Serum carnitine and acyl-carnitine in patients with meningitis due to tick-borne encephalitis virus infection.

BACKGROUND: Hard ticks are the main vectors of tick-borne encephalitis virus (TBEV). Free carnitine (FC) and acylcarnitines (AC) have the basic role in ß-oxidation as well as the modulation of immune and nervous system. Homeostasis of carnitines in the TBE patients was not studied so far. OBJECTIVES: This study aimed to evaluate FC and AC serum concentrations in patients with meningitis due to TBEV infection before and after 14 ± 3 days of treatment. MATERIAL AND METHODS: The study was performed in 14 patients aged 48 ± 29 years that were divided a posteriori (based on their FC level before and after treatment) into 2 subgroups: 1-8 and 9-14. Diagnosis was based on the neurological, serological and pleocytosis evaluation. RESULTS: The FC level in patients 1-8 before treatment (24.1 ± 8.1) was significantly lower than in patients post-treatment (34.4 ± 8.3), lower than in the control group (40.5 ± 7.6), and lower than in patients 9-14 before treatment (40.0 ± 13.5) but not lower than in the patients 9-14 after treatment (24.7 ± 7.3 µmol/L), respectively, p < 0.05. AC concentration in the patients 1-8 before treatment (4.7 ± 2.2) was apparently lower than in patients post-treatment (9.5 ± 3.9 µmol/L) but the values were not significantly different. In patients 9-14 before treatment the AC concentration (16.3 ± 12.6) was higher than in patients after treatment (5.3 ± 4.0 µmol/L), but the difference was not statistically significant. CONCLUSIONS: FC and AC homeostasis in circulation was disturbed in the patients with meningitis due to TBEV infection patients. The mean levels of FC and AC in 60% of the patients were below the normal range but normalized after treatment whereas in 40% of the patients they were near or at a normal range and significantly decreased after treatment. Explanation of this intriguing finding and its clinical significance is not easy without further studies.

Serum Concentrations of Insulin, Ghrelin, Adiponectin, Leptin, Leptin Receptor and Lipocalin-2 in Children with Celiac Disease Who Do and Do Not Adhere to a Gluten-Free Diet.

BACKGROUND/AIMS: The roles of the many bioactive peptides in the pathogenesis of celiac disease remain unclear. To evaluate the serum concentrations of insulin, ghrelin, adiponectin, leptin, leptin receptor, and lipocalin-2 in children with celiac disease who do and do not adhere to a gluten-free diet (GFD, intermittent adherence). METHODS: Prepubertal, pubertal, and adolescent celiac children were included in this study (74 girls and 53 boys on a GFD and 80 girls and 40 boys off of a GFD). RESULTS: Insulin levels in prepubertal (9.01±4.43 µIU/mL), pubertal (10.3±3.62 µIU/mL), and adolescent (10.8±4.73 µIU/mL) girls were higher than those in boys (5.88±2.02, 8.81±2.88, and 8.81±2.26 µIU/mL, respectively) and were neither age-dependent nor influenced by a GFD. Prepubertal children off of a GFD exhibited higher ghrelin levels than prepubertal children on a GFD. Adiponectin levels were not age-, sex- nor GFD-dependent. Adherence to a GFD had no effect on the expression of leptin, leptin receptor, and lipocalin-2. CONCLUSIONS: Adherence to a GFD had no influence on the adiponectin, leptin, leptin receptor, and lipocalin-2 concentrations in celiac children, but a GFD decreased highly elevated ghrelin levels in prepubertal children. Further studies are required to determine whether increased insulin concentrations in girls with celiac disease is suggestive of an increased risk for hyperinsulinemia.

Evaluation of the immunoradiometric and electrochemiluminescence method for the measurement of serum insulin in children.

