Abnormal cervical cytology in bone marrow transplant recipients

Particular human papillomavirus (HPV) subtypes are implicated in the genesis of abnormal cervical cytology and cervical cancer. While most immunocompetent hosts clear HPV infection with no sequelae, some develop premalignant cytological changes of whom a minority subsequently progress to overt carcinoma. Immunocompromised patients, such as renal allograft recipients and HIV-infected individuals, have a higher rate of cytological abnormalities. This is thought to be due to prolonged persistence of virus due to impaired clearance by the immune system. We undertook a retrospective review of the cervical cytology of all women who underwent BMT at two transplant centres and who had cervical smears performed between 1990 and 1998. The rate of cytological abnormalities was significantly higher than in the general population before BMT (age-adjusted odds ratio (OR) 2.2, P = 0.02) and after BMT (OR 7.0, P < 0.0001). After BMT, allogeneic recipients had a higher rate of abnormalities than did autologous patients (OR 2.6, P = 0.02) although only allogeneic recipients had a higher rate of abnormalities post-BMT compared to pre-BMT (allogeneic OR 6.8, P = 0.004). These observations suggest that pre-transplant disease and treatment factors increase the risk of cytologic abnormalities and that transplant-related factors such as conditioning therapy and immunosuppression further increase this risk. These data suggest that more frequent screening may be required in these at-risk groups, especially allogeneic recipients. Prospective studies are required to further evaluate cytological abnormalities and HPV shedding in these populations.