Diagnostic performance and therapeutic impact of LightCycler SeptiFast assay in patients with suspected sepsis

Rapid and reliable identification of pathogens is very important in the management of septic patients. We retrospectively evaluated the diagnostic accuracy and clinical utility of a multiplex real-time polymerase chain reaction (PCR) assay (SeptiFast (SF)) in patients with suspected sepsis in a tertiary care hospital in Tallinn, Estonia. A total of 160 blood samples from 144 patients were included in the study. SF results were compared with corresponding blood culture (BC) results. The concordance between SF and BC was 78.8%. The rate of positive results was significantly higher in SF than in BC (33.7% vs. 21.2%, respectively; p < 0.001). A total of 27 samples were found positive by both SF and BC, 27 by SF only, and seven by BC only. Of a total of 83 microorganisms detected SF identified 71, and BC 42 (p < 0.001). SF detected markedly more patients with candidemia: 11 patients were detected by SF compared to four patients by BC. Antimicrobial treatment was changed in 21 (38.9%) of 54 SF positive cases. In conclusion, our results demonstrated the high diagnostic accuracy of SF in detection of sepsis pathogens. In conjunction with its impact on therapeutic decisions, SF proved to be a useful adjunct to conventional blood culture in the diagnosis of sepsis etiology.

Strategies to work with HLA data in human populations for histocompatibility, clinical transplantation, epidemiology and population genetics: HLA-NET methodological recommendations

HLA-NET (a European COST Action) aims at networking researchers working in bone marrow transplantation, epidemiology and population genetics to improve the molecular characterization of the HLA genetic diversity of human populations, with an expected strong impact on both public health and fundamental research. Such improvements involve finding consensual strategies to characterize human populations and samples and report HLA molecular typings and ambiguities; proposing user-friendly access to databases and computer tools and defining minimal requirements related to ethical aspects. The overall outcome is the provision of population genetic characterizations and comparisons in a standard way by all interested laboratories. This article reports the recommendations of four working groups (WG1-4) of the HLA-NET network at the mid-term of its activities. WG1 (Population definitions and sampling strategies for population genetics’ analyses) recommends avoiding outdated racial classifications and population names (e.g. ‘Caucasian’) and using instead geographic and/or cultural (e.g. linguistic) criteria to describe human populations (e.g. ‘pan-European’). A standard ‘HLA-NET POPULATION DATA QUESTIONNAIRE’ has been finalized and is available for the whole HLA community. WG2 (HLA typing standards for population genetics analyses) recommends retaining maximal information when reporting HLA typing results. Rather than using the National Marrow Donor Program coding system, all ambiguities should be provided by listing all allele pairs required to explain each genotype, according to the formats proposed in ‘HLA-NET GUIDELINES FOR REPORTING HLA TYPINGS’. The group also suggests taking into account a preliminary list of alleles defined by polymorphisms outside the peptide-binding sites that may affect population genetic statistics because of significant frequencies. WG3 (Bioinformatic strategies for HLA population data storage and analysis) recommends the use of programs capable of dealing with ambiguous data, such as the ‘gene[rate]’ computer tools to estimate frequencies, test for Hardy–Weinberg equilibrium and selective neutrality on data containing any number and kind of ambiguities. WG4 (Ethical issues) proposes to adopt thorough general principles for any HLA population study to ensure that it conforms to (inter)national legislation or recommendations/guidelines. All HLA-NET guidelines and tools are available through its website http://hla-net.eu.

Survival role of superoxide dismutase 1 on human granulosa luteinized cells in vitro

OBJECTIVE

Deleterious effects of free radicals do not only result from the amount of free radicals produced but also are related to the efficiency and to the activities of enzymatic antioxidant systems. We investigated the effect of exogenous superoxide dismutase (SOD1) or Cu-chelating agent diethyldithiocarbamate (DDC) on the apoptosis (caspase-3 activity) of human granulosa luteinized cells (hGLC) in vitro.

METHODS

The effects of SOD1 and DDC were studied using in vitro culture system, caspase-3 and the total SOD activity in hGLCs were measured using AcDEVD-PNA substrate and Beaushap and Fridovich methods, respectively, after 48 h of the culture period.

RESULTS

The activity of SOD1 was the lowest in GLCs treated with 100 µM DDC as compared to control cells and to the cells supplemented with Cu, Zn-SOD or DDC (10 µM). The effect of DDC was associated with elevated caspase-3 activity as compared to control cells.

CONCLUSIONS

It was demonstrated for the first time that the supplementation of cultured hGLCs with Cu2+, Zn2+-SOD (200 U/ml) maintains the viability of hGLCs via caspase-3 suppression.

