Tuesday, October 31, 2017

Head Trauma in Adolescence is Associated with Multiple Sclerosis Risk

Multiple sclerosis (MS) is a progressive, debilitating disease in which the body's immune system attacks the fatty layer that insulates some nerves, leading to permanent nerve damage. Based on studies in animals, there has been a suspicion that trauma to the central nervous system may be a risk factor for the development of MS. Now a Swedish study provides new evidence that repeated concussions during adolescence are associated with increase the risk of MS later in life. (Sweden keeps particularly good medical records on all its citizens, making comprehensive population studies possible).

The study's authors examined the records of all Swedes who had been diagnosed with MS since 1964 - over 7,000 people in all. Then they looked at the number of concussions each person with MS had had during adolescence, comparing it to the number of concussions in 10 other people without MS matched for age, gender, and county of residence. The key finding was that persons who had had two or more concussions during adolescence were more than twice as likely to develop MS as persons who had not had any concussions.

No one knows yet how concussions might trigger the development of MS, if indeed they do. One theory is that damage to central nervous system might lead to the release of nervous tissue breakdown products that cause the immune system to attack neural tissue. But that remains to be tested.

Monday, October 30, 2017

Underweight Women are at Higher Risk of Early Menopause

A study in Human Reproduction reports that women who are underweight are at higher risk than women of normal weight of going through menopause before age 45.

The study enlisted nearly 80,000 women starting back in 1989. Over the next 22 years, 2,804 of them went through natural menopause. After controlling for several factors including smoking, oral contraceptive use, and pregnancies, the study found that women who had a Body Mass Index (BMI) under 18.5 were 30% more likely to go through menopause before age 45 than women with BMIs between 18.4 and 22.4 (defined as normal weight).

The study does not tell us why a low body weight increases the likelihood of early menopause. And to be clear, menopause is a natural phenomenon for all women, eventually. However, early menopause does have implications for family planning, and it is sometimes associated with other conditions such as osteoporosis later in life. Women who are concerned should consult their doctor.

Thursday, October 26, 2017

Restasis Patents are Invalidated by a Federal Court

A U.S. Circuit Court judge has issued a 136-page ruling that effectively invalidates four key patents for Allergan's blockbuster drug, Restasis. You may recall that Allergan tried to protect their patents from administrative review by the U.S. Patent and Trademark Office by transferring the patents to a Native American tribe (see this blog, Sept. ). The Circuit Court decision is independent of review by the Patent and Trademark Office, but experts agree that U.S. Circuit Court decisions generally take precedence over administrative review by the Patent and Trademark Office. In effect, Allergan's attempt to protect its drug patents by transferring them to a Native American tribe is, at the moment, a non-starter.

In his ruling Judge William Bryson wrote, "The court has concerns about the legitimacy of the tactic that Allergan and the tribe have employed" (to protect Allergan's patents). An Allergan representative would only say, "We are carefully reviewing the decision and are considering all options", according to an article in Business Insider. This story may not be over yet.

Monday, October 23, 2017

Ebola Infection May Lead to Cataracts in Children

The Ebola virus epidemic that swept through several West African nations from 2013 to 2016 killed more than 11,000 people. An additional 17,000 people were infected but survived. But now a new problem has surfaced, according to an article in The Seattle Times; in some patients, the Ebola virus remained in the fluid inside the eyes, leading eventually to severe inflammation of the eyes (uveitis), a thickening and scarring of the lens (cataracts), and a potential loss of vision. Cataracts are generally a condition found in the elderly. But they've been found in Ebola survivors as young as five, even if the child had seemingly recovered from the Ebola infection and the virus was no longer detectable in his/her blood.

The findings are disturbing, because they show that patients who were thought to have "recovered" from their Ebola infection can still harbor the virus in bodily fluids not normally tested by health officials. How and when those hidden reservoirs of infection might re-emerge is anybody's guess. You can be sure that health officials will be asking questions and following up.

Monday, October 16, 2017

How Much are Gene-Therapy Treatments Likely to Cost?

An article about the potentially high costs for cures for genetic diseases reveals a subtle shift in how pharmaceutical companies intend to justify their high prices.

In the past, the usual argument was that high drug costs were justified by the high costs of drug development. The standard argument was that since it costs upwards of a billion dollars to take a drug all the way from initial research through Phase I, II, and III clinical trials, drug companies justifiably needed to charge high prices to recoup their costs. In some cases, drug companies needed to recoup losses incurred by drugs that never made it to market at all.

The paradigm has shifted with the advent of genetic therapy. Now, cells can be removed from a patient with a specific genetic mutation, modified by gene therapy techniques for that patient (and only for that patient) and then returned to the patient, affecting a complete cure. Since these cures are specific to individual patients, the FDA has begun to approve these new gene therapy techniques when they have been shown to work on just a few patients (perhaps several dozen). Gone are those lengthy Phase II and Phase III clinical trials, with their thousands of patient at dozens of medical centers. And gone, too, most of the costs of drug development.

As a result, drug companies are being forced to come up with new arguments to justify their high prices. And their new argument is shaping up to be something along the lines of "What's it worth to you?" How much will you or your insurance company pay for what one drug company spokesperson calls "long-term transformative benefits"?

Potential prices ranging from about $475,000 to $900,000 have been floated by some companies. At some point we may have wrestle with the question, "What is the value of life"?

Wednesday, October 11, 2017

The First Gene Therapy to Cure a Fatal Brain Disease

Gene therapy has now been used to cure a fatal brain disease called adrenoleukodystrophy (ALD), a genetic disorder that occurs in approximately one in 20,000 boys. Even more startling is that the vectors used to deliver the normal form of the ALD gene to the boy's cells are disabled viruses similar to the AIDS virus, called lentiviruses.

In the new technique, hematopoietic (blood-forming) stem cells are removed from the patient's bone marrow and exposed to lentiviruses that contain normal copies of the ALD gene. (Lentiviruses are used because like the AIDS virus, they are better than most other viruses at inserting genes into cells.) The stem cells are then returned to the patient's bone marrow, where they grow and multiply.

Now for the really interesting part. Some of the corrected stem cells make their way to the brain, where (apparently because of the environment there) they develop into neural supporting cells called glial cells, correcting the original defect in glial cell formation.

The timing of treatment is critical, however. It takes about a year between initial diagnosis and the time the treatment is effective. Unfortunately, ALD can progress so fast that patients who already have obvious symptoms of the disease may not be able to be saved. The best candidates for a cure are patients who (by virtue of hereditary history) are thought to be at risk for the disease, and whose only signs of the disease so far are changes in their brain scans.

Monday, October 9, 2017

HPV Vaccination Rates are (Finally) Rising

Vaccination rates against the HPV virus responsible for most cases of cervical cancer have been rising (finally), according to a recent CDC report.   Currently, more than 60 percent of teens have received at least one of the two recommended doses of the vaccine; that compares favorably to the 30% who had received the vaccine just ten years ago.

In 2016, the Advisory Committee on Immunization Practices (ACIP) updated its vaccinations recommendations to include a two-dose schedule instead of the previous three, making it easier for teens to be fully vaccinated.  Nearly 50% of all 17-year-old girls and 38% of all boys are now fully vaccinated, according to the new two-dose schedule.

Health officials are encouraged, but there is still room for improvement in vaccination rates. More than 40% of Americans aged 18-59 are infected with genital HPV.  There are nearly 40,000 new cases of cancers each year in areas of the body where the HPV virus is found (cervix, vagina, vulva, penis, anus, rectum, and oropharynx), according to the CDC.  Nearly 80% of these cancers could be prevented by vaccination.