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Cystic changes of the thyroid remain a diagnostic dilemma with regard to malignancy due to insufficient information gained by fine needle aspiration, sonography and routine nuclear medicine procedures. As complementary soluble parameters we measured neopterin and thyroglobin levels in cyst fluids and in serum of 81 patients with disorders of the thyroid. Based on clinical, cytological and histological information, patients were divided into five groups. (I): Serous cysts (n=41), (II): hemorrhagic cysts (N=18), (III): cysts ' with evidence for inflammation clinically or by histology (n= 11), (IV): malignancy in cysts by histology (n = 6), (V): cysts containing "honey" like, brownish fluid of high viscosity (n = 5). Neopterin concentration in cyst fluids vs. serum in group (I) were not different, 8.8± 4.3 nmol/l in vs. 6.67± 3.34 nmol/l. In groups II-V neopterin concentration in cysts were higher than in serum, (II): 21.1 ± 18.7 nmol/l vs. 5.6± 2.56 nmol/l, (III): 30.6± 24.9 nmol/l vs. 6.1 ± 2.9 nmol/l, in (IV): 35± 23.5 vs. 10.98± 7.0 nmol/l and (V): 36.0± 23.9 vs. 5.9± 3.32 nmol/l respectively. In patients with proven benign histology at surgery, neopterin levels in cystic fluid were significantly lower than in cysts harbouring malignancy, 8.5±4.6 vs. 35.4±23.5 (Z=3,17, p=O. 0015). There were no significant differences between groups II, III IV and V regarding neopterin concentrations in cysts. Elevated serum neopterin levels were observed in 2/6 patients with aggressive thyroid cancer (group IV). However, average neopterin concentrations in serum of patients of group IV were not higher than in 15 patients from group I with benign histology (P=O.l). Significantly lower levels of thyroglobin in cyst fluid were found in group V ("honey" cysts) in comparison to all other groups pooled, 2.67± 1.82 f..lg/rnl vs. 6.76± 3.97 f..lg/ml, (Z=2.l5, p=0.031), four of five cysts in group V resolved after fine needle aspiration. We found no correlation between thyroglobin levels in cyst fluid and in serum.

Neopterin is released from human monocyte-derived macrophages preferentially upon stimulation with the Thlcell cytokine interferon-γ. In humans, increased concentrations of neopterin in serum and urine have been found in viral infections including human immunodeficiency virus type 1, various malignant disorders, autoimmune diseases and during allograft rejection episodes. In order to find additional parameters which might influence neopterin production, serum neopterin concentrations of 1156 blood donors were compared with other parameters routinely determined in blood transfusion. There existed correlations between serum neopterin concentration and blood donors' age (Spearman's rank correlation: rs = 0.259, ρ

We have evaluated a new commercially available enzyme-linked immunorsorbant assay for neopterin :or its suitability in the context of screening of voluntary blood donors. The assay was performed on 1040 consecutive blood donors, and compared with radioimmunoassay and. in a fraction of 142 donors . . : Iso with high performance liquid chromatography. On repetitive assays of all donations showing a concentration exceeding 8.0 nmol/L in the initial assay. three of the radioimmunoassay results were identified as gross outliers. No such gross outliers were detected for the enzyme-linked immunosorbant assay. RegarJing the reproducibility of results exceeding a cut-off limit of \0 nmol/L neopterin. the enzyme-linked ;mmunosorbant assay was better than the radioimmunoassay. Moreover. the enzyme-linked immunosorbant assay was slightly superior to radioimmunoassay when both tests were compared with high performance liquid chromatography (based on linear regression analysis. evaluation of frequencies of concentrations bant assay was slightly superior to radioimmunoassay when both tests were compared with high performance liquid chromatography (based on linear regression analysis. evaluation of frequencies of concentrations rations. Its slight superiority compared to the conventional radioimmunoassay likely results from the higher degree of automatization employed.

Objectives: An HPLC method was developed to quantify serum concentrations of phenylalanine and tyrosine simultaneously using fluorescence detection without derivatization., Methods: Serum protein is precipitated with trichloroacetic acid, 0.015mM dihydrogen-phosphate solution is used for separation on reversed-phase C18 material, and acetonitrile is avoided. Both amino acids are monitored utilizing their natural fluorescence at 210nm excitation and 302nm emission wavelengths., Results: One analytical run is completed within 7min. Lower detection limit for Phe and Tyr is 0.3μM. Comparison of the new method with a classical HPLC method for total amino acids and using UV-absorption detection reveals a highly significant relationship for Phe and Tyr., Conclusion: The new HPLC method allows rapid and very sensitive measurement of phenylalanine and tyrosine concentrations., (© 2013. Published by Elsevier Inc. on behalf of The Canadian Society of Clinical Chemists. All rights reserved.)

Background: Acute virus infections are indicated by increased serum neopterin concentrations. Testing of blood donations for increased neopterin was introduced in the Austrian Tyrol in 1986 and throughout Austria in 1994 to improve the safety of blood transfusions. Radioimmunoassay (RIA) was the first available test, and the 98th percentile for neopterin concentrations from 76,500 donations was defined as the cut-off threshold, excluding donations with neopterin >or=10 nmol/L. When ELISAs were introduced on fully automated test systems to measure neopterin concentrations, results were generally higher and the cut-off was adjusted up to 12 nmol/L., Methods: In early 2006, new equipment (Hamilton Microlab Star pipettor + Dade Behring ELISA Processor III, BEP III) became available which monitors sample and reagent volumes for each uptake and dispense, and takes the viscosity of the fluids into account. Using this system, the performance of neopterin determinations was evaluated over 21 months and compared to earlier data., Results: When the new apparatuses were introduced, an immediate decrease in mean neopterin concentrations and the percentage of samples with neopterin concentrations >or=10 nmol/L was observed. The 55,516 measurements performed in 2007 showed a mean value of 5.5 nmol/L. Neopterin in 680 donations (1.23%) were >or=10 nmol/L., Conclusions: The new Hamilton diluter increased the accuracy of the neopterin test procedure. Results are now identical with those of RIA and ELISA when run in a semi-automated manner. Differences in pipetting performance of standards and samples are considered as one possible explanation for the earlier discrepancies seen with the automated apparatus.

