56 +/- 0.21 at 5 hours (P = .045) after the initial OKT3 injection. These monocytes displayed increased tissue factor expression at the same moments (mean flourescence intensity: 14 +/- 2 before OKT3 injection versus 54 +/- 14 at 3 hours, P = .008 and 34 +/- 7 at 5 hours, P = .01). Tissue factor mRNA was detected in blood by reverse transcriptase-polymerase chain reaction as early as 2 hours after OKT3 administration. The circulating monocytes also displayed a steady increase in membrane expression upregulation of ICAM-1, CD29, CD11b, and CD11c. In vitro experiments showed that OKT3 as well as 2 mitogenic, humanized anti-CD3 antibodies potently induced monocytic PCA whereas the 4 nonmitogenic anti-CD3 antibodies tested were over 1,000-fold less potent than OKT3. We conclude that (1) OKT3 induces in vivo tissue factor gene upregulation and membrane expression resulting in increased PCA of circulating monocytes; and (2) nonmitogenic anti-CD3 antibodies seem devoid of significant procoagulant properties.

Blood Coagulation↗
PubMed1996

The IgE humoral response in OKT3-treated patients. Incidence and fine specificity.

We recently described a case of anaphylaxis occurring at the time of retreatment with OKT3 of a renal allograft recipient in whom, for the first time, high anti-OKT3 IgE levels were documented. This led us to examine a large series of sera from 181 OKT3-treated patients to better define the frequency of IgE sensitization, its fine specificity (anti-isotypic and/or anti-idiotypic) and its relation to the appearance of IgG anti-OKT3 antibodies (Abs). Six patients out of the 181 assayed have developed anti-OKT3 IgE Abs as detected by ELISA. The earliest time of appearance of IgE anti-OKT3 Abs was 10 days after starting OKT3 (range, 10-25). The IgE response peaked by day 18 (range, 11-35) and had usually disappeared at 3 months after treatment. A more careful dissection of the fine specificity of the IgE response revealed that three of the four patients tested had developed an exclusive anti-idiotypic response. In the last patient, an anti-isotypic component was present since anti-OKT3 IgE Abs also reacted with control IgG2a, IgG2b, and IgG3 monoclonal antibodies. Importantly, anti-OKT3 IgE Abs were only detected in heavily sensitized patients also showing high titers of IgG specific Abs by ELISA (> or = 1/1000) as well as "blocking" anti-OKT3 antibodies, as assessed by immunofluorescence. We conclude that (1) exposure to OKT3 may lead to specific IgE sensitization that, however, only appears in about 38% of the patients; (2) IgE Abs mostly appear in patients also showing high levels of conventional IgG anti-OKT3 Abs including the presence of "blocking" anti-idiotypic Abs, and (3) IgE Abs may be directed to both idiotypic and isotypic determinants of the monoclonal antibody.

Animals↗
PubMed1996

CD40 engagement induces monocyte procoagulant activity through an interleukin-10 resistant pathway.

Interactions between membrane-bound molecules were previously shown to be involved in the induction of tissue factor-dependent monocyte procoagulant activity (PCA) by activated T cells. To investigate the potential role of the CD40/CD40 ligand (CD40L) pathway in this process, we first determined the effects of blocking anti-CD40 or anti-CD40L monoclonal antibodies (mAb) on the development of monocyte PCA during mixed lymphocyte reaction (MLR) between allogeneic peripheral blood mononuclear cells (PBMC). The strong inhibitory effect exerted by both mAb (mean percentages of inhibition: 88 and 91% for anti-CD40 and anti-CD40L mAb, respectively) indicates that CD40/CD40L interactions are required for the induction of PCA in MLR. These data led us to measure monocyte PCA after incubation of PBMC or purified monocytes with a stimulating anti-CD40 mAb (BL-C4) or with 3T6 fibroblasts transfected with the gene encoding CD40L. In both systems, we found that CD40 engagement strongly induced monocyte PCA which was related to tissue factor expression as shown by flow cytometric analysis. Finally, we observed that recombinant interleukin (IL)-10, which inhibits lipopolysaccharide-induced PCA, did not significantly influence CD40-dependent PCA. We conclude that CD40 engagement on monocytes induces tissue factor-dependent PCA through an IL-10-resistant pathway. These findings have implications for the control of coagulation events triggered by interactions between T cells and monocytes.

