[Detection and analysis of serum food-specific IgG antibody in Beijing area]

Objective: The level of food specific IgG antibody in serum of patients with suspected food intolerance in Beijing area was detected and analyzed, so as to provide a basis for patients to eliminate the food that causes disease in their diet. Methods: Data were retrospectively analyzed in a total of 2368 suspected chronic food intolerance patients (all resident population in Beijing) admitted to Beijing Jishuitan Hospital from October 2015 to December 2019, including 859 males and 1509 females. The age range ranged from 2 months to 90 years, (40.2±18.6) years, and the median age was 36 years. Serum specific IgG (sIgG) antibody concentrations in 14 kinds of food (beef, chicken, pork, cod, shrimp, crab, egg, milk, corn, wheat, mushroom, soybean, tomato and rice) were determined by enzym-linked immunosorbentassay (ELISA).SPSS V22.0 was used for statistical analysis, and χ² was used to compare the positive rate of each group. Results: The positive rate of food sIgG in 2 368 patients was 82.7% (1959/2368), the higher sIgG positive rates were found in eggs (54.7%), shrimp (29.0%) and milk (26.0%), and the lowest sIgG positive rates were found in pork (4.1%) and beef (1.2%) (P<0.05).There was significant gender difference in egg (χ²=10.885) and shrimp (χ²=6.607) sIgG, and female was significantly higher than male (P<0.05).The sIgG positive rates of egg (χ²=515.645), shrimp (χ²=74.20.4), milk (χ²=305.65), soybean (χ²=39.413), wheat (χ²=133.222), cod (χ²=25.540), crab (χ²=55.521), corn (χ²=20.645), tomato (χ²=118.108), chicken (χ²=32.821), pork (χ²=26.539), beef (χ²=21.632) and rice (χ²=25.335) were significant in different age groups. The positive rate of shrimp and crab sIgG increased with age (P<0.05).The positive rate of tomato sIgG decreased with age, and then increased slightly after 45 years. However, egg, milk, soybean, wheat, corn, and rice all showed a decreasing positive rate with the increase of age. The increase of chicken, pork and cod was observed in childhood, and then decreased with age, and then increased in middle and old age. Conclusions: There may be a certain correlation between food intolerance and elevated food sIgG levels in Beijing area. It is suggested that patients of different genders and ages should be optimized and adjusted according to their own characteristics, and children patients are still the key population for food intolerance control.