Immunogenetics of ageing

The ageing process is very complex. Human longevity is a multifactorial trait which is determined by genetic and environmental factors. Twin and family studies imply that up to 25% of human lifespan is heritable. The longevity gene candidates have generally fallen into the following categories: inflammatory and immune-related factors, stress response elements, mediators of glucose and lipid metabolism, components of DNA repair and cellular proliferation and mitochondrial DNA haplogroups. Because of the central role of HLA molecules in the development of protective immunity and the extraordinary degree of polymorphism of HLA genes, many studies have addressed the possible impact of these genes on human longevity. Most of the data available so far demonstrated a possible role of HLA class II specificities in human longevity but definitive evidence has remained elusive. Although the data are limited and controversial, it has been hypothesized that longevity could be associated with cytokine gene polymorphisms correlating with different levels of cytokine production, thereby modulating immune responses in health and disease. Because of the essential role of cytokines in immune responses, the regulation of cytokine gene expression and their polymorphic nature, the genetic variations of these loci with functional significance could be appropriate immunogenetic candidate markers implicated in the mechanism of successful ageing and longevity. In addition, several other genes such as Toll-like receptor genes, Cycloxygenases (COX)/Lipoxygenases (LOX), CCR5, NK receptor genes and MBL2 have been assessed as a possible biomarkers associated with ageing. This review will summarize the data on the role of these immune genes in human longevity.

'Immunogenetics of Aging': report on the activities of the 15th International HLA and Immunogenetics Working Group and 15th International HLA and Immunogenetics Workshop

'Immunogenetics of Aging' is a component that was first included in the 14th International HLA and Immunogenetics Workshop (IHIWS) and developed further within the 15th Workshop. The aim of this component was to assess the impact of human leukocyte antigen (HLA) genes, cytokine genes, and some innate immunity genes such as killer-cell immunoglobulin-like receptors (KIRs) and mannose-binding lectin 2 (MBL2) in successful aging and their contribution to the better understanding of immune dysfunction in old age. Within the 15th IHIWS new populations were included in the analysis. Additional cytokine gene polymorphisms were assessed and innate immunity genes were analyzed for possible relevance in longevity. The results showed that longevity might be associated with anti-inflammatory cytokine gene profiles, decreased frequency of interleukin-10 (IL-10) and transforming growth factor-B1 haplotypes associated with a low level of gene expression, and increased frequency of haplotypes determining a high level of expression. Extended tumor necrosis factor-A and IL-12B genotypes were also likely relevant to longevity. Data also showed that innate immunity genes are associated with susceptibility to infections in the elderly and showed that these genes might be an important genetic marker in aging. Decreased frequencies of KIR2DS5 and A1B10 haplotypes, and an increased proportion of MBL2-deficient haplotypes were found in the group with higher cytomegalovirus-specific IgG antibody levels. Together, these studies emphasize the relevance of genes regulating immune functions in maintaining human longevity and stress the importance of further clarifying their impact on successful aging.

Hormones of hypothalamic-pituitary-thyroid axis are significant regulators of synthesis and secretion of vitamin K-dependent plasma coagulation factors

Present data about hormonal regulation of haemostasis are often contradictory and are mostly based on clinical observations. The aim of the current research is to study the effects of the hormones of hypothalamic-pituitary-thyroid (HPT) axis on plasma levels (i.e. on the synthesis and secretion) of vitamin K-dependent coagulation factors in rats. The study was carried out on 65 male Wistar rats, divided into five groups. The animals were injected subcutaneously (s.c.) once daily for three consecutive days as follows: the first group was injected with Thyrotropin releasing hormone (TRH), in a dose of 0.06 mg/kg b.w.; the second group by Thyroid stimulating hormone (TSH), with a dose of 1 MU/kg b.w., the third and the fourth group respectively with Liothyroninum (Triiodothyronin ? T3) and Levothyroxinum (Thyroxin ? T4) with a dose of 0.08 mg/kg b.w. each. The control group rats were injected with saline (the solvent of the hormones), following the same schedule and volume per kg b.w. The necessary quantity of blood was acquired by a cardiac puncture under ether narcosis, and antigen levels of plasma factors II, VII, IX and X (FII:Ag, FVII:Ag, FIX:Ag and FX:Ag) were determined by ELISA kits (Diagnostica Stago, France). TRH, TSH, T3 and T4 significantly decreased the plasma antigen levels of FII and FVII (p<0.001). TRH, T3 and TSH reduced significantly FIX:Ag level( p<0.001 for TRH and T3 and p<0.05 for TSH) while T4 did not exert significant changes ( p>0.05). FX:Ag level was also significantly reduced by TRH, T3 (p<0.001), TSH and T4 (p<0.01). Plasma levels of vitamin K-dependent coagulation factors FІІ:Ag, FVІІ:Ag, FІХ:Ag and FХ:Ag are significantly reduced under the influence of the hormones of hypothalamic-pituitary-thyroid axis which signifies their decreased synthesis and secretion. T4 does not induce substantial changes in FIX:Ag plasma level.