Validation of standard operating procedures in a multicenter retrospective study to identify -omics biomarkers for chronic low back pain.

Chronic low back pain (CLBP) is one of the most common medical conditions, ranking as the greatest contributor to global disability and accounting for huge societal costs based on the Global Burden of Disease 2010 study. Large genetic and -omics studies provide a promising avenue for the screening, development and validation of biomarkers useful for personalized diagnosis and treatment (precision medicine). Multicentre studies are needed for such an effort, and a standardized and homogeneous approach is vital for recruitment of large numbers of participants among different centres (clinical and laboratories) to obtain robust and reproducible results. To date, no validated standard operating procedures (SOPs) for genetic/-omics studies in chronic pain have been developed. In this study, we validated an SOP model that will be used in the multicentre (5 centres) retrospective "PainOmics" study, funded by the European Community in the 7th Framework Programme, which aims to develop new biomarkers for CLBP through three different -omics approaches: genomics, glycomics and activomics. The SOPs describe the specific procedures for (1) blood collection, (2) sample processing and storage, (3) shipping details and (4) cross-check testing and validation before assays that all the centres involved in the study have to follow. Multivariate analysis revealed the absolute specificity and homogeneity of the samples collected by the five centres for all genetics, glycomics and activomics analyses. The SOPs used in our multicenter study have been validated. Hence, they could represent an innovative tool for the correct management and collection of reliable samples in other large-omics-based multicenter studies.

Complement C4A and C4B Gene Copy Number Study in Alzheimer's Disease Patients.

BACKGROUND/OBJECTIVES: Increasing evidence suggests the importance of neuroinflammation in the pathogenesis of Alzheimer's disease (AD), which is a complex neurodegenerative disorder. Complement activation occurs in the brain of patients with AD and seems to contribute to an important local inflammatory state. Increased expression of the fourth serum complement component 4 (C4) has been observed in AD patients in many studies. This protein has two isoforms, encoded by two genes: C4A and C4B localized to the HLA class III region. These genes exhibit copy number variations (CNVs) and this different gene copy number can influence C4 protein levels. We focalized our attention on these two genes, determining the distribution of CNVs in AD patients, compared with healthy controls, in order to analyse their possible involvement in AD pathogenesis. METHODS: We investigated 191 AD patients and 300 healthy controls. The C4A and C4B copy numbers were assessed by quantitative PCR (qPCR). RESULTS: The results obtained showed a statistically significant increase in the number of copies for both C4A and C4B in AD patients, compared with healthy controls (p<0,001). CONCLUSION: The presence of high C4A and C4B copy numbers in AD patients could explain the increased C4 protein expression observed in AD patients, thus highlighting a possible role for C4A and C4B CNVs in the risk of developing AD.