Preliminary establishment and validation of a loop-mediated isothermal amplification assay for convenient screening of 13 types of high-risk human papillomaviruses in cervical secretions

The detection of human papillomaviruses (HPV) is a well-recognized strategy in early screening and prevention of cervical cancer. However, it's hard to carry out in undeveloped area because the sophisticated equipment that required in traditional methods is usually unavailable. To overcome this situation, we aim to establish a loop-mediated isothermal amplification (LAMP) method, which is simple and reliable for on-site detection of HPV.At least 3 sets of LAMP primers for each of the 13 types of high risk HPV were designed. After preliminary validation, the candidate primers were used in the detection of clinical samples and the results were head-to-head compared with a clinically approved real-time PCR assay. The performance of the LAMP method was assessed by kappa concordance test.Cervical secretions samples from 1412 patients were included, with 224 samples were used in the preliminary screening of the LAMP primers and the other 1188 samples were used in the verification. Compared with real-time PCR method, the specificity of our LAMP method for each type of HPV were 100 %, and 11 of the 13 types had a sensitivity greater than 80 %. Among them, HPV 31 and 52 demonstrated the best performance, both with Kappa value of 0.913 (P < 0.0001). Besides, HPV 18, 35 and 56 only achieved a Kappa value less than 0.7, indicating their primers or reaction conditions may need further optimization. In general, the sensitivity, specificity, positive predictive value, negative predictive value and agreement of the LAMP assay in all HPV types was 86.9 %, 100 %, 100 %, 71.4 %, and 90.2 %, respectively (Kappa = 0.766, P < 0.0001).In present study, we preliminary established and validated a LAMP method for HPV detection. This method could combine with self-sampling, thermostatic device, and appropriate dyes to form a simple and effective assay in the future, which would has good prospect and practical value in cervical cancer prevention, especially in undeveloped area.