Polyradiculonévrite chronique chez des patients avec une greffe d’organe solide : une étude clinique, neurophysiologique et neuropathologique de 4 cas

INTRODUCTION

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) rarely develops in patients with solid organ transplantation.

PATIENTS AND METHOD

We describe the clinical, biological, electrophysiological and neuropathological features of 4 patients with solid organ transplantation who developed CIDP. Two patients had liver transplantation, one had kidney transplantation and one had lung transplantation.

RESULTS

All 4 patients developed in the months following transplantation a syndrome that fulfilled criteria for definite CIDP. All patients had immunosuppressive therapy, with ciclosporin + prednisolone in 2 cases, tacrolimus in 1 case and azathioprine + prednisolone + ciclosporin in one case. One patient had chronic HCV and HBV infection. Treatment with intravenous immune globulin (IVIG) and/or a change in immunosuppressive therapy improved the neuropathy in all cases.

CONCLUSION

CIDP is a rare and potentially treatable condition that should be considered in all patients with solid organ transplantation who develop a rapidly disabling sensorimotor polyneuropathy.

Is Sirolimus Responsible for Proteinuria?

Sirolimus (SRL) is suspected to induce proteinuria. We retrospectively studied proteinuria in a population of liver (n = 29) and kidney transplant (n = 30) recipients switched to SRL with progressive diminution or withdrawal of calcineurin inhibitors (CNI). We also observed estimated glomerular filtration rate (GFR), modification of treatment with antiproteinuric drugs, and changes in concentration of SRL. Collection of data started 3 months before SRL introduction at a mean follow-up of 21 months. Following SRL introduction, proteinuria was not detected in the 28 liver transplant patients, and was stable in the two others. In the kidney transplant group, proteinuria did not occur in 12 patients, remained stable in three, and was slightly increased in 14 (0.57 +/- 0.93 g/d vs 1.83 +/- 1.26 g/d). For all patients, eGFR remained stable; there was no difference in management of antiproteinuric drugs. As suspected, cyclosporin (CsA) and tacrolimus (FK) serum concentrations were decreased. We observed a significant correlation between the variation of proteinuria and the variation of serum concentration of CsA or FK (respectively, P = .001 and P = .007). On the other hand, we did not find any correlation between variation in proteinuria and concentration of SRL. This retrospective study suggests that in our cohort of liver transplant patients without previous renal damage, SRL did not provoke proteinuria. On the other hand, the slight aggravation of proteinuria in a subgroup of kidney transplant patients seems to be linked to the hemodynamic renal effects due to CNI withdrawal.

[Pharmacokinetics and dose adaptation of ofloxacine, pefloxacine and ciprofloxacine during haemodialysis and continuous ambulatory peritoneal dialysis]

Fluoroquinolones present various pharmacokinetic properties. That's the way we carried out a bibliographic summary about the pharmacokinetics of pefloxacin, ofloxacin and ciprofloxacin in patients hit by chronic renal failure, under haemodialysis or under continuous ambulatory peritoneal dialysis. Then, we will describe how to adapt drug dose according to the degree of renal insufficiency and the used molécule.

Posttransplant lymphoproliferative disorders in renal allograft recipients: report of 53 cases of a French multicenter study. PTLD French Working Group

