We have compared the expression of different isoantigenic determinants of ABH and Lewis blood groups in uterine cervix tissues where we have normal epithelium and a spectrum of preneoplasias and neoplasias, from low-grade lesions (morphologic changes of epithelium related with HPV infection, condylomas and CIN I) to the invasive carcinoma.
These antigens resisted fixation with saline formaline very well. In order to compare the results with the monoclonal antibodies used, we employed different types of lectines: Ulex Europeaus I, Lotus Tetragonolobus, Dolichus Biflorus, and Shopora Japonica Agglutinins .
The results of both methods permitted us to observe a better stain definition when we used the MoAbs, although the patterns of stain tended to be similar in both.
This work stands in the fact that the study of cellular glycoconjugates can provide valuable information concerning the events related with neoplastic cellular transformation. Accordingly, much evidence shows that in different neoplasias the phenomena of glycosylation of certain molecules of the cellular membrane show modifications that could play an important role in relation to their malignant behavior .
The first works in which we began to observe those alterations date from the beginning of the 1930s  (Hirschfelt 1929 and Thomsen 1930). Kovarick, Davidsohn and colleagues 1968, 1969, with immunofluorescence techniques and mixed cellular reaction agglutination (MCRA), were the first authors to describe that uterine cervix neoplasias showed losses of expression of specific antigens of ABH blood groups. This fact was interpreted as a manifestation of the function of dedifferentiation analogous to morphological dedifferentiation and was related, also from the first studies, to a greater incidence of metastases. The same findings were found in adenocarcinomas of the gastrointestinal tract, ovary, tumors of transitional cells originating in the urinary tract, and in squamous carcinomas of the skin, tongue and larynx [37, 17].
Likewise, since then it was recognized that in the sequence: metaplasia, dysplasia and carcinoma in situ of the cervix, a good model is reproduced in which the alterations of the isoantigen ABH expression can be followed.
Several authors have confirmed the findings of Kovarik and Davidsohn in the cervix [18, 36, 38]. Bonfiglio and colleagues were the first in publishing a work using, in addition to the immunofluorescence technique, an immunoperoxidase technique for the determination of the A and B isoantigens .
Mambo observed that 33% of the condyloma acuminatum of the uterine cervix had complete losses of some of the blood group ABH isoantigens, and partial losses in 47% . We could not confirm those findings, although the number of cases in our study is smaller and our objective was not centred on low-grade lesions.
The pattern of expression of the ABH antigens in the middle of the epithelium that we have observed was previously described by Stubbe Teglbjang and colleagues using immunofluorescence. These authors found that the exocervical epithelium had a progressive pattern in the expression of the blood group isoantigens, with expressions in the basal and parabasal cells of N-Acetyllactosamine, of the antigen H in the parabasal and in the cells of the low spinosus stratum, and of the A antigen in cells of the high spinous stratum. They also observed that the premalignant and malignant lesions had irregular decreases in the content of the antigens A and H, with an almost complete loss of them, and precursor chain accumulation .
Following a technique using immunohistochemistry with the avidin-biotin complex, we have not been able to observe a clear accumulation of precursor chains although we have found significant results in the loss of expression of the A antigen.
To and colleagues have described that the expression of the blood group antigens, in combination with the depth of the tumoral invasion, could serve as a predictor of survival in cervical carcinoma . In the same direction, Sakamoto and colleagues observed a greater frequency of complete loss of the antigen H in small cell carcinomas, which have also a worse survival to the two years, versus to the squamous carcinomas with a better survival .
The sum of this evidence has led to us to study, after our experience with the respiratory mucosa [13, 14], the alterations of the glycosylation in different cervical lesions. Our findings are very similar to those from our previous studies, leading us to believe that these alterations could be a phenomenon common in different tumors with different etiological implications.
Our work, unlike its precedents, is complemented with the use of lectins, a tool that has served to control the results by means of immunohistochemistry to discard possible artefacts motivated by the fixation or the different processing of the tissues.
On the other hand, HPV infection has been strongly related to cancers of the lower female genital tract, penis, larynx, lungs and anus. It is known that the subtypes 16, 18, 45 and 56 in cervical lesions are related to a greater relative risk of developing invasive carcinomas [44, 45].
Some papers point out that the percentage of PCNA positive proliferation cells is significantly higher in premalignant and malignant lesions of the uterine cervix than in nonneoplastic lesions .
To investigate the possible differential expression of PCNA in negative and positive lessions of the cervix for E6 HPV-16 lesions, we have studied, using immunohistochemistry and PCR, different cases from flat condylomas to invasive caricinomas. We also inquired into the overexpression of p53 in order to explain the cases with a possible alteration of this tumor supressor gen.
We did not find a significant expression of p53 as other authors have reported . Only occasional basal or parabasal nucleus could be seen as positive with the DO-7 MoAB clone. However PCNA was expressed more progressively from a lower grade to the higher degrade and invasive carcinomas. Our results are consistent with the observations that the cell proliferating index as detected immunohistochemically using PCNA may be a useful parameter to indicate the degree of CIN. In addition, we found in our study a higher PCNA proliferation index in CIN III and invasive carcinomas of cervix positive for HPV-16 versus the cases that are negative for this type of virus.