The in situ immunological reactivity and its significance in the clinical behavior of the cervical human papillomavirus lesions.

The in situ immunocompetent cell (ICC) infiltrates in 286 cervical punch biopsies derived from the women prospectively followed-up since 1981 (16 +/- 14 months, M +/- SD) for an established human papillomavirus (HPV) infection with or without coexistent cervical intraepithelial neoplasia (CIN) were characterized using the histochemical ANAE (acid alpha-naphthyl acetate esterase) staining. Only minor fluctuations in the relative proportions of ANAE T+, ANAE M+, and ANAE- cells were found between the three types of HPV lesions (flat, inverted and papillomatous condylomas), as well as between the lesions with varying degree of HPV-CIN. The percentage of ANAE- cells (mediators of humoral immune response) increases in parallel with the increasing density of the ICC infiltrate. The intensity of the local infiltrate was inversely correlated with the progression, but not with regression or persistence of the HPV lesions. The percentage of ANAE T+ cells was highest in the 32 (18.7%) HPV lesions progressed during the follow up, almost identical in the 88 (51.5%) persistent lesions and lowest in those 51 (29.8%) lesions showing clinical regression. The results are discussed in terms of the proposed immune surveillance functions attributed to the local ICCs according to the MALT (mucosal-associated lymphatic tissue) concept. Conclusion is drawn that no major imbalance in the ANAE- definable main populations of ICCs exist in the cervical HPV lesions, which readily could explain their divergent clinical behavior. Other factors (like HPV type, synergistic action of cocarcinogens or a deranged balance between the ICC subsets) should be searched for to elucidate this issue.