Human insulin is a polypeptide hormone produced, stored, and secreted by the ß-cells in the pancreatic islets of Langerhans. Its secretion is stimulated by an increase of the glucose concentration in circulation. Non-radioactive assays are frequently used in many laboratories to measure hormone concentrations, as an alternative to the traditional "gold standard" radioimmuno- and immunoradiometric assays. The precise and reliable determination of the insulin concentration is an important concern in numerous diagnostic procedures. The aim of this study was to compare two commercially available assays (manual and automated) for measurement of serum insulin concentrations. Aliquots of the 86 randomly selected serum samples were measured by Elecsys Insulin Assay (cobas e411 immunoassay analyzer, Roche Diagnostics GmbH, Mannheim, Germany) and DIAsource INS-IRMA Kit (DIAsource ImmunoAssays S.A., Louvain-la-Neuve, Belgium). Compared assays exhibit good correlation (r = 0.996). Insulin concentrations were on average 4.2 µ IU/mL lower (p < 0.05) with the cobas e411 immunoassay analyzer when compared to those measured with DIAsouce Immunoassay. Our findings suggest that electrochemiluminescence method on the cobas e411 analyzer and manual IRMA method offered by the DIAsource for the serum insulin determination could be considered interchangeable.

Serum carnitine concentration is decreased in patients with Lyme borreliosis.

BACKGROUND: Lyme borreliosis (LB) is a serious infectious disease. Carnitine plays a crucial role in metabolism and inflammatory responses. Carnitine may be important in improving neuronal dysfunction and loss of neurons. AIM: To evaluate serum carnitine concentration in adult patients with various clinical types of LB. MATERIAL/METHODS: Groups: 1) patients with erythema migrans (EM, n=16), 2) neuroborreliosis (NB, n=10), 3) post-Lyme disease (PLD, n=22) and healthy controls (HC, n=32). Total (TC) and free (FC) carnitine were determined with the spectrophotometric method. RESULTS: TC levels (44.9±10.4, 28.0±8.4, 35.9±15.6 µmol/L) in the EM, NB and PLD patients were lower than in HC (54.0±11.4 µmol/L), p < 0.001. FC levels (32.7±7.7, 23.6±6.8, 26.3±11.2 µmol/L) in the EM, NB and PLD patients were lower than in HC (40.5±7.6 µmol/L), p < 0.001. AC levels (12.2±5.2, 4.4±2.6, 9.6±7.4 µmol/L) in the EM, NB and PLD patients were lower in the NB and PLD patients than in HC (13.5±8.40 µmol/L), p <0.001. AC/FC ratio was 0.31±0.14, 0.18±0.09, 0.39±0.33 in the EM, NB and PLD patients. CONCLUSIONS: LB patients exhibit a significant decrease of their serum carnitine concentrations. The largest changes were in the NB and PLD patients. To prevent late complications of the disease a possibility of early supplementation with carnitine should be considered. Further studies are required to explain the pathophysiological significance of our findings.

Neutrophil gelatinase-associated lipocalin in blood in children with inflammatory bowel disease.

BACKGROUND: Neutrophil gelatinase-associated lipocalin (NGAL) is a 25 kDa glycoprotein present in the bodily fluids and tissues. It is secreted by neutrophils, epithelial cells, hepatocytes and adipocytes, and its expression is highly increased in response to cellular stress. The role of NGAL in the pathophysiology of inflammatory bowel disease including Crohn's disease and ulcerative colitis in children has thus far not been studied. METHODS: The following groups of children were included: (i) inflammatory bowel disease group, n = 36, aged from 1 to 18 years with Crohn's disease (n = 19) and ulcerative colitis (n = 17); (ii) control group, n = 126; and (iii) disease control group, n = 27, without inflammatory bowel disease, with a food and/or inhalant allergy. RESULTS: Healthy children aged from 1 to 8 years exhibited lower NGAL level than those of 9 to 18 years old (39.0; 18.1-83.7 ng/mL vs 57.6; 28.7-107 ng/mL, P = 0.001). In the younger, but not in the older children, the serum NGAL level correlated with their age, r = 0.334, P = 0.001. In children with inflammatory bowel disease, serum NGAL level was higher (108; 37.3-245 ng/mL) than in healthy (42.0; 18.1-107 ng/mL) and allergic, noninflammatory bowel disease children (49.3; 19.3-107 ng/mL), P = 0.001. Serum NGAL levels in Crohn's disease and ulcerative colitis children did not correlate with age, gender, disease activity, and indices of the inflammation. CONCLUSION: Serum NAGL levels are highly elevated in Crohn's disease and ulcerative colitis in children compared to the healthy control group. Systematic studies are needed to explain the role of this protein in the inflammatory bowel disease.

