Cervical dysplasia associated with the use of natalizumab.

N O V E M B E R 2 0 1 3 , V O l . 7 1 , N O 9 © Van Zuiden Communications B.V. All rights reserved. Dear editor, Natalizumab is a monoclonal antibody against anti-α4integrin, which was registered in the Netherlands in June 2006. It is indicated for severe and highly active relapsingremitting multiple sclerosis (MS) in adult patients. In the product information of natalizumab it is stated that opportunistic infections such as progressive multifocal encephalopathy due to reactivation of the John Cunningham (JC) virus, herpes infections and a fatal case of herpes encephalitis have occurred during therapy. Human papilloma virus (HPV) expression is not mentioned and until now no cases of HPV expression or cervical dysplasia in association with natalizumab have been reported. HPV is the major cause of cervical intraepithelial neoplasia (CIN), the premalignant lesion of cervical carcinoma. Usually, acquired HPV infections are cleared by the immune system by 90% of women within two years. However, in immunocompromised patients persistent HPV infections, namely high-risk HPV types 16 and 18, may lead to progression of cervical squamous epithelial lesions. The risk of invasive carcinoma is increased in CIN-I (mild dysplasia), CIN-II (moderate dysplasia) and CIN-III (includes both severe dysplasia and carcinoma in situ). A case series is presented where the use of natalizumab may have led to persistent HPV infections which resulted in cervical dysplasia in four patients with MS.