However, other serological studies have shown that 20-50% of women suffering from HPV-associated lesions, with HPV DNA presence, do not present detectable levels of anti-VLP antibodies; this is in part due to the lack of an optimized test and the fact that these antibodies reactivity is type-specific for the virus. An optimized VLP-based ELISA test has been recently reported showing 93% sensitivity and 98.5% specificity for discriminating between positive and negative control sera. However, there was no report to evaluate the antibody response in patients with HPV-infected cervical lesions and with the prognosis of these patients.