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M M Couttenye

Publications and source records attributed to M M Couttenye.

18 recordsLinked to original sources
PubMed1997

High prevalence of adynamic bone disease diagnosed by biochemical markers in a wide sample of the European CAPD population.

BACKGROUND: Adynamic bone disease (ABD) has been described in the current dialysis population to have an unexpectedly high prevalence. Moreover, it is clearly more prevalent in CAPD patients, compared to haemodialysis patients. Recently we demonstrated that both a low (< or = 27 U/1) level of bone alkaline phosphatase (BAP) as determined by an optimized agarose gel electrophoretic technique and a low (< or = 150 pg/ml ) level of iPTH are good markers of ABD with sensitivities of 78.1% and 80.6% and specificities of 86.4% and 76.2% respectively. METHODS: In this study (n = 212), the prevalence of ABD in the European CAPD population was evaluated by means of these biochemical markers. Clinical data on the patients included were recorded at the moment of blood sampling. In patients under CAPD treatment for longer than 9 months, we calculated an index of calcium exposure through PD fluid. RESULTS: In this population with a low exposure to aluminium, the prevalence of ABD as indicated by either a low level of BAP or PTH was 43%. The following risk factors could be identified: advanced age, shorter time on renal replacement therapy, male gender, and high calcium content of PD fluid. The index of calcium exposure was significantly higher in the patients with low BAP and low iPTH levels compared to those with either BAP > or = 27 U/1 or iPTH > 150 pg/ml. The latter finding gives further support to the hypothesis that a high calcium load administered to renal failure patients may lead to 'oversuppressed' parathyroids in ABD. In a subgroup of patients with a high level of BAP associated with a low iPTH level a profile previously shown to be associated in the presence of aluminium overload, significantly higher serum aluminium levels were noted. suggesting that even in patients with low exposure to aluminium, this element still can affect bone metabolism. CONCLUSION: A high prevalence of ABD--as diagnosed by biochemical markers--was observed in the European CAPD population. A number of risk factors could be put forward. The aetiology and pathogenesis of this type of renal osteodystrophy remain to be elucidated, but appear, however, to be multifactorial.

Adult↗
PubMed1996

Diagnosis and treatment of aluminium bone disease.

Aluminium accumulation in serum and tissues is a well-known complication in patients with chronic renal failure, and retention of the element in bone has been implicated in the pathogenesis of the so-called aluminium-related bone disease (ARBD). Regular serum aluminium monitoring remains mandatory to detect patients and centres at risk for aluminium intoxication. Early recognition of ARBD however requires a desferrioxamine (DFO) test in combination with a serum iPTH measurement. Definite diagnosis of ARBD is made by histological examination of a bone biopsy. Once ARBD has been identified DFO treatment should be initiated and all potential sources of aluminium exposure eliminated. In order to minimize the risk for DFO-related cerebral, auditory and visual side-effects, and siderophore-mediated opportunistic infections the chelator should be used at low doses (5 mg/kg) and administered widely spaced (once weekly) following well-defined strategies of administration.

Aluminum↗
PubMed1996

Low serum levels of alkaline phosphatase of bone origin: a good marker of adynamic bone disease in haemodialysis patients.

BACKGROUND: Adynamic bone disease was recently described to be increasingly prevalent in the dialysis population. At present the diagnosis of this type of renal osteodystrophy can only be made by bone histomorphometry. We assessed the value of different biochemical serum markers in the diagnosis of adynamic bone disease. METHODS: In 103 haemodialysis patients a bone biopsy was performed after double tetracycline labelling, and the serum levels of intact PTH, osteocalcin, and the bone isoenzyme of alkaline phosphatase were determined. Bone alkaline phosphatase was measured by an optimized agarose gel electrophoretic method, recently shown to have a high accuracy, precision and reproducibility, also in the lower range. RESULTS: In 38 (37%) of the patients the diagnosis of adynamic bone disease was histologically established. Constructing receiver operator curves optimal cut-off levels for the diagnosis of adynamic bone disease were determined, being <=27 U/litre for the bone isoenzyme of alkaline phosphatase, <=14 microg/litre for osteocalcin and <=150 pg/ml for intact PTH. Concentrations of bone alkaline phosphatase or intact PTH below these cut-off levels, were shown to be the best performing tests in the detection of adynamic bone disease as indicated by a sensitivity of 78.1 and 80.6% and a specificity of 86.4 and 76.2% respectively. Applying Bayes' theorema, it was calculated that in the current haemodialysis population in which a prevalence of adynamic bone disease up to 35% has been described, the positive predictive values for the proposed cut-off values are 75% for bone alkaline phosphatase, 65% for intact PTH and 55% for osteocalcin. Moreover, in this population, levels of bone alkaline phosphatase and intact PTH below the optimal cut-off excluded hyperparathyroid bone disease. CONCLUSION: In view of the relative easy and accurate methodology for bone alkaline phosphatase determination, the closer physiological link with osteoblast function and the lesser expense for its determination we suggest that this marker is a useful tool in the non-invasive diagnosis of the adynamic type of bone disease in the individual patient.

