Anti-adalimumab antibodies in juvenile idiopathic arthritis: frequent association with loss of response.

OBJECTIVES: We aimed to determine how loss of response (LOR) to adalimumab (ADA) in juvenile idiopathic arthritis (JIA) may be related to anti-ADA antibodies (AAA). METHOD: AAA and ADA levels were measured in 23 consecutive patients with JIA responding significantly to treatment with ADA. RESULTS: Six out of 23 (26%) patients developed AAA and had low ADA levels. Five out of six AAA-positive patients experienced LOR. In these patients use of concomitant methotrexate (MTX) was significantly lower. CONCLUSIONS: The occurrence of AAA is a frequent event associated with LOR. Monitoring of AAA and serum ADA levels should be considered in JIA patients under ADA therapy.

Time-of-intake (morning versus evening) of extended-release fluvastatin in hyperlipemic patients is without influence on the pharmacodynamics (mevalonic acid excretion) and pharmacokinetics.

OBJECTIVE: Statins inhibit the rate-limiting step in cholesterol biosynthesis, the conversion of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) to mevalonate by HMG-CoA reductase. Statins are usually taken in the evening as the HMG-CoA reductase activity is high during the night. This recommendation might not apply if statins are given as extended-release (ER) formulations. The present study investigated the influence of time of intake of fluvastatin 80 mg ER on cholesterol biosynthesis. Main objectives were to measure the change in 24-hour urinary mevalonic acid excretion, to determine plasma concentrations of mevalonic acid and fluvastatin and to monitor triglycerides, total cholesterol, HDL-cholesterol and LDL-cholesterol. METHODS: This was a randomized, 2-period crossover study in 26 hypercholesterolemic patients who received a single daily dose of fluvastatin both in the morning and in the evening. RESULTS: At baseline, the amount of mevalonic acid was 204.9 +/- 68.1 microg/g creatinine. After a single dose of fluvastatin mean urine values of mevalonate were significantly reduced to 129.8 +/- 66.2 micro/g (evening) and to 118.7 +/-34.3 microg/g (morning; n.s. between groups), thus representing a reduction of about 39%. Compared to baseline, plasma mevalonate concentrations were decreased by fluvastatin resulting in similar 24-hour profiles after the morning and the evening dosage. The pharmacokinetics of fluvastatin were similar in both periods of the study, with higher plasma concentrations for several hours following the evening dosage. CONCLUSION: This study demonstrates that fluvastatin ER is equally effective in inhibiting cholesterol biosynthesis when given once daily in the morning and once daily in the evening.

Pipecolic acid as a diagnostic marker of pyridoxine-dependent epilepsy.

Pyridoxine-dependent epilepsy, although described some decades ago, may still be an underdiagnosed disorder. We have recently described isolated pipecolic acid elevations in the plasma and/or CSF of three patients with pyridoxine-dependent epilepsy with an intriguing inverse correlation to the oral intake of pyridoxine. We have now confirmed these findings in a further 6 unrelated patients with pyridoxine-dependent epilepsy. Pipecolic acid in plasma was 4.3- to 15.3 fold elevated compared to the upper normal range before pyridoxine and remained in the mildly elevated range while on pyridoxine. Pipecolic acid was even more markedly elevated in CSF. The extent of pipecolic acid elevation in CSF exceeded that of plasma by a factor of 2.2 to 4.8. This clearly discriminates pyridoxine-dependent epilepsy from other possible defects with elevated pipecolic acid. Determination of pipecolic acid in plasma and/or CSF should be included in the diagnostic work-up of patients with therapy-resistant seizures. It will in addition prevent patients with pyridoxine-dependent epilepsy from experiencing potentially dangerous pyridoxine-withdrawal, which until now has been necessary to prove the diagnosis.

High-performance liquid chromatographic method for the simultaneous determination of cyclosporine A and its four major metabolites in whole blood.

