Cell-free plasma hemoglobin removal by dialyzers with various permeability profiles.

The release of hemoglobin from mechanically stressed erythrocytes into plasma is a general side effect of extracorporeal therapies, such as extracorporeal membrane oxygenation or hemodialysis. In many reported cases dialysis patients showed elevated cell-free plasma hemoglobin (CPH) levels which are associated with pathophysiological effects. In this in vitro study, the CPH clearance capacity of various filters with different permeability profiles was measured. Simulated dialysis treatments were conducted and clearance was calculated from variations in CPH concentrations over time by measuring plasma absorbance at 405 nm. Conventional high-flux filters exhibited no detectable clearance of CPH. High-flux filters with extended permeability exhibited clearances between 5.8 ± 1.2 and 12.7 ± 1.7 ml/min when tested with plasma and between 5.8 ± 1.2 and 11.3 ± 1.6 ml/min when tested with whole blood. septeX high-cutoff filters had clearances between 13.8 ± 1.8 and 15.5 ± 1.7 ml/min when tested with plasma and of 22.6 ± 2.9 ml/min when tested with whole blood. This study demonstrated that filters with extended permeability and the septeX filter enable CPH removal when used as in chronic and acute settings.

Single-stage surgical approach in complicated paediatric ureteral duplication: surgical and functional outcome.

PURPOSE: Surgical approach to children with complicated ureteral duplication is discussed controversially. Our aim was to determine the outcome of children with complicated renal duplication undergoing a single-stage surgical approach with laparoscopic partial nephrectomy and open bladder reconstruction. METHODS: Data of patients from 2004 to 2008 were investigated retrospectively. Outcome was analyzed in terms of postoperative course, renal function, urinary tract infection and functional voiding. RESULTS: Thirteen patients were treated with laparoscopic partial nephrectomy and reconstruction of the lower urinary tract in a single-stage approach. Median age at operation was 15 months (2-63 m). One girl had a renal triplication. 7/13 patients presented with an ectopic ureterocele, two with an ectopic ureter, severe vesicoureteral reflux occurred in 6 patients. All patients had non-functioning renal moieties. Mean operative time was 239 min (129-309; SD 50). One re-operation was necessary 4 years after primary surgery due to a pole remnant. All patients had uneventful recoveries without evidence of recurrent UTI. Postoperative 99mTc-MAG3 scans showed no significant reduction of partial renal function (p = 0.4), and no signs of obstruction (p = 0.188). During a median follow-up of 60 months (49-86), dysfunctional voiding occurred in one patient. CONCLUSIONS: In children with complicated ureteral duplication a definitive single-stage procedure is feasible and shows excellent functional results.

Activity of childhood lupus nephritis is linked to altered T cell and cytokine homeostasis.

PURPOSE: Standard therapy for lupus nephritis is based on non-specific immunosuppression. We aimed to identify specific alterations in T cell and cytokine homeostasis and possible associations with disease activity in children with lupus nephritis (LN). METHODS: The phenotype of circulating T cells from children with LN and healthy controls (HC) was analyzed by flow cytometry. Intracellular expression of IL-17 and INF-γ was assessed after stimulation with anti-CD3 and anti-CD28. Serum concentrations of IP10, CCL2, TGF-ß, IL-17, and IL-23 were measured by ELISA. Disease activity was determined using the Systemic Lupus Erythematosus Disease Activity Index 2000 update (SLEDAI-2K). RESULTS: Children with active LN displayed increased frequencies of effector memory CD4(+)CD45RO(+)CCR7(-) and terminal differentiated CD4(+)CD45RA(+)CCR7(-) T cells and reduced naive CD4(+)CD45RA(+)CCR7(+) T cells compared to those with inactive LN or HC. Circulating CD4(+)CXCR3(+) and CD4(+)CCR2(+) T cells correlated inversely with the renal SLEDAI-2K, whereas IP10 and CCL2 showed a positive correlation. Reduced CD4(+)Foxp3(+) T cells and serum TFG-ß levels in active LN were associated with high serum IL-17 and IL-23 levels and correlated inversely with the renal SLEDAI-2K (r = -0.5855, p = 0.0013 and r = -0.6246, p = 0.0005, respectively), whereas IL-17 and IL-23 correlated positively (r = 0.5516, p = 0.0029 and r = 0.6116, p = 0.0007, respectively). Expansion of Th17 and Th1/Th17 cells in children with LN was significantly greater than in HC (p = 0.0304 and p = 0.0067, respectively). CONCLUSION: Children with active LN display high levels of pro-inflammatory cytokines associated with an increase in effector T cells and reduction of regulatory T cells. Therapeutic regulation of the aberrant cytokine profile might specifically interrupt pathogenic mechanisms.

Prophylactic eculizumab prior to kidney transplantation for atypical hemolytic uremic syndrome.

