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Biomedical subjects

E Alamartine

Publications and source records attributed to E Alamartine.

At least 19 recordsLinked to original sources

TNFA2 and d2 alleles of the tumor necrosis factor alpha gene polymorphism are associated with onset/occurrence of idiopathic membranous nephropathy.

Idiopathic membranous nephropathy (IMN) has a strong association with the major histocompatibility complex HLA B8DR3(17)DQ2 haplotype. The tumor necrosis factor (TNF)A gene is located within the major histocompatibility complex region on chromosome 6. We have studied the influence of two functional polymorphisms; the -308 (promoter region) and the TNFd microsatellites on initiation and/or progression of IMN. This was a case-control study comparing data from 100 Caucasians patients (67 male subjects; 67%) with IMN to 232 Caucasians local controls (171 male subjects; 74%). We have analyzed genotypes and alleles distributions and the role of these polymorphisms in disease progression towards end-stage renal failure or patient death. For -308 TNFA polymorphism, distribution of genotypes was significantly different between IMN and controls (chi(2)=16.25; P=0.0003): the A2 allele frequency was 28.0% in IMN vs 15.3% in controls (chi(2)=14.57; P=0.0001). For TNFd polymorphism, alleles distribution (from d1 to d7) was also significantly different between IMN and controls (chi(2)=56.74; P<0.0001) with both diminished d3 allele frequency (chi(2)=27.30; P<0.0001; Pc=0.001) and increased d2 allele frequency (chi(2)=29.95; P<0.0001; Pc=0.001) in IMN. We could not isolate any significant and independent influence of these different genotypes on IMN disease progression. The TNFA2 and TNFd2 alleles were strongly associated with occurrence/initiation of IMN and should be considered as susceptibility genes for this disease.

Adult↗

Sentinel lymph node detection in primary melanoma with preoperative dynamic lymphoscintigraphy and intraoperative gamma probe guidance.

BACKGROUND: This study assessed the value of the radioisotopic method used alone, and factors influencing relapse rates, for sentinel lymph node (SLN) mapping in primary melanoma. METHODS: One hundred and thirty-three patients with a diagnosis of melanoma (thickness greater than 0.75 mm) underwent gamma probe-directed lymphatic mapping in a prospective single-centre study. RESULTS: Mean Breslow thickness was 3 mm. At least one SLN was identified in 132 patients (mean 1.8 nodes per patient); the success rate was 99.2 per cent. Twenty-two patients (16.7 per cent) had a metastasis within the SLN. The mean tumour thickness in patients with a metastatic SLN was 4.4 mm compared with 2.7 mm for patients with a negative SLN (P < 0.001). The median time to recurrence was 20.4 months in SLN-negative patients compared with 8.5 months in those with SLN metastasis (P < 0.001). Ten (9.1 per cent) of the 110 SLN-negative patients developed recurrence. Three patients relapsed in the previously mapped lymphatic basin after a median follow-up of 27.1 months. CONCLUSION: This study confirmed the reliability and accuracy of SLN mapping using a radioisotope technique, and also the importance of the SLN as a predictive factor for survival. There was a low risk of locoregional recurrence when the SLN was not involved.

Adolescent↗

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.

Adult↗

Excessive body weight as a new independent risk factor for clinical and pathological progression in primary IgA nephritis.

Experimental evidence suggests a role for obesity in the formation and progression of some glomerular lesions, but data for human glomerulonephritis are lacking. In a cohort of 162 incident patients with biopsy-proven immunoglobulin A (IgA) nephropathy, we assessed whether the presence of an elevated body mass index (BMI >/= 25 kg/m(2)) at the time of the first renal biopsy (RB1) correlated with clinical data at RB1 (24-hour proteinuria, arterial hypertension, and renal function), pathological data (global optical score [GOS] with detailed pathological indices), and clinical progression to both arterial hypertension and chronic renal failure (CRF). In both univariate and multivariate analyses, the presence of an elevated BMI at RB1 was significantly associated with the severity of pathological renal lesions (GOS and vascular, tubular, and interstitial indices). Hypertension-free survival was significantly less in overweight patients (P: < 0.0001) compared with those with normal weight. In a Cox regression analysis for hypertension-free survival including 24-hour proteinuria greater than 1 g, GOS, and metabolic parameters, only elevated BMI and GOS were independent factors for the development of arterial hypertension. CRF-free survival was also significantly less in patients with an excessive BMI. In a multivariate Cox regression analysis for CRF-free survival, hypertension, GOS, and BMI at RB1 were independent risk factors for CRF. In IgA nephropathy, excessive body weight and/or BMI are underestimated predictive factors for the development of arterial hypertension and, ultimately, CRF.

