Volume 21, Issue 1

Neopterin is produced by monocytes and is a biomarker for inflammation. We recently found that neopterin induces stromal cells to produce cytokines that suppress erythropoiesis in the bone marrow of mice. Despite this suppression, the peripheral hematocrit values are not decreased. The goal of the present study was to determine whether the maintenance of hematocrit values is caused by a neopterin-induced acceleration of extramedullary erythropoiesis. We examined the effects of intravenously injected neopterin on splenic erythropoiesis in C57BL/6J mice and found a marked increase (259% of the pretreatment level) in the number of splenic erythroid progenitor cells (BFU-E and CFU-E) after a slight temporal decrease in the number of erythroid progenitor cells. These results suggest that neopterin increases splenic erythropoiesis to compensate for the suppression of erythropoiesis in the bone marrow, resulting in the maintenance of hematocrit levels in peripheral blood.

Increased neopterin concentrations are observed in many diseases in which cellular immunity is stimulated. Gastroenteritis is still a major cause of childhood morbidity and mortality worldwide. Over 75% of all cases are caused by viral infections. Therefore a non-specific, quick, sensitive, cheap and easy-to-perform marker of viral infection, such as neopterin concentration in serum, would be a cost-effective method of identifying patients with gastroenteritis into probable viral etiology and therefore it would optimize treatment and reduce inappropriate antibiotic treatment. This study evaluated whether serum neopterin concentration can be a reliable marker of viral etiology of gastroenteritis in children. The study group consisted of 67 children: 29 girls and 38 boys, aged from 0.1 to 16.1 years with symptoms of gastroenterits and with confirmed rotavirus or adenovirus infection; the control group consisted of 105 healthy children. Clinical examinations and laboratory test including whole blood count, serum C-reactive protein, procalcitonin, and creatinine concentration were conducted. The serum neopterin level was analyzed by Elisa. Serum neopterin concentration in the study group varied from 6.03 to 171 nmol/L (median 23.7 nmol/L) and it was significantly higher than in the control group (from 2.88 to 14.8 nmol/L; median 4.73 nmol/L) (P <0.001). Neopterin concentration was above the normal value (>11 nmol/L) in 58 children from the study group and only in 6 from the control group (86.6% sensitivity and 94.3% specificity). Serum neopterin concentration did not differ significantly between children with rotavirus and adenovirus infection (P = 0.47). The correlation between serum neopterin and C-reactive protein concentrations was of borderline significance (rs = 0.23, p = 0.06); and there was no correlation between serum concentrations of neopterin and procalcitonin, white blood count, lymphocytes count, monocytes count or the body temperature. Serum neopterin concentration is highly increased in children suffering from viral gastroenteritis, regardless of the virus type. When a cut-off of 11.0 nmol/L neopterin was applied, comparison yields 86.6% sensitivity and 94.3% specificity for the diagnosis of viral gastroenteritis in pediatric patients. Further studies are necessary for other etiological agents of gastroenteritis.

The aim of the study was to determine folate reserve in patients with thyroid and breast diseases. Erythrocyte folate concentrations of ninety-eight patients and thirty healthy subjects were determined by a modified microbiological assay. An increase in folate levels was observed in of both thyroid (n = 15) and breast (n = 22) cancer patients compared to controls, while a decrease was observed in benign breast disease patients (n = 24) compared to both control group and breast cancer patients. Patients with benign thyroid diseases (n = 37) had significantly lower folate concentrations as compared to both control and thyroid cancer groups. The results pointed out the elevated erythrocyte folate levels in the patients with malignant tumors.

