Influence of pre-analytical procedures on genomic DNA integrity in blood samples: the SPIDIA experience.

BACKGROUND: DNA integrity is a critical part of the definition of genomic DNA (gDNA) quality and can influence downstream molecular applications. Pre-analytical variables as sample storage and DNA extraction methods can influence the quality and quantity of isolated DNA and affect molecular test performances. The aim of this paper is to investigate the role of blood sample storage and DNA extraction procedures on gDNA integrity and gDNA fragmentation impact on a molecular test. METHODS: 157 DNA samples deriving from the Pan European 1st SPIDIA DNA External Quality Assessment (EQA), aimed to investigate the influence of blood storage on gDNA quality and quantity, have been analyzed by Pulsed Field Gel Electrophoresis and ImageJ imaging software. 157 DNA samples derived from the Pan European 1st SPIDIA DNA External Quality Assessment (EQA), which aimed to investigate the influence of blood storage on gDNA quality and quantity, have been analyzed by Pulsed Field Gel Electrophoresis and ImageJ imaging software. RESULTS/CONCLUSIONS: Our results demonstrate that blood sample storage and DNA extraction procedures influence gDNA integrity and that the same blood sample which underwent a long range multiplex PCR based analytical test can provide different results if the adopted pre-analytical procedures are not standardized.

SPIDIA-DNA: an External Quality Assessment for the pre-analytical phase of blood samples used for DNA-based analyses.

BACKGROUND: The EC-funded project SPIDIA is aimed to develop evidence-based quality guidelines for the pre-analytical phase of blood samples used for DNA molecular testing. To this purpose, a survey and a pan-European External Quality Assessment (EQA) were implemented. METHODS: SPIDIA facility sent to all the participants the same blood sample to be processed without time or temperature limitation. DNA quality parameters performed at SPIDIA facility included: UV spectrophotometric analysis of DNA purity and yield, PCR interferences study by Kineret software and DNA integrity analysis by pulsed field gel electrophoresis. RESULTS: 197 applications have been collected from 30 European countries. A high variability of DNA fragmentation was observed whereas purity, yield and PCR interferences had a narrow distribution within laboratories. A significant difference between the RNase P single copy gene quantity obtained in the DNA samples extracted with the precipitation-based method respect to those obtained with beads and column-based methods was observed. CONCLUSIONS: The results of this study will be the basis for implementing a second pan-European EQA and the results of both EQAs will be pooled and will provide the basis for the implementation of evidence-based guidelines for the pre-analytical phase of DNA analysis of blood samples.

SPIDIA-RNA: first external quality assessment for the pre-analytical phase of blood samples used for RNA based analyses.

The diagnostic use of in vitro molecular assays can be limited by the lack of guidelines for collection, handling, stabilization and storage of patient specimens. One of the major goals of the EC funded project SPIDIA (www.spidia.eu) is to develop evidence-based quality guidelines for the pre-analytical phase of blood samples used for molecular testing which requires intracellular RNA analytes. To this end, a survey and a pan-European external quality assessment (EQA) were implemented. This report is the summary of the results of that trial. With the European Federation of Laboratory Medicine (EFLM) support, 124 applications for participation in the trial were received from 27 different European countries, and 102 laboratories actually participated in the trial. Each participating laboratory described their respective laboratory policies and practices as well as blood collection tubes typically used in performing this type of testing. The participating laboratories received two identical blood specimens: in an EDTA tubes (unstabilized blood; n=67) or in tubes designed specifically for the stabilization of intracellular RNA in blood (PAXgene® Blood RNA tubes; n=35). Laboratories were requested to perform RNA extraction according to the laboratory's own procedure as soon as possible upon receipt of the tubes for one tube and 24h after the first extraction for the second tube. Participants (n=93) returned the two extracted RNAs to SPIDIA facility for analysis, and provided details about the reagents and protocols they used for the extraction. At the SPIDIA facility responsible for coordinating the study, the survey data were classified, and the extracted RNA samples were evaluated for purity, yield, integrity, stability, and the presence of interfering substances affecting RT-qPCR assays. All participants received a report comparing the performance of the RNA they submitted to that of the other participants. All the results obtained by participants for each RNA quality parameter were classified as "in control", "warning", "out of control" and "missing" by consensus mean analysis. From the survey data, the most variable parameters were the volume of blood collected and the time and storage temperature between blood collection and RNA extraction. Analyzing the results of quality testing of submitted RNA samples we observed a data distribution of purity, yield, and presence of assay interference in agreement with expected values. The RNA Integrity Number (RIN) values distribution was, on the other hand, much wider than the optimal expected value, which led to an "in control" classification, even for partly degraded RNA samples. On the other hand, RIN values below 5 significantly correlated with a reduction of GAPDH expression levels. Furthermore, the distribution of the values of the four transcripts investigated (c-fos, IL-1ß, IL-8, and GAPDH) was wide and the RNA instability between samples separated by 24h were similar. Assuming the presence of at least two quality parameters "out of control" as an indication of a critical performance of the laboratory, 33% of the laboratories were included in this group. The results of this study will be the basis for implementing a second pan-European EQA and the results of both EQAs will be pooled and will provide the basis for the implementation of evidence-based guidelines for the pre-analytical phase of RNA analysis of blood samples.

Red or white wine assumption and serum antioxidant capacity.

