New approach in TB treatment

New research has revealed that that a high dose of Intravenous Immunoglobin (IVIg) has a greater effect in reducing the numbers of tuberculosis (TB) organisms than the bacille Calmette-Guerin (BCG) vaccination.

Tuberculosis is responsible for over two million deaths annually and BCG, the only current licensed vaccination, is not effective in the developing world.

Current conventional treatments for TB involve the combination of antibiotics over a long period of time, which is not always successful.

The research, published in the latest edition of Infection and Immunity​ showed that high dose IVIg enhanced the immune response to TB and produced a 100 fold reduction in the numbers of TB organisms in a mouse model, in both the early and late infection stages of TB infection.

The study revealed that the reduction in TB organisms was long lasting after a single treatment cycle of IVIg suggesting an enhanced immune response.

This effect was lost if the same study was carried out in a mouse lacking T cells, the white blood cells critical to the immune response against TB. This suggests that these T cells may mediate the immune enhancing effect of IVIg.

This type of approach already has applications in treating such autoimmune neuromuscular disorders as Multiple Sclerosis and autoimmune diabetic neuropathy and immunological disorders such as hypogammaglobulinemia.

Intravenous immunoglobulin (IVIG) therapy is the infusion of immunoglobulins into a vein. These immunoglobulins are a type of protein found in human blood that helps to fight off harmful bacteria, viruses and other germs.

Patients receiving IVIG therapy for primary immune deficiencies usually receive the therapy for life, while patients receiving IVIG therapy for autoimmune neuromuscular disorders receive the therapy intermittently over a period of months, and sometimes years, depending on their condition.

"These are encouraging results as this type of therapy uses the existing immune response and is likely to be effective even with drug resistant organisms," said Dr Stephen Jolles, consultant clinical immunologist at the Royal Free Hospital, who also led the research.

IVIg is a licensed product with an excellent safety record so these results suggest further research in a clinical setting is possible," he added.

IVIg is already a commonly used product consisting of human antibodies purified from plasma donations. It is currently used at replacement doses to treat immunodeficient patients who are unable to make their own antibodies.

IVIG therapy does not come without any side effects. In some patients, headache is the most common adverse symptom associated with IVIG in a typical infusion setting. It is usually dose-and rate-dependent but is sometimes delayed.

Some patients tolerate rapid infusions, and others can have IVIG trickled in and still develop headaches. Analgesics can manage these headaches.

Hypertension, particularly in the elderly, is a common problem, so blood pressure should be monitored. It is important that patients take their hypertension medication on the day of an IVIG infusion.

Blood pressure elevations may require reducing the rate of infusion and/or adjusting the dosage of their blood pressure medication.