Changes of cytokine profiles during electroconvulsive therapy in patients with major depression.

OBJECTIVES: Electroconvulsive therapy (ECT) is an effective treatment of depression, but its mechanism of action still remains unknown. Some studies emphasize that epileptic seizures result in cerebral production of cytokines, including the cytokine network in association with the pathophysiology of depression. We hypothesized that depressed patients would show a dysregulated profile of peripheral cytokines before and after ECT treatment. METHODS: Fifteen hospitalized subjects with major depressive disorder were recruited. Human cytokine array IV was used to determine the profile of cytokines in the serum during the course of ECT. Positive results of the cytokine assay were verified by reverse transcriptase-polymerase chain reaction. Depressive symptoms were evaluated before and after ECT series. RESULTS: The signal intensity of eotaxin-3 and interleukin (IL)-5 changed statistically significantly between the first ECT and 24 hours after the last ECT. Furthermore, there were significant correlations between the signal intensities of eotaxin-3, bone morphogenetic protein 6, IL-5, and transforming growth factor-ß and the severity of depression. The results of Cytoray assays were confirmed partly by reverse transcriptase-polymerase chain reaction. The changes of tumor necrosis factor ß in pre-post comparison of ECT and the correlation of the Montgomery-Asberg Depression Scale score with tumor necrosis factor ß, IL-5, and bone morphogenetic protein 6 expression could be verified. Only the relative signal intensity of IL-16 correlated significantly with the clinically as well as electroencephalographically measurable seizure duration. CONCLUSION: Electroconvulsive therapy treatment seems to change the expression of various cytokines in relation to changes of affective states such as mood. Therefore, cytokines might play a specific role within the treatment and pathogenesis of affective disorders.

The influence of insulin infusion on the metabolism of amyloid ß peptides in plasma.

BACKGROUND: Accumulating body of evidence suggests pathophysiologic links between Alzheimer's disease and diabetes mellitus (DM). For example, the two crucial peptides playing a role in both degenerative disorders, amyloid ß (Aß) and insulin, are metabolized by the same enzyme, insulin degrading enzyme. Euglycemic hyperinsulinemic clamp is a method of estimating insulin sensitivity, based on the assumption that during steady-state hyperinsulinemic euglycemia, glucose infusion rate equals tissue glucose uptake, that is, the higher the glucose infusion rate, the higher the insulin sensitivity. OBJECTIVE: The aim of this study was to analyze the influence of insulin on the plasma concentrations of Aß peptides. METHODS: Blood samples were collected from 20 healthy young male volunteers before insulin infusion (clamp) and then at 120 and 360 minutes. In the second protocol, insulin was accompanied by Intralipid, which is mainly a mixture of triacylglycerols, and heparin, given as an activator of lipoprotein lipase, inducing insulin resistance. Analyses of plasma Aß1-42, Aßx-42, Aß1-40, and Aßx-40 were performed with multiplexing technology. Furthermore, concentrations of the Aß peptides in healthy persons were compared with those in 16 type 1 DM patients receiving chronic insulin therapy. RESULTS: When applied alone (i.e., without Intralipid), insulin infusion increased concentrations of Aß42 (full length and N-terminally shortened) but not of Aß40. When combined with Intralipid, infusion of insulin resulted in increased concentrations of all peptides (nonsignificant tendency in case of Aßx-40). We did not observe differences between Aß peptide concentrations in healthy subjects and those in type 1 DM patients. CONCLUSION: Infusion of insulin in nonphysiologic high doses increases plasma concentrations of Aß peptides; in case of Aß40, only when applied together with Intralipid, which perhaps might be explained by hypothetical shift of insulin degrading enzyme activity from degradation of Aß peptides to the degradation of insulin.

Multiplexing analysis of the polyspecific intrathecal immune response in multiple sclerosis.