New immunosuppressive therapies are currently being developed in renal transplantation and their relative risk in terms of posttransplant lymphoproliferative disorders (PTLD) must be carefully evaluated. For this purpose, a French registry of PTLD occurring after renal transplantation was set up. Among 10,000 patients presently followed up in 30 French renal transplantation centers, we prospectively identified 53 new PTLD (0.5%) since January 1998. Patients (34 male, 19 female) ranged from 3 to 72 years (mean age: 46 years), and the median time between grafting and diagnosis of PTLD was 63 months (2 months to 14 years). Ninety percent of recipients were Epstein-Barr virus (EBV) positive before transplantation. Most patients received a quadruple sequential therapy with polyclonal anti-lymphocyte globulin. Sites involved in PTLD were isolated lymph nodes in 13 cases, stomach or bowel in 10 cases, allograft in 14 cases, central nervous system in 6 cases, oropharynx in 4 cases, and skin or mucosa in 4 cases. Only three PTLD expressed markers of T lineage. Out of 40 studied tumors, 31 (78%) were EBV positive. Tumors were classified as polymorph in 26 cases and monomorph in 23 cases. Genotype studies in 18 PTLD showed a monoclonal pattern in 13 cases. In most patients, treatment consisted of reduction of immune suppression, 21 patients were given additional anti-viral therapy, 13 patients had anti-CD20, 23 patients underwent chemotherapy, and 4 patients were given cerebral radiotherapy. Five patients underwent transplantectomy. Sixteen patients (30%) died within the 1st year and 7 patients returned to dialysis (13%). The outcome of patients with PTLD remains poor, and the optimal approach to therapy is largely unknown. This ongoing registry is not only a national observatory but also a task force designed to improve the treatment strategy of PTLD.

Compared ontogenesis of courtship song components of males from the sibling species, D. melanogaster and D. simulans

The courtship song of Drosophila is known to be an important signal involved in sex and species recognition. It consists of pulse song and sine song, which have been studied in a quantitative way with different parameters. For the first time the setting of both components of the acoustic signaling is described and compared for males belonging to the sibling species D. melanogaster and D. simulans. At early ages, these two species share similar interpulse interval values but maturation establishes the species specificity of this character. For D. melanogaster the variations of several acoustic parameters take place in two successive periods, whereas for D. simulans the majority of the acoustic features does not change much with age. In D. melanogaster, copulation success seems to be linked to the maturation of the acoustic performance, which is not the case for D. simulans.

[From the first symptoms to terminal renal failure: need for a nephrologic follow-up]

PURPOSE

As patients with chronic renal failure are frequently referred late to nephrologists, we decided to quantify the magnitude of late referral and its consequences.

METHODS

We studied retrospectively an inception cohort of 62 patients starting dialysis (either hemodialysis or continuous ambulatory peritoneal dialysis) during 1993 with a 4-year follow-up.

RESULTS

The mean delay between either first symptoms of renal disease, or first evidence of renal failure and nephrologist referral was 10 years and 3 years 56 days, respectively. About 47% of the patients were referred less than 6 months before starting dialysis, and 27.5% less than 1 month. Blood pressure levels were higher in patients referred less than 6, 3 and 1 month (P < 0.05), as was creatinine concentration in patients referred less than 1 month (P < 0.05). In contrast, plasma calcium was lower for referral less than 6 months (P < 0.05) and 3 months (P < 0.005), as was bicarbonate concentration for referral less than 3 and 1 month (P < 0.05). Initial hospitalisation stay was prolonged (x1.5) for late referral less than 3 months (56.4 +/- 39 days vs 35.9 +/- 33.6 days, P < 0.05) as was 6 months hospitalisation length for referral less than 3 months (x1.6) (52.9 +/- 40.6 days vs 33.2 +/- 28.7 days, P < 0.05) and less than 1 month (x1.8) (61 +/- 45 days vs 33.9 +/- 28.7 days, P < 0.05) and < 1 month (x1.8) (61 +/- 45 days vs 33.9 +/- 28.7 days, P < 0.05). Only 44.1% of patients started hemodialysis with a functioning arteriovenous fistula, and patients requiring temporary access had a 4.4-fold longer initial (60.1 +/- 41.7 days vs 13.6 +/- 11.6 days, P < 0.005) and 6-month (59.6 +/- 39 days vs 13.6 (9.1, P < 0.005) hospitalisation stay. The four-year mortality rate was unaffected by the delayed referral but strongly and independently predicted by age, diabetes and hypoalbuminemia.