Alkaline Phosphatase↗
PubMed1996

Herpes zoster myelitis occurring during treatment for systemic lupus erythematosus.

A woman with systemic lupus erythematosus (SLE) presented with a zoster eruption. Transverse myelitis developed at the site of the dermatomal distribution of the rash. SLE and varicella zoster virus (VZV) can both cause myelitis, and are difficult to differentiate. The topographic association between the cutaneous and the neurological involvement suggesting VZV myelitis was confirmed by polymerase chain reaction (PCR) for VZV in the cerebrospinal fluid. This case illustrates the potential role of the selective amplification of VZV DNA in cerebrospinal fluid to diagnose central neurological complications associated with VZV. The value of magnetic resonance imaging of the spinal cord in the evaluation of patients with myelitis is emphasized.

DNA, Viral↗
PubMed1995

Immunoradiometric method and electrophoretic system compared for quantifying bone alkaline phosphatase in serum.

Agarose electrophoresis (Isopal, Beckman) and an immunoradiometric assay (IRMA) involving specific monoclonal antibodies (Ostase, Hybritech), two methods for the quantification of serum bone alkaline phosphatase (ALP, EC 3.1.3.1), a marker of osteoblastic activity, were compared in 293 patients: 79 with end-stage renal failure treated with hemodialysis and 214 with malignant disease. Overall correlation between the two methods was good (r = 0.92), except (a) for low values of bone ALP and (b) in some samples with high total liver ALP activity--both due to considerable cross-reactivity of the anti-bone ALP antibodies of the Ostase kit with liver ALP. This interference was not constant and was not evenly distributed across all concentrations of bone ALP. Low bone ALP determined with the IRMA (< or = 5 micrograms/L) was confirmed by electrophoresis (< or = 21 U/L), but bone ALP activity determined by electrophoresis to be low (< or = 21 U/L) was not correlated with the IRMA results. After standardizing our results by computing z-values for bone ALP, delta z (= zOstase - zIsopal) was significantly correlated with liver ALP activity (r = 0.73, P < 0.0001). We conclude that the IRMA for quantifying bone ALP is acceptable as a screening method. However, when high values for bone ALP are found with the Ostase method, confirmation by electrophoresis remains mandatory to rule out cross-reactivity with high amounts of liver ALP. For detecting low bone ALP activities, electrophoresis remains the method of choice.

Alkaline Phosphatase↗
PubMed1995

Use of the low-dose desferrioxamine test to diagnose and differentiate between patients with aluminium-related bone disease, increased risk for aluminium toxicity, or aluminium overload.

BACKGROUND: Aiming at a safe method in the diagnosis of aluminium-related bone disease (ARBD)/aluminium overload the low-dose desferrioxamine (DFO) test was developed. In a multicentre study histological and histochemical data and aluminium bulk analysis of bone biopsies of 77 dialysis patients were correlated with the results of both the 5 mg/kg and 10 mg/kg DFO tests. METHODS: ARBD was considered to be present when > 15% of the bone surface was positively stained for aluminium and the bone formation rate was below 220 microns 2/mm2/day. Patients in which the Aluminon staining was positive (> 0%) were considered at an increased risk for aluminium toxicity independent of the type of renal osteodystrophy. Patients were considered aluminium overloaded when the bone aluminium content was > 15 micrograms/g wet weight and/or the Aluminon staining was positive (> 0%). RESULTS: Using the proposed criteria 15 patients were found to have ARBD; 13 of them presenting with a serum iPTH below 150 ng/l. In conjunction with an iPTH measurement the DFO test had a more than acceptable sensitivity and specificity in the diagnosis of ARBD. The test was considered positive when a post-DFO serum aluminium increment (delta sA1) above 50 micrograms/l (5 mg/kg) or 70 micrograms/l (10 mg/kg) together with a serum iPTH below 150 ng/l was found. Using these cut-off levels the 5 and 10 mg/kg tests in the diagnosis of ARBD had a sensitivity of 87% and a specificity of 95% and 92% respectively whereas the predictive value for a positive test for the population under study was 80% (5 mg/kg). Not a single patient with a serum iPTH > 650 ng/l had a positive staining (> 0%) even when the bone aluminium level was elevated (> 15 micrograms/g wet weight). In the detection of patients at risk for aluminium toxicity delta sA1 thresholds of 50 micrograms/l (5 mg/kg) and 70 micrograms/l (10 mg/kg) in combination with a serum iPTH < 650 ng/l had a sensitivity of 92% and specificity of 86% and 84% respectively. In the clinical setting of aluminium overload, threshold delta sA1 levels of 50 micrograms/l (5 mg/kg) and 70 micrograms/l (10 mg/kg) had a sensitivity of 91% and a specificity of 95% and 90% respectively. CONCLUSIONS: The low-dose DFO test is a reliable test for the detection of aluminium overload; however, it is not specific enough to differentiate between ARBD, increased risk of aluminium toxicity, and aluminium overload unless it is used in combination with a serum iPTH measurement. In conjunction with a serum iPTH measurement it is an important tool in the differential diagnosis and may avoid the necessity of a bone biopsy in the majority of patients. Data obtained in the present study have allowed us to update the strategies for monitoring, diagnosis and patient follow-up proposed at the Consensus Conference on Diagnosis and Treatment of Aluminium Overload in End-Stage Renal Failure; Paris, 1992.