The treatment of diabetes mellitus type 1 is a major challenge in health care. The diabetes associated antigen Glutamic Acid Decarboxylase (GAD 65) has been described as strictly intracellular. However an intracellular antigen would never have access to the immune system. In a previous study with the high sensitive fluorescence correlation spectroscopy (FCS), we detected the GAD 65 antigen in the sera of patients with type 1 diabetes and related autoimmune diseases. FCS is a time consuming measurement procedure and very sensitive to disturbance, which makes unsuitable for a routine screening of the patient sera for GAD 65. Since the measured GAD 65 concentrations were surprisingly high (2.65 microgram/ml) and therefore within the detection range of less sensitive methods, in this study we used the SELDI-TOF (Surface enhanced laser desorption ionisation - time of flight) technique to confirm the FCS results in view of an early diabetes diagnosis. For this purpose we developed an array with the SELDI-TOF method and analysed 4 patient sera (2 diabetes and 2 controls) in a pilot experiment. For one diabetes serum, we found some evidence for the diabetic antigen GAD 65 in the mass spectra in a peak close to albumin with a molecular weight of 65 kDa. The 3 other samples remained negative. Because of the higher concentration of albumin in the sera, a peak evaluation in regard of GAD 65 was difficult and not reliable in this setup. Troubles and experiences with SELDI-TOF for the detection of GAD 65 are discussed.

Biopterin as a stable metabolite is produced by oxidation of 5,6,7,8-tetrahydrobiopterin (BH4). It is known that many diseases may cause changes in BH4 concentration and/or dihydropteridine reductase (DHPR) enzyme activity. There is only a limited number of studies correlating DHPR activity in malignancies. The main goal of the present study was to evaluate alterations in the DHPR activity and biopterin levels in patients with breast and thyroid cancers. The breast cancer patients (n=24) were compared to patients with benign breast diseases (n=19) and controls (n=30). In addition; the patients with thyroid cancer (n=17) were compared to patients with benign thyroid diseases (n=42) and the control group. We did not observe any significant difference between the benign disorders and the malignancies. Biopterin concentrations in patients with benign and malign thyroid and breast diseases were lower than the controls (all p <0.05). DHPR activities in thyroid diseases were significantly higher than the controls while insignificant decreases in DHPR activities in breast patients were detected. Our results suggested significant alterations in unconjugated pteridine pathway in thyroid and breast disorders.

1',2'-Di- O -acetyl- N2 -( N,N -dimethylaminomethylene)-3-[2-(4-nitrophenyl)ethyl]neopterin (1) was prepared from neopterin in 5 steps. Glycosylation of 1 with methyl 2,3,4-tri- O -benzoyl-α-D-glucopyranosyluronate bromide in the presence of silver triflate and tetramethylurea afforded the corresponding 3'- O -(methyl β-D-glucopyranosyluronate) neopterin derivative (2) in 64% yield. The first synthesis of 3'- O -(β-D-glucopyranosyluronic acid)neopterin was achieved by successive removal (4 steps) of the protecting groups of 2.

Bevacizumab, monoclonal antibody targeting vascular endothelial growth factor, is effective in different tumors, including colorectal carcinoma, non-small cell lung cancer, renal cell carcinoma and breast cancer. Increased serum or urinary concentrations of neopterin, an indicator of systemic immune response, have been described in patients with tumors of different primary locations, and further increase has been observed during anticancer therapy. An increase of urinary neopterin has been described after administration of cytokines, cytotoxic chemotherapy, or external beam radiation, but less is known about the effects of targeted agents on systemic immune response. We have studied serum homocysteine, C-reactive protein, α-tocopherol and retinol, and urinary neopterin in patients with metastatic breast cancer treated with bevacizumab, taxane and carboplatin. Homocysteine and C-reactive protein were determined immunochemically. α-tocopherol, retinol and urinary neopterin were determined by high performance liquid chromatography. Homocysteine, C-reactive protein and urinary neopterin decreased, while retinol and α-tocopherol increased during the therapy. In conclusion, the treatment of patients with metastatic breast cancer with bevacizumab, taxane and carboplatin resulted in the suppression of systemic inflammatory and immune response. The suppression of systemic inflammatory and immune response was associated with an increase in serum vitamin concentrations.