CONCLUSION

Early nephrologic referral and timely initiated dialysis decrease morbidity at the start of dialysis and both hospitalisation length and costs.

[Kidney and statins]

Patients with chronic renal diseases (CRD) have a high prevalence of lipid abnormalities. Elevated levels of total and low density lipoprotein cholesterol are associated with cardiovascular diseases in patients with CRD. The 3-hydroxy-methylglutaryl co-enzyme A reductase inhibitors appear to be the most effective agents to lower LDL cholesterol in this category of patients and are generally safe if used with caution. They should be drugs of first choice in CRD but dosage reduction and close monitoring may be required to avoid side effects in case of renal failure or in combination with calcineurin inhibitors. Moreover recent studies suggest that in addition to lowering plasma LDL cholesterol, theses compounds may modify several factors implicated in the development of atherosclerosis and the progression of chronic renal failure. Such newly defined effects may contribute to extend the use of statins in the management of renal patients.

Comparison of cystatin C versus creatinine for detection of mild renal failure

AIM

Serum cystatin C (SCyst) has been proposed as a novel indicator of GFR.

PATIENTS AND METHODS

We compared SCyst, serum creatinine (SCreat) and Cockcroft and Gault's estimated clearance (CCG) using inulin clearance (Cin) as gold standard. 140 subjects (161 samples; aged 39 +/- 14; male/female: 79/82) underwent simultaneous measurements.

RESULTS

A highly significant correlation r = 0.70, 0.74, 0.77 (p < 0.0001) was found between 1/SCyst, 1/SCreat, C(CG), respectively, and Cin. Receiver-operating characteristic (ROC) analysis was performed on SCyst, SCreat and C(CG) using a Cin cut-off of 90 ml/min/1.73 m2. Best fit for SCyst was 0.90 mg/l with a sensitivity of 75% and a specificity of 92%. The area under the ROC curve was not significantly greater for SCreat or C(CG) than for SCyst (p = 0.91,0.13, respectively). When relationship between Cin and SCyst was plotted, experimental data deviated from the theoretical model, suggesting that cystatin C may not be solely filtered. Additional patients were selected in our database on the basis of discordant SCreat/GFR values: false negative (n = 46 samples, 31 patients) and false positive (n = 16 samples, 9 patients). In this highly selected subgroup, 38% of the SCreat false positive had normal SCyst values and 48% of the false negative SCreat had abnormally elevated SCyst.

CONCLUSION

This study suggests that SCyst is not more sensitive than SCreat or C(CG) for detecting renal failure, however, SCyst could be proposed as a confirmatory test for patients with elevated SCreat.

[The HIV/AIDS pandemic: African women at the heart of the control program or the difficulties with regard to gender]

The AIDS pandemia in developing countries forces forth the question of women's rights in Africa and underscores their extreme physical and sociocultural vulnerability. Experience gained during a program designed to reduce mother-to-child transmission of HIV in the Ivory Coast highlights the socially imposed and therefore intricate nature of differences between men and women and of the resulting relationships. Defending a woman's right to know her serologic status empowers her in the fight for emancipation but can also make her more fragile by undermining support from medical staff and family environment. To prevent the risk of outcasting, exclusion, and fragilization, gender must be given greater emphasis in planning future programs. Careful consideration must be devoted to the special sociocultural factors that affect women in Africa.