Intrathecal synthesis of the antibodies specific to neurotrofic viruses: measles (M), rubella (R), Varicella-Zoster (Z), and/or H. simplex (H), known as "MRZH-reaction" plays important diagnostic role in multiple sclerosis (MS). Whereas the analysis of the oligoclonal IgG bands provides high sensitivity, the MRZH-reaction shows high specificity, and hence these methods complement each other. For the first time we applied multiplexing bead-based technology to simultaneously analyze cerebrospinal fluid (CSF) and serum concentrations of antibodies against these viruses, and to calculate the antibody specific indices (ASI's). The method shows reasonable precision: intra-assay, 2.9-6.7%, and inter-assay, 2.0-3.2%. The results are comparable with these obtained with other methods (ELISAs), including two runs of the certified external quality control schemes. Eighty-one percent of the MS cases (n=27) and none of the sex- and age-matched controls (n=14), except one subject with "borderline" anti-measles ASI of 1.5, showed intrathecal synthesis of IgG against at least one of the viruses discussed. The ratios of the MRZH-positive cases in the MS group were: 12/22 for M, 12/19 for R, 13/26 for Z, and 7/26 for H. We conclude that the multiplexing technology can be applied as a tool to study the intrathecal immune response in the diagnosis of MS.

Transient increase of plasma concentrations of amyloid ß peptides after electroconvulsive therapy.

BACKGROUND: Electroconvulsive therapy (ECT) is applied to effectively treat depressive episodes, and it can be considered an ideal model of generalized seizures induced and performed under precisely controllable conditions. OBJECTIVE: We hypothesize that ECT causes a transiently increased blood-brain barrier permeability. METHODS: We measured plasma concentrations of amyloid ß (Aß) peptides: 1-42, 1-40, x-42, and x-40 before ECT, within 30 minutes after 2, and 24 hours after ECT treatment in 33-36 sessions of n=13 different patients. RESULTS: We observed a significant increase of the plasma concentrations of all four peptides within 30 minutes after the ECT, followed by the normalization of the peptides concentrations 2 hours after the ECT. CONCLUSION: Different physiologic phenomena may be responsible for the transient increase of the Aß peptides concentrations in plasma shortly after ECT session, and further studies are necessary to explain these mechanisms. For example, decreased integrity of the blood-brain barrier permeability, an increased release from neurons due to their activation or increased release from peripheral sources, like thrombocytes or muscles, or a combination of different factors must be taken into consideration.

Preanalytical sample handling and sample stability testing for the neurochemical dementia diagnostics.

Preanalytical sample handling and storage procedures play an extremely important role in reliably measuring neurochemical dementia diagnostics (NDD) biomarkers: Aß(1-40), Aß(1-42), Tau, and pTau181. To test different handling and storage conditions, the following protocols were applied: (a) storage at room temperature for one week, (b) deep-freezing and thawing up to three cycles, (c) deep-freezing, thawing and keeping under +4°C for two days before the analysis, and (d) long-term stability of a deeply frozen sample. Between the first and the seventh day of the storage at room temperature, the percentage of the concentrations (compared to the starting concentrations) fluctuated: 104.3-105.3, 97.6-93.2, 100.6-96.8, and 97.9-90.2 for Aß(1-40), Aß(1-42), Tau, and pTau181, respectively. Re-freezing cycles resulted in the percentage fluctuations of the concentrations: 101.1-105.5, 95.4-99.7, 98.3-100.0, and 100.5-101.4 for Aß(1-40), Aß(1-42), Tau, and pTau181, respectively. Keeping previously frozen/thawed samples under +4°C for two days resulted in the percentage differences of the concentrations: +15.9, +2.2, -1.1, and -0.1 for Aß(1-40), Aß(1-42), Tau, and pTau181, respectively. During long-term stability, the coefficients of linear correlation (R(2)) were: Aß(1-40), 0.007; Aß(1-42), 0.02; Tau, 0.011; and pTau181, 0.02, and the corresponding inter-assay coefficients of variation: 13.9%, 13.9%, 11.0%, and 10.7% for Aß(1-40), Aß(1-42), Tau, and pTau181, respectively. We conclude that the NDD biomarkers are relatively stable when the cerebrospinal fluid sample is kept at room temperature for about four days; one or two thawing/refreezing cycles do not profoundly affect the biomarkers concentrations, however three cycles result in increased unsystematic variation. The four biomarkers seem to be stable in a sample stored deeply frozen for more than two years.

