Pyridoxine-dependent seizures in Dutch patients: diagnosis by elevated urinary alpha-aminoadipic semialdehyde levels

Background

Pyridoxine‐dependent seizures (PDS) is a rare, autosomal recessively inherited disorder. Recently α‐aminoadipic semialdehyde (α‐AASA) dehydrogenase deficiency was identified as a major cause of PDS, which causes accumulation of both α‐AASA and pipecolic acid (PA) in body fluids.

Methods

We studied urinary and plasma α‐AASA and PA levels in 12 Dutch clinically diagnosed patients with PDS.

Results

α‐AASA was elevated in both urine and plasma in 10 patients. In these patients plasma PA levels were also elevated but urinary PA levels were normal.

Discussion

In all patients with clinically definite PDS, and in most patients with probable or possible PDS, the clinical diagnosis of PDS could be confirmed at the metabolite level. Non‐invasive urinary screening for α‐AASA accumulation provides a reliable tool to diagnose PDS and can save these patients from the classical and potentially dangerous pyridoxine withdrawal test to prove PDS.Pyridoxine‐dependent seizures (PDS) is a rare, autosomal recessively inherited disorder usually presenting very shortly after birth and in some cases in the womb. For 50 years PDS has been a clinical and biochemical conundrum which has puzzled physicians and scientists.¹ Plecko et al and Willemsen et al observed isolated pipecolic acid (PA) elevations in the plasma and cerebrospinal fluid of PDS patients, yet the biochemical relationship with pyridoxine metabolism remained unclear.^2,3,4 Recently, α‐aminoadipic semialdehyde (α‐AASA) dehydrogenase deficiency due to pathogenic mutations in the ALDH7A1 gene, was shown to be a major cause of PDS.⁵ In mammals, the essential amino acid L‐lysine is degraded via PA into the intermediate α‐AASA, which is subsequently oxidised to L‐2‐aminoadipic acid, a reaction catalysed by the enzyme α‐AASA dehydrogenase (EC 1.2.1.31, also named antiquitin) (fig 1​1).). In PDS patients, the lack of α‐AASA dehydrogenase leads to an accumulation of α‐AASA and PA in body fluids. α‐AASA is in spontaneous reversible equilibrium with piperideine‐6‐carboxylate (P6C) in the cytosol. Accumulated P6C irreversibly reacts with active pyridoxine, ie, pyridoxal‐5‐phosphate (P5P), by forming a Knoevenagel condensation product. This irreversible reaction causes a secondary deficit of P5P in affected children, which subsequently leads to epileptic seizures. Restoration of the P5P pool can easily be achieved by oral pyridoxine supplementation, which resolves the seizures.Open in a separate windowFigure 1 Metabolic pathway of L‐lysine.Recently, we reported on the epidemiology and clinical features of PDS in the Netherlands in this journal.⁶ In that paper the classical clinical criteria according to Baxter were used to establish the diagnosis of PDS. We therefore re‐evaluated that series of PDS patients by measuring their levels of α‐AASA and PA in urine and plasma.     

Plasma androgens after a single oral dose of testosterone undecanoate

Total plasma androgens (PA) were measured in 9 hypogonadal males aged between 13 and 21 1/2 years after a single oral dose of testosterone undecanoate (TU). With the exception of one patient, all showed a rise in PA with peak values between 7.7 and 38.0 nmol/l at 2 to 7 hours. A further patient aged 15.7 years who was given an 80-mg dose had a peak PA level of 71.2 nmol/l. In all patients PA returned to basal levels at 24 hours. In 4 patients plasma testosterone and dihydrotestosterone were measured, both rose after oral TU, and relatively high plasma dihydrotestosterone values were obtained. While these results indicate that TU is effective in young people, the very high peak androgen levels found in several of them after 40 mg TU suggest that this dose may be excessive in patients in whom growth is not complete.     

Plasma androgens after a single oral dose of testosterone undecanoate.

Total plasma androgens (PA) were measured in 9 hypogonadal males aged between 13 and 21 1/2 years after a single oral dose of testosterone undecanoate (TU). With the exception of one patient, all showed a rise in PA with peak values between 7.7 and 38.0 nmol/l at 2 to 7 hours. A further patient aged 15.7 years who was given an 80-mg dose had a peak PA level of 71.2 nmol/l. In all patients PA returned to basal levels at 24 hours. In 4 patients plasma testosterone and dihydrotestosterone were measured, both rose after oral TU, and relatively high plasma dihydrotestosterone values were obtained. While these results indicate that TU is effective in young people, the very high peak androgen levels found in several of them after 40 mg TU suggest that this dose may be excessive in patients in whom growth is not complete.     

