Immune reaction to papilloma virus is stronger in normal women
and those with less severe cervix disease - Papilloma viruses
(HPV), particularly types 16, 18 and 31, have been targeted as a
major cause of cervix cancer. Do differences in immune response
to the virus influence the actual risk for developing cervix
cancer? A report describing work carried out with cytology
smears from 140 women, at the National Cancer Institute, the
University of Texas Southwestern Medical School, Kaiser
Permanente, Albert Einstein College of Medicine, Digene
Diagnostics, and the Torrey Pines Institute for Molecular
Studies, appearing in the September 1, 1996 issue of Cancer Research,
suggests that they do. The researchers found that the fraction
of women having a strong reaction against virus strain 16
proteins (measured by interleukin-2 production) was greatest
(35%) among those with normal cervix cytology, was 20% in those
with low-grade epithelial lesions, and declined further to 17% in
those with high-grade lesions and then to 7% in women with
invasive cancer. (Tsukui, Cancer Res 56:3967, 1996)
Editor's Comment: - What the study could not distinguish clearly
is whether the results indicated a protective effect of the
immune response in preventing development of cancer, or an action
of the disease itself on the immune system. Response against an
influenza antigen was measured, and did not differ among the
groups, suggesting that overall immune function was not affected.
This makes the first possibility more likely, but there are many
uncertainties. For example, normal women did not all show a
reaction, and among them none of those who had been positive for
HPV-16, but only more than 4 years previously showed a reaction.
More study is needed before we can say there is definitely an
immune mechanism for natural prevention of cervix cancer.
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