Atypical hemolytic uremic syndrome (aHUS) in childhood is a rare disease associated with high morbidity and mortality. Most cases progress to end-stage renal failure. In approximately 50% of affected patients, mutations in genes encoding complement proteins are causative of the impairment in the regulation of the complement alternative pathway. This leads to deficient host cell protection and inappropriate complement activation on platelets and endothelial cells, particularly in the kidneys. Complement factor H (FH) heterozygosity induces unregulated activation of the membrane attack complex (MAC) C5b-9. Present therapeutic strategies for aHUS include lifelong plasmapheresis and renal dialysis. Unfortunately, kidney transplantation is frequently an unsatisfactory intervention due to the high rate of post-transplantation HUS recurrence, particularly in patients with FH mutation. Combined liver-kidney transplantation is also associated with poor outcome, mostly as a result of premature liver failure secondary to uncontrolled complement activation. Eculizumab is a complement C5 antibody that inhibits complement factor 5a (C5a) and the formation of the MAC. Thus, this antibody may be a promising new agent for patients with an aHUS undergoing kidney transplantation. We present the first case of a young patient with aHUS who received eculizumab as prophylactic treatment prior to a successful kidney transplantation.

Single kidney and ureteral atresia in a newborn girl: a treatment concept.

OBJECTIVE: To demonstrate a rare case of urological pathology, we report a combination of a single kidney and ureteral atresia. The treatment concept and outcome are outlined. PATIENT AND METHOD: Antenatal ultrasound had revealed urinary ascites which lead to caesarean section in the 34th gestational week. Persisting anuria was confirmed postnatally and peritoneal dialysis started on the second day of life. Subsequent laparotomy revealed ureteral atresia after 3 cm of patent ureter. We created an ileum conduit after discussing various other therapeutic options. RESULT AND CONCLUSION: A follow up of 12 months has shown steady function of the stoma with stable renal parameters. An ileal conduit represents a good option if high drainage is necessary in early childhood.

Markers of childhood lupus nephritis indicating disease activity.

Current treatment regimens for childhood lupus nephritis (LN) are associated with significant side-effects and toxicity in vulnerable phases of growth and development. The paucity of biomarkers particularly in childhood impedes the appropriate clinical management and the development of new therapeutics. We analyzed markers of immune system (BAFF, RANTES), complement (Bb, C1q, C3d-CIC, C5a) and endothelial cell activation (sVCAM-1) in children with LN (n=22, mean age 14.8±4.7 years), nephrotic syndrome (n=13) and age-matched healthy controls (n=20) to define parameters that correlate with LN activity. Complement fragments of the alternative (Bb, p=0.0004) classical (C3d-CIC, p<0.0001) and common pathway (C5a, p<0.0001) and the levels of BAFF (p<0.0001), RANTES (p=0.0002) and sVCAM-1 (p=0.0004) were significantly higher in active compared to inactive LN. Activation of complement was associated with the occurrence of anti-C1q antibodies and reduced complement C1q. Complement-activation fragments highly correlated with the markers for immune system and endothelial cell activation. The ensemble of these parameters may be of great value in identifying early flares or remissions of childhood LN, and moreover may prove useful in the assessment of new treatments and in determining the optimization of their use.

Suicidal death of erythrocytes in recurrent hemolytic uremic syndrome.

Hemolytic uremic syndrome (HUS) is characterized by hemolytic anemia with fragmented erythrocytes, thrombocytopenia, and acute renal failure. Lack of complement inactivating factor H predisposes to the development of atypical HUS. Little is known about mechanisms linking complement activation with loss of erythrocyte integrity during HUS. Recent studies disclosed that increased cytosolic Ca2+ activity and cellular ceramide trigger programmed erythrocyte death or eryptosis, characterized by cell shrinkage and phosphatidylserine exposure at the erythrocyte surface. In the present study, we investigated whether eryptosis occurs during the course of HUS. To this end, erythrocytes from healthy volunteers were exposed to plasma from a patient with severe idiopathic recurrent HUS secondary to factor H depletion. Phosphatidylserine exposure (Annexin binding), cell volume (forward scatter), cytosolic Ca2+ activity (Fluo3 fluorescence), and ceramide formation [anti-ceramide antibody and enzymatic (diacylgycerol kinase) analysis] were determined. Exposure of erythrocytes to plasma from the patient, but not to plasma from healthy individuals, triggered Annexin binding. The effect of plasma on erythrocyte Annexin binding was abolished by plasmapheresis or filtration at 30 kDa. It was paralleled by formation of ceramide and increase of cytosolic Ca2+ activity. Enhanced Annexin binding of erythrocytes from healthy individuals was observed after exposure to plasma from three other patients with HUS. The proeryptotic effect of patient plasma was mimicked by exposure to the Ca2+ ionophore ionomycin, and eryptosis was potentiated in the presence of cell membrane-permeable C6-ceramide. Furthermore, in vitro complement activation similarly triggered erythrocyte phosphatidylserine exposure, an effect which was blunted by the addition of factor H. In conclusion, our present observations disclose a novel, pathophysiological, factor-H dependent mechanism leading to injury of erythrocytes during the course of hemolytic uremic syndrome.