Adult↗
PubMed1993

Immunogenicity of a recombinant DNA hepatitis B vaccine in renal transplant patients.

In renal transplant patients hepatitis B infection is associated with a higher morbidity and mortality. Therefore, we investigated the immunogenicity of an enhanced vaccination scheme with a recombinant DNA hepatitis B vaccine in renal allograft recipients. Injections of 40 micrograms were given at months 0, 1, 2 and 6. Conversion rate (anti-HBS antibody titre > 10 mIU ml-1) was only 36%. On the other hand, in patients vaccinated before transplantation, a booster injection of 40 micrograms was highly successful, resulting in a rise of antibody titre > 10 mIU ml-1 in 86%. In view of the poor vaccination results after transplantation, we strongly recommend hepatitis B vaccination prior to transplantation.

Adult↗
PubMed1988

Acquired immunodeficiency syndrome mimicking Sjögren's syndrome and systemic lupus erythematosus.

We describe a patient in whom the diagnosis of transfusion-associated acquired immunodeficiency syndrome (AIDS) was delayed because her clinical symptoms were similar to those of systemic lupus erythematosus and Sjögren's syndrome and because of a false-negative result on a Western blot test for human immunodeficiency virus. The importance of using different diagnostic tests for AIDS and the pitfalls in diagnosing AIDS in patients who appear to have connective tissue disease are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Functional acute renal failure in a patient with carcinoid syndrome.

Acute renal failure occurred in a patient with a carcinoid syndrome whenever he developed a flushing episode. Renal biopsy performed during one of these oliguric episodes did not reveal any lesions which could explain this reversible form of renal insufficiency. Urinary indices were not conclusive. Alteration of intrarenal hemodynamics by vasoactive compounds is proposed to be the causative mechanism of this relapsing acute oliguric renal failure.

Acute Kidney Injury↗
PubMed1981

Relaxation properties of mammalian atrial muscle.

The properties of relaxation, particular the sensitivity of relaxation to load, were analyzed in isolated intact atrial muscle and in manually dissected, detergent-treated cellular preparations from cat, dog, and rat atria. Force and length traces under increasing afterloads and following load clamps were obtained using an electromagnetic lever-force transducer system for the intact muscles and a capacitance transducer system for the cellular preparations. In both types of preparations, the time course of relaxation was hardly affected by the load or by alterations in load (load clamps), unlike intact mammalian ventricular muscle. This load independence of relaxation, which was hardly influenced by variations of initial muscle length, resembled relaxation in intact frog ventricular muscle and in detergent-treated mammalian ventricular single cells. As relaxation of these ventricular preparations with poorly developed (frog) or absent (detergent-treated single cells) calcium-sequestering systems was shown to be governed by the dissipation of activation, these results suggest a similar control mechanism for relaxation in mammalian atrial muscle. Furthermore, load independence of relaxation of mammalian atrial muscle in late diastole may promote optimal filling of the ventricle.

Animals↗
PubMedDate not supplied

Effects of prostacyclin on contractile properties of isolated mammalian cardiac muscle.

We studied the influence of prostacyclin (PGI2) on the contractile performance of isolated mammalian ventricular muscle. PGI2 had no direct influence on myocardial contractility, as evidenced by experiments on single cardiac cells and papillary muscle. Moreover, PGI2 did not interfere with the inotropic action of isoproterenol. In comparison, neither prostaglandin E1 nor E2 appeared to have any cardiotonic action.

Alprostadil↗
PubMedDate not supplied

Limited acute dissections of the abdominal aorta. Report of five cases.

Within a two year period, the diagnosis of acute dissection of a segment of the abdominal aorta was made in five cases without aneurysmal dilation or leakage and with virtually no ischaemia. All patients presented with an atypical painful abdominal syndrome and the diagnosis was made by computed tomography. Only one patient, suffering persistent pain was treated by resection and graft interposition of the infrarenal aorta. All the others were treated conservatively and kept under close follow-up. Two of them died from intercurrent disease. The remaining three patients are doing well after 30 and 42 months conservative treatment and 43 months after surgery respectively. A non-complicated dissection of the abdominal aorta must be considered in the differential diagnosis of atypical painful abdominal syndromes. In cases of persistent pain, progression, ischaemia, aneurysmal dilatation or leakage, surgical treatment is mandatory. In uncomplicated cases conservative treatment is recommended, similar to the principles of management for dissections of the descending thoracic aorta.

Acute Disease↗