Comparison of the Chemiluminescence Immunoassay LIAISON® with the Radioimmunoassay for Aldosterone and Renin Measurement.

Determination of renin plasma levels is useful in the diagnosis of hypertension and in the therapeutic follow-up of hypertensive patients. Plasmatic concentration of renin decreases in patients with hypertension due to a primary hyperaldosteronism, contrary to renovascular hypertension where concentrations of renin and aldosterone are both elevated. Blood samples (serum, EDTA plasma) were analysed using two different chemiluminiscent methods CLIA LIAISON® and radioimmunoassay for aldosterone (IMMUNOTECH Beckman Coulter) and renin (Cisbio Bioassay) measurements were compared. We used both methods to ascertain the correlation between serum vs. EDTA plasma levels of aldosterone (RIA, CLIA) and renin (IRMA, CLIA) and to compare aldosterone to renin ratios for CLIA and for radioimmunoassay: serum aldosterone to plasma renin and plasma aldosterone to plasma renin. We compared serum aldosterone CLIA vs. RIA (rP=0.933, P<0.001) and plasma renin determined using CLIA vs. IRMA (rP=0.965, P=0.062). Furthermore, we used both methods to establish the correlation between the serum vs. plasma levels of aldosterone: RIA (rP=0.980, P<0.001); CLIA (rP=0.994, P=0.353) and serum vs. plasma levels of renin: IRMA (rP=0.948, P<0.001); CLIA (rP=0.921, P=0.011). Aldosterone (serum, plasma) to plasmatic renin ratios for CLIA (rP=0.999, P=0.286) and for radioimmunoassay (rP=0.992, P=0.025). Our data demonstrate that renin and aldosterone concentrations obtained using CLIA correlate with renin and aldosterone concentrations using radioimmunoassay methods. Correlation coefficients of pair results ranged from 0.921 to 0.994. Aldosterone (serum, EDTA plasma) to plasmatic renin ratios are comparable and any of them can be used with no significant differences found.

Plasma homocysteine in Alzheimer's disease with or without co-morbid depressive symptoms.

OBJECTIVE: Elevated homocysteine is associated with a variety of diseases, including Alzheimer's disease (AD) and depressive disorder. This study was designed to detect an association between plasma homocysteine and AD with or without co-morbid depressive symptoms. METHODS: Plasma homocysteine concentrations were measured in 85 AD patients (36 of them with depressive symptoms), 33 non-AD patients with a depression diagnosis and 44 healthy controls, all aged above 50 years. RESULTS: Positive correlation between age and homocysteine was confirmed. Significantly higher mean plasma homocysteine was found in AD patients, but not in depressive patients, when compared with controls. We confirmed significant correlation between homocysteine concentration and the degree of cognitive impairment in AD patients. There was no incremental effect of concurrent depressive symptoms on homocysteine concentration in AD patients. CONCLUSION: The association of high homocysteine with degree of cognitive impairment or stage of dementia in AD indicate potential role of high plasma homocysteine as a biomarker of the disease and/or indicator of brain damage during the progression of AD dementia.

Elimination and penetration of amikacin into urine in patients with decreased glomerular filtration rate.

