Food-Specific IgG4 Antibody-Guided Exclusion Diet Improves Conditions of Patients with Chronic Pain

Abstract

Introduction: Chronic pain is related to gastrointestinal (GI) functions because food components affect inflammation and pain through their action on the GI immune and/or neural system and because many analgesics interact with the gut to alter its structure and function. Immunoglobulin G4 (IgG4) are food-specific antibodies resulting from exposure of the gut immune system to nutrients. High IgG4 levels have been found to be associated with inflammation.

Methods: IgG4 were determined (both with the rapid test and enzyme-linked immunosorbent assay, ELISA) in men and women outpatients with chronic pain. All subjects were asked to exclude for 4 weeks all foods to which they had high blood levels of IgG4 antibodies. Pain and quality of life questionnaires were administered before (visit 1) and after (visit 2) the personalized exclusion diet period. Visual analogue scale (VAS), Italian Pain Questionnaire (QUID) and Margolis (MA) questionnaires were administered to determine pain intensity, pain features and pain extent, while Short Form Health Survey (SF-36) and Profile of Mood States (POMS) were used to test the quality of life and mood state. The nutritional status was evaluated in all subjects. Subject groups were women of reproductive age (pre-MW), women in menopause for at least 1 year (MW) and men.

Results: Fifty-four subjects with chronic pain (n = 12 neuropathic, n = 14 diffuse pain, n = 11 headache, n = 17 low back pain) completed the two visits and the 1-month exclusion diet. At visit 1, 47 (87%) subjects showed medium/high levels of IgG4 to at least one food. The foods showing the highest IgG4 values were eggs, dairy products, cereals and dried fruit. At visit 2, IgG4 levels were decreased, increased or unchanged. In all groups, the 4-week exclusion diet resulted in a significant reduction in all pain measures and an improvement of quality of life parameters. In particular, at visit 2, the VAS score determined in the morning decreased by more than 50%.

Conclusions: A food elimination diet based on IgG4 antibody levels may be effective in reducing pain and improving quality of life in patients with chronic pain.

Keywords: Chronic pain; Gastrointestinal functions; IgG4.

Fig. 1

Total amount of IgG4 determined (ELISA method) in the 80 foods divided into 10 classes at visit 1

Fig. 2

IgG4 levels determined in the four pain groups: NP, neuropathic pain (N = 12); LBP, low back pain (N = 17); HA, headache (N = 11); DP, diffuse pain (N = 14)

Fig. 3

Visual analogue scale (VAS) scores determined in pre-MW (premenopausal women, n = 17), MW (menopausal women, n = 18) and men (n = 7), during visit 1 (T1) and visit 2 (T2) at three times of the day (morning, afternoon, night). *p < 0.05 VAS morning vs VAS afternoon in pre-MW, ^#p < 0.05 VAS morning vs VAS afternoon in MW, ^###p < 0.001 VAS morning vs VAS night in MW, ^§§p < 0.01 VAS morning in MW vs VAS morning in pre-MW

Fig. 4

Present pain intensity (PPI) determined in pre-MW (premenopausal women, n = 16), MW (menopausal women, n = 18) and men (n = 7) during visit 1 (T1) and visit 2 (T2). PPI was lower at visit 2 than at visit 1 independently of group

Fig. 5

IgG4 levels. a IgG4 total for all groups; b pre-MW (premenopausal women); c MW (menopausal women) and d men during visit 1 (T1) and visit 2 (T2). *p < 0.05 cereals vs all the other foods; dairy products vs all the other foods except cereals; eggs vs all the other foods except cereals, dairy products and dried fruit; dried fruit vs fish, meat, fruit and various