Anticardiolipin antibodies in children on chronic haemodialysis

IgG and IgM anticardiolipin antibody (Ab) concentrations weredetermined in serum samples of 48 children with end-stage renaldisease (ESRD) on haemodialysis using ELISA technique in anattempt to analyse their possible role in the occurrence ofthrombosis of the vascular access. Ten normal healthy childrenwere studied as a control group. The positivity of anticardiolipinAb isotypes both IgM and IgG was high in children with ESRDon haemodialysis. Children with positive anticardiolipin Abhad significantly higher incidence of prior thrombosis of vascularaccess. Also, these antibodies should be considered as markersof high risk for fistula thrombosis.     

Procalcitonin serum levels in children undergoing chronic haemodialysis

Infections account for considerable morbidity and mortality in patients requiring haemodialysis (HD). Procalcitonin (PCT)—a low molecular weight protein of 13 kDa—helps one to distinguish viral from bacterial infections and to evaluate the severity of bacterial infections. We investigated (1) PCT baseline levels in eight children undergoing chronic HD with high-flux membranes and (2) changes in the serum levels of PCT, C-reactive protein (CRP) and beta-2-microglobulin (β2-MG)—a peptide with biochemical characteristics similar to those of PCT—before and after haemodialysis sessions. Blood sampling was performed three times in the mid-week session. Serum PCT of the seven uninfected children before HD sessions was increased (0.75±0.07 ng/ml), whereas CRP levels were normal. PCT after dialysis decreased significantly by 40% (P<0.0001) compared with initial values, whereas CRP levels before and after HD were not different. β2-MG decreased by 70%, probably due to different biochemical proprieties of both proteins. PCT serum levels 15 min and 60 min after the HD session remained unchanged in comparison with those at the end of the HD session, suggesting accumulation of PCT between HD sessions rather than HD-induced production to be responsible for the increased baseline PCT serum levels. We concluded that CRP serum levels were not affected by HD in our group. Moderately elevated baseline PCT serum levels that are presumably due to reduced renal clearance and uraemia and dialysability of PCT should be taken into consideration. However, increase of serum PCT in patients with severe bacterial infections is generally massive (10-fold to 1,000-fold), suggesting a low risk for false negative results in such cases.     

Somatostatinergic tone in children on chronic haemodialysis and after renal transplantation

The role of somatostatinergic tone (SST) in growth hormone (GH) neuroregulation in children with chronic renal failure (CRF) and short stature (mean height standard deviation score –3.47) was investigated. Ten children (9 males, 1 female), mean age 13.4 years (range 8–17 years), five with renal transplants (TP) and five on chronic haemodialysis (HD), underwent three separate investigations: (1) measurement of spontaneous GH secretion; (2) measurement of GH after infusion of GH releasing hormone (GHRH); (3) measurement of GH following treatment with pyridostigmine bromide (PD) and subsequent infusion of GHRH. All patients showed normal or exaggerated spontaneous nocturnal GH secretion (mean concentration values ranging between 3.8 and 19.07 ng/ml). In four of ten patients GHRH was not able to cause an increase in GH levels (mean peak GH 7.35±2.05 ng/ml) while PD pretreatment reinstated the GH response to GHRH (mean peak GH 55.25±17.23 ng/ml) in these children. In the other patients in whom GHRH-induced GH release was normal or exaggerated (mean peak GH 42.0±13.8 ng/ml), PD did not potentiate the GH response to GHRH (mean peak GH 54.83±7.88 ng/ml). These different types of responses were observed both in TP and HD patients. Our data indicate that: (1) PD potentiates the response to GHRH only when GHRH alone is not able to cause GH release, suggesting that SST is already reduced in patients with a normal or exaggerated GH response to GHRH; (2) in CRF patients the SST can be either reduced or increased, at least during the daytime.     

Increased arterial stiffness in children on haemodialysis.

BACKGROUND: Measures of aortic stiffness--aortic pulse wave velocity (PWV) and augmentation index (AIx)--have been shown to be powerful predictors of survival in adult haemodialysis (HD) patients. Very few data have been reported regarding arterial stiffness in paediatric renal populations. METHODS: PWV and aortic AIx were determined from contour analysis of arterial waveforms recorded by applanation tonometry using a SphygmoCor device in 14 children on HD (age = 14.1 years) and in 15 age, height matched children controls. RESULTS: Pre-HD AIx (29.7 +/- 15.4%) and PWV (6.6 +/- 1.0 m/s) were significantly higher compared with children controls (8.3 +/- 8.0% and 5.4 +/- 0.6 m/s, respectively, P < 0.0001). The only significant difference between normal and HD children was BP level: 103/61 vs 114/72 mmHg, P < 0.05. In children of HD patients, a multiple linear regression model including BP, age, height, weight, Ca and P levels as independent variables accounted for 57% of the variability in AIx. Dialysis had no impact on AIx (post-HD: 28.5 +/- 12.7%) or on PWV (post-HD: 6.7 +/- 0.8 m/s). CONCLUSIONS: We show, in this first-ever report of increased arterial stiffness in children on dialysis, that end-stage renal disease is associated with abnormalities in arterial wall elastic properties, comparable with adult levels, even in childhood. Most importantly, the absence of a discernible amelioration with dialysis implies that purely structural and not functional alterations lie behind the increased arterial stiffness.     

Candesartan reduces cardiovascular events in patients on chronic haemodialysis.

Sir, We read with great interest the recent report by Takahashi etal. [1] on the beneficial effects of candesartan administeredto patients on chronic haemodialysis. The reduction in cardiovascularevents     

Challenges in taking care of patients on chronic haemodialysis.