Plasma dopa and catecholamines in the diagnosis and follow-up of children with neuroblastoma

Plasma dopa and the catecholamines--dopamine, norepinephrine, and epinephrine--were assayed by a radioenzymatic method in 15 children with active neuroblastoma and in eight others without evidence of disease to assess the value of these determinations in the diagnosis and management of the tumor. Thirty-four children with solid tumors and hemopoietic malignancies served as our controls. Elevated plasma dopa levels were observed in 13 children with active neuroblastoma (87%); dopamine and norepinephrine were elevated in 1/4 of these patients. In the group of children with neuroblastoma without evidence of disease, dopa and catecholamine levels were within the range observed in the controls. Total urinary catecholamines, homovanillic acid (HVA) and/or vanilmandelic acid (MVA) were elevated in 11 of the 15 (73%) neuroblastoma patients with active disease. While serial plasma dopa determinations correlated with the course of the disease in practically all patients and thus were useful in their follow-up, the catecholamines were of limited value in assessing tumor status. Our results suggest that plasma dopa, assayed by a radioenzymatic method, may be more reliable than the traditional urinary catecholamine determinations in the diagnosis of neuroblastoma, and it appears useful in the management of this disease.     

Are growth factors and leptin involved in the pathogenesis of premature adrenarche in girls?

A transient increase in height and bone age as well as hyperinsulinism is seen in patients with premature adrenarche (PA). In addition, the weights of these patients are more than those of healthy peers. The aim of this study was to evaluate the role of leptin, IGF-I and IGFBPs in hyperandrogenemia and increased body weight observed in girls with PA. In this study, IGF-I, IGFBP-3, IGFBP-1 and leptin levels were investigated in 27 children with PA aged 5.4-8.6 years and 13 healthy children aged 5.7-8.58 years. Twenty patients were lean. The bone ages and BMIs of the children with PA were significantly higher than those of the healthy controls (p < 0.05). IGF-I (p < 0.005), IGFBP-3 (p < 0.05) and leptin (p < 0.0001) levels of lean PA girls were higher than controls. The leptin level of the obese PA girls was higher than that of the lean PA girls (p < 0.05) and controls (p < 0.0001). The IGFBP-1 level of the PA girls with and without obesity was lower than controls (p < 0.05). A negative correlation was observed between IGFBP-1 and leptin levels of the girls with PA (r = -0.64, p < 0.05). Serum leptin levels were influenced by BMI (p = 0.001), basal 17-OHP (p = 0.002) and stimulated 17-OHP (p = 0.019) in patients with PA. In conclusion, we suggest that elevated IGF-I and insulin give rise to increased adrenal androgens and leptin levels. On the other hand, both insulin and leptin cause decreased levels of IGFBP-1 in girls with PA, even if they are lean.     

Feeding preterm infants with L-carnitine supplemented formula

A total of 29 preterm infants maintained on mixed enteral nutrition (50% pooled human milk, 50% formula daily) were studied over a 15 days period. 16 of them received L-carnitine supplemented formula during the first seven consecutive days (600 nmol/ml, as added supplement), 13 infants served as controls. In response to enhanced dietary intake, the plasma levels and urinary excretion rates of carnitines were increased by the 7th day of study. The plasma carnitines then returned to the initial values, whilst the urinary excretion remained elevated at the 14th day of study. The elevated daily urinary excretion of carnitines was accompanied by increased clearance and decreased relative reabsorption rates in the supplemented group. In the control group the plasma carnitine levels remained unchanged throughout the observations, while the daily excretion of free carnitine decreased by the end of the study. In the supplemented group statistically significant decrease was found in the daily excreted ammonia and urea with a decrease of plasma alanine and glutamine levels by the 7th day of study. The plasma levels of beta-hydroxybutyrate, glucose and creatinine remained unchanged in both groups.     