Background: Amikacin monotherapy is recommended for urinary tract infection (UTI) treatment with multi-resistant pathogens. Even though amikacin efficacy in the treatment of UTIs is dependent on its urinary concentration, there are no robust data proving that sufficiently high urinary concentration is reached in patients with reduced glomerular filtration rate (GFR). Methods: A prospective study to monitor amikacin penetration into urine of 70 patients [40 males, median (interquartile range) age 70 (65-79) years] with different levels of glomerular filtration decline, including patients treated by dialysis, was conducted. The bactericidal efficacy of amikacin in urine samples has been evaluated. Results: Patients with estimated GFR (eGFR) <30 mL/min had significantly lower median amikacin urinary concentration than patients with eGFR >30 mL/min (89.75 vs 186.0 mg/L, P < .0001; 200.5 vs 830.0 mg/L, P < .0001; and 126.0 vs 408.0 mg/L, P < .0001 for minimal, maximal and minimal together with maximal concentrations, respectively). The amount of amikacin eliminated in the first 10-13 h after dose administration was dependent on eGFR (r2 = 0.6144, P < .0001). The urinary concentration of amikacin in patients treated by dialysis was indirectly proportional to pH of urine. The plasma concentrations of amikacin did not correlate with urinary levels in patients in either of the GFR categories. Microbiological evaluation showed that the critical urinary concentration for efficacy of amikacin during UTI monotherapy in patients treated by dialysis is 100 mg/L. We found that 4 out of 11 patients treated by dialysis did not reach this level during the treatment. Conclusion: Systemic administration of amikacin monotherapy in patients treated by dialysis is questionable as the concentrations of amikacin in their urine are often below the threshold of effectivity. Amikacin plasma concentrations are not a major determinant of amikacin concentration in urine, therefore pulse dosing is neither necessary nor safe in patients treated by dialysis, and may cause undesirable toxicity.

Placental growth factor may predict increased left ventricular mass index in patients with mild to moderate chronic kidney disease--a prospective observational study.

BACKGROUND: Placental growth factor [PlGF) is a cardiovascular (CV) risk marker, which is related to left ventricle hypertrophy (LVH) in animal models. Currently there are no data available regarding the possible relationship of PlGF and the development of LVH or diastolic dysfunction in patients with chronic kidney disease (CKD) and the relationship of PlGF to other CV risk factors in CKD patients. The aim of our study was to determine the possible association of PlGF and several other CV risk markers to echocardiographic parameters in CKD population. METHODS: We prospectively examined selected laboratory (PlGF, fibroblast growth factor-23 -FGF23, vitamin D, parathyroid hormone, extracellular newly identified RAGE-binding protein - EN-RAGE, B-type natriuretic peptide - BNP) and echocardiographic parameters in 62 patients with CKD 2-4. Mean follow-up was 36 ±10 months. Laboratory and echocardiographic data were collected 2-3 times, at the shortest interval of 12 months apart. Multivariate regression analysis was used to detect independent correlations of variables. RESULTS: Increased left ventricular mass index (LVMI, g/m2.7) was found in 29% patients with CKD 2-4, left ventricular (LV) diastolic dysfunction was detected in 74.1% patients (impaired LV relaxation in 43.5% patients and pseudonormal pattern in 30.6% patients). After 36 ± 10 months increased LVMI was found in 37.1% patients with CKD 2-4, LV diastolic dysfunction was detected in 75.8% patients (impaired LV relaxation in 43.5% patients and pseudonormal pattern in 32.3% patients). Following independent correlations were found: LVMI was related to PlGF, cholesterol, BNP, systolic blood pressure and serum creatinine. EN-RAGE correlated positively with left atrial diameter and inversely with E/A ratio. During the follow-up we found a significant increase in LVMI and left atrial diameter, whereas a significant decrease in LVEF was noted. CONCLUSION: According to our data, PlGF is independently related to increased LV mass in CKD, whereas EN-RAGE is more likely related to diastolic dysfunction in this population.

Intraperitoneally Administered Vancomycin in Patients with Peritoneal Dialysis-Associated Peritonitis: Population Pharmacokinetics and Dosing Implications.

Peritonitis is a limiting complication of peritoneal dialysis, which is treated by intraperitoneal administration of antibiotics. Various dosing strategies are recommended for intraperitoneally administered vancomycin, which leads to large differences in intraperitoneal vancomycin exposure. Based on data from therapeutic drug monitoring, we developed the first-ever population pharmacokinetic model for intraperitoneally administered vancomycin to evaluate intraperitoneal and plasma exposure after dosing schedules recommended by the International Society for Peritoneal Dialysis. According to our model, currently recommended dosing schedules lead to possible underdosing of a large proportion of patients. To prevent this, we suggest avoiding intermittent intraperitoneal vancomycin administration, and for the continuous dosing regimen, we suggest a loading dose of 20 mg/kg followed by maintenance doses of 50 mg/L in each dwell to improve the intraperitoneal exposure. Vancomycin plasma level measurement on the fifth day of treatment with subsequent dose adjustment would prevent it from reaching toxic levels in the few patients who are susceptible to overdose.