Bovine colostrum (BC) is the early thick yellow fluid produced by cows during the first several days after birth of the calf. BC is different from "mature" milk as it contains nutrients and immune factors, which strengthen the immune system of the newborn calf in its first week of life. BC has a long history of use in traditional medicine throughout the world and is currently also used in a topical cream for the treatment of immuno-related skin problems such as atopic dermatitis or psoriasis. However, despite a large amount of literature concerning the properties of human or bovine colostrum, there are only few reports on the effects of colostrum on the human immune system. In this study, the effects of cross-linked BC containing hyaluronic acid on the T-cell/macrophage interplay were investigated in human peripheral blood mononuclear cells (PBMC) and the results were compared with the effects of euxyl 9010, which was used to preserve the BC ingredients. The cross-linked BC preparations showed significant immunomodulatory effects on unstimulated and phytohaemagglutinin (PHA)-stimulated human PBMC by modulating tryptophan degradation and formation of neopterin in a biphasic manner. These results could be relevant for some of the beneficial effects of BC observed in the treatment of skin lesions of patients with atopic dermatitis or psoriasis. However, additional studies are needed to confirm the first positive results obtained in patients.

The aim of the present study was to explore the influence of age and gender, on the association between the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and plasma total homocysteine (tHcy) concentrations in patients with cardiovascular disease (CVD). Fasting tHcy and the MTHFR C677T mutation were evaluated in 98 patients with CVD, 46 were men and 52 women (aged 20-96 years). There was a significant elevation of plasma tHcy with age (<45 yr: 33.9 μmol/L vs. >75 yr: 43.6 μmol/L; p <0.01). The mean tHcy concentration increased significantly with age in men (<55 yr: 33.4 μmol/L vs. >55yr: 42.45 μmol/L; p 0.01). However, the plasma tHcy was not increased with older age in women. The frequency of the TT genotype was 19.6% in the younger patients group (>55 yr) compared with 4.7% in the older patients group (>55 yr; p <0.01). In conclusion, the data presented here are consistent with genetic factors that influence tHcy levels being more prominent in old patients (>55 yr). Then, the MTHFR mutation does not seem to be associated with either high tHcy or the occurrence of CVD.

In Helicobacter pylori seropositive individuals, the subsequent risk of non-cardia gastric cancer development is frequently attributed to the infection agent. Although the link between inflammation and gastric cancer is formally recognized, the molecular basis of evading mechanisms of Helicobacter pylori from host immune system remains unclear. The aim of this study was to determine the effect of systemic factors in gastric cancer patients such as serum kynurenine to tryptophan ratios, neopterin, nitric oxide and urinary biopterin levels which may sustain the persistence of Helicobacter pylori seropositivity. This prospective randomized study involved 95 adults with gastric cancer and 108 cancer free patients with extradigestive diseases. Each group was assigned into two subgroups according to Helicobacter pylori IgG seropositivity. Exposure to Helicobacter pylori was detected by serum IgG test (ELISA). Serum tryptophan, kynurenine, neopterin and nitrite concentrations were measured. In simultaneous urinary samples, neopterin, biopterin, and creatinine levels were assayed. Significant decreases were found in serum tryptophan levels of both Helicobacter pylori seronegative and seropositive gastric cancer patients versus controls without malignant disease. However, marked increase in kynurenine/tryptophan was observed only in Helicobacter pylori seropositive cancer patients. Highly significant correlation between the serum neopterin and kynurenine/tryptophan indicated interferon gamma stimulated tryptophan degradation. Decrease in serum nitrite levels, and a parallel increase in urinary biopterin concentrations in Helicobacter pylori seropositive cancer cases might result from the excessive nitric oxide consumption due to reactive oxygen radical overproduction. Significantly higher kynurenine to tryptophan ratio and its correlation with increased neopterin levels suggested a role of tryptophan-degrading enzyme indoleamine 2,3-dioxygenase (IDO) and that persistence of Helicobacter pylori seropositivity might participate in enhanced immune tolerance of cancer patients.