Antibodies, Monoclonal↗
PubMed1996

Effects of steroids on the progression of renal failure in chronic interstitial renal fibrosis: a pilot study in Chinese herbs nephropathy.

Chinese herbs nephropathy is characterized by an extensive interstitial fibrosis and by a rapid evolution to end-stage renal failure. We thus decided to try steroid therapy (prednisolone 1 mg/kg for 1 month, tapered off 0.1 mg/kg every 2 weeks) in cases with moderate renal failure and evidence of deterioration in renal function. Our steroid group (SG) consisted of 12 female patients with biopsy-proven renal fibrosis who were followed for at least 12 months after the initiation of steroids. Plasma creatinine level (Pcreat) ranged from 1.8 to 3.9 mg/dL (mean +/- SEM, 2.8 +/- 0.2 mg/dL) when steroids were initiated at t = 0. Renal failure was in progression since Pcreat was 2.1 +/- 0.1 mg/dL (P = 0.022) 3 months before t = 0. Our control group (CG; N = 23) was selected retrospectively from among the 81 patients in the Belgian Register of Chinese Herbs Nephropathy. Compared with the CG, renal function was better preserved in the SG (Pcreat; mean +/- SEM): SG v CG, 2.9 +/- 0.3 mg/dL v 5.3 +/- 0.5 mg/dL at 6 months (P = 0.0024) and 4.0 +/- 0.7 mg/dL v 7.1 +/- 0.5 mg/dL at 1 year (P = 0.001). The slope of the reciprocal serum creatinine concentration was similar in both groups before t = 0 (-0.0463 mg/dL/mo in the SG v -0.0438 mg/dL/mo in the CG; P = 0.83), but it became less steep after initiation of steroid therapy (between 0 and 6 months, -0.000742 mg/dL/mo in the SG v -0.0284 mg/dL/mo in the CG; P < 0.001). Finally, only two of the 12 patients in the SG required dialysis at 1 year compared with 16 of the 23 patients in the CG (P = 0.0045). We conclude that steroid therapy slows the progression of renal failure in a disease characterized by an interstitial fibrosis that progresses quickly despite the fact that the insulting agent has been withdrawn. This supports the hypothesis that renal interstitial fibrosis may be an immune-mediated process.

Aristolochic Acids↗
PubMed1996

OKT3 prophylaxis in renal grafts with prolonged cold ischemia times: association with improvement in long-term survival.

The data on patients participating in two randomized, prospective studies with similar immunosuppressive regimens were updated and combined to evaluate the long-term effects of OKT3 according to cold ischemia time (< or = or > 24 hr). Among 159 patients in the OKT3 and 153 in the cyclosporine A (CsA) group, 8 and 12 deaths occurred, respectively (P = NS). In patients with cold ischemia > 24 hours, OKT3 prophylaxis resulted in a lower mean number of rejection episodes per patient than did CsA prophylaxis within one year (mean +/- SEM: 0.87 +/- 0.11 vs. 1.35 +/- 0.14, respectively; P = 0.008) and within five years (1.07 +/- 0.12 vs. 1.49 +/- 0.15, respectively; P = 0.032). In contrast, rejection incidences in patients with cold ischemia < or = 24 hours was not significantly different in the two groups. In all study patients, there was a trend towards higher graft survival rates in the OKT3 group versus the CsA group (at 5 years, 73% vs. 66%, respectively; P = 0.182). Among recipients of kidneys with cold ischemia times > 24 hours, OKT3 patients had significantly higher graft survival than CsA patients at two years (84% vs. 64%, respectively) and at five years (71% vs. 56%, respectively; P = 0.045). Significant differences were not observed in recipients of kidneys with cold ischemia times < or = 24 hours. In conclusion, patients receiving renal grafts with long cold ischemia times strongly benefit from OKT3 prophylaxis.