Cerebrospinal fluid leakage--reliable diagnostic methods.

Prompt diagnosis and early treatment of cerebrospinal fluid (CSF) leakage minimizes the risk of severe complications. In patients presenting with clear fluid nasal discharge it is important to identify the nature of the rhinorrhea. The CSF leakage may occur as post-traumatic, iatrogenic, spontaneous or idiopathic rhinorrhea. The differential diagnosis of CSF rhinorrhea often presents a challenging problem. The confirmation of CSF rhinorrhea and localization of the leakage may be diagnosed by CT, MRI cisternography and MRI cisternography in combination with single photon emission tomography or radioisotopic imaging. Although these methods allow estimation of the CSF leakage with high accuracy, they are expensive and invasive procedures. Therefore, biochemical methods are still used in the differentiation. Although the most common diagnostic method for screening CSF leakage is glucose oxidase, its diagnostic sensitivity and specificity is generally unsatisfactory. False negative results may occur with bacterial contamination and false positive results are common in diabetic patients. Glucose detection is not recommended as a confirmatory test. As such, other biomarkers of the CSF leakage, such as beta-2-transferrin (beta-2 trf) and beta-trace protein (betaTP) are necessary to identify and confirm of this condition.

Cerebrospinal fluid under non-steady state condition caused by plasmapheresis.

We present an unusual constellation of the CSF/serum biomarkers of Guillain-Barré syndrome caused by unsteady-state condition of protein diffusion induced by plasmapheresis. Low blood concentrations of immunoglobulins were accompanied by their normal concentrations in the CSF, and hence the corresponding CSF/serum quotients seemed 'increased' suggesting intrathecal humoral response. This was in contrast to the results of isoelectrofocusing showing identical IgG bands pattern in the CSF and serum. Control lumbar puncture performed 6 weeks after the cessation of plasmapheresis, revealed normalization of the immunoglobulins' quotients. It must be stressed that the results of the CSF/serum analysis performed under non-steady state condition may be easily misinterpreted, and only considering the whole pattern of the CSF/serum biomarkers can assure correct interpretation of the results.

Confirmation rate of blinded (99m)Tc-SPECT compared to neurochemical dementia biomarkers in CSF in patients with Alzheimer disease.

In Alzheimer disease, CSF biomarkers and nuclear imaging are of particular interest. Many studies investigated only one technique, limiting comparison. Here, in 76 patients blinded 99mTc-SPECT was compared to CSF. Sensitivity of CSF was 92%; and 51% for SPECT. Specificity favored SPECT (90 vs. 80%). Both techniques showed no coherence (p = 0.17-0.47). Our results confirm that CSF biomarkers show higher sensitivity. SPECT has higher specificity and can also be used for other dementias without established CSF biomarkers.

Intrathecal IgG synthesis in patients with alterations in the neurochemical dementia diagnostics.

Neurochemical Dementia Diagnostics (NDD), i.e., analysis of the cerebrospinal fluid (CSF) concentrations of amyloid-beta peptides and tau/phospho-tau proteins plays important role in the diagnosis of neurodegeneration and dementias. Several studies show alterations of these biomarkers in Alzheimer's disease (AD), however, only a few reports address alterations of other CSF biomarkers (albumin and immunoglobulins' quotients, cell count, lactate concentration, etc.) in the pathophysiology and diagnostic procedures of dementias. Therefore, we analyzed these biomarkers in patients diagnosed for dementia syndromes and carefully characterized with the state-of-the-art NDD analysis: Abeta1-42, Abetax-42, Abetax-42/x-40 ratio, tau, and ptau181. We found intrathecal IgG synthesis in 5 out of 112 patients showing alterations of the NDD biomarkers, and in four out of these five subjects, we could not find any satisfying reason for the intrathecal humoral response. In 25.9% of the patients with altered NDD biomarkers, we found an increased albumin quotient indicating a dysfunction of the blood-CSF barrier; however a similar figure of 25.2% was found in the group of patients without alterations in the NDD. Our findings suggest that at least some patients with increased CSF concentrations of tau/ptau proteins and decreased concentrations of Abeta{42} peptides show simultaneously CSF alterations found otherwise in neuroinflammatory processes. This, in turn, suggests that extended diagnosis should be performed in patients with "isolated" alterations of NDD biomarkers or intrathecal immunoglobulin synthesis.