Renal injury in sick newborn infants: a prospective evaluation using urinary beta 2-microglobulin concentrations

Urinary concentrations of beta 2-microglobulin and creatinine were measured serially in 140 sick infants, of whom 109 were asphyxiated, and in 35 healthy preterm and term infants. First voided urines and samples from days 3 and 7 postpartum were studied. Urinary beta 2-microglobulin concentrations in healthy infants averaged 1.34 +/- 1.34 mg/L (mean +/- SD) in first voided specimens and 1.32 +/- 0.98 mg/L in day 3 samples; the calculated upper limit of normal (95% confidence limit) was 4.00 mg/L. Elevated values (those exceeding the 95% confidence limit) occurred most often in the sick asphyxiated patients (56%); the first voided sample value in these patients was 10.0 +/- 10.4 mg/L. The equivalent value in the sick nonasphyxiated infants was 8.32 +/- 7.27 mg/L. Values were significantly and persistently elevated in the sick infants on days 3 and 7. Factoring beta 2-microglobulin levels by urinary creatinine concentration did not affect the significance of the findings. The increased urinary beta 2-microglobulin levels were not (1) related to gestational age; low beta 2-microglobulin values occurred at all gestational ages for both healthy and sick infants; (2) a consequence of urine flow rate; urinary beta 2-microglobulin did not correlate with urinary creatinine concentration or with urine to plasma creatinine ratio; and (3) a consequence of increased production of beta 2-microglobulin; urinary and serum beta 2-microglobulin values did not correlate (r = .03). Thus, we propose that the elevated levels of urinary beta 2-microglobulin in the sick infants were the consequence of tubular injury. This was associated with hematuria but not with a high incidence of azotemia or oliguria.(ABSTRACT TRUNCATED AT 250 WORDS)     

Plasma and urinary catecholamines in patients with cystic fibrosis

In 43 patients with cystic fibrosis (age 8-23 yr, 26 boys and 17 girls) attending a summer camp in a mountain rehabilitation center and in 25 parents (heterozygotes) plasma epinephrine, norepinephrine, dopamine and plasma activity of dopamine-beta-hydroxylase were determined as well as the 24-h excretion of the free urinary amines (epinephrine, norepinephrine, dopamine), their O-methylated products (metanephrine, normetanephrine, 3-methoxytyramine) and the urinary phenolic acids (vanilmandelic and homovanillic). Also the metabolic breakdown product of serotonin in urine, the 5-hydroxyindoleacetic acid, was determined. Significantly elevated plasma dopamine (0.03-0.45 nmol/liter for controls versus 1.70-2.21 nmol/liter for cystic fibrosis) and slightly higher plasma norepinephrine levels were found in patients with cystic fibrosis. An increased 5-hydroxyindoleacetic acid excretion was noticed in adolescent patients which correlated with the disease state and the extent of lung involvement. No abnormalities of plasma amine levels were seen in the parents of the patients. Despite controversial results, CF patients seem to have an alteration in catecholamine metabolism which is reflected in higher plasma dopamine levels.     

The application of a serum 17OH-progesterone radioimmunoassay to the diagnosis and management of congenital adrenal hyperplasia.

Serum concentrations of 17OH-progesterone were studied serially over 24 hours in 13 treated and untreated patients with the C21 hydroxylase form of congenital adrenal hyperplasia. The results were correlated with measurements of plasma renin activity, serum electrolytes, and urinary 17-ketosteroids and pregnanetriol. In 500 healthy subjects from birth to adult life, serum 17OH-pregesterone levels ranged from 5 to 315 ng/dl. In untreated CAH, serum 17OH-progesterone was markedly elevated (2,000 to 80,000 ng/dl). Treatment with cortisol (20 to 30 mg/m2/day in 3 doses) resulted in normal serum 17OH-progesterone levels in both non-salt-losing and salt-losing patients receiving adequate mineralocorticoid. Even slightly inadequate mineralocorticoid therapy (shown by high plasma renin activity with normal serum electrolytes) was associated with elevated 17OH-progesterone (to 65,000 ng/dl) in spite of usually effective doses of cortisol. Some patients showed isolated 17OH-progesterone elevations (usually early morning), a situation which requires only revision of the cortisol dosage schedule without an increase in total dosage. The data confirm the value of 17OH-progesterone assays in both the diagnosis and management of CAH. Taken together with determinations of plasma renin activity, serum 17OH-progesterone assays can permit more exact control of CAH without excessive doses of glucocorticoid.     

