Fibromyalgia (FM) is a severe female chronic pain syndromes. FM pathogenesis is not clear yet but it seems to be characterized by the combination of familiar, environmental, psychological and physical factors. Considering pain as the main symptom, recent studies underline a correlation between immune, nervous and opioid systems because of the presence of opioid receptors on the surface of circulating lymphocytes. 
Here we show a diagnostic trial, by proposing lymphocytes opioid receptors as FM markers. Biological data were correlated with psychological analysis to define new rehabilitation strategy. 
Methods
 FM patients and healthy people, as control group, were enrolled. Blood samples were done to apply molecular analysis. Lymphocytes opioid receptors immunophenotyping, genes and proteins expression and functional analysis were run.  All the patients were subjected to psychological tests. The collected data were correlated with the biological ones. 
Results
Our preliminary data have shown a modulation of µ opioid receptor (MOR) in FM patients. In particular we found MOR over-expression on circulating B-lymphocytes (LB) surface in contrast with the control group.  Considering the % of MOR on LB surface, we found two specific FM patients subgroups. Psychological analysis will help to understand the meaning of these two FM patients groups. Functional analysis of MOR are still running. 
Conclusion 
The combined results will be pivotal  to consider MOR receptor modification as  FM marker, easy to check with a simple blood sample.
Acknowledgements
ISAL Foundation and Nando and Elsa Peretti Foundation, PON03PE_00078_2, PON03PE_00078_1/F1, PON03PE_00078_2/F1

MULTIDISCIPLINARY STUDY PROTOCOL FOR FIBROMYALGIA DIAGNOSIS: CIRCULATING LYMPHOCYTES OPIOID RECEPTORS AS INNOVATIVE BIOMARKERS