Pregnancy-associated plasma protein A as an independent mortality predictor in long-term hemodialysis patients.

BACKGROUND/AIMS: Pregnancy-associated plasma protein A (PAPP-A) is a biomarker related to vascular damage. The aim of the study was to focus on PAPP-A and related parameters and their relationship to the prognosis of long-term hemodialysis (HD) patients. METHODS: This is a prospective observational cohort study which included 261 long-term HD patients followed up for 5 years and 66 healthy subjects. PAPP-A, placental growth factor (PlGF), matrix metalloproteinase 2 and 9 (MMP-2, MMP-9), insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein-4 (IGFBP-4), and cardiac, nutritional and inflammatory parameters were measured at the beginning of the study and tested as predictors of mortality. RESULTS: PAPP-A, PlGF, IGF-1, IGFBP-4 and MMP-2 were significantly increased in HD patients compared to controls (PAPP-A 27.6 ± 15.5 mIU/l in HD vs. 9.4 ± 2.5 mIU/l in controls, p < 0.001). Increased PAPP-A was a significant independent predictor of overall mortality and mortality due to infection in the multivariate Cox analysis [HR (95% CI): 1.237 (1.060-1.444), p = 0.007, and 1.416 (1.115-1.798), p = 0.004, per standard deviation, respectively]. PAPP-A was not related to cardiovascular mortality. CONCLUSION: Increased PAPP-A is a significant independent predictor of overall mortality and mortality due to infection but it was not related to cardiovascular mortality in this study.

Pregnancy-associated plasma protein A (PAPP-A) and soluble receptor for advanced glycation end products (sRAGE)--intra- and inter-individual variability in chronic hemodialysis patients.

BACKGROUND: Dialysis patients are at high risk of cardiovascular complications. Pregnancy-associated plasma protein A (PAPP-A) as well as sRAGE (soluble receptor for advanced glycation end products) are new biomarkers related to cardiovascular disease. The aim of our study was to describe their intra- and inter-individual variability. METHODS: The studied group consisted of 21 chronic hemodialysis patients. PAPP-A, sRAGE and selected routine parameters were measured monthly during a 1-year prospective study. RESULTS: Our results show high intra-individual variability of both PAPP-A and sRAGE. Both PAPP-A and sRAGE were closely linked to serum transferrin levels. Additionally, sRAGE was significantly associated with leukocyte count and haemoglobin. CONCLUSION: Our study demonstrates high intra-individual variability of PAPP-A and sRAGE in stable clinical status. This finding could be helpful for further evaluation of the significance of PAPP-A and sRAGE in chronic kidney disease.

Interlaboratory study of free monoclonal immunoglobulin light chain quantification.

BACKGROUND: Quantification of monoclonal immunoglobulin free light chains (FLCs) in serum is used increasingly in clinical practice for the diagnosis, prognostic assessment, and treatment monitoring of monoclonal gammopathies. It is used as an adjunct to standard serum protein electrophoresis and immunofixation. However, methods for FLC quantification need further standardization and validation. METHODS: The Czech Myeloma Group and the Czech Society of Clinical Biochemistry have initiated an interlaboratory study where six laboratories collaborating with the primary myeloma treatment centres measured FLC concentrations in 12 serum samples from patients with monoclonal gammopathies. RESULTS: Repeatability of the measurements in five laboratories was calculated based on differences between the results of duplicate measurements. We found that repeatability depended more on the laboratory than on the device used for measurement. CONCLUSIONS: The study revealed several weak points in the methodology, including the need for a uniform sample dilution procedure. Interlaboratory reproducibility was comparable with values achieved in the NEQAS programme. Because the κ/λ ratio cannot be measured with high precision, κ and λ FLC concentrations should be used where possible. Due to its impact on the clinical management of patients with gammopathy, FLC quantification needs to become a part of the regular quality control cycle in myeloma centres.