Control of plasma aldosterone in infancy and childhood. A study of plasma renin activity, plasma cortisol and plasma aldosterone.

In order to elucidate the main factors controlling plasma aldosterone in infancy and childhood, plasma renin activity (PRA), plasma cortisol (PC, as a parameter of ACTH activity), plasma aldosterone (PA) and serum sodium and potassium were measured simultaneously in 84 healthy children (62 recumbent, 22 upright) ranging in age from 6 days to 16 years. 10 healthy male students served as adult controls. As compared to the controls, PRA levels were significantly higher in the children up to the age of 12 years. PA was also elevated in most children; the highest values for PA and for PRA were observed during the first 4 years of life. A significant positive correlation between PRA and PA (n = 84, r = 0,62, p less than 0.001) was found. There were no significant differences in serum sodium or potassium or in PC. All PC values were - with one exception - within the range found in healthy adults. Our results indicate that high PA values are freuqently observed in healthy children. They are mainly caused by elevated PRA. The physiological significance of increased activation of the renin-angiotensin-aldosterone system in infancy is not yet clear.     

Hyperlipidemia and fatty acid composition in patients treated for type IA glycogen storage disease

Because glycogen storage disease type IA (GSD-IA) is characterized by recurrent episodes of hypoglycemia that promote a marked elevation in blood triglyceride levels, we evaluated plasma lipid levels in 12 patients with GSD-IA on a regular basis. Six of the 12 patients had plasma fatty acid composition measured; because of possible essential fatty acid deficiency, urinary prostaglandin excretion was also measured. All patients had triglyceride levels between 1440 and 6120 mg/dl (16.25 to 69.09 mmol/L) before treatment. After treatment to promote blood glucose levels of 75 to 85 mg/dl (4.2 to 4.7 mmol/L), triglyceride levels in each of 11 patients were between 189 +/- 31 (2.13 +/- 0.35 mmol/L) and 510 +/- 60 mg/dl (5.76 +/- 0.68 mmol/L). The lipoprotein fatty acid composition in six patients showed a substantial elevation in C16:0, C16:1 omega 7, and C18:1 omega 9, but no increase in C20:3 omega 9 (the fatty acid that characteristically increases in essential fatty acid deficiency). In addition, each of the six patients had normal 24-hour urinary excretion of prostaglandin. One patient, whose triglyceride levels remained elevated despite dietary treatment, was given either clofibrate, lovastatin, niacin, or fish oil. With the exception of lovastatin, these agents produced a decrease in triglyceride values for 1 to 2 months; however, by 3 months triglycerides reached pretreatment levels. Combined treatment with clofibrate and niacin resulted in a sustained decrease in plasma triglyceride levels for 4 months. The findings indicate that dietary management of GSD-IA is usually associated with improvements in triglyceride levels; however, patients maintain triglyceride values between 300 and 500 mg/dl (3.38 to 5.65 mmol/L). No patient had biochemical evidence of essential fatty acid deficiency.     

Elastase-alpha 1-proteinase inhibitor: an early indicator of septicemia and bacterial meningitis in children

In 26 infants and children with septicemia or bacterial meningitis, significantly elevated plasma levels of elastase-alpha 1-proteinase inhibitor (E-alpha 1-PI) were present at time of recognition of infection, even in those patients with neutropenia (range of reference values: 25 to 190 micrograms/L, n = 142; patients: 444 to 2049 micrograms/L, n = 26). After initiation of therapy, normalization of E-alpha 1-PI levels was observed in all patients who recovered from infection. In addition, 18 of 19 children with bacterial meningitis had increased cerebrospinal fluid concentrations of E-alpha 1-PI above the range of normal (range of reference values: 0 to 39 micrograms/L, n = 62; patients: 30 to 3490 micrograms/L, n = 19); concentrations of E-alpha 1-PI in bacterial meningitis were significantly increased when compared with those in aseptic meningitis (range 25 to 194 micrograms/L; n = 15). In 30 patients with local bacterial infections (pneumonia, urinary tract infections, etc.), E-alpha 1-PI was also elevated. These data suggest that E-alpha 1-PI is a sensitive indicator of systemic and local bacterial infection in childhood.     