Serum neopterin concentrations were determined in 20,000 blood donations. For the 400 donations with neopterin concentrations above the 98 th percentile and another 1200 donations with neopterin concentrations in the lower range, results of human parvovirus (HPV) B19 tests were compared. Infectious specimens were identified by dot blot hybridization assay and polymerase chain reaction (PCR) that used the outer primers and detected 1 pg of HPV B19 DNA, corresponding to approximately 10(5) copies of the genome, in the specimens and by a nested PCR that detected 1-10 fg of DNA, corresponding to 10(2)-10(3) copies of the genome. Of 400 specimens with neopterin concentrations > or =12 nmol/L (98th percentile, current cutoff), 10 tested positive by dot blot hybridization assay (9 of these were confirmed by nested PCR). Among 1200 specimens with low neopterin concentrations (<12 nmol/L), no specimen containing HPV B19 DNA was detected. These findings suggest an association between elevated neopterin concentrations and HPV B19 infectivity.

A high percentage of HIV-1-infected infants and children in Romania are coinfected with hepatitis B virus. Little information is available on the impact of concurrent hepatitis B infection on the course of HIV-1 infection. We conducted a prospective cohort study over 1 year in a group of 68 HIV-1-infected infants and children to determine whether hepatitis B surface antigenemia, neopterin, and beta 2-microglobulin (B2M) predicted death. Among the 44 hepatitis B surface antigen-positive (HBsAg+) subjects at enrollment, 13 (30%) died during 1 year of follow-up. In comparison, two of 24 (8%) HBsAg-negative subjects died (RR = 7.7; p = 0.05). Higher initial serum concentrations of neopterin and B2M were negatively associated with survival. After stratifying by baseline clinical evidence of HIV-related disease, survival was negatively associated with HBsAg+ status (p = 0.04) in 33 children in stage P-2, adjusting for age, serum neopterin, and serum B2M levels. The results of this study suggest that serum neopterin is a marker for severity of clinical illness and that HBsAg+ status increases the mortality rate among children with clinical evidence of HIV infection.

Human endogenous retrovirus (HERV) K is present in about 50 copies in the human genome and transcription of HERV-K has previously been detected in several tumor cell lines as well as in peripheral blood lymphocytes from healthy donors. By means of immunoblotting we investigated the presence of antibodies recognizing recombinant HERV-K-envelope outer membrane constructs in different serum collectives. A total of 12.6% of sera obtained from normal blood donors was found positive. In serum collectives from breast carcinoma patients, HIV-1-positive individuals, and persons with cytomegalovirus infections no significant difference from the normal blood donor serum collective could be observed. Only a group of persons with a repeatedly raised serum neopterin concentration (> 10 nmol/liter) of unknown cause (HIV and hepatitis B and C virus infections were excluded) showed a significant higher percentage of HERV-K-outer membrane envelope-positive sera (21%). Furthermore we could observe a parallel HIV-1/HERV-K seroconversion, which probably is not due to an HIV-1/HERV-K-outer membrane envelope cross-reactivity. Possible implications of these findings are discussed.

Serologic markers of immune activation, neopterin and beta-2-microglobulin (B2M), have been shown to predict progressive human immunodeficiency virus type 1 (HIV-1) disease based on cohort studies in adults. Both parameters appear also to be valuable in distinguishing HIV-1 infants with progressive disease from asymptomatic infants and HIV-1 seronegative infants. In a cross-sectional study we examined the utility of neopterin and B2M testing in 135 infants of an orphanage in Romania, 69 of the infants (51%) were found to be HIV-1 antibody seropositive; 95% of the 135 infants were either hepatitis B virus (HBV) antigen or antibody seropositive. In the HIV-1 seronegative infants B2M was higher in those with HBV antigenaemia. Serum neopterin and B2M concentrations were higher in HIV-1 seropositive than in seronegative infants (p = 7 x 10(-12) and 1 x 10(-6)). Children with CDC stage P2 had only slightly higher neopterin and B2M values as compared to stage P1 (P = 0.04 and 0.08). Our study indicates that measurement of neopterin and B2M is useful to monitor HIV-1 infection, particularly in areas where laboratory facilities are limited. Both parameters continue to be associated with HIV-1 infection even when there is a high background rate of other infections.

The homage of 135 abandoned children in the city of Resita, south west Rumania, has been checked by a medical team from the University of Innsbruck for social, clinical and hyginical situation. The local government had applied for such an investigation. Most of the infections and other diseases are based on a dramatically bad hygienical situation. 52% of checked sera were HIV positiv by RIA and Western Blot, moreover 60% Hepatitis B antigen positiv. We assume a high rate of horizontal transmission of the HIV virus. One of the main clinical symptoms was maternal-deprivation syndrome, with an incidence of 80%. Consequences in personal policy of the homage as well as medical strategies have to follow.