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J R Delanghe

Publications and source records attributed to J R Delanghe.

At least 37 records · Page 2Linked to original sources
PubMed1999

Automated flow cytometry compared with an automated dipstick reader for urinalysis.

Recently, the Sysmex UF-100 flow cytometer was developed to automate urinalysis. We compared UF-100 test results with those of an automated dipstick reader. A cross-check of UF-100, dipstick, and microscopic sediment data was performed in 1001 urine samples. Good agreements (P <0.001) were obtained between UF-100 and dipstick data for erythrocytes (r = 0.636) and leukocytes (r = 0.785). Even in urine with low conductivity, the UF-100 could detect lysed erythrocytes. The UF-100 bacterial count was higher among nitrite-positive urine samples (P <0.0001) and was positively correlated with the UF-100 leukocyte count (r = 0.745; P <0.001). In stored urine (24 h), bacterial counts increased, whereas the forward light scatter of leukocytes decreased (P <0.01). Casts and yeast cells reported by the UF-100 should be confirmed by microscopic review because false positives occurred. We suggest that a computer-assisted cross-check of UF-100 and dipstick data allows a clinically acceptable sieving system to reduce the workload of microscopic sediment urinalysis.

Autoanalysis↗
PubMed1998

Haptoglobin polymorphism, iron metabolism and mortality in HIV infection.

BACKGROUND: Three phenotypes of the antioxidant protein haptoglobin are known: Hp 1-1, Hp 2-1 and Hp 2-2. OBJECTIVES: To investigate the outcome of HIV infection according to haptoglobin type. DESIGN AND METHODS: Haptoglobin phenotypes were determined using starch gel electrophoresis in serum obtained from 653 HIV-infected Caucasians in the AIDS reference centers of Gent (n = 184), Antwerp (n = 309), and Luxembourg (n = 160). Survival was compared between haptoglobin types using Kaplan-Meier curves. Plasma HIV-1 RNA was quantified by reverse transcriptase PCR. Serum iron, transferrin saturation, ferritin, and vitamin C were assayed to evaluate iron-driven oxidative stress in 184 HIV-infected patients and 204 controls. RESULTS: The haptoglobin type distribution amongst the patients (17.6% Hp 1-1, 49.9% Hp 2-1, 32.5% Hp 2-2) corresponded to that of the controls. Kaplan-Meier curves showed a higher mortality for the Hp 2-2 group (P = 0.0001; adjusted mortality risk ratio, 1.78; 95% confidence interval, 1.25-2.54). Median survival time was 11.0 years (Hp 1-1 and Hp 2-1) versus 7.33 years (Hp 2-2). Plasma HIV-1 RNA levels prior to antiviral therapy and their increase over 1 year were highest in Hp 2-2 patients (P = 0.03 and 0.003, respectively). The Hp 2-2 type was associated with higher serum iron, transferrin saturation, and ferritin levels and with low vitamin C concentrations. Furthermore, ferritin concentrations were higher in HIV-infected patients than in controls (P < 0.0001). CONCLUSION: HIV-infected patients carrying the Hp 2-2 phenotype show a worse prognosis, which is reflected by a more rapid rate of viral replication (in the absence of antiviral treatment). They also accumulate more iron and oxidize more vitamin C, suggesting that less efficient protection against haemoglobin/iron-driven oxidative stress may be a direct mechanism for stimulating viral replication.

Adult↗
PubMed1998

Serum creatine kinase activity is not a reliable marker for muscle damage in conditions associated with low extracellular glutathione concentration.

Creatine kinase (CK, EC 2.7.3.2) assays usually contain thiol-reducing compounds to restore the enzyme activity. In this study, we investigated the effect of endogenous extracellular glutathione on serum CK activity. We examined CK activity and glutathione concentrations in serum from 200 healthy subjects (107 males, 93 females) and 38 patients with multiple organ failure, muscle wasting, and low serum CK activity (<50 U/L) (24 males, 14 females). Muscle damage was further evaluated using serum myoglobin concentrations and aldolase activity. In the overall group, serum glutathione concentrations correlated with serum CK activity (r = 0.791) but not with myoglobin concentrations and aldolase activity. In patients with multiple organ failure, low serum CK activities were accompanied by extremely low serum glutathione concentrations (<0.5 ,micromol/L, P <0.001). Endogenous glutathione can be regarded as a CK-preserving agent during the lifetime of the enzyme in the circulation (22 h on average). Serum CK activity should be interpreted with caution in patients with liver disease and multiple organ failure. In these conditions, the loss of CK activity due to extracellular glutathione depletion cannot be restored by the presence of thiol-reducing compounds in the CK assays.