Neuropeptide Y as a marker in pediatric neuroblastoma

Neuropeptide Y (NPY) was investigated as a possible tumor marker in pediatric patients with tumors of the sympathetic nervous system. Seven patients with neuroblastoma, 3 patients with ganglioneuroblastoma, and 2 with ganglioneuroma, were compared with 12 matched healthy controls and 34 tumor controls. NPY-like immunoreactivity (NPYLI) was analyzed in extracted plasma using a competitive radioimmunoassay. At diagnosis, plasma NPYLI was significantly increased (p less than .001) in the neuroblastoma patients (352 +/- 99 pM; mean +/- SEM) when compared with healthy controls (36 +/- 4 pM) and tumor controls (30 +/- 2 pM). Ganglioneuroblastoma and ganglioneuroma patients had lower levels (57 +/- 8 pM) than neuroblastoma patients but still significantly higher than the controls. In all patients with sympathetic tumors, the NPYLI level was decreased after treatment. Five neuroblastoma patients relapsed; all had increasing NPYLI levels. In 3 of these patients, incresing NPYLI was the first sign of relapse. Plasma NPYLI correlated well to urinary levels of homovanillic acid. NPY in plasma (NPYLI) may be a clinically useful marker of pediatric neuroblastoma for diagnosis and differential diagnosis. NPYLI correlates well with the clinical course and can be the first sign of relapse. Plasma determinations of NPYLI make it possible to monitor rapid alterations of disease.     

新生儿呼吸衰竭时内源性一氧化氮及内皮素的动态观察

目的　了解新生儿呼吸衰竭时内源性一氧化氮（ＮＯ） 和内皮素（ＥＴ） 的动态变化及其在新生儿呼衰的发病中所起的作用。方法　测定了３８ 例新生儿呼衰患儿的尿ＮＯ代谢产物亚硝酸和硝酸根离子（ＮＯ２ － ＋ ＮＯ３ － ＝ ＮＯｘ） 和血浆ＥＴ 水平,同时监测患儿的动态肺顺应性和计算氧合指数（ＯＩ） 。结果　呼吸衰竭的患儿尿ＮＯｘ （２６４．９８±２１８．３２ μｍｏｌ／ｍｇ Ｃｒ） 水平明显降低,血浆ＥＴ（７３ ．０１ ±１０．０６ ｎｇ／Ｌ）水平明显升高,其中的ＲＤＳ组（２０８ ．６４ ±８８．５３ μｍｏｌ／ｍｇ Ｃｒ,８２．３６ ±１７ ．８３ ｎｇ／Ｌ） 变化最为明显。对照组尿ＮＯｘ 和血浆ＥＴ 水平分别为３９７ ．２６ ±２０６ ．６１ μｍｏｌ／ｍｇ Ｃｒ,４０ ．６６ ±１６．８６ ｎｇ／Ｌ。随着疾病的恢复,存活者尿ＮＯｘ 水平上升,而血ＥＴ水平下降,逐渐恢复正常。相关性分析显示尿ＮＯｘ 与ＯＩ呈负相关,与肺顺应性呈正相关,而血ＥＴ与ＯＩ呈正相关,与肺顺应性呈负相关。结论　肺部疾病越重,尿ＮＯｘ 水平越低,血ＥＴ水平越高;严重缺氧所致的内源性ＮＯ合成不足和ＥＴ 合成增加在新生儿呼吸衰竭的发生中可能起了重要的作用。     

Is globotriaosylceramide a useful biomarker in Fabry disease?

AIM: The aim of this study was to determine whether globotriaosylceramide (Gb3) is a useful biomarker in Fabry disease. METHODS: The levels of Gb3 were measured in plasma and urine by tandem mass spectrometry in untreated hemizygotes and heterozygotes with Fabry disease and in healthy controls, and the levels were monitored in patients on treatment with enzyme replacement therapy (ERT). RESULTS: Hemizygotes with classic Fabry disease showed elevated levels of Gb3 in both plasma and urine and could readily be distinguished from normal controls. Male patients with the N215S mutation had normal levels in their plasma but 50% had marginally elevated levels in their urine. Thirty-three percent of proven heterozygotes had elevated Gb3 concentrations in plasma but 97% of those without the N215S mutation (36/37) had an elevated level in urine. The four heterozygotes with the N215S mutation had normal Gb3 levels in urine. The level of Gb3 in plasma initially fell following the start of ERT in all patients who had an elevated level before treatment. However, in a few patients the level subsequently rose. Similar results were found for the levels of Gb3 in urine. CONCLUSION: Gb3 is not an ideal marker of Fabry disease or the response to treatment in all patients. Plasma and urine levels of Gb3 cannot be used as a marker of Fabry disease in patients with the N215S mutation and many heterozygotes do not have elevated Gb3 levels in plasma. The urine concentration is more informative in heterozygotes and can be used as a measure of the response to therapy. The fall in Gb3 levels in patients receiving ERT was not sustained in some patients, despite a clinical improvement. Additionally, Gb3 cannot be used to monitor the response to treatment in patients who initially have normal plasma and urine concentrations of this glycolipid.     

