Fibromyalgia/chronic fatigue syndrome. Aspects on biology, treatment, and symptom evaluation

Abstract

Background. Fibromyalgia (FM) and chronic fatigue syndrome (CFS) are prevalent clinical conditions of unknown aetiology with substantial comorbidity. The diagnoses are based on internationally established criteria. Women are more often affected. Immunological abnormalities have been implicated and the onset is sometimes related to infection. The objective was to evaluate the clinical effect of immune modulation with the staphylococcal vaccine Staphypan Berna (SB) in FM/CFS, to explore mechanisms of action and predictors of outcome, to develop a rating instrument and to provide case reports on a subgroup of CFS patients with genetically related folate deficiency. Methods. One hundred women with both FM and CFS were included in a 6-month randomised controlled trial of SB. The preparation was administered subcutaneously in doses of 0.1 to 1.0 mL at weekly intervals for 8 weeks and then in booster doses of 1.0 mL 4-weekly. Main outcome measures were proportion of responders on ratings and proportion of 'good responders', defined as patients with a symptom reduction of =50% from baseline. Withdrawal was evaluated. The staphylococcal antibody levels were measured in serum of patients. Nickel allergy and smoking habits were recorded and related to outcome of treatment. Rating data were also analysed in order to develop a new rating instrument for symptom evaluation. Results. The injection programme was well tolerated and 65% responded to active treatment. The placebo response was 18% (P < 0.001). Patients on active treatment were significantly more often 'good responders'. Impairment was found at withdrawal. A serological response was found to several staphylococcal antigens and a significant positive correlation between antibody levels and clinical effect was noted. In 204 women with FM/CFS, 52% were found to have nickel allergy and 28% were cigarette smokers. Outcome of SB treatment was poorer among nickel allergic patients, especially among concomitant cigarette-smokers. The new rating instrument assesses 12 symptoms. The inter-rater reliability was found to be high. In a subgroup of CFS patients with genetically related folate deficiency, treatment with folate led to normalised serum homocysteine, which parallelled clinical improvement. Conclusion. FM and CFS are related conditions that respond to immune modulation with a staphylococcal preparation. Data indicate a relation between antibody response and clinical effect. Nickel allergy is prevalent and predicts poor response to staphylococcal vaccine. The results support that FM/CFS patients have underlying immune dysfunctions.