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Women’s Health: What You Should Know About Abnormal Smears, HPV And The HPV Vaccinations

There is much to remember when it comes to looking after your gynaecological health, and if you are between the ages of 25 and 60, having a smear test is one of them.

Women's Health: What you should know about abnormal smear, HPV and the HPV Vaccination

You may be familiar with the term already, but a smear test is a screening that can detect abnormal cells on the cervix. An abnormal smear test can suggest the possibility that an area of skin on the cervix contains cells that are growing a bit faster than normal. We know that if such an area of rapidly growing cells is present then, if left over a number of years, it may become a cancer. However, these abnormalities can be easily treated to prevent any later problems.

It is important to remember that the changes described involve only the skin of the cervix and do not mean you have cancer. These cells however, do have the ability to change into cancer if ignored over many years. The changes in the skin of the cervix do not cause bleeding or discharge and there will be no pain or change in the menstrual cycle.

The smear test is about 95% accurate in the best of laboratories but unfortunately, many labs show only 80% accuracy. This is because the cells seen on the smear come from all parts of the cervix, not just from the abnormal area. If the abnormality is very small, most of the cells will be normal, and only a very few abnormal cells may be present. This makes diagnosis very difficult for the pathologist and explains why it is important to follow up when smear tests are “borderline” or “inconclusive” with their results. Although the possible ramifications can seem scary, chances are there is nothing to worry about. However it is still best to always talk through everything with your doctor.

The Human Papillomavirus

HPV Infection
As part of the national programme to prevent cancer of the cervix, HPV testing has become common practice. HPV stands for human papillomavirus and commonly cause warts in various parts of the body. Almost 200 different virus types within this group have been discovered so far. These viruses are remarkably specific about where they will grow, so a virus that causes warts on the hands will not grow on feet and genital warts will only grow on the genitals.

Infection with HPV usually causes a harmless self-limiting skin lesion that disappears within a few months or years. The virus infection causes the cells to grow faster than normal but does not cause any other cell changes. However, some HPV types have the ability to occasionally alter the control mechanisms within the cell, and set the cell on the first step of the multistep process that may lead to a cancer. Viruses that have the ability to do this are called “high-risk types”.

Most infections, even with high-risk virus types, remain just as a virus infection. Only a small percentage of HPV cases cause the cells to grow a little faster than usual leading to the development of abnormalities. The abnormalities within the cell are what a smear test detects.

The virus infection is not usually treated, as HPV infection will usually disappear spontaneously after one or more years as the body mounts an immune response to the virus. There is no reliable way to treat HPV infection on the cervix, and it is only when the cells become abnormal that there is any need to treat the cervix.

HPV testing is sometimes used as part of a screening programme. If the HPV test is negative, the woman is very unlikely to have a significant abnormality on the cervix. However, if the HPV test is positive, it is less helpful, as many women have HPV but never get any abnormal cells.

HPV testing can also be used after treatment for abnormal cells as women who test negative at this stage have a very low risk of getting a recurrence of the abnormality. Women who are still HPV positive have more risk of recurrence but the risk is still not very high depending upon how well the treatment has been performed.

Antibodies To HPV
Most virus infections enter the human blood stream and cause the production of antibodies, which then prevent reinfection by the same virus. So, for example, once infected with chicken pox, we remain immune during any subsequent exposure to the same virus. The antibodies produced by an infection are usually very effective at preventing recurrent infection.

Because HPV does not enter the blood stream, at best only very weak antibody levels are caused by a natural infection with HPV. The principle way that the body fights HPV is by a cell-mediated immune response, which does not involve antibodies. Because of this lack of antibodies, it seems that people can be reinfected with the same virus type repeatedly. Women who used condoms, which would help prevent reinfection from their partners, had a lower incidence of subsequent HPV positivity compared to those who did not use protection and were at risk of reinfection.

HPV Vaccination

HPV Vaccination
The HPV vaccine is composed of “virus-like particles” which are empty shells of the virus coat or capsid and contain no DNA. The vaccine is usually injected into the muscle of the upper arm, and three doses are administered to complete the course over a six-month period. The vaccine is available on the NHS for young girls in the vaccination programme while others may be able to access the vaccine through their general practitioners or from a private clinic.

There are two different vaccines against HPV — Gardasil and Cervarix. They both protect against HPV 16 and HPV 18, the two viruses thought to cause most cases of cancer of the cervix as well as other cancers. In addition, Gardasil protects against HPV 6 and 11, which cause most of the cases of genital warts. However, Cervarix is said to have a better adjuvant and does seem to produce higher antibody levels in women who have been immunised. It may also provide better cross protection against other high-risk HPV types.

HPV vaccination is offered to girls aged 12 to 13, usually in year 8 at school, as part of a national vaccination programme. Many feel that this is a very young age to vaccinate girls against a sexually transmitted virus, but trials have shown that a better immune response is mounted at this age and very good antibody levels result.

The vaccination is safe with very few side effects reported, however it may be a little uncomfortable whilst it is being administered and usually for a few hours after that. Injection site problems such as redness, bruising, itching, swelling, pain or cellulitis are common as are headaches. Some people experience nausea or pain in the arms, hands, legs or feet. An itchy rash is a very rare side effect.

It is too early to know how long vaccination will give protection for, or whether a booster will be needed. However, antibody levels have been well maintained for 6 years after vaccination and will probably last much longer. This will be the subject of further studies as experience with the vaccines increases.

Vaccination For Adults
Interestingly, research is now emerging that suggests that individuals may be reinfected later in life with HPV. One infection with the virus does not necessarily confer life long immunity to further infection. This suggests that vaccination may be useful to prevent reinfection after the teenage years.

We thank Mr Angus McIndoe of The McIndoe Centre, for providing specialist knowledge for this article.

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