Stem Cell Transplants and HIV Patients

I recently came across a very intriguing story about HIV patients who had undergone chemotherapy and stem cell transplants as part of lymphoma therapy.  This is a story about the potential involved in stem cell treatments, and something that continues to reveal the vast array of diseases that may one day be treated this way.

The story is about HIV-positive patients who have undergone what is being called the "sterilizing cure", wherein the above-mentioned medical therapy removes all traces of the virus.  These HIV-positive patients developed lymphoma that required chemotherapy followed by bone marrow transplants as a cure for the cancer.  The bone marrow (stem cell) transplants effectively removed the virus from their bodies.  These two patients represent the second and third known cases where the sterilizing cure has apparently worked.  An earlier patient had a similar result after treatment for leukemia. 

Most recently, the two patients with HIV were being treated with long-term antiretroviral therapy when they developed lymphoma.  The antiretroviral medications were continued through the duration of chemotherapy and also the bone marrow transplants.  After these treatments, both patients have shown no traces of virus.  Lead researcher Dr. Timothy Henrich, from Harvard Medical School and Brigham and Women's Hospital in Boston, said that "we have been unable to detect virus in either the blood cells or the plasma of these patients."  He also biopsied intestinal tissue from one of the patients and could not detect virus there either.

The research team withdrew the patients' antiretroviral medications in order to test how effective the cancer therapy had worked to eliminate the virus.  One patient has been off medication for 15 weeks, and the other for 7 weeks, both without showing any rebound of the virus. 

The researchers are not calling it a true cure as of yet, as the virus could still be present in extremely low amounts that just aren't detectable. 

In bone marrow transplants, donor cells replace the host's blood cells, and in these patients, the antiretroviral medications seemed to allow the donor stem cells to replace the host cells without becoming infected with the virus.

These results were presented at the International AIDS Society Conference in Kuala Lumpur, Malaysia and are considered preliminary findings.