Adult↗
PubMed1997

Effect of haptoglobin on the metabolism of vitamin C.

Haptoglobin is a hemoglobin-binding antioxidant showing a genetic polymorphism with three types: Hp 1-1, Hp 2-1, and Hp 2-2. The Hp 2-2 type has been associated with an increased risk of atherosclerosis. We investigated vitamin C metabolism in vivo and in vitro according to haptoglobin type in a study group of 135 healthy volunteers. Serum vitamin C concentrations were associated with haptoglobin type, showing lowest values in serum from Hp 2-2 subjects (P < 0.01). Renal threshold for L-ascorbic acid was within the normal range and metabolization to oxalate was not different among haptoglobin-type groups. Serum concentrations of other endogenous antioxidants (uric acid, bilirubin, albumin, ceruloplasmin, and total antioxidative status) were not different among haptoglobin-type groups. In vitro experiments showed a lower stability of L-ascorbic acid in blood from subjects with the Hp 2-2 type (P < 0.01). L-Ascorbic acid depletion in vitro was inversely related to haptoglobin concentration (r = -0.738). The results of this study indicate a higher rate of L-ascorbic acid oxidation in Hp 2-2 carriers because they have less protection against hemoglobin-iron driven peroxidation.

Adult↗
PubMed1997

Difficulties in evaluating urinalysis following combined pancreas-kidney transplantation.

Combined pancreas-kidney transplantation has been introduced in the treatment of patients with type 1 diabetes and renal failure 20 years ago. By 1985 374 combined pancreas-kidney transplantations had been reported to the International Pancreas Transplant Registries. Surgical drainage of the transplanted exocrine pancreas into the urinary bladder solves most of the postoperative problems encountered with the exocrine secretions. Furthermore, monitoring of pancreatic enzyme (amylase) activity in urine has been shown to be useful in diagnosis of rejection of the pancreatic graft. However, little attention has been paid to the biochemical consequences of high activities of proteolytic pancreatic enzymes on the determination of urinary proteins. The present case illustrates the difficulties in interpreting proteinuria in patients with combined pancreas-renal transplant with pancreaticocystostomia. In the propositus, interpretation of the urinary protein electrophoresis is hampered by the presence of pancreatic juice proteins and peptides originating from digestion of proteins by activated pancreatic enzymes. Results of immunochemically determined marker proteins ([micro]albumin, transferrin, beta 2-microglobulin) are unreliable due to digestion by pancreatic enzymes.

Biomarkers↗
PubMed1997

Evolution of haptoglobin concentration in serum during the early phase of acute myocardial infarction.

Haptoglobin (Hp) is a haemoglobin-binding acute phase protein with three genetic types: Hp 1-1, Hp 2-1, Hp 2-2. We investigated 45 patients during the first 48 hours of acute myocardial infarction, and studied determinant factors and clinical correlates. Upon hospital admission, serum haptoglobin concentration was increased (1.95 +/- 0.94 g/l, mean +/- SD, P < 0.001) versus the reference population (0.97 +/- 0.46 g/l, n = 107), independent of haptoglobin type: 1.84 +/- 0.64 g/l (Hp 1-1, n = 11) (P < 0.01), 1.98 +/- 0.79 g/l (Hp 2-1, n = 25) (P < 0.001), 1.98 +/- 1.58 g/l (Hp 2-2, n = 9) (P < 0.001). Moreover, during the first hours of hospitalization, a temporal lowering of haptoglobin was observed suggesting acute haemolysis, independent of the haptoglobin type. Minimal serum haptoglobin was reached 9.6 +/- 5.8 hours after admission. The amplitude of the haptoglobin decrease correlated with initial serum haptoglobin (r = 0.78) and was more pronounced (P < 0.05) in men (0.53 +/- 0.57 g/l) than in women (0.18 +/- 0.17 g/l). Decrease of serum haptoglobin did not correlate with infarct size (based on creatine kinase-MB release). Out of the other acute phase proteins measured upon admission, only C-reactive protein was significantly increased (P < 0.05). During the next 36 hours, haptoglobin increased as a result of the acute phase response to myocardial injury. Our findings suggest that acute myocardial infarction is also preceded by an acute phase response, characterized by an initial high haptoglobin and followed by a temporal haptoglobin decrease due to haemolysis.

Aged↗
PubMed1996

Genetic polymorphisms and erythrocyte sodium-lithium countertransport in essential hypertension.