Procalcitonin interference in an immunometric calcitonin assay.

BACKGROUND: Procalcitonin (PCT) increases in septic patients, and is not transformed into calcitonin (CT). We found in septic patients, a significant increase of CT, as determined by an immunoassay using polyclonal antibodies. We compare determination using polyclonal and monoclonal AB. METHODS: We included 34 patients: 17 with clinical signs of sepsis, a positive haemoculture (PCT > 0.5 µg/L) and 17 without them (PCT < 0.1 µg/L). CT was determined by two above-mentioned methods. The influence on CT levels was observed after using the high-concentration PCT calibrator addition to a mixed serum sample with a low concentration of CT. The dilution test of the high-concentration calibrator PCT was performed by an IBL calibrator, with a zero calcitonin concentration. RESULTS: In the septic patients we found an interference in calcitonin determination using the polyclonal AB (IRMA); 24.1-718 µg/L, proportional to the PCT levels (r = 0.814, p < 0.0001). When using the monoclonal AB (ELISA), the calcitonin levels < 6.5-46.3 ng/L, and no interference of PCT was observed. In the non-septic group, we did not record any PCT interference using either the polyclonal or the monoclonal AB, and the CT levels were within the reference ranges using the two methods (r = 0.997, p < 0.0001). The recovery and dilution tests confirmed interference by PCT on the calcitonin determination with the polyclonal antibody. CONCLUSIONS: Results show that in septic patients there is visible interference of PCT in the calcitonin determination, principally in the IRMA method (polyclonal AB); while no such relationship was observed in the ELISA method (monoclonal AB).

Increased uric acid and glucose concentrations in vitreous and serum of patients with diabetic macular oedema.

BACKGROUND: Diabetic retinopathy (DR) is characterized by blood-retina barrier breakdown induced by local changes in the retina and systemic factors. We investigated vitreous and serum levels of glucose and uric acid (UA) in patients with DR and aimed to describe their correlation with the grade of DR. METHODS: Prospective study of 81 patients with DR and 48 non-diabetic controls. Biochemical analysis of vitreous and serum samples was performed. RESULTS: UA and glucose concentrations in vitreous and serum were significantly higher in diabetic patients than in controls. Absolute ratios (vitreous level/serum level) of UA and glucose were higher in proliferative compared with non-proliferative DR. CONCLUSIONS: The results suggest that, apart from glucose, increased levels of UA in diabetic patients may also be involved in the pathogenesis and progression of DR.

Vancomycin-releasing cross-linked collagen sponges as wound dressings.

The study presents a novel vancomycin-releasing collagen wound dressing derived from Cyprinus carpio collagen type I cross-linked with carbodiimide which retarded the degradation rate and increased the stability of the sponge. Following lyophilization, the dressings were subjected to gamma sterilization. The structure was evaluated via scanning electron microscopy images, micro-computed tomography, and infrared spectrometry. The structural stability and vancomycin release properties were evaluated in phosphate buffered saline. Microbiological testing and a rat model of a wound infected with methicillin-resistant Staphylococcus aureus (MRSA) were then employed to test the efficacy of the treatment of the infected wound. Following an initial mass loss due to the release of vancomycin, the sponges remained stable. After 7 days of exposure in phosphate buffered saline (37°C), 60% of the material remained with a preserved collagen secondary structure together with a high degree of open porosity (over 80%). The analysis of the release of vancomycin revealed homogeneous distribution of the antibiotic both across and between the sponges. The release of vancomycin was retarded as proved by in vitro testing and further confirmed by the animal model from which measurable concentrations were observed in blood samples 24 hours after the subcutaneous implantation of the sponge, which was more than observed following intraperitoneal administration. The sponge was also highly effective in terms of reducing the number of colony-forming units in biopsies extracted from the infected wounds 4 days following the inoculation of the wounds with the MRSA solution. The presented sponges have ideal properties to serve as wound dressing for prevention of surgical site infection or treatment of already infected wounds.