This study aimed to develop a simple and efficient optimized high-performance liquid chromatograph (HPLC) method for simultaneous determination of cyclosporine A (CyA) and its major, partly active metabolites AM1, AM9, AM4N, and AM19 in whole blood from transplant patients using cyclosporine D (CyD) as internal standard. The method used a CN analytical column maintained at 60 degrees C with hexan-isopropanol (93:7, v/v) as mobile phase; detection was at 212nm. Linearity for all five compounds was tested in the range of 31-1500ngml(-1) for CyA and of 31-1000ngml(-1) for metabolites. The limit of detection was found to be 15ngml(-1) for all compounds. This modified, inexpensive method is also suitable for measuring cyclosporine A and metabolite concentrations in routine monitoring of patients undergoing treatment with CyA.

Gender, age and seasonal effects on IgA deficiency: a study of 7293 Caucasians.

BACKGROUND: The frequency of serum IgA deficiency (SIgAD) differs between populations. We examined the prevalence of SIgAD in healthy Caucasians. MATERIALS AND METHODS: Serum immunoglobulin A (SIgA) was measured in 7293 volunteers (2264 women, 5029 men) aged 30 +/- 14.2 years (mean +/- SD; range: 12-66). Serum immunoglobulin A and subnormal SIgA levels were defined by a SIgA level < 0.07 g L(-1), and between 0.07 and 0.7 g L(-1), respectively. Means were compared by analysis of variance (anova) and analysis of covariance (ancova); frequencies by the chi(2) test. RESULTS: Fifteen subjects (0.21%; one woman, 14 men) had SIgAD. Subnormal SIgA levels were found in 155 persons (2.13%): 21 females (0.93% of the females) and 134 males (2.66% of the males; difference: 1.74%; 95% CI: 1.12-2.33%; P < 0.001). Males were more likely to have subnormal SIgA levels or SIgAD (odds ratio 3.09, 95% CI: 1.97-4.85). The prevalence of SIgAD and subnormal SIgA was lowest in winter (chi(2) = 14.8; P = 0.002; 3 d.f.; and chi(2) = 43.2; P < 0.001; 3 d.f., respectively). Serum immunoglobulin A concentrations were significantly higher during winter. Serum immunoglobulin A levels increased with age on average by 0.2 +/- 0.06 g L(-1) per decade of life (P < 0.001). Taking into account the influence of age, SIgA concentration was lower in females as compared with males. CONCLUSION: The prevalence of SIgAD and subnormal SIgA levels is increased in males. There exists a significant influence of gender, age and seasons on SIgA levels.

Determinants of homocysteine during weight reduction in obese children and adolescents.

Plasma homocysteine levels have been shown to be associated with indexes of obesity and insulin resistance in obese children and adolescents. We, therefore, investigated the contribution of changes in body composition, markers of insulin resistance, folate, and vitamin B(12) to changes in homocysteine during a weight reduction program in obese children and adolescents. Thirty-seven obese white girls (mean SD; age, 12 +/- 1.8 years, body mass index [BMI], 26.9 +/- 5.25) and 19 obese white boys (age, 11.9 +/- 1.7 years; BMI, 26.2 +/- 5.2) were investigated for body composition, fasting total plasma homocysteine (tHcy), insulin, C-peptide, folate, and vitamin B(12) before and after a 3-week weight reduction program including physical activities. During weight reduction BMI, fat mass (FM), percentage fat mass, insulin, and C-peptide decreased significantly, whereas homocysteine and vitamin B(12) showed a significant increase. Folate and lean body mass (LBM) remained unchanged. tHcy concentration before weight reduction was a function of age, folate, and C-peptide, whereas tHcy concentration after weight reduction was a function of folate and baseline LBM. Changes in tHcy during weight reduction correlated significantly with baseline LBM and were related inversely to changes in LBM during weight reduction. Children who increased LBM showed lower increases in tHcy compared with children who lost LBM. In multiple linear regression analysis, only baseline LBM contributed independently and significantly to changes in tHcy. Our study suggests that LBM has a significant impact on tHcy metabolism during weight reduction.