Erythrocyte sodium-lithium countertransport (SLC) activity is elevated in essential arterial hypertension. With the growing attention to the genetic substrate of disturbed biochemical tests associated with essential arterial hypertension, we were particularly interested in the involvement of key genes for the regulation of SLC, possibly related to the pathophysiology of essential arterial hypertension. Consequently, the aim of the present study was to investigate SLC and its determining factors in essential hypertension. The influence of haptoglobin (Hp)-polymorphism, insertion/deletion polymorphism of angiotensin converting enzyme (ACE-I/D) and MNS blood group system on the regulation of SLC was studied. SLC activity was studied in a cross-sectional case-control study including 90 Caucasians: 60 patients with essential arterial hypertension who had been treated for at least 1 year and 30 normotensive controls. In essential hypertension, the SLC activity is significantly higher (P = 0.00005) than in controls. In normotensive patients, no differences in SLC are observed for the different polymorphisms studied. However, in the hypertensive group, SLC activity is higher (P = 0.003) in Hp 2-1 phenotype and independent of ACE-I/D genotyping and MNS blood group polymorphism. Multifactor analysis of variance in essential hypertension reveals significant (P = 0.001) differences in SLC activity for the presence or absence of Hp 2-1 phenotype and for body weight (P = 0.0003). Multivariate regression analysis shows the same parameters to be independent determining factors of SLC in essential arterial hypertension. No relation is found between SLC activity and target organ damage which includes coronary artery disease, peripheral arterial occlusive disease, left ventricular hypertrophy and cerebrovascular accident. We conclude that erythrocyte SLC activity is elevated despite pressure-lowering therapy. In essential arterial hypertension, individuals of Hp 2-1 phenotype show higher SLC activity than patients of other Hp-types, suggesting genetic heterogeneity of essential arterial hypertension. The presence or absence of Hp 2-1 phenotype is an independent determining factor of SLC activity whereas body weight codetermines SLC activity in essential hypertension.

Adult↗
PubMed1996

Haptoglobin polymorphism and chronic hepatitis C.

BACKGROUND/AIMS: Haptoglobin (Hp) is a hemoglobin-binding acute phase protein characterized by a genetic polymorphism due to the existence of two different alleles encoding for the alpha chain of the protein. Three phenotypes have been described: Hp 1-1, Hp 2-1 and Hp 2-2. The latter two forms are known to possess immunoglobulin-like properties and play a role in the immune response. Recently, it has been shown that in subjects suffering from hepatitis C, serum Hp concentrations were lower than in the reference population. In the present study we examined whether the haptoglobin phenotype distribution in chronic HCV patients was different from the reference population. We also looked for possible relationships between Hp phenotypes and hepatitis C virus types and response to interferon alpha therapy. Moreover, Hp concentrations were determined. METHODS: The study population consisted of 239 Caucasian patients with proven hepatitis C. Hp phenotypes were determined using starch gel electrophoresis of hemoglobin-supplemented serum, followed by peroxidase staining. Serum Hp concentrations were assayed with an immunonephelometric method. Hepatitis C virus was genotyped and classified according to an internationally accepted system. Two hundred and twenty healthy Caucasian blood-donors served as the reference population. RESULTS: In the reference population, 35 individuals (15.9%) had Hp 1-1, 106 persons (48.2%) had Hp 2-1 and 79 had Hp 2-2 (35.9%), resulting in an Hp 1 allele frequency of 0.400, which is in agreement with the Hardy-Weinberg equilibrium. Hp phenotype distributions and Hp allele frequencies in the chronic hepatitis C virus patient group differed significantly from those obtained in the reference population. In the patient population, 59 individuals (24.7%) had Hp 1-1, 112 persons (46.9%) had Hp 2-1 and 68 had Hp 2-2 (28.5%). This resulted in an Hp 1 allele frequency of 0.481, which is in agreement with the Hardy-Weinberg equilibrium. No statistically significant differences were found between Hp phenotype distribution and hepatitis C virus types or response to interferon alpha therapy. CONCLUSIONS: The observed shift in Hp phenotype distribution in chronic hepatitis C may point to a role of Hp in the natural evolution of hepatitis C.

Adult↗
PubMed1996

Biological and clinical significance of haptoglobin polymorphism in humans.

Haptoglobin is a hemoglobin-binding protein expressed by a genetic polymorphism as three major phenotypes: 1-1, 2-1, and 2-2. Most attention has been paid to determining haptoglobin phenotype as a genetic fingerprint used in forensic medicine. More recently, several functional differences between haptoglobin phenotypes have been demonstrated that appear to have important biological and clinical consequences. Haptoglobin polymorphism is associated with the prevalence and clinical evolution of many inflammatory diseases, including infections, atherosclerosis, and autoimmune disorders. These effects are explained by a phenotype-dependent modulation of oxidative stress and prostaglandin synthesis. Recent evidence is growing that haptoglobin is involved in the immune response as well. The strong genetic pressure favoring the 2-2 phenotype suggests an important role of haptoglobin in human pathology.

