The objectives of our study were to evaluate the presence of antipolymer antibody (APA) seropositivity in 285 Italian patients affected by primary Fibromyalgia (FM) and to verify if APA levels correlate with the disease severity and cytokine levels. [Note: Some research has suggested that levels of APA (antibody to silicone polymers and their breakdown products) in Fibromyalgia patients’ blood serum may be a marker for FM, and that APA levels might be associated with FM symptom severity
APA levels were determined on serum samples by an indirect ELISA kit that detect IgG APA. Cytokines (IL-1, IL-6, IL-8, IL-10 and TNF-alpha) were measured by ELISA in plasma. The impact of Fibromyalgia on the quality of life was estimated using the "Fibromyalgia Impact Questionnaire" (FIQ), while pain severity was evaluated using a Visual Analogic Scale (VAS). Patients were also characterized by the presence of tiredness, stiffness, non restorative sleep, anxiety, depression, tension headache, irritable bowel syndrome, temporomandibular dysfunction, Raynaud phenomena.
Using a cut-off value of 30 U, APA positive values were detected in 60 FM patients (21.05%) and in 15 healthy controls (15.00%) without significant differences among their levels or percentage of seropositivity.
FM patients with moderate and severe symptoms had slightly higher APA levels with respect to patients with mild symptoms.
APA seropositive patients exhibited significant correlations between APA levels and FIQ (P=0.042), tiredness (P=0.003) and IL-1 levels (P=0.0072).
In conclusion, APA cannot be considered a marker of disease in Italian FM patients. However, its presence might permit the identification of a subset of FM patients with more severe symptoms and who may respond differently to different therapeutic strategies.
Source: Arthritis Research & Therapy. 2007 Sep 6;9(5):R86 [E-publication ahead of print] PMID: 17822528, by Bazzichi L, Giacomelli C, De Feo F, Giuliano T, Rossi A, Doveri M, Tani C, Wilson RB, Bombardieri S.