Insulin is an independent correlate of plasma homocysteine levels in obese children and adolescents.

OBJECTIVE: The aim of the study was to investigate whether anthropometric and metabolic risk factors for coronary heart disease (CHD) contribute to the variation in homocysteine levels in obese children and adolescents. RESEARCH DESIGN AND METHODS: A total of 84 children and adolescents were assessed for fasting total homocysteine, methylenetetrahydrofolate reductase polymorphism (C677T mutation), folate and vitamin B12 status, and anthropometric and metabolic risk factors for CHD. RESULTS: No significant sex differences were found for all available anthropometric and metabolic characteristics except for homocysteine, which was significantly higher in boys than in girls (7.1 vs. 6.3 micromol/l; P<0.05). After adjustment for age and sex, homocysteine correlated significantly with BMI, fat mass, percentage of fat mass, and insulin and showed an inverse correlation with folate levels. Homocysteine did not correlate with vitamin B12; total cholesterol; LDL, HDL, and VLDL; triglycerides; and glucose. BMI and fat mass correlated significantly with insulin and showed a significant inverse correlation with folate. We found no association between homocysteine and the C677T mutation. In multiple regression analyses, insulin was found to be the main correlate of homocysteine. CONCLUSIONS: Our study demonstrates for the first time that insulin is a main correlate of homocysteine in obese children and adolescents and suggests that fat mass-associated hyper-insulinism may contribute to impairment of homocysteine metabolism in childhood obesity

Cystatin C, an early indicator for incipient renal disease in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic disease requiring potential nephrotoxic therapy with nonsteroidal antiinflammatory drugs (NSAIDs) and disease modifying antirheumatic drugs (DMARDs). The rationale of our study was to examine the renal status of patients suffering from prolonged RA by means of plasma cystatin C, a new parameter of renal function. Fifty-six patients affected with RA for more than 5 years, and treated with NSAIDs for more than 50 months, were included in the study. Besides conventional markers of renal function (i.e. plasma creatinine, estimated glomerular filtration rate, creatinine clearance), we analysed plasma cystatin C by an automated, nephelometric immunoassay on a Behring nephelometer. Sixty percent of the RA patients exhibited elevated levels of plasma cystatin C, whereas only three out of 56 patients showed an elevated plasma creatinine, even though the creatinine clearance was decreased in 57% of these patients. Cystatin C exhibited a by far better correlation with creatinine clearance than plasma creatinine. In conclusion, patients with prolonged RA for more than 50 months, show a disturbed renal function despite normal plasma creatinine. Elevated cystatin C indicates such incipient renal disease, and is, not least because of a simple, well reproducible technique, more recommendable for screening purposes than tedious clearance determinations.

Pipecolic acid elevation in plasma and cerebrospinal fluid of two patients with pyridoxine-dependent epilepsy.

Diagnosis of pyridoxine-dependent epilepsy is based on the clinical response to high-dosage application of pyridoxine. Here, we report on 2 patients with pyridoxine-dependent epilepsy with significant elevation of pipecolic acid concentrations in plasma and cerebrospinal fluid (CSF) and further increase of pipecolic acid in CSF during a 72-hour pyridoxine withdrawal in 1 of them. Patients with non-pyridoxine-dependent epilepsy had normal pipecolic acid concentrations in plasma and significantly lower concentrations in CSF. High plasma and CSF pipecolic acid concentrations might provide a diagnostic marker in pyridoxine-dependent epilepsy.

Urinary N-acetyl-beta-D-glucosaminidase activity in patients with cystic fibrosis on long-term gentamicin inhalation.