Blood pressure, diabetes and diabetic nephropathy

Despite multiple evidence-based data that diabetic nephropathy is largely preventable and its progression slowed by currently available interventions diabetic patients are often undertreated, especially for the lowering of blood pressure. Recent studies, (HOT Syst-Eur, SHEP, UKPDS, CAPPP, ABCD, HOPE) have confirmed the efficiency of intensively treated blood pressure in reducing morbidity-mortality in this group of patients at high risk. Low blood pressure targets are mandatory, but may not be that easy to achieve, especially in the presence of renal failure. Early prescription of a combination of antihypertensive drugs is often neccessary. Thus, the clinical question relates to the best combination of drugs. Most studies in hypertensive diabetic patients have dealt with 3 classes of antihypertensives drugs: diuretics, beta-blockers and ACE-inhibitors. Diuretics are one of the most efficient hypotensive drugs available for treatment of hypertension in diabetic patients. Their use must be encouraged early in the stepped approach since diabetes is usually associated with mid-volume expansion due to hyperinsulinism and hyperadrenergic state. In spite of the proven benefit of beta-blockers in diabetic patients, these drugs are largely underused. The indications for selective beta-blockers should probably be broadened for most diabetic patients in primary prevention. Beta-blockers are essential in secondary prevention for patients with coronary artery disease and hypertension. ACE-inhibitors are now more and more widely prescribed in diabetic patients at all stages of hypertension and nephropathy, but paradoxally their use has not been validated in Type 2 diabetic nephropathy. When the desired blood pressure target is obtained, cardiovascular outcome and probably also progression of diabetic nephropathy are significantly improved independently of a specific drug. Early combination therapy, including ACE-inhibitors, diuretics and beta-blockers, should be promptly proposed to all hypertensive diabetic patients to achieve low blood pressure and prevent high cardiovascular burden and progression of nephropathy.

Prediction of colloid osmotic pressure in renal patients

BACKGROUND

Colloid osmotic pressure (COP) plays a major role in transcapillary fluid shift, including in the glomerular capillary. However, COP is generally estimated by quadratic equations derived from total plasma protein and/or albumin concentrations. The aim of this study was to assess the accuracy of such equations, and to determine the potential role of liver-derived non-albumin proteins in the maintenance of COP, especially in patients presenting a nephrotic syndrome.

METHODS

COP was directly assessed with an osmometer in 170 patients (347 samples), and the results compared with calculated COP, using 4 previously published formulas [Brenner 1972, Canaan-Kühl 1993, Landis-Pappenheimer 1963, Navar 1977].

RESULTS

The 4 calculated COP values were strongly correlated with measured COP (range r = 0.88 - 0.96). However, in absolute terms, measured COP differed significantly from each of the 4 calculated mean values of COP (p < 0.001). Fibrinogen exerted per se a weak oncotic effect as measured in vitro. However, fibrinogen was highly related to albumin and presumably reflected the oncotic effect of other liver-derived non-albumin proteins. Inclusion of albumin and fibrinogen in a linear model provided an excellent fit for predicted COP with a highly significant correlation (r = 0.96, p < 0.001) over a wide range of COP values. The predicted equation was: COP(mmHg) = 6.89 x (albumin + fibrinogen) (g/dl) - 5.68.

CONCLUSION

None of the 4 most commonly used formulas correctly predicted COP, and direct measurement of COP is still preferable for research studies. The introduction of fibrinogen into the formula estimating COP leads to higher accuracy, and therefore represents a more convenient model for routine evaluation.

Cardiovascular morbidity and endothelial dysfunction in chronic haemodialysis patients: is homocyst(e)ine the missing link?

BACKGROUND

Haemodialysis patients exhibit an excessive burden of atherothrombotic disease, which is not explained adequately by traditional risk factors. Hyperhomocyst(e)inaemia, a consistent finding in uraemic patients, is now widely recognized as an independent risk factor for vascular disease. The aim of this study was to examine the hypothesis that hyperhomocyst(e)inaemia is associated with cardiovascular complications in dialysed patients.

METHODS

In a cohort of 63 stable chronic haemodialysis patients, we examined the causal relationship between hyperhomocyst(e)inaemia and vascular endothelial and haemostatic function. All their markers were determined before and after an 8-week course of a 10 mg per day oral folate supplementation, a manoeuvre known to decrease hyperhomocyst(e)inaemia in uraemic patients.

