A team of international researchers has turned to stem cells in a quest to find an a more effective treatment for patients with drug-resistant tuberculosis (TB). The new method being investigated involves using the patients’ own bone marrow mesenchymal stromal cells (MSCs) to boost immune response and heal damaged tissue.

Multi-drug resistant TB effects around 450,000 in Eastern Europe, Asia, and South Africa according to the World Health Organization, and conventional treatments have a low rate of success.

Currently in its preliminary stages, the study is designed to investigate the possibility that MSCs can help organs to regulate themselves and repair damaged or traumatized tissues. Specifically in this case, the stem cells migrate to the lung with TB bacteria inflammation and improve the immune response to help the body get rid of the bacteria.

Between September 2009 and June 2011, the study looked at 30 patients from a specialist center in Minsk, Belarus, whose age varied from 21 to 65 years old, and who were resistant to TB drugs. They chose Belarus because of the high rate of resistant tuberculosis (76 percent) among treated patients in that region. They also observed 30 patients who met the inclusion criteria and who opted not to have MSC therapy.

Besides giving patients the anti-TB antibiotics, the researchers collected cells from their own bone marrow, cultured them and introduced them back into the patient within four weeks of the start of the anti-TB drug treatment. Eighteen months later, the rate of cure for patients who received MSC therapy was more than three times higher compared with those who didn’t get treated with the cells.

MSC therapy produced a few side effects, which the researchers considered mild. Fourteen patients had high cholesterol, 11 patients suffered from nausea while 10 others had lymphopenia (low level of lymphocytes in the blood) or diarrhoea.

The researchers noted MSC cells harvested from TB patients did not present any aberrant features in comparison with those extracted from healthy donors. Neither did the anti-TB drugs seem to have a negative impact on the harvest. Concerns over the risk of suppressing an immune response, leading to the worsening of tuberculosis, did not materialize. However, they highlight that future studies would need to assess whether certain anti-M tuberculosis drug combinations or concomitant M. tuberculosis infection (a type of TB infection) could have an impact.

“The results of this novel and exciting study show that the current challenges and difficulties of treating multi-drug resistant TB are not insurmountable, and they bring a unique opportunity with a fresh solution to treat hundreds of thousands of people who die unnecessarily of drug-resistant TB," says co-author Professor Alimuddin Zumla. "Further evaluation in phase 2 trials is now urgently required to ascertain efficacy and further safety in different geographical regions such as South Africa where multi-drug resistant and extensively-drug resistant TB are rife.”

Details of the study are published in The Lancet Respiratory Medicine.

Source: UCL