Adult↗
PubMed1996

Prevention of OKT3 nephrotoxicity after kidney transplantation.

In our experience the use of OKT3 as prophylaxis in renal transplantation has been associated with an increased incidence of both delayed graft function and thromboses of graft vessels. OKT3 nephrotoxicity might have been favored by restriction of perioperative fluid infusion to prevent pulmonary edema and by the use of very high dose (30 mg/kg) of methylprednisolone (mPDS) before the first OKT3 injection to reduce the release of cytokines. This led us to modify our perioperative management in three ways: (1) hydration status was optimalized; (2) the calcium-channel blocker diltiazem, considered beneficial for recovery of graft function, was administered on the day of transplantation; and (3) the dose of mPDS given before the first OKT3 injection was fixed at 8 mg/kg. Comparison of two consecutive series of patients (group 1, control patients, N = 172; group 2, managed as described above, N = 173) showed that: (1) the incidence of delayed graft function fell from 52% in group 1 to 22% in group 2 (P < 0.0001): (2) the incidence of pulmonary edema was not significantly increased in group 2 (3.5% vs. 1.7% in group 1, P = 0.5); and (3) the frequency of intragraft thrombosis fell from 7.6% in group 1 to 1.2% in group 2 (P = 0.0034). Multivariate analysis showed that the volemia/diltiazem program and avoidance of high mPDS dose were the most important factors responsible for the reduced occurrence of delayed graft function and graft vessels thrombosis, respectively. We conclude that a combined strategy of appropriate dosage of steroids before the first OKT3 injection, administration of a calcium-channel blocker and optimalization of volemia is safe and efficiently prevents against OKT3 nephrotoxic effects.

Adult↗
PubMed1995

Influence of donor-recipient HLA-DR mismatches and OKT3 prophylaxis on cadaver kidney graft survival.

Previous studies from our center have shown that donor-recipient HLA-DR mismatches (MM), characterized by the presence of the DR antigen in the donor but not in the recipient or vice versa, are associated with differential effects on graft survival (GS): some of them are beneficial (BEN) with results similar to those of HLA-DR identical or compatible pairs (85% 18 months GS) and some are detrimental (DET) (64% 18 months GS), whereas the other MM, neither BEN nor DET (neutral [NEU]) yield intermediate results (78% 18 months GS). The aim of the present study was to update the results at a longer follow-up time and to assess whether they are influenced or not by prophylactic administration of anti-CD3 mAb (OKT3). The analysis of 234 transplantations performed from 1980 to 1994 with only 1 HLA-DR MM confirmed the BEN effects of HLA-DR5 in either the donor or the recipient and the DET effects of HLA-DR1 or -DR2 in the donor and of HLA-DR2 or -DRW6 in the recipient. These effects were independent of those exerted by other, HLA-DR not related, prognostic factors. The transplants with 1 HLA-DR MM were then compared with those with zero HLA-DR MM (n = 378) and 4 groups were formed according to 2 levels of HLA-DR MM (zero or BEN MM vs. NEU or DET MM) and immunosuppression (with vs. without OKT3 prophylaxis). GS at 5 years was 63% in the group with either zero or BEN MM as compared with 41% in the group with either NEU or DET MM in the absence of OKT3 prophylaxis (P < 0.02); in comparison, with OKT3 prophylaxis, GS at 5 years was 73% in the group with either zero or BEN MM as compared with 58% in the group with either NEU or DET MM (P = 0.07). We conclude that the differential effects of HLA-DR MM on GS are still observed under OKT3 prophylaxis, that the effects of HLA-DR and immunosuppression on graft outcome are additive, and that OKT3 induction therapy is superior to therapy without OKT3. These observations could have important implications for the allocation policy and management of renal transplants.

Adult↗
PubMed1995

Critical role of interleukin 4 in the induction of neonatal transplantation tolerance.