Adult↗

A randomized prospective study comparing low-dose OKT3 to low-dose ATG for the treatment of acute steroid-resistant rejection episodes in kidney transplant recipients.

Acute steroid-resistant rejection episodes in kidney allograft recipients require treatment with antilymphocyte antibodies. Monoclonal anti-CD3 and polyclonal antilymphocyte antibodies have been widely used but seldom compared. Recent data have suggested that these antibodies could be used at reduced doses without jeopardizing their efficacy. In this study, we randomized renal transplant recipients who encountered a first acute steroid-resistant rejection episode to low-dose ATG or low-dose OKT3 treatment. Sixty patients were enrolled in the study. They received prophylactic immunosuppression with cyclosporin, azathioprine, and prednisolone. Treatment of biopsy-proven rejection consisted of a 10-day course of either ATG (n = 31) or OKT3 (n = 29). The total ATG dose was 484 +/- 110 mg, i.e., 0.75 mg/kg per day. The total OKT3 dose was 32 +/- 4 mg, i.e., 0.05 mg/kg per day. We compared reversion of rejection, side effects, immunodepression, and graft function. Reversion of rejection was similar in the two groups, although we noted a trend in favor of ATG. Results were 3% vs 10% early graft failures, 13% vs 23% overall graft failures, 28% vs 38% 3-month actuarial incidence of rebound rejection, and 89% vs 81% 1-year graft survival rate in the ATG and OKT3 groups, respectively. Tolerance was worse in the OKT3 group due to the first-dose syndrome. Infections and cancers occurred with the same frequency. ATG resulted in a deeper and longer decrease in peripheral lymphocyte subsets. Graft function was similar in the two groups. We conclude that low-dose ATG and low-dose OKT3 are equally effective in reversing steroid-resistant acute rejection. Tolerance was better with ATG, which also gave a more potent and longlasting immunodepression. The use of reduced doses of ATG and OKT3 did not appear to lessen their efficacy.

Adult↗

Advantage of antithymocyte globulin induction in sensitized kidney recipients: a randomized prospective study comparing induction with and without antithymocyte globulin.

BACKGROUND: Sensitized kidney allograft recipients require special management to improve their outcome. One strategy is heavy immunosuppression with antilymphocyte antibodies. Controversy continues about the actual advantage of induction protocols whilst infections and cancers are a constant risk. In addition, little is known about how to handle sensitized patients with low levels of sensitization. METHODS: In this study, we randomized sensitized renal transplant recipients, who received prophylactic treatment with or without antithymocyte globulin (ATG), in addition to a standard triple regimen consisting of cyclosporin, steroids and azathioprine at ATG discontinuation. The induction treatment consisted of a low-dose ATG course over 10 days. Randomization was stratified on the maximum PRA, according to the five following classes: 5% < PRA < or = 20%, 20% < PRA < or = 40%, 40% < PRA < or = 60%, 60% < PRA < or = 80% and 80% < PRA < or = 100%. RESULTS: Eighty nine patients were enrolled: 47 patients received ATG and 42 did not. ATG induction lowered the incidence of biopsy-proven acute rejection episodes from 64 to 38%, increased 1 year graft survival from 76 to 89% and was associated with a higher 1 year inulin clearance (37+/-15 vs 49+/-18 ml/min). ATG-associated side effects were restricted to leucopenia and thrombocytopenia, whereas bacterial and viral infections, gammopathies and cancers did not occur more frequently. ATG induction benefited all sensitized patients, and not only the hypersensitized patients. CONCLUSIONS: We conclude that ATG induction is beneficial for all sensitized patients, regardless of their level of sensitization, with regard to acute rejection episodes, graft survival and graft function. Low-dose ATG is sufficient and prevents additional complications.