Abnormal steroidogenesis in three patients with Antley–Bixler syndrome: Apparent decreased activity of 17α-hydroxylase, 17,20-lyase and 21-hydroxylase

BACKGROUND: Antley-Bixler syndrome (ABS) is characterized mainly by abnormal skeletal morphogenesis such as craniosynostosis and radiohumeral synostosis, and by ambiguous genitalia in some cases. The mechanisms resulting in these deformities have not been determined. Methods: The adrenal and gonadal function of three Japanese ABS patients were evaluated. Patient 1 (17-year-old-male) had bilateral cryptoorchidism, delayed puberty and symptoms of glucocorticoid deficiency. Patient 2 (14-year-old male) and patient 3 (4-year-old female) presented with emaciation. Additionally, patient 3 had partial labial fusion and common urogenital sinus. In each patient, blood sampling for steroid analysis before and after rapid adrenocorticotropic hormone (ACTH) stimulation was carried out. Additionally, urinary steroids were quantified. Molecular analysis of CYP17 and CYP21A2 were also performed. Results: All patients showed elevated basal 17alpha-deoxysteroid levels. Although the 17alpha-deoxysteroid levels further increased after rapid ACTH stimulation, 17alpha-hydroxysteroids including cortisol did not respond, suggesting impaired 17alpha-hydroxylation. Patient 1 and patient 2 showed low adrenal androgen blood levels both before and after rapid ACTH stimulation. Patient 3 showed lower than normal excretions of urinary androgens. Additionally, a prolonged ACTH stimulation in patient 3 failed to elicit significant increase of adrenal androgens. These findings suggested impaired 17,20-lyase activity. In contrast to attenuated 17alpha-hydroxycorticosteroids, notably cortisol, elevated 17alpha-hydroxyprogesterone (17OHP) levels were observed, not only in pubertal patients (1 and 2) but also in prepubertal patient 3, indicating impaired 21-hydroxylation. This assumption was supported by increased urinary 21-deoxycortisol metabolite excretion in patients 2 and 3. With the exception of a heterozygous mutation of CYP17 in one of the patients, other mutations of this gene or CYP21A2 were identified in any of the patients. CONCLUSION: Combined decreased 17alpha-hydroxylation, 17,20-lyase activity and 21-hydroxylation was detected in three ABS patients. Considering that the enzymes responsible are all cytochrome P450 enzymes and that another cytochrome P450 enzyme, lanosterol 14alpha-demethylase, has recently been shown to be impaired in an ABS patient, we speculate that dysfunction of a system which commonly regulates cytochrome P 450 activity may be responsible for the ABS phenotype.     

Dietary threonine reduces plasma phenylalanine levels in patients with hyperphenylalaninemia

BACKGROUND: In order to achieve normal intellectual development, the plasma phe-nylalanine (PHE) levels of patients with hyperphenylalaninemia should not exceed toxic levels. This goal is usually accomplished by employing special diets in which the patient's protein intake is in the form of PHE-free mixtures of amino acids. There is evidence from our own observations in animals and a preliminary observation in patients with hyperphenylalaninemia that supplemental dietary threonine (THR) might decrease plasma PHE concentrations. METHODS: In this placebo-controlled crossover study, the effect of supplemental oral THR on the plasma amino acid concentrations of 12 patients with hyperphenylalaninemia was investigated. Before starting the first treatment period of this cross-over study, the patients were randomly assigned to one of two groups supplemented either with approximately 50 mg THR/kg per day or with a similar amount of maltodextrin as placebo. After a feeding period of 8 weeks and a wash-out period of 8 weeks, the supplements were crossed over and the study continued for an additional 8 weeks. Blood was obtained at the start and the end of each supplementation period. RESULTS: Dietary THR supplementation of approximately 50 mg/kg per day resulted in a significant decrease of plasma PHE levels ( P = 0.0234). There was a close positive correlation between plasma and urinary PHE concentrations ( P < 0.001) indicating that the lower plasma PHE levels in the THR supplemented patients were not caused by higher urinary excretion of PHE. CONCLUSIONS: The data of the present study show that oral THR supplementation has a clear plasma-PHE-reducing effect but they do not allow any conclusion about the mechanisms responsible for the observed effect. Although it seems attractive on the basis of the present data to use THR supplementation in patients with hyperphenylalaninemia, the mechanism of the observed effect should be clarified before introduction of such a treatment in these patients.     