OBJECTIVE: To investigate possible renal toxicity of long-term gentamicin inhalation in patients with cystic fibrosis. METHODS: Urinary N-acetyl-beta-D-glucosaminidase (NAG) activity was measured during routine respiratory clinic visits. Outpatient records were reviewed for data on long-term gentamicin inhalation, and parents and patients were interviewed for compliance. Exclusion criteria were irregular gentamicin inhalation, urinary infection or other febrile illness, intravenous aminoglycoside treatment during the previous three months, and diabetes mellitus. Patients were assigned to three groups: group 1, current gentamicin inhalation; group 2, previous gentamicin inhalation that had been stopped at least three months ago; and group 3, never any gentamicin inhalation. RESULTS: 52 patients (34 girls, 18 boys), mean (SD) age 11.5 (5.7) years, entered the study. Patients currently on gentamicin inhalation (n = 20) were significantly younger and had higher urinary NAG activity (0.83 (0.57) U/mmol creatinine) than the 23 patients without gentamicin inhalation (0.26 (0.10) (p = 0.0001) and the nine patients with previous gentamicin inhalation (0.32 (0.15) (p = 0.0125). Twelve patients on current gentamicin inhalation had raised NAG values but all those in groups 2 and 3 had NAG values within the normal range. In patients currently on gentamicin inhalation, there was a positive correlation between urinary NAG activity and cumulative dose of nebulised gentamicin (r = 0.60, p = 0.0049). CONCLUSIONS: Long-term gentamicin inhalation in patients with cystic fibrosis poses a risk of renal toxicity. It is not known whether further treatment might result in more severe renal damage.

Partial N-acetylglutamate synthetase deficiency in a 13-year-old girl: diagnosis and response to treatment with N-carbamylglutamate.

UNLABELLED: We report on a now 13-year-old girl, who presented with recurrent episodes of vomiting, psychotic behaviour and confusion during puberty until the diagnosis of partial N-acetylglutamate synthetase deficiency was established. She had suffered one prior unclear episode of acute vomiting, lethargy and somnolence at the age of 13 months, and from childhood onward had aversion to high protein food. Treatment with a protein-restricted diet and administration of phenylbutyrate as well as L-arginine were sufficient to normalize ammonia levels but glutamine concentrations remained high. Supplementation with N-carbamylglutamate rapidly improved her protein tolerance and reduced the need for co-medication. To our knowledge, so far only seven patients with N-acetylglutamate synthetase deficiency have been reported. CONCLUSION: Partial N-carbamylglutamate deficiency has to be considered in the differential diagnosis of hyperammonaemia. If proven by enzyme determination in liver tissue, the disorder should be cautiously treated with N-carbamylglutamate.

Urinary excretion of N-acetyl-beta-D-glucosaminidase in proteinuric states.

Urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG) was studied in 22 children with proteinuria and a normal glomerular filtration rate. Twelve patients had minimal change nephrotic syndrome (MCNS), 10 children suffered from different types of glomerulonephritis (GN) without tubulointerstitial renal disease. Sixty-six random urine samples were analyzed for protein, creatinine and NAG. There was a strong positive correlation between proteinuria and urinary NAG activity (r = 0.79, p = 0.0001). The raised NAG activities in proteinuric states turned to normal during remission of the disease. Patients with MCNS and GN did not differ significantly and had nearly identical correlation curves. Our results seem to indicate that functional changes in the renal tubular cells probably caused by protein resorption are responsible for this association. Raised NAG activities in proteinuria reflect the activity of the disease but cannot distinguish patients with MCNS and GN.

Amniotic fluid N-acetyl-beta-D-glucosaminidase activity and renal abnormalities.

Amniotic fluid N-acetyl-beta-D-glucosaminidase (NAG) activity was measured in 21 normal pregnancies to determine reference values, and in 10 pregnancies with fetuses who had prenatally recognised renal and urinary tract malformations. The normal values obtained at 17-19 and 28-31 gestational weeks did not differ, and an activity of 105 units NAG/mmol creatinine was the upper limit of the normal range. Raised NAG activities were found in four fetuses with oligohydramnios and severe bilateral renal disease, and also in two infants with a normal amount of amniotic fluid, only unilateral renal lesions, and a normal renal function after birth. Three of four cases with normal NAG activities had malformations without kidney damage, but one baby with prune belly syndrome was subsequently found to have dysplastic kidneys and renal failure. Our preliminary results suggest that a high level of NAG activity in the amniotic fluid indicates unilateral or bilateral kidney damage but is not proof of intrauterine renal failure.