Dissociative symptoms and neuroendocrine dysregulation in depression.

BACKGROUND: Dissociative symptoms are traditionally attributed to psychological stressors that produce dissociated memories related to stressful life events. Dissociative disorders and dissociative symptoms including psychogenic amnesia, fugue, dissociative identity-disorder, depersonalization, derealization and other symptoms or syndromes have been reported as an epidemic psychiatric condition that may be coexistent with various psychiatric diagnoses such as depression, schizophrenia, borderline personality disorder or anxiety disorders. According to recent findings also the somatic components of dissociation may occur and influence brain, autonomic and neuroendocrine functions. At this time there are only few studies examining neuroendocrine response related to dissociative symptoms that suggest significant dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis. The aim of the present study is to perform examination of HPA axis functioning indexed by basal cortisol and prolactin and test their relationship to psychic and somatoform dissociative symptoms. MATERIAL/METHODS: Basal cortisol and prolactin and psychic and somatoform dissociative symptoms were assessed in 40 consecutive inpatients with diagnosis of unipolar depression mean age 43.37 (SD=12.21). RESULTS: The results show that prolactin and cortisol as indices of HPA axis functioning manifest significant relationship to dissociative symptoms. Main results represent highly significant correlations obtained by simple regression between psychic dissociative symptoms (DES) and serum prolactin (R=0.55, p=0.00027), and between somatoform dissociation (SDQ-20) and serum cortisol (R=-0.38, p=0.015). CONCLUSIONS: These results indicate relationship between HPA-axis reactivity and dissociative symptoms in unipolar depressive patients that could reflect passive coping behavior and disengagement.

Depression, cortisol and somatoform dissociative symptoms.

OBJECTIVE: According to recent findings neuroendocrine response related to dissociative symptoms is related to dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis but HPA axis functioning as related to dissociation is only partially understood. METHOD: With the aim to test the relationship between basal serum cortisol and dissociative symptoms measured as somatoform and psychic dissociation we performed clinical testing and biochemical analysis in 30 inpatients with diagnosis of unipolar depression (mean age 41.46, SD=13.68). RESULTS: The results show that cortisol as an index of HPA axis functioning manifests significant relationship to somatoform dissociative symptoms (r=-0.40; p=0.014). CONCLUSIONS: The result indicates relationship between HPA-axis reactivity and somatoform dissociative symptoms in unipolar depressive patients and suggests that somatoform dissociation presents a defense mechanism related to a passive coping response.

Interplay between the APOE Genotype and Possible Plasma Biomarkers in Alzheimer's Disease.

BACKGROUND: Alzheimer's disease (AD) is a progressive neurodegenerative disorder with a complex pathogenesis and a common occurrence of comorbid diseases such as depression. It is accepted that the presence of the ε4 allele of the gene that encodes apolipoprotein E (APOE) is the strongest genetic risk factor for the development of sporadic AD. Melatonin, cortisol, homocysteine, and prolactin are presumed to be risk factors or biomarkers for stress- and age-related disorders. OBJECTIVE: The interplay between the APOE genotype and plasma biomarkers was examined in patients with AD presenting with or without depression to contribute to understanding the interdependence of various molecular mechanisms in the pathophysiology of AD. METHOD: The APOE genotype and morning plasma melatonin, cortisol, homocysteine, and prolactin concentrations were measured in 85 patients with AD and 44 elderly controls. RESULTS: A significant association between AD and the allele (ε4) or genotype (ε3/ε4 or ε4/ε4) frequencies of APOE was confirmed. Plasma homocysteine and cortisol levels were significantly increased in patients with AD compared to those in controls, independent of the presence of comorbid depressive symptoms or the severity of dementia. Significantly lower plasma melatonin concentration was found in patients with AD but not in controls, who were noncarriers of the APOE ε4 allele, regardless of the presence of depression or the severity of dementia in AD. CONCLUSION: Our findings indicate the existence of a little-known specific APOE-mediated mechanism that increases the plasma melatonin level in a subgroup of patients with AD who are carriers of the APOE ε4 allele.