The biochemistry of reactive oxygen species is an important field with wide implications. Both preventive and chain breaking antioxidants have a role in the limitation of oxidative stress that accompanies aging and diseases. The potent antioxidant activity of phenolic substances of red wine, in particular, have been proposed as an explanation for the "French Paradox" (the apparent incompatibility of a high fat diet with a low incidence of coronary heart diseases). A lot of researchers emphasize beneficial effects of red wine and insist on lower or no antioxidant effect of white wine. We have been studying the effect of both white and red wine on blood antioxidant capacity in humans. The white wine we have been testing was produced by an ancient Tuscany procedure (the same used for red winemaking) which includes fermentation with grapes juice together with peelings and seeds. A statistically significant increase in total antioxidant capacity (TAC) levels was observed after 2h from red or white wine ingestion. White wine effect appears to be faster than that of the red one, since a significant difference can also be reported after 1h. We can conclude that the big difference in the results of serum TAC due to white wine reported by us, in comparison to those reported by others relatively to white wine produced using the French method, can be explained by the difference in the winemaking procedure we adopted.

Centenarians in Tuscany: The role of the environmental factors.

Statistical data of Italy, issued on 1st January 2005, show that Tuscany has a high percentage of elderly subjects, and that to reach 100 years is a common possibility, mainly for women. Comparable values appear for longevity index (LI%), either calculated on the basis of the various resorts above sea level, or on the basis of the number of inhabitants. However, some differences are observed considering the various provinces: Grosseto Province has the second higher value of >65-year-old subjects, while its LI% is the lowest. Centenarity index (CI%) considerably differs from LI%: if ranking Tuscany according to the various heights of territorial positions, the first displays a negative, while the second one shows a positive correlation with the local height. If comparing for inhabitants number, CI% is maximal in provincial cities, while LI% is higher in smaller communities. All these data indicate that residents in small communities of the mountains reach easily 90 years, while 100 years are more frequently reached in larger cities in the plane areas. In conclusion, the highest province longevity (Lucca) coincides with the highest centenarian sex ratio, and it suggests that in this province the older women may enjoy particular forms of environmental protection, which helps them for reaching 100 years of age. Differences between the results of this study and others performed in Sardinia are discussed.

Cognitive and functional status in the extreme longevity.

Usually, the effects of cognitive decline are not noted before the age of 70 years, which involve the intellectual capacities, the attention, the processes of elaboration and the memory. The studies on the cognitive disturbances of the elderly are numerous, and document the progressive increase of cerebral deterioration with advancing age. However, only a few studies refer to the significance of the cognitive disturbances in the clinical conditions and autonomy of the long living subjects. For this reason, we studied the cerebral deterioration of an adequate number of centenarians in correlation with their clinical conditions and autonomy. Our centenarian sample derived from the Italian multi-center study on centenarians (IMUSCE), which was an epidemiological study which identified 1173 centenarians (202 males, 971 females) in the age range of 100-109 years. From this sample, we analyzed 346 subjects as far as the cognitive functions and the degree of autonomy by using the psychometric tests of the mini-mental state examination (MMSE) and the instrumental activities of daily living (IADL) for the functional evaluations. In addition, we evaluated the clinical conditions of the subjects dividing them in three groups: Group A (those in good clinical conditions), Group B (those in discrete clinical conditions), and Group C (those in deteriorated clinical conditions). These analyses revealed that 187 (54.1%) of the 346 examined centenarians have shown an MMSE score in the normal range (score ratio from 1.0 to 0.63). The cognitive disorders are present in the centenarians in a clearly higher frequency (13.1%), than found in the common elderly (5.1%). The severe cognitive disorders do not allow a total autonomy or even a slight dependency. Only six subjects (1.7%) of the total sample were totally independent. These subjects had no cognitive disorders, and were in good clinical conditions. The results show that having an MMSE score in the normal range, and being in good clinical conditions are necessary but not sufficient prerequisites for a total autonomy in the IADL scores.

Physical performance and creative activities of centenarians.

The human functional autonomy is reduced progressively with advancing age, although a considerable proportion of the centenarians maintain a good level of autosufficiency for the basic performance of the everyday life. Even if males have a lower probability to reach the centenarian age than females do, the male centenarians display generally better functional conditions than the females. Actually, there are no systemic studies on centenarian works or activities; nevertheless, the examples of several representative persons (artists, scientists, explorers, etc.) who remained active even after this age indicate that such a possibility is realistic, and that the maintenance of vital interest and passions, thus preserving competence and professional attitudes, is not in conflict with the reaching of extreme longevity.

Longevity index (LI%) and centenarity index (CI%): new indicators to evaluate the characteristics of aging process in the Italian population.

Centenarians represent a group of population displaying the most rapid expansion. This progressive increase of the presence of centenarians is a multi-factorial phenomenon, which is due to the improvements of the environmental conditions and the life style and also to the progress of the medical science. In order to obtain a more reliable estimate of the longevity per gender and territorial entities, we propose two new indicators. (i) The ratio between the ultranonagenarians and the total population above 65 years old (called longevity index: LI%); (ii) the ratio between the centenarians and the total population above 90 years old (called centenarity index: CI%). An analysis of the data of the Italian National Office of Statistics (ISTAT, ) using these two indicators demonstrates that the subjects above the age of 90 are more frequent in the regions of Central and Northern Italy, which are more developed regarding the economic conditions and technological progress. Nevertheless, the Southern and Insular regions of Italy have a higher occurrence of centenarians among the ultranonagenarian population, and also a higher prevalence of male centenarians, as compared to the northern regions. This demonstrates that achievement of the threshold of 100 years old does not require only particular socio-economic conditions, but also an adequate climate and environment, as well as a favorable genetic composition.

Healthy centenarian subjects: the effect of red wine consumption on liver function tests.

Liver function is well maintained with increasing age. The aim of our study was to investigate if long-term moderate (