A Medical Device Daily

Confirming again what physicians have frequently speculated, a new study published in the April edition of Otolaryngology-Head and Neck Surgery says that the presence of cochlear implants increases the risk of bacterial infections that can cause meningitis. The report says that the finding increases the need to educate the public on the need for meningitis vaccinations in potential cochlear implant recipients.

The study involved making cochleostomy incisions — that is, opening of the inner ear spaces of the cochlea, the most important moment in the procedure — in the ears of 54 healthy rats, implanting cochlear devices in 36 of them, and then monitoring them for the presence of meningitis. A third of the rats with cochlear implants were stricken with meningitis.

The report reconfirms early reports by the FDA, in 2002, and in an article in the New England Journal of Medicine in 2003, that children are at risk for meningitis when implanted with certain cochlear implants and not vaccinated against bacterial meningitis, researchers said (Medical Device Daily, Aug. 1, 2003).

And researchers at the National Center on Birth Defects and Developmental Disabilities of the National Institutes of Health found that children with cochlear implants with "positioner" attachments were at significantly higher risk of developing the disease.

The new study indicates that cochlear implantation lowers the threshold needed for pneumococcal bacterial infection, the bacterium that causes meningitis. The authors stress, however, that they still believe that the benefits of cochlear implants far exceed the risk of meningitis, which can be managed by education and vaccination efforts.

Worldwide, 90 of the 60,000 people receiving cochlear implants have been stricken with meningitis, drawing concern within the international medical community.

Otolaryngology Head and Neck Surgery is the journal of the American Academy of Otolaryngology-Head and Neck Surgery (Alexandria, Virginia), which represents more than 12,000 physicians and allied health professionals who specialize in the diagnosis and treatment of disorders of the ears, nose, throat, and related structures of the head and neck.

Stem cells successful in diabetes treatment

As the U.S. Senate debates new ways to support stem cell research, a Brazilian study indicates that stem cell transplants in patients with Type 1 diabetes may boost the ability of the pancreas to produce insulin again. Some patients that have received the treatment have gone 20 months without needing insulin. The study is published in the current issue of the Journal of the American Medical Association (JAMA).

Since 1996, other autoimmune diseases have been treated successfully by suppressing the immune system and then transplanting blood stem cells to kick-start fresh cell production of damaged tissue. This transplant of blood stem cells is called autologous nonmyeloablative hematopoietic stem cell transplantation or AHST. Also, previous trials have shown that newly diagnosed Type 1 diabetes responds to moderate suppression of the immune system and can stop further loss of the cells that produce insulin, as well as reduce the need for external insulin.

The new study is said to be the first to combine both the immunosuppression and the stem cell transplant in newly diagnosed Type 1 diabetes patients. Julio Voltarelli and colleagues from the Regional Blood Center (Hemocentro), University of Sao Paulo (Sao Paulo, Brazil), enrolled 15 recently diagnosed Type 1 diabetes patients, ages 14 to 31, all dependent on supplemental insulin.

After receiving drugs to stimulate stem cell production, the patients had some bone marrow removed to harvest a supply of blood stem cells. Then their immune systems were suppressed with drugs, and they also took antibiotics and stayed in isolation to protect them from infection. After two weeks their extracted and conditioned stem cells were infused into their bloodstream via the jugular vein.

The treatment took place between November 2003 and July 2006 with further observation until February 2007 at the Bone Marrow Transplantation Unit of the School of Medicine (Ribeir o Preto, Brazil).

As the treatment took effect, the patients gradually, at different rates, reduced their need for external insulin; 14 of the 15 patients were insulin-independent over the seven to 36-month follow-up period. The average insulin free-period was nearly 19 months. One patient was insulin-free at 35 months, another four for 21 months, seven for 6 months and two with late response were insulin-free for 1 and 5 months, respectively. The treatment failed in the first patient, probably because his beta cell count was too low when they started the treatment. The remaining patients were more carefully selected after this.

In an accompanying editorial, Jay Skyler, director of the Diabetes Research Institute at the University of Miami (Miami), said the results should be assessed cautiously. He noted in recently diagnosed Type 1 patients a "honeymoon" period where for some reason they experience a rise in their own bodily insulin production. And he noted that the study used no control group that would have compared for the effects of a honeymoon period.

Also, he said it was not clear if the insulin level went up because the stem cells generated extra beta cells, or because the immune system stopped attacking the beta cells and the 20 or so percent that were still left in the patients was enough to keep insulin production at the right level, or a mixture of the two.