Suggestive evidence of erythropoietin level abnormality in patients with sporadic and familial cases of the restless legs syndrome.

BACKGROUND: The restless legs syndrome (RLS) is divided into two forms: idiopathic and secondary. About half the cases of the former are found to have a positive family history. The lack of objective and quantitative parameters in familial RLS also represents a drawback for genetic studies. We tried to find a feature distinguishing the sporadic from the familial forms of the RLS. METHODS: RLS patients were examined for clinical picture and laboratory markers including erythropoietin levels. Patients with a priori known causes of secondary RLS, were excluded. All biochemical and hematological parameters were standardized for sex and age groups relative to the population mean and standard deviation. RESULTS: In our set of 311 patients (65.3% women, mean age 54.6 years, SD 14.7 years) 96 reported positive family history (64.6% women, mean age 53.1 years, SD 15.8 years). We found a significantly lower age at the onset of RLS symptoms in familial cases (mean 29.3 vs. 44.0, Z 5.9, p<0.0001), and, in sporadic cases, a significantly lower absolute count of red blood cells (Z -2.02, p=0.043 respectively). Erythropoietin levels in the familial cases were significantly lower than in the reference population (median -2.26 SDs from the mean). None of the other parameters were significantly different between the groups. CONCLUSIONS: Our results confirm previously published lower age at symptom onset in familial RLS and provide the first evidence of lower erythropoietin levels in RLS patients. These observations might help to identify the specific phenotype for genetic association studies.

Chaotic neural response during conflicting Stroop task reflects the level of serum cortisol in patients with unipolar depression.

OBJECTIVE: According to recent findings detecting a cognitive conflict is related to activation of anterior cingulate cortex (ACC) and central autonomic network. Several recent findings also suggest the hypothesis that the cognitive conflict is related to specific nonlinear chaotic changes of the neural signal. This conflict related activation elicits autonomic responses which can be assessed by psychophysiological measures such as heart rate variability calculated as beat to beat R-R intervals (RRI). METHOD: The present study used Stroop word-colour test as an experimental approach to psychophysiological study of cognitive conflict in connection with RRI measurement, assessment of serum cortisol and calculation of largest Lyapunov exponents in nonlinear data analysis of RRI time series in 30 patients with unipolar depression. RESULTS: Significant correlation -0.45 (p<0.01) between largest Lyapunov exponents during conflicting Stroop task and serum cortisol levels has been found. CONCLUSIONS: The study indicates that a defect of neural inhibition during conflicting Stroop task is closely related to decreased serum cortisol levels which probably reflect defense psychological mechanisms.

Evening and morning plasma levels of protein S100B in patients with obstructive sleep apnea.

OBJECTIVE: Responsible for sleep brain perfusion changes, obstructive sleep apnea (OSA) constitutes a cardiovascular risk. To find out about any diffuse damage to the brain tissue, we studied the S100B protein, whose serum level is known to rise in stroke and craniocerebral trauma. METHODS: 60 men (mean age 51.7+/-11.8 years) referred to us for OSA without any major comorbidity were examined polygraphically. S100B was determined with electrochemiluminiscence immunoassay (ECLIA) from evening and morning blood samples. RESULTS: All sixty men were diagnosed with OSA. The difference between the evening level of S100B 0.068+/-0.030 microg/l and the morning level 0.059+/-0.029 microg/l was significant (p=0.0004). Patients with mild OSA were found to have the evening S100B 0.063+/-0.023 microg/l, the morning level 0.042+/-0.012 microg/l, the difference being significant (p=0.00051). In moderate OSA the difference between the evening -0.070+/-0.017 microg/l and morning levels -0.055+/-0.025 microg/l was less significant (p=0.043). In severe OSA no difference was found between the evening and morning concentrations of S100B (0.070+/-0.036 microg/l and 0.070+/-0.031 microg/l respectively). The difference between the evening and morning S100B levels correlated negatively with AHI and ODI and positively with basal saturation and average minimal oxygen saturation. CONCLUSIONS: Sleep with signs of severe OSA influences S100B protein release.