Chemistry, Clinical↗
PubMed1996

Quantitative nephelometric assay for determining alpha-foetoprotein evaluated.

A recently introduced automated nephelometric immunoassay involving shell/core particles for determination of alpha-foetoprotein in serum and amniotic fluid was evaluated with the Behring Nephelometer analyser II. Method stability was good: reconstituted reagents and calibration curve were stable for at least one week. The intra-assay CV varied between 2.3% and 4.0%. The inter-assay CV varied between 3.5% and 4.6%. Samples with alpha-foetoprotein concentrations up to 273000 micrograms/l were analysed without high-dose "hook" effect after automatic dilution. No significant interference from haemoglobin, bilirubin, rheumatoid factors, or human anti-mouse antibodies was detected up to concentrations of 0.15 mmol/l haemoglobin, 268 mumol/l bilirubin, 470 int, units/l rheumatoid factor and a titre of 1/1000 human anti-mouse antibodies. Interference due to triacylglycerols depended on the size of triacylglycerol containing particles: for VLDL, interference did not occur up to triacylglycerol levels of 6.0 mmol/l, for chylomicrons interference was already noted at triacylglycerol levels of 1.0 mmol/l. Correlation with a commercial RIA (Kabi Pharmacia) was excellent both for serum (n = 65) and amniotic fluid (n = 100). The effect of the molecular variation of the carbohydrate moiety of alpha-foetoprotein on the test results was studied using concanavalin A affinity chromatography. The detection of both concanavalin A-reactive and concanavalin A-non-reactive alpha-foetoprotein was equivalent by both methods. Multimeric forms of alpha-foetoprotein were prepared by gel permeation chromatography. The effect of autopolymerization of alpha-foetoprotein on the nephelometric determination of alpha-foetoprotein was negligible. We conclude that latex-enhanced immunonephelometry is a rapid, practical, and reliable method for measuring alpha-foetoprotein in serum and amniotic fluid.

Adult↗
PubMed1995

Refractory hypertension is associated with the haptoglobin 2-2 phenotype.

BACKGROUND: Many cases of refractory hypertension cannot be attributed to specific identifiable factors. Haptoglobin polymorphism has been suggested as a candidate genetic marker in essential hypertension. The aim of this study was to investigate the distribution of haptoglobin types in patients with refractory hypertension. METHODS: Haptoglobin polymorphism was studied in 383 patients with non-refractory and 62 patients with refractory hypertension. Haptoglobin was typed using starch gel electrophoresis of haemoglobin-supplemented serum. RESULTS: In the group of patients with refractory hypertension, the relative allele frequency of haptoglobin 1 (0.266) was lower than in the group with non-refractory hypertension (0.385: P < or = 0.05). The relative frequency of haptoglobin 2-2 was 39% in the non-refractory compared with 56% in the refractory group (P < or = 0.05). In the latter group, the relative frequency of haptoglobin 2-2 was highest (75%) in patients requiring medication with four classes of drug. CONCLUSION: Hypertension patients with the haptoglobin 2-2 phenotype are at higher risk of developing refractory hypertension than those with other haptoglobin phenotypes.

Alleles↗
PubMed1995

Characteristics of creatine release during acute myocardial infarction, unstable angina, and cardiac surgery.

Creatine release was compared in various conditions of muscle damage: acute myocardial infarction (AMI), unstable angina, and cardiac surgery. After AMI, serum and urine creatine concentrations increased transiently. After cardiopulmonary resuscitation, serum creatine values were significantly higher because of impaired renal function, whereas urinary creatine concentrations were comparable. In 38 patients with unstable angina, no significant changes in serum and urine creatine concentrations were seen. In 37 of 92 AMI patients, secondary creatine peaks were observed 20.9 +/- 8.1 h after onset of symptoms. The magnitudes of the first and second peaks were correlated: Spearman r = 0.66. In 24 patients who underwent cardiac surgery, the changes in creatine concentration in serum during surgery were very small, despite the presence of muscle trauma.

Adult↗
PubMed1994

Glomerular filtration rate and creatinine production in adult icteric patients.