RESULTS

History of at least one cardiovascular atherothrombotic event was present in 47.6% of the haemodialysed patients, and radiographic evidence of vascular calcifications in 70%. Hyperhomocyst(e)inaemia was found in all patients, averaging 3.5-fold the upper limit of normal values (P<0.001), despite the lack of clinical and biological evidence of malnutrition. Fibrinogen, von Willebrand factor and plasminogen activator inhibitor type 1, but not endothelin 1, were significantly higher in haemodialysis patients than in controls. After adjustment for all variables, past history of cardiovascular events was independently associated with higher levels of homocyst(e)inaemia only (odds ratio (OR) 1.06; 95% confidence interval (CI) 1.01-1.12; P<0.026). The presence of aortic calcifications was independently and significantly associated with age (OR 1.37; 95% CI 1.07-1.75; P<0.025), homocyst(e)inaemia (OR 1.14; 95% CI 1.02-1.27; P<0.05) and fibrinogen concentration only (OR 9.74; 95% CI 1.25-75.2; P<0.05). None of the endothelial haemostatic factors was, however, related to homocyst(e)ine levels. Mid-term folate supplementation decreased plasma homocyst(e)ine levels significantly without achieving normal values. No significant change of endothelial-haemostatic markers was observed, however, despite the drop in plasma homocyst(e)ine.

CONCLUSIONS

Hyperhomocyst(e)inaemia is associated with increased cardiovascular risk in haemodialysis patients. Folate supplementation was partially effective in lowering hyperhomocyst(e)inaemia, but its usefulness in terms of reduction in cardiovascular morbidity and mortality remains to be determined in prospective trials.

Nodular glomerulosclerosis with deposition of monoclonal immunoglobulin heavy chains lacking C(H)1

The objective of this study was to further characterize the clinical and immunopathologic features of heavy chain deposition disease (HCDD), a recently described entity. Four patients were diagnosed as having HCDD on a kidney biopsy. All presented with nodular glomerulosclerosis with deposition of gamma1 heavy chains lacking CH1 epitopes, but without light chains. Two different patterns were observed in the serum. First, patients 1 and 2 had a circulating monoclonal IgGlambda containing a short gamma1 heavy chain lacking CH1 epitopes, with an apparent molecular weight of 40 kD consistent with a complete CH1 deletion. Biosynthetic experiments also showed that the deleted heavy chain was produced in excess compared with light chains, and was secreted in vitro together with half Ig molecules, although these abnormal components were not detected by Western blot analysis of whole serum. Second, patients 3 and 4 had a circulating monoclonal IgG1lambda with an apparently normal, nondeleted heavy chain subunit, but serum fractionation followed by immunoblotting revealed an isolated monoclonal gamma1 chain lacking CH1 epitopes. These data strongly suggest that renal deposition of a CH1-deleted heavy chain circulating in low amounts in the serum as a free unassembled subunit is a major feature of HCDD. The CH1 deletion is most likely responsible for the premature secretion in blood of the heavy chain by a clone of plasma cells.

[Post-transplantation lymphomas and Epstein-Barr virus]

Post-transplant lymphoproliferative disorders (PTLD) are recognized as a devastating complication of organ transplantation. Their occurrence appears to vary according to the transplanted organ and the type and the level of administered immunosuppressive therapy. In kidney transplants the incidence is estimated between 1 and 2%. PTLD represent a clinically and morphologically heterogeneous group of lymphoid proliferations. They have been closely associated with Epstein-Barr virus (EBV), and the spectrum of manifestations after transplantation range from an infectious mononucleosis-like syndrome to more serious polyclonal or monoclonal lymphoproliferation, the treatment of which is not well defined and, relying on immuno- and chemotherapy. Oncogenicity of EBV is not yet completely understood, but may implicate latent viral gene expression of EBNA or LMP as well as Th2 cytokines. Detection and monitoring of EBV induced lymphoid abnormalities are necessary to start early efficient antiviral treatment. Prophylactic antiviral therapy has to be considered.