Role of the rat gastrointestinal mucosa in catabolism of endothelin peptides.

Endothelin-1 is involved in physiology and pathophysiology of the alimentary tract. The peptide modulates blood flow in the gastrointestinal microvasculature and regulates contractility of smooth muscles and, when present in excess, may be an important factor contributing to pathogenesis of various forms of mucosal injury and peristaltic disorders. Mechanisms that regulate endothelin concentration in the gastrointestinal tissues are unknown. Therefore, the aim of our study was to identify and characterize endothelin inactivating peptidases in the rat gastrointestinal mucosa and smooth muscle cells. We have found three high affinity and efficient endothelin-1 inactivating peptidases. The acidic (pH optimum 5.5), membrane-bound, thiorphan- (ED(50) 1.2+/-0.2 nM) and phosphoramidon (ED(50) 150+/-25 pM) sensitive, endothelin-1 inactivating peptidase (K(M) 0.12+/-0.03 microM) was present in the mucosal cells of duodenum and small intestine. The enzyme exhibited high molecular weight (>100 kDa) and characteristics similar to that of the rat and human kidney, acidic metalloendopeptidase that was recently described. Two forms of the unique, low molecular weight (100>MW>30 kDa), alkaline (pH optimum 8.5), specific (K(M) 0.5+/-0.2 microM), thiorphan- and phosphoramidon insensitive, 1,10 phenanthroline inhibitable (ED(50) 0.65+/-0.20 mM, mean+/-S.E.M.) endothelin-1 inactivating peptidase were present exclusively in the duodenal mucosal cells; soluble form in cytosol and membrane-bound form exhibiting an abundance ratio 5:1, respectively. Mucosa of the stomach and large intestine, and gastrointestinal smooth muscle cells do not contain the specific endothelin-1 inactivating peptidases. The enzymes may play a crucial role in regulation of endothelin concentration in the gastrointestinal tissues. Whether impairment of activity of the mucosal endothelin inactivating peptidases, resulting in the increase of concentration of endothelin peptides in gastrointestinal tissues, occurs in various pathological conditions is actually studied in our laboratory.

Neutral endopeptidase activity is not elevated in serum in children with cholestatic liver disease: a unique role of aminopeptidase-m in sequential hydrolysis of peptides.

The aim of this study was to determine whether neutral endopeptidase activity is elevated in serum in children with cholestatic liver disease (Alagille syndrome), and whether the enzyme cooperates with the serum aminopeptidase-M in degradation of peptides. Our data suggest that neutral endopeptidase activity remains at a very low level,.undetectable with the assays we have applied, both in the serum from healthy children and those with cholestasis. In contrast, the serum aminopeptidase-M activity is highly increased in cholestasis. We have demonstrated that aminopeptidase-M alone is capable of sequential and complete hydrolysis of enkephalins and low-molecular-weight, nonspecific peptides. The rate of release of free amino acids from both exogenous or endogenous substrate peptides was statistically significantly higher in serum in children with cholestasis compared with healthy children (P < 0.05). Substance P (Ki = 2.5 micromol/liter) and bradykinin (Ki = 27 micromol/liter) were shown to be potent inhibitors of the serum aminopeptidase-M. We postulate that aminopeptidase-M, except when regulating the activity of bioactive peptides, may serve as a scavenger of short, nonspecific peptides in the circulation. Our data seem to provide new insights for further studies on the role of serum peptidases both in physiology and pathophysiology.