Full Papers; Authors: M. Favretti, G. Dolcini, C. Iannuccelli, D. Franculli, C. Gioia, P. Sarzi-Puttini, F. Conti, M. Di Franco

Full Papers; Authors: M. Tenti, W. Raffaeli, V. Malafoglia, M. Paroli, S. Ilari, C. Muscoli, E. Fraccaroli, S. Bongiovanni, C. Gioia, C. Iannuccelli, M. Di Franco, P. Gremigni

Background: Geographic origin may represent a variable capable of influencing health status. This study aims to investigate the presence of differences of disease severity in Italian patients with fibromyalgia from different macro‐regions.Methods: This retrospective, cross‐sectional study involved patients included in the Italian Fibromyalgia Registry. Three geographical macro‐regions were identified, comprising patients from Northern Italy, Central Italy and Southern Italy. Clinical differences (evaluated through PolySymptomatic Distress Scale [PSD], revised Fibromyalgia Impact Questionnaire [FIQR] and modified Fibromyalgia Assessment Status [FASmod]) among the geographical macro‐regions were studied using one‐way analysis of variance (ANOVA) and the Scheffé's test.Results: A total of 6095 patients (5719 females and 376 males) were included, with 1957 from Northern Italy, 2979 from Central Italy and 1159 from Southern Italy. All studied clinical indices showed a trend indicative of greater disease severity in Southern Italy, followed by Northern Italy and then Central Italy (mean values for PSD: 19.97 ± 6.20 in Northern Italy, 18.61 ± 7.12 in Central Italy, 23.01 ± 5.66 in Souther Italy). These differences were statistically significant for the overall scores of all studied indices, evaluated with ANOVA (all p < 0.001) and in the head to head comparisons, evaluted with Scheffé's test.Conclusions: Geographic background is significantly associated with variations in the severity of fibromyalgia in Italian patients.Significance Statement: This is the first study to demonstrate geographical origin‐dependent intra‐national differences in the severity of fibromyalgia. The results confirm the necessity of considering fibromyalgia within the context of the biopsychosocial model and of implementing healthcare policies targeted towards the most underserved regions.

Introduction: Before COVID-19 pandemic, we identified the percentage of B cells expressing the Mu-opioid receptor (Mu+ B cells) as a potential marker, named Mu-Lympho-Marker (MLM), for chronic pain (CP) in patients with fibromyalgia (FM) and osteoarthritis. Objectives: Here, we demonstrate the stability of MLM over time through a comparative analysis of biological, clinical, and psychological data collected from a subgroup of patients with FM across 2 distinct research periods. Methods: This is an observational, longitudinal study. Fibromyalgia participants enrolled in the first study were called back for follow-up sampling. Clinical data were recorded. Pain score was reported using the Numerical Rating Scale. Mu+ B cells percentage of expression was analyzed by flow cytometry. Immunofluorescence analyses were performed to explore the cellular localization of Mu-opioid receptor. Pain-free subjects served as control group. All the participants filled out self-reported psychological tests. Data were statistically analyzed. Results: Mu+ B cells percentage of expression was constant in patients with FM, who consistently showed lower values than control group after 2 years (difference in the mean: 32.0 ± 4.4, t = 7.330, IC 95% [23.2–40.9], P < 0.0001). Confocal microscopy analyses revealed Mu cytoplasmic localization in patients with FM. We observed no significant changes between psychological outcomes during the 2 phases of the study, nor did we find any correlations with biological findings. Conclusion: Mu-Lympho-Marker could be a promising marker for CP, as seen in FM cohort, and could be helpful for accurate diagnosis and tailored rehabilitation strategies. Further studies are needed to study MLM in CP of different aetiologies.

Full Papers; Authors: C. Gioia, G. Dolcini, C. Iannuccelli, M. Favretti, D. Franculli, P. Sarzi-Puttini, F. Conti, R. Priori, M. Di Franco