Sir, Dr Tozawa and his colleagues [1] bring out several interestingissues in their article on multiple medication use and increasedmortality in chronic haemodialysis patients. Patients on a larger number of medications had multiple co-morbidities(i.e. type 2 diabetes, Table 1). This article,     

The basic needs of children on haemodialysis in Turkey.

BACKGROUND: Haemodialysis treatment can be very tiring and unpleasant, particularly for paediatric patients, families and also for the treatment team. In this study, the basic needs of children on haemodialysis were determined in order to improve the conditions of their therapy environment. METHODS: The requirements of 20 children and 40 adults, who were on haemodialysis therapy for a minimum of five sessions, were recorded by means of a questionnaire. RESULTS: The majority of children and adults preferred to be treated in separate units. All children and adults stated that they needed a constant transportation facility to be provided by the dialysis unit. All children wanted their parents/relatives to be with them during the dialysis sessions while only a minority of adults required an accompanying relative. The majority of both paediatric and adult patients preferred daytime sessions. The majority of children preferred to have the same nurse to needle their fistula and supervise their therapy session. CONCLUSIONS: The health authority should recognize the role of the therapy team, including a paediatric nephrologist, in providing the basic needs and fulfilling the expectations of paediatric haemodialysis patients in order to increase the efficiency of the treatment.     

Glycoxidation and inflammation in chronic haemodialysis patients.

BACKGROUND: Uraemia and haemodialysis treatment are associated with microinflammation and oxidative as well as carbonyl stress, which result in enhanced formation of glycoxidation products. Although both glycoxidation and inflammation can contribute to severe vascular and cardiovascular complications, the role that these pathogenic mechanisms play in the complex response of the whole organism remains to be elucidated. METHODS: We performed a cross-sectional study in 34 clinically stable chronic haemodialysis patients and in 14 healthy controls while determining serum concentrations of pentosidine, fluorescent advanced glycation end-products (AGEs), advanced oxidation protein products (AOPPs) and acute phase reactants. We further assessed the relationship between these glycoxidation products and parameters of inflammation. RESULTS: Glycoxidation products as well as certain acute phase reactants were elevated in haemodialysis patients. There were significant correlations between AOPPs and inflammatory parameters such as orosomucoid (0.39, P < 0.05), fibrinogen (0.49, P < 0.05) and pregnancy-associated protein A (PAPP-A; 0.46, P < 0.05), but no correlations between pentosidine or fluorescent AGEs and any of the inflammatory parameters. CONCLUSION: Oxidative damage showed a closer relationship to inflammation than advanced glycation (glycoxidation). AOPPs may represent a superior acute biochemical marker, whereas AGEs may better describe chronic long-lasting damage.     

Microsurgical creation and follow-up of arteriovenous fistulae for chronic haemodialysis in children

Three hundred and eighty children underwent 434 angioaccesses. Of these angioaccesses, 113 were constructed in 74 children weighing under 10 kg. Most accesses (n=340) were distal arteriovenous fistulae (AVF). After microsurgery there was a 96% immediate patency. Seventy percent of AVF, excluding distal ulnarbasilic AVF, were functional, sometimes after secondary superficialization of the vein. Eighty-five per cent of the distal radial-cephalic AVF are still patent after 2 years, 60% are still patent after 4 years. These radial-cephalic AVF required 65 repeat anastomoses, and 12 ligations of the proximal-radial artery in order to reduce to 50% the high blood flow (pre-reduction average index = 900 ml/min per m²). The patency rate of arteriovenousbridge grafts was not encouraging. The severity of stenoses in the proximal-venous trunks, sometimes related to previous catheterization, is emphasized. Advantages of the radial-cephalic wrist AVF in children are highlighted.     

Increased plasma S-nitrosothiol levels in chronic haemodialysis patients.

BACKGROUND: An impairment of nitric oxide (NO) bioavailability and/or metabolism may contribute to the excessive incidence of atherosclerotic complications observed in haemodialysis (HD) patients. Recent evidence indicates that NO metabolism involves a family of NO-related molecules that have not yet been explored in such patients. The aim of our study was to determine the plasma levels of S-nitrosothiol and nitrotyrosine in chronic HD patients, and to evaluate potential factors influencing their levels. METHODS: Plasma levels of S-nitrosothiols and nitrotyrosine were determined in 22 non-smoking HD patients and 12 healthy control subjects, together with albumin, homocysteine, haemoglobin, highly sensitive C-reactive protein (hsCRP) and various components of the oxidant-antioxidant system at the plasma and erythrocyte levels. RESULTS: While plasma nitrosothiol levels were significantly higher in HD patients than in controls (2.25 +/- 1.17 vs 0.45 +/- 0.45 micromol/l, respectively, P < 0.0001), nitrotyrosine levels were not different. HD patients also exhibited a marked deficit of ascorbate and low plasma glutathione peroxidase activity. An inverse relationship was found between plasma S-nitrosothiol and blood haemoglobin in HD patients (P < 0.005). No direct relationship was observed between plasma S-nitrosothiol levels and any of the oxidative stress markers, or hsCRP levels. CONCLUSION: This study demonstrates high plasma S-nitrosothiol levels in HD patients, which are partially related to low blood haemoglobin concentrations. The pathophysiological significance of this elevation remains to be elucidated. A possible protective role against nitrosative stress is suggested in presence of normal plasma nitrotyrosine levels in such patients.     

Upper gastrointestinal haemorrhage

Upper gastrointestinal (UGI) haemorrhage is bleeding from any point of the GI tract proximal to the ligament of Treitz. There are multiple causes and various presentations, some of which can be quite subtle. With dramatic bleeding, aggressive resuscitation is required in the first instance. The gold standard investigation for diagnosis is endoscopy and this in turn can facilitate certain therapeutic interventions. Other forms of management include radiological and surgical interventions.