Ovarian hyperthecosis in the adolescent patient.

The endocrine findings in two adolescents with hyperthecosis are compared to those in a patient with an androgenic ovarian tumor. In patients with hyperthecosis, luteinizing hormone values were elevated or in the upper normal range, and plasma testosterone and androstenedione values were increased. Following dexamethasone suppression, testosterone and androstenedione values remained elevated, but after administration of human chorionic gonadotropin, they increased further in only one patient. Baseline 17-ketosteroid values were normal, suppressed with dexamethasone, and stimulated to baseline levels following HCG. The patient with a lipoid cell ovarian tumor had low baseline LH levels, and elevated testosterone, androstenedione, and 17-ketosteroid values. Dexamethasone produced little change in urinary or plasma values, but the 17-ketosteroids increased markedly after administration of HCG. The finding of low serum LH values in patients with hirsutism and elevated androgen secretion should alert the clinician to the possibility of a tumor.     

Evaluation of newborn screening for medium chain acyl-CoA dehydrogenase deficiency in 275 000 babies

OBJECTIVE: To evaluate newborn screening by tandem mass spectrometry for detection of medium chain acyl-CoA dehydrogenase (MCAD) deficiency, a fatty acid oxidation disorder with significant mortality in undiagnosed patients. DESIGN: The following were studied: (a) 13 clinically detected MCAD deficient subjects, most homozygous for the common A985G mutation, whose newborn screening sample was available; (b) 275 653 consecutive neonates undergoing routine newborn screening. Screened infants with blood octanoylcarnitine levels > or = 1 micromol/l were analysed for the A985G mutation, had analysis of plasma and repeat blood spot acylcarnitines and urinary organic acids, and had fibroblast fatty acid oxidation or acylcarnitine studies. RESULT: Twelve of the 13 patients later diagnosed clinically had newborn octanoylcarnitine levels > 2.3 micromol/l. Twenty three screened babies had initial octanoylcarnitine levels > or = 1 micromol/l. Eleven of 12 babies with persistent abnormalities had metabolite and/or enzyme studies indicating MCAD deficiency. Only four were homozygous for the A985G mutation, the remainder carrying one copy. CONCLUSIONS: Most patients with symptomatic MCAD deficiency could be detected by newborn screening. Infants actually detected had a lower frequency of A985G alleles than clinically diagnosed cases and may have a lower risk of becoming symptomatic.     

Increased levels of urinary interleukin-6 in Kawasaki disease

Kawasaki disease (KD) often presents with abnormal urinary findings, such as aseptic pyuria, mild proteinuria and microscopic haematuria. In this study, we measured urinary interleukin-6 (IL-6) by a sensitive sandwich ELISA assay using mouse monoclonal antibodies against recombinant IL-6 to elucidate the role of IL-6 in the pathogenesis of renal lesions in KD. Serum IL-6 levels were increased in acute KD as well as in febrile controls. Importantly, urinary IL-6 levels were consistently elevated in patients with acute KD, but much lower in febrile controls. Urinary IL-6 levels returned steadily to normal during the convalescent phase. In addition to IL-6, urinary levels ofN-acetyl--d-glucosaminidase (NAG) and ₂-microglobulin (₂-mg) were also elevated during the acute phase of this disease. Eosinophils and macrophages were identifiable in urinary sediments from these patients. The increased levels of urinary IL-6 in combination with increased NAG and ₂-mg seemed to suggest the presence of certain renal parenchymal lesions with cellular infiltration during the acute phase of the disease. IL-6 may serve as clinically useful parameter for the detection and monitoring of the renal involvement in KD.