A recent study published in the journal Clinical Infectious Diseases evaluates the infection risk presented by different multiple myeloma therapies. The authors conclude that while current therapies, particularly high-dose regimens and novel agents, improve the outcomes of patients with myeloma, they also introduce a much greater risk of infection.

Myeloma impairs the quality and quantity of immune system proteins that an individual produces. As a result, more than 75 percent of myeloma patients will experience marked immune system depression, becoming vulnerable to potentially life-threatening infections. In fact, infections are the leading cause of death among myeloma patients.

Some multiple myeloma treatments, however, further contribute to immune system suppression and infection risk.  Drugs which halt the uncontrolled proliferation of myeloma cells can simultaneously suppress even healthy immune system cells.

This is particularly a concern with the newer myeloma drugs. “Be aware of the risk for infection with the new agents,” Dr. Elias Anaissie, a coauthor of the study, states. “We now have much more powerful anti-myeloma agents, particularly when used together.”

Illnesses common during treatment with newer therapies include the herpes simplex virus (HSV) and varicella-zoster virus (VZV). Pneumonia and bacteremia, the presence of bacteria in the blood, are also common with patients in early stages of treatment.

In the study, Velcade (bortezomib), a powerful immune suppressing drug, was linked with increased risk of VZV when compared with dexamethasone (Decadron). The study recommends that patients being treated with Velcade receive preventative care, such as antibiotics or vaccines.

Thalidomide (Thalomid), another drug commonly used in myeloma treatment, did not increase the risk of infection in newly diagnosed patients.

The study authors also identified other factors associated with increased infection risk. Both unusually high iron levels and the risk of kidney failure were independently linked with higher infection rates. To reduce patients’ infection risk, the researcher advocated at least one simple change: quit smoking.

The study offered suggestions to help patients avoid infections, including buying a new toothbrush every three months, washing fruits and vegetables thoroughly before eating, and avoiding crowded places. The most effective way to control infections, however, remains knowing when patients are at risk during treatment and instituting appropriate prophylactic measures.

For more information, please see the article in Clinical Infectious Diseases (abstract).