Various methods for serum creatinine determination were compared and validity of the Cockroft-Gault algorithm for calculating creatinine clearance was tested in adult icteric patients. Using conventional Jaffé assays, negative interference is proportional to the serum bilirubin content. Pretreatment of the serum with bilirubin oxidase was more efficient in eliminating bilirubin than pretreatment with potassium ferricyanide. Due to a continued creatine-poor diet and liver dysfunction, erythrocyte creatine levels and creatinine output rate were decreased. Median effect (creatinine equivalent) of non-specific chromogens in the unmodified Jaffé assay was 21 mumol/l (range: 1-108 mumol/l), vs. 19 mumol/l (range: 16-26 mumol/l) for the reference population. In the absence of multi-organ failure, the Cockroft-Gault algorithm could be used for estimating glomerular filtration rate. In patients with multiple organ failure however, we recommend correction for both bilirubin and non-specific chromogens for measuring the serum creatinine concentration.

Adult↗
PubMed1994

Posttranslational heterogeneity of bone alkaline phosphatase in metabolic bone disease.

Bone alkaline phosphatase is a marker of osteoblast activity. In order to study the posttranscriptional modification (glycosylation) of bone alkaline phosphatase in bone disease, we investigated the relationship between mass and catalytic activity of bone alkaline phosphatase in patients with osteoporosis and hyperthyroidism. Serum bone alkaline phosphatase activity was measured after lectin precipitation using the Iso-ALP test kit. Mass concentration of bone alkaline phosphatase was determined with an immunoradiometric assay (Tandem-R Ostase). In general, serum bone alkaline phosphatase mass and activity concentration correlated well. The activity : mass ratio of bone alkaline phosphatase was low in hyperthyroidism. Activation energy of the reaction catalysed by bone alkaline phosphatase was high in osteoporosis and in hyperthyroidism. Experiments with neuraminidase digestion further demonstrated that the thermodynamic heterogeneity of bone alkaline phosphatase can be explained by a different glycosylation of the enzyme.

Adult↗
PubMed1993

Haptoglobin polymorphism and complications in established essential arterial hypertension.

OBJECTIVE: Salt sensitivity and the magnitude of systolic blood pressure have been linked to haptoglobin (Hp) polymorphism in normotensives. The aim of the present study was to investigate the indices of hypertension, the severity of complications and the occurrence of coronary and peripheral artery disease for the various haptoglobin phenotypes and their relation to the therapeutic needs (number and class of drugs) of established arterial hypertensives. DESIGN: Haptoglobin polymorphism was studied in 302 Caucasians with established essential arterial hypertension who had been treated for at least 1 year. METHODS: Haptoglobin polymorphism was studied using starch-gel electrophoresis of haemoglobin-supplemented serum. RESULTS: The relative allele frequencies of Hp 1 and Hp 2 (0.036 and 0.640, respectively) in established hypertensives were comparable with those of the control population. Logistic regression analysis confirmed that Hp 2-2 contributes to the therapeutic needs in hypertension. The most important factors determining therapeutic needs were coronary artery disease, Hp 2-2 phenotype, body mass index (BMI) and left ventricular hypertrophy. Although no contributive effect of serum haptoglobin concentration could be derived from the logistic regression approach, analysis of serum haptoglobin concentration demonstrated a concentration-related effect on therapeutic needs for the Hp 2-2 phenotype only. CONCLUSIONS: The present study suggests that hypertensives with an Hp 2-2 phenotype need more complex combinations of antihypertensive drugs to reduce blood pressure to the same level. The hypertensive patient carrying Hp 2-2 is more likely to accumulate atherosclerotic lesions of the coronary or peripheral arteries, despite comparable lipid levels, smoking habits and BMI. Hp 1-1 patients are characterized by a younger age at diagnosis and a lower complication rate. In view of the greater therapeutic needs and the higher complication rate, Hp 2-2 hypertensives need more careful follow-up.

Aged↗
PubMed1992

Glycation of human tissue and serum creatine kinase.

Human creatine kinase (CK) was demonstrated to be partly present as a glycated molecule. Sialic acid, galactose and sulfate were also found to be present on the molecule. The glycated forms were characterized by higher activation energies and were thermally unstable. Skeletal muscle CK showed lower relative binding towards the lectin concanavalin A (Con A) in comparison with the heart tissue forms. After skeletal muscle trauma, CK in serum was found to be less glycated than in tissue. After acute myocardial infarction (AMI), no glycated CK could be detected in serum. Following injury, it appears that the transfer from tissue to plasma is accompanied by a loss of glycated isoforms. High-voltage electrophoresis showed no differences in the distribution of CK isoforms between the glycated and non-glycated forms.

Adult↗