Depression, prolactin and dissociated mind.

OBJECTIVES: Usual neuroendocrinological manifestation of traumatic stress and dissociation is dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis. The aim of the present study is to perform examination of HPA axis as indexed by basal serum prolactin and test its relationship to dissociative symptoms and symptoms of traumatic stress. PATIENTS AND METHODS: 25 inpatients treated at the university hospital with diagnosis of unipolar depression mean age 41.23 (SD=11.53) were assessed using psychometric measures of dissociation (DES) and traumatic symptoms (TSC-40), and using standard biochemical analytical methods basal serum prolactin levels were investigated. RESULTS: Data show that prolactin manifests significant relationship to dissociative symptoms (r=0.52, p=0.004). Significant correlation was not found between prolactin and traumatic symptoms measured by TSC-40 (r=0.31, p=0.07). CONCLUSIONS: The present data suggest that serum prolactin levels in unipolar depressive patients are related to dissociative symptoms that is likely caused by passive coping mechanisms leading to dissociation.

Long-term treatment for hyperphenylalaninemia and phenylketonuria: a risk for nutritional vitamin B12 deficiency?

PURPOSE: The objective of the study was to determine the incidence of vitamin B12 deficiency in patients under long-term treatment for phenylketonuria (PKU) and hyperphenylalaninemia (HPA), as well as its associations with B12 vitamin parameters (holotranscobalamin - active vitamin B12, serum folate, total plasma homocysteine, and plasma methylmalonic acid concentration). PATIENTS AND METHODS: The group consisted of 51 PKU (n=29) and HPA (n=22) patients aged 3-48 years (28 children, 23 adults). RESULTS: A significant difference in serum folate levels was discovered between adult HPA patients and PKU patients (p=0.004, Mann-Whitney U-test). A significant difference in plasma homocysteine concentrations within the normal levels (p=0.032, χ2-test) was detected between adult HPA and PKU patients. In the group of adults, we also found significant differences in serum holotranscobalamin concentrations regarding both concentration levels and the proportion of patients with concentrations within the normal levels (p=0.031, Mann-Whitney U-test; p=0.006, χ2-test). CONCLUSION: We have proven that adult patients with PKU and HPA are at risk of vitamin B12 nutritional deficiency. The most effective parameter for these adults is the monitoring of holotranscobalamin in the serum.

Asbestos exposure and antineutrophil cytoplasmic Antibody (ANCA) positivity.

The authors used indirect immunofluorescence to examine the association of antineutrophil cytoplasmic antibodies (ANCAs) with exposure to asbestos among 61 asbestos-exposed patients (mean exposure = 24.6 yr) and 39 nonexposed controls. ANCA positivity was detected significantly more frequently (p = 0.034) in the asbestos-exposed group (21.3%) than in the control group (5.1%). ANCA-associated diseases did not occur more frequently among subjects exposed previously to asbestos than among unexposed controls. These findings confirmed that exposure to asbestos is another occupational factor, as is silica exposure, that is associated with ANCA positivity. The influence of asbestos appears stronger than that of silica because ANCA positivity was found among subjects who had histories of exposure to asbestos but who did not exhibit typical radiographic signs of asbestosis on their chest x-rays. Additional stimuli may be necessary to induce systemic vasculitis in asbestos-exposed persons.