Neurochemical dementia diagnostics: a simple algorithm for interpretation of the CSF biomarkers.

Cerebrospinal fluid (CSF)-based neurochemical dementia diagnostics (NDD) is a well-established diagnostic tool for neurodegenerative disorders, including Alzheimer's disease (AD). However, the direct comparison of the concentrations of the biomarkers between laboratories is often very misleading, due to relatively high inter-laboratory discrepancies of normal/abnormal ranges (cutoff values). Therefore, an interpretation tool might be useful for centers performing NDD to facilitate a standardized, diagnostic-oriented reporting of the data on biomarkers. In this study, we present a simple, easy-to-implement algorithm allowing diagnostic-relevant categorization of patients according to the outcome of the CSF NDD results and, correspondingly, enabling reporting of the data to clinicians in a clear and easy-to-follow form. The algorithm is flexible and cutoff values independent, meaning each laboratory can easily supplement it with the cutoff values and normal/abnormal ranges according to the needs; the only prerequisite is to perform the standard CSF NDD assays (amyloid beta peptides and Tau/pTau).

Neurochemical dementia diagnostics: assays in CSF and blood.

In this review, current neurochemical dementia diagnostics (NDD) procedures are presented with a focus on biomarkers in the cerebrospinal fluid (CSF) and blood: amyloid beta peptides, tau protein, and its phosphorylated form (pTau). CSF analysis is an increasingly important tool for early and differential diagnosis of dementia syndromes. Although lumbar puncture is a mildly invasive procedure with a low incidence of complications, establishing blood assays capable of reliably measuring NDD biomarkers is an aim of several studies worldwide.

Amyloid beta peptide ratio 42/40 but not A beta 42 correlates with phospho-Tau in patients with low- and high-CSF A beta 40 load.

Neurochemical dementia diagnostics (NDD) can significantly improve the clinically based categorization of patients with early dementia disorders, and the cerebrospinal fluid (CSF) concentrations of amyloid beta peptides ending at the amino acid position of 42 (A beta x-42 and A beta 1-42) are widely accepted biomarkers of Alzheimer's disease (AD). However, in subjects with constitutively high- or low-CSF concentrations of total A beta peptides (tA beta), the NDD interpretation might lead to erroneous conclusions as these biomarkers seem to correlate better with the total A beta load than with the pathological status of a given patient in such cases. In this multicenter study, we found significantly increased CSF concentrations of phosphorylated Tau (pTau181) and total Tau in the group of subjects with high CSF A beta x-40 concentrations and decreased A beta x-42/x-40 concentration ratio compared with the group of subjects with low CSF A beta x-40 and normal A beta ratio (p<0.001 in both cases). Furthermore, we observed significantly decreased A beta ratio (p<0.01) in the group of subjects with APOE epsilon 4 allele compared with the group of subjects without this allele. Surprisingly, patients with low-A beta x-40 and the decreased A beta ratio characterized with decreased pTau181 (p<0.05), and unaltered total Tau compared with the subjects with high A beta x-40 and the A beta ratio in the normal range. We conclude that the amyloid beta concentration ratio should replace the 'raw' concentrations of corresponding A beta peptides to improve reliability of the neurochemical dementia diagnosis.