Neonatal injection of semiallogeneic cells is known to promote differentiation of donor-specific CD4+ T cells into TH2-like cells in the peripheral lymphoid organs. We reasoned that the propensity of neonatal T cells to synthesize high levels of IL-4 might be involved in this polarization of the alloreactive response and thereby in the development of neonatal transplantation tolerance. First, analysis of cytokine gene expression in lymph nodes after neonatal injection of 10(7) (A/J x BALB/c)F1 cells in BALB/c mice indicated that IL-4 but not IL-2 is rapidly produced by CD4+ cells after allogeneic challenge in vivo. To determine whether the early production of IL-4 was involved in the establishment of allotolerance, BALB/c mice neonatally injected with (A/J x BALB/c)F1 spleen cells received on days 1 and 3 after birth 1 mg of anti-IL-4 mAb (11B11) or the same amount of control mAb. When grafted with A/J skin at 4 weeks, 88% of mice treated with control mAb retained their graft for more than 50 days, whereas rejection occurred within 30 days in 93% of mice treated with anti-IL-4 mAb. Analysis of T cell functions after in vitro restimulation with A/J spleen cells indicated that early IL-4 neutralization did not prevent donor-specific CTL unresponsiveness but allowed the emergence of alloreactive T cells secreting increased levels of IL-2 and IFN-gamma. We conclude that early production of IL-4 is critical for the establishment of neonatal transplantation tolerance in this strain combination, which has disparities across the entire H-2 region.

Animals↗
PubMed1995

Soluble tumor necrosis factor-receptors are not a useful marker of acute allograft rejection: a study in patients with renal or cardiac allografts.

In this study, we investigated soluble tumor necrosis factor receptor (sTNF-R) levels in plasma of patients with either a kidney or cardiac allograft when clinical suspicion of acute rejection was raised. In plasma of patients with acute renal graft rejection, the sTNF-R levels were strongly enhanced (20-150 ng/ml) as compared to plasma of patients with stable renal function. Following successful treatment of the rejection, a gradual decline in sTNF-R levels occurred with improving renal function, and an inverse correlation between creatinine clearance and sTNF-R was found. To determine whether the increase was caused by an accumulation of constitutively released sTNF-R and lack of clearance by the kidney, or whether the immunological process of the rejection caused the enhancement, we measured sTNF-R in patients suffering from acute cardiac graft rejection but with predominantly stable kidney function. Rejection of a cardiac graft did not lead to a significant enhancement of sTNF-R levels. However, treatment with ATG or OKT3 did cause enhanced sTNF-R levels, followed by a decline that reached starting values after 7 days. These results provide evidence that the immune reaction that occurs during rejection of a graft does not per se induce discernible changes in sTNF-R levels, whereas that induced by ATG or OKT3 does. Thus, sTNF-R levels are not reliable marker in transplant recipient monitoring.

Acute Disease↗
PubMed1995

The induction of human T cell unresponsiveness by soluble anti-CD3 mAb requires T cell activation.

In order to obtain an in vitro model of human T cell unresponsiveness induced by soluble anti-CD3 mAb in the presence of accessory cells, T cells purified from peripheral blood of healthy volunteers were cultured for 4 days with irradiated accessory cells and OKT3. After a 48 h resting period allowing TCR-CD3 complex re-expression, T cells were rechallenged with plastic-immobilized OKT3, and their proliferative response as well as their secretion of IL-2, IFN-gamma and IL-10 measured. Primary culture with OKT3 induced a state of unresponsiveness characterized by defective responses to OKT3 rechallenge but normal or enhanced responses to PMA and A23187 calcium ionophore, indicating a defect in the early steps of TCR-CD3-mediated signal transduction. Indeed, we found that unresponsive T cells displayed an impaired mobilization of intracellular calcium stores upon TCR-CD3 ligation. In order to determine whether the development of unresponsiveness depends on the initial T cell activation triggered by OKT3, we compared several versions of OKT3 differing in their ability to bind Fc receptors. We found that only the activating antibodies that bind Fc receptors on accessory cells induced T cell unresponsiveness. We conclude that human resting T cells can be rendered unresponsive by anti-CD3 mAb in soluble form provided that they trigger T cell activation.

Antigen-Presenting Cells↗