Eculizumab for atypical hemolytic uremic syndrome recurrence in renal transplantation.

Eculizumab (anti-C5) has been sporadically reported as an efficient therapy for atypical hemolytic uremic syndrome (aHUS). However, the lack of series precludes any firm conclusion about the optimal use of anti-C5 for preventing or treating aHUS posttransplant aHUS recurrence. We thoroughly studied 22 renal transplant recipients with aHUS who received off-label therapy with anti-C5, including 12 cases, which have not been reported yet. Nine patients, all carrying a complement genetic abnormality associated with a high risk of aHUS recurrence, received prophylactic anti-C5 therapy to prevent posttransplant recurrence. Eight of them had a successful recurrence-free posttransplant course and achieved a satisfactory graft function, while the remaining patient experienced early arterial thrombosis of the graft. Thirteen renal transplant recipients were given anti-C5 for posttransplant aHUS recurrence. A complete reversal of aHUS activity was obtained in all of them. Importantly, the delay of anti-C5 initiation after the onset of the aHUS episode inversely correlated with the degree of renal function improvement. Three patients in whom anti-C5 was subsequently stopped experienced a relapse. Altogether these data suggest that long-term eculizumab is highly effective for preventing and treating posttransplant aHUS recurrence. Our study also indicates that anti-C5 should be promptly started if a recurrence occurs.

[Verocytotoxin positive haemolytic uremic syndrome and HIV-associated nephropathy]. / Syndrome hémolytique et urémique typique et néphropathie à VIH.

UNLABELLED: Haemolytic uremic syndrome (HUS) and HIV-associated nephropathy (HIVAN) are common renal diseases in the course of HIV-infected patients. CASE REPORT: We report the case of a 13-month-old Caucasian boy hospitalised for a verocytotoxin positive HUS associated with HIV infection. After the acute phase of HUS the creatinine level returned to normal values. Because of progressive renal failure with severe overload hypertension and glomerular proteinuria despite antiretroviral therapy and angiotensine converting enzyme inhibitor, the child required peritoneal dialysis 12 months later. Clinical and biological course together with pathological findings were consistent with both typical HUS and HIVAN. CONCLUSION: This is the first paediatric case of typical HUS revealing a HIVAN. The association of HUS and HIVAN may explain the progression to end-stage renal failure despite antiretroviral therapy associated with angiotensine converting enzyme inhibitor and a good control of HIV replication. HIVAN is rare in children and may occur in the early phase of HIV infection even not only in black patients.

[Central venous access for hemodialysis: use and practice with the child in France]. / Accès veineux centraux pour hémodialyse: usage et pratique chez l'enfant en France.

Central venous catheter (CVC) are being increasingly used as hemodialysis vascular access. In order to evaluate the indications, practice and uses in the pediatric population, we conducted a study in children with renal failure (RF). A questionnaire was sent to the 21 french paediatric hemodialysis centers to inquire population deserved, number, type, site and indications of CVC, procedure of management and attitude towards infection and thrombosis. A prospective survey was added to compile information about CVC during the period 7/2000-31/12/2000. Results (exhaustivity response 80%) showed 1. large diversity in choice of material with predominance of pediatric permcath QUINTON; 2. exclusive surgical insertion for 8 out of 19 centers; 3. rare use of femoral route (never and exceptionally reported, respectively by 4 and 6 centers and predominantly in acute RF; 4. heterogene attitude towards fixing, dressing, heparine locking and procedure of urokinase administration in case of thrombosis, whilst procedure towards infection was homogeneous; 5. indications of insertion of the 31 prospective study CVC were distributed in 4 subgroups a) breakdown of vascular permanent access (6 cases) or of peritoneal dialysis (2 cases), b) unexpected terminal renal failure (6 cases), c) deliberate choice to wait transplantation (4 cases) or to face breakdown of transplantation (4 cases), d) dysfunction of a previous CVC (7 cases); 6. a rate of 20% of dysfunction (flow problem); 7. a rate of replacement of 11%. AVC are effective forms of vascular access. However CVC indications should be carefully analysed and balanced if possible with alternative route such as anticipated creation of arterioveinous fistula, peritoneal dialysis and preemptive transplantation.

Renal artery vasomotion: in vivo assessment in the pig with intravascular Doppler.

Intravascular Doppler is widely used for experimental studies in the coronary circulation. We designed this study to assess baseline bloodflow and arteriolar resistance in the porcine renal circulation and to study the vasomotor responses of vasoactive drugs. In anesthesized piglets (n = 15), renal arterial diameter was measured with quantitative angiography and blood flow velocity with a Doppler wire (Cardiometrics). Bloodflow and resistances were calculated at baseline and after injection of vasoactive drugs (isosorbide dinitrate, papaverine). This allowed us to determine the renal bloodflow reserve (the capacity of the kidney to augment basal bloodflow). Injection of isosorbide dinitrate was associated with an increase in average peak velocity of 64% (P < 0.01) and a small (from 4.5 to 4.74, P < 0.01) but significant increase in renal artery diameter, resulting in an increase in bloodflow of 82% (P < 0.01) and a decrease in arteriolar resistance of 46% (P < 0.01). Bloodflow returned to baseline (4.76 +/- 1.48 mL/s) approximately 5 min after isosorbide injection. Average Peak Velocity increased almost twofold after papaverine injection (60 +/- 10 to 108 +/- 24 cm/sec, P < 0.01). There was a significant (P < 0.01) increase in arterial bloodflow of 96% in the right and 79% in the left renal artery after injection of papaverine with a corresponding significant (P < 0.01) decrease in arteriolar resistance of 49% in the right and 44% in the left renal artery. Using a combination of quantitative angiography and intravascular Doppler allows easy measurement of baseline renal blood flow and of the effects of vasodilator drugs on bloodflow and resistance. The results show that a vasodilatator reserve exists in the renal circulation but is less marked than that reported in the coronary circulation.

Percutaneous angioplasty of arteriovenous (Brescia-Cimino) fistulae in children.

The development of a stenosis in a Brescia-Cimino fistula is a major clinical problem that threatens vascular access for dialysis. We reviewed the case notes of 46 children undergoing hemodialysis via Brescia-Cimino fistulae. Ten children (mean age 12.5 years) developed 14 stenoses located in the venous (10), anastomotic (3), or arterial (1) part of the fistula. Three (1 arterial and 2 anastomotic stenoses) of the 14 stenoses were treated surgically; the remaining 11 (10 venous and 1 anastomotic stenoses) were treated by angioplasty. Seventeen angioplasty procedures were performed by the percutaneous venous route under local anesthesia. Mean follow-up was 24 months. Restenosis within 6 months occurred in 5 patients, predominantly those who had angioplasty with low balloon inflation pressures; 1 was treated surgically; 4 underwent repeat angioplasty using higher balloon inflation pressures (3 patients) or a bigger balloon (1 patient). None subsequently developed restenosis. Angioplasty can be safely used to treat stenosis of arteriovenous fistulae, with a high initial (60% freedom from restenosis at 6 months) success rate. In summary, balloon angioplasty, repeated if necessary, is a safe and effective treatment for the majority of stenoses occurring in Brescia-Cimino fistulae. Restenosis can be safely treated by further angioplasty, which is associated with a high rate of ultimate clinical success.