Import of human bifunctional enzyme into peroxisomes of human hepatoma cells in vitro.

A polypeptide containing the carboxyl-terminal fragment of human peroxisomal enoyl-CoA hydratase:3-hydroxyacyl-CoA dehydrogenase bifunctional enzyme was synthesized in vitro from its cDNA clone. This expression polypeptide was transported into purified rat liver peroxisomes. When the expression polypeptide was incubated with postnuclear supernatant fractions of human hepatoma cells and analyzed by Nycodenz gradient SDS-PAGE and fluorography, it was imported specifically into peroxisomes as indicated by its resistance to proteinase K degradation. A deletion of the last nine amino acid residues at the carboxyl-terminus of this polypeptide prevents its peroxisomal import. A tripeptide sequence, SKL, located at the carboxyl-terminus of human bifunctional enzyme appears to be the targeting signal for the peroxisomal importation of bifunctional enzyme in human cells.

[N-acetyl-beta-D-glucosaminidase (NAG) in the urine. An additional parameter for diagnosing the site of urinary tract infection]. / N-acetyl-beta-D-Glucosaminidase (NAG) im Urin. Ein zusätzlicher Parameter zur Lokalisationsdiagnostik eines Harnwegsinfekts.

Urinary excretion of NAG was determined in 32 patients aged four months to 15 years with urinary tract infection (UTI). Level diagnosis was made by means of commonly accepted clinical and laboratory criteria. Pathological enzymuria was present in all 15 patients with pyelonephritis while 12 of 14 children with cystitis had a normal urinary NAG excretion. Two patients with cystitis and 3 patients with questionable level diagnosis had elevated urinary NAG levels. According to these data the level diagnosis of UTI was changed in 16% of the patients by including the NAG values. Follow-up studies of nine patients showed a significant decrease of initially elevated urinary NAG levels after a 10-days course of antibiotic treatment and the values were within the normal range in 8 of 9 patients. Determination of urinary NAG excretion seems to be of definite value as an additional parameter for level diagnosis of childhood urinary tract infection.

Infantile type of sialic acid storage disease with sialuria.

We describe a male infant of Austrian ancestry, the main clinical features including attacks of dyspnea due to laryngomalacia, severe mental and motor retardation, pronounced splenohepatomegaly and vacuolisation of peripheral lymphocytes. The clinical condition deteriorated progressively and the child died at the age of 21 months. Phase and electron microscopy of cultured skin fibroblasts showed multiple vacuoles and inclusions suggestive of a lysosomal storage disorder. Increased excretion of free sialic acid was demonstrated by resorcinol staining after routine thin-layer screening for urinary oligosaccharides. Quantitative analyses of urine, leucocytes and cultured fibroblasts revealed 10 to 30-fold increased concentration of free sialic acid. In addition, 3-fold elevated amounts of sialyloligosaccharides were found in the urine. The activities of a variety of lysosomal enzymes, including sialidase, were normal. Our case is compared with infantile sialic acid storage disease recently observed by other authors. The close convergence of clinical, morphological and biochemical signs support the concept of a distinct lysosomal disease entity. The basic defect is so far unknown.

[Postoperative T cell suppression in relation to preoperative nutritional status in childhood]. / Postoperative T-Zell-Suppression in Abhängigkeit vom präoperativen Ernährungszustand im Kindesalter.

The influence of moderate malnutrition on the cellular immunity was studied in 59 operated infants and children aged 1 day to 14 years. Except during the neonatal period the number of blood T-cells preoperatively and the degree of the postoperative T-cell suppression did not show a significant difference between children suffering from moderate malnutrition (weight for age less than or equal to 10 percent, less than or equal to 90% of the normal median weight) and the control group. However some datas indicate that even borderline malnutrition impairs the cellular immune-status.