Adult↗

Lack of evidence for natural cytotoxicity deficiency against human ex vivo tumour cells in allograft recipients.

BACKGROUND: Allograft recipients, who have a high risk of developing malignancies, are deficient in natural killer cells which mediate natural cytotoxicity against tumour cells. We evaluated the relevance of NK deficiency in transplant patients with regard to the natural lysis of human tumour cells. METHODS: Target cells were ex vivo tumour cells, obtained from solid tumours from kidney transplant patients and non-immunocompromised patients. Peripheral blood was extracted from kidney recipients and from normal controls. Mononuclear cells were separated after anti-CD3 and anti-TCR immunostaining to obtain NK and T cell subsets. LAK cells were obtained by in vitro IL2-activation. For each tumour, natural cytotoxicity assays were performed to compare effector cells from a kidney recipient with those from a normal control. Twenty-seven solid tumours, either allogenic or syngenic, were analysed, mainly consisting of renal, colon, and skin carcinomas. RESULTS: Natural cytotoxicity assays on K562 targets confirmed the expected NK deficiency in the kidney recipients. However, the NK and LAK cells from the kidney recipients did not kill a smaller number of tumour target cells than the controls, whatever the tumour type, under both the syngenic and allogenic conditions. CONCLUSIONS: We conclude that natural cytotoxicity against human tumour cells cannot be extrapolated from the cytotoxicity assays with established cell lines, and that natural lysis of ex vivo human tumour cells is not impaired in transplant patients.

Case-Control Studies↗

[Can one graft with a positive cross-match?].

Differential cross-matches have been proposed to allow immunised patients to be grafted, whereas the dogma of a global positive cross-match discarded them from renal transplantation. We report our one-center experience considering current T positive cross-match as the only contra-indication to grafting, as well as patients whose sera comprise specific anti-donor antibodies. A comprehensive characterization of the antibodies was achieved by identification of auto-antibodies and specification of IgM and IgG isotype, class I and class II specificities, as well as HLA specificities. The differential cross-match comprised an auto and an allo-cross-match, against T and B lymphocytes. Historical and current sera were analysed either untreated or after DTT-treatment, at +4 degrees C and +22 degrees C. We performed 79 renal transplantations across positive cross-matches, which were 20 historical T positive cross-matches, 26 historical B positive cross-matches and 33 current B positive cross-matches. Results and graft survival were strictly identical as those obtained in the transplantations achieved with negative cross-matches throughout the same period, especially in sensitized patients. Current positive B cell cross-matches due to IgG were associated with an increased risk for early graft failure. We conclude that differential cross-match is a safe strategy permitting immunised patients to be grafted.

Autoantibodies↗

Glomerular disease during HCV infection in renal transplantation.

In general nephrology, HCV infection has been associated with type I membranoproliferative glomerulonephritis (MPGN type I) associated with cryoglobulinaemia. In a cohort of 399 renal transplantation (RT) recipients, 117 of whom (29%) were HCV-positive, we selected all patients diagnosed as having membranous GN or type I MPGN by graft biopsy. The prevalence of MGN was 16/399 (4%) with three recurrences, and 13 de novo cases. Only 5/16 (31%) were HCV+, not different from the general RT population. Five patients had an outcome of graft failure after 43 months. Conversely, there were 15 cases of type I MPGN (two recurrences, 13 de novo) but with eight HCV+ recipients (53%, P = 0.02). Considering only the French patients, prevalence was 44% vs 12% in the French RT population (P = 0.006). Eight patients had graft rejection after 59 months (five HCV+). In this type I MPGN subgroup, there were two positive cryoglobulins, two rheumatoid factors and four hypocomplementaemias. In conclusion, there is a clear association between HCV infection and the occurrence of type I MPGN in the allograft in renal transplantation, with terminal renal failure as an outcome.

Adolescent↗