HIV virus used to cure teenager of blood disorder

Scientists relied on “defanged” version of HIV virus to treat a teenager with a genetic blood disorder. The 18-year-old suffered from the inherited condition beta thalassemia and required monthly blood transfusions from the age of three.

He felt ill and drained of energy because his system could not produce red blood cells due to a faulty haemoglobin gene. The only known cure was stem-cell transplantation, but few patients are able to find a suitable donor.

Now scientists have found a new potential cure using gene therapy, according to the journal Nature. The team, led by Marina Cavazzana-Calvo of the University Paris-Descartes, extracted haematopoietic stem cells (HSCs) from the young patient’s bone marrow.

These are the cells that go on to produce all types of blood cell. The cells were mixed in a test tube with an engineered version of the HIV virus that carried the correct version of the haemoglobin gene.

The patient had chemotherapy to destroy his remaining stem cells and then the treated cells were injected into his system.
Within a year, the teenager was able to stop receiving blood transfusions. Although he is mildly anaemic he has remained stable for 22 months since then.

Study co-author Philippe Leboulch of the Harvard Medical School said the treatment had been “life-changing”. He added, “Before this treatment, the patient had to be transfused every month. Now he has a full-time job as a cook.”

However, some researchers have voiced concerns that the success of the case could be due to a lucky accident. The team noticed the patient had a high level of a protein called HMGA2, after it randomly integrated into his chromosomes. This led to an enlargement of the patient’s red blood cells.

Michael Antoniou of King’s College London, suggested that the patient would not have been able to stop having transfusions without the fortunate effect of over-expressing  this protein.