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Journal of Tuberculosis and Lung Disease ›› 2022, Vol. 3 ›› Issue (5): 360-363.doi: 10.19983/j.issn.2096-8493.20220084

• Original Articles • Previous Articles     Next Articles

Preliminary study on the colloidal gold method to evaluate the lserum pertussis toxin antibody IgG

Hu Yahong, Liu Dandan, Gao Wei, Meng Qinghong, Yao Kaihu()   

  1. Key Laboratory of Major Diseases in Children, Ministry of Education, National Key Discipline of Pediatrics (Capital Medical University), Laboratory of Microbiology, Beijing Pediatric Research Institute, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health, Beijing 100045, China
  • Received:2022-05-08 Online:2022-10-20 Published:2022-10-14
  • Contact: Yao Kaihu E-mail:yaokaihu@bch.com.cn
  • Supported by:
    National Natural Science Foundation of China(81973100);Natural Science Foundation of Beijing-Haidian Original Innovation Fund Joint Project(19L2041)

Abstract:

Objective: To evaluate the accuracy of colloidal gold method in the determination of serum anti-pertussis toxin IgG (PT-IgG). Methods: Samples with PT-IgG concentration <20 IU/ml (n=100) and ≥20 IU/ml (n=100) within 6 months were selected continuously from the serum samples frozen at -30 ℃ from Beijing Children’s Hospital affiliated to Capital Medical University in the reverse order, and one sample with insufficient quantity was excluded. Finally, 199 samples were included. ELISA kit and colloidal gold method (the positive detection limit was 20 IU/ml and 80 IU/ml) were used to detect the concentration of PT-IgG in the two groups, respectively, and the consistency between the concentration range of the colloidal gold method and the results of ELISA was evaluated. Results: Taking the results of ELISA as the standard, the sensitivity and specificity of colloidal gold strip with the detection limit of 20 IU/ml were 76.2% (80/105) and 95.7% (90/94), respectively; the positive predictive value and the negative predictive value were 95.2% (80/84) and 78.3% (90/115), and Youden index was 0.7. The sensitivity and specificity of colloidal gold strip with the detection limit of 80 IU/ml were 100.0% (23/23) and 69.9% (123/176); the positive predicted value and the negative predictive value were 30.3% (23/76) and 100.0% (123/123), and Youden index was 0.7. Conclusion: Taking the results of ELISA as the standard, the colloidal gold method with 20 IU/ml as the detection limit has high specificity and positive predictive value, and the positive results are reliable, which indicates that the body has a certain level of pertussis immunity. However, the colloidal gold method with the detection limit of 80 IU/ml has high sensitivity and negative predictive value, which can be used to exclude acute or recent pertussis infection in combination with clinical practice.

Key words: Whooping cough, Immunoglobulin G, Immunotoxins, Enzyme-linked immunosorbent assay, Gold colloid

CLC Number: