New types of human papillomaviruses and intracytoplasmic inclusion bodies: a classification of inclusion warts according to clinical features, histology and associated HPV types.

Two new types of intracytoplasmic inclusion bodies (ICBs) associated with distinct clinical features, and the presence of DNA of distinct types of human papillomaviruses (HPVs) are reported. One hundred and seven cutaneous warts containing ICBs were grouped into three categories according to distinct clinicopathological features: 67 were wart lesions with well-known granular (Gr)-ICB, 13 were punctate keratotic lesions with filamentous (Fl)-ICB and 31 were pigmented warts with homogeneous (Hg)-ICB. Molecular biological studies were performed in order to assess a specific association of each group of warts with distinct types of HPV. HPV-1 DNA sequences were detected in all the lesions with a Gr-ICB. Punctate keratotic lesions with Fl-ICB were associated with HPV-63, which was newly cloned from such a lesion. One of the samples also contained HPV-1 DNA. Pigmented warts with Hg-ICBs contained one of the related HPVs, i.e. HPV-4, HPV-60 or a novel type of HPV, HPV-65. Based on these associations, a classification of inclusion warts is proposed.