In a letter published in the new issue of the journal AIDS, Gero Hütter and Eckhard Thiel provide an update on their efforts to find a second candidate for the stem cell transplant procedure that appears to have cured Timothy Ray Brown of HIV infection. The work has been facilitated by a meeting the doctors convened on April 20 2009, which brought together an international group of hematologists, HIV specialists and representatives from bone marrow donor registries and donor centers to promote cooperation in the search or appropriate stem cell donors (in addition to being homozygous for the CCR5 delta 32 mutation, donors have to be matched for specific immune system genes called HLA genes, in order to reduce the chances of the stem cell transplant being rejected as foreign).
So far, eight HIV-positive individuals with cancers requiring stem cell transplants have been reported to them, and they have searched for possible donors homozygous for the CCR5 delta 32 mutation. Unfortunately, no appropriate matches have yet been found. Hütter and Thiel are nevertheless continuing to search in hopes of reproducing their original approach and bolstering the proof-of-concept that an HIV cure is possible.
14 January 2011 - Volume 25 - Issue 2 - p 273–274
Hütter, Gero a; Thiel, Eckhard b
a Institute of Transfusion Medicine and Immunology, University Heidelberg, Mannheim, Germany
b Medical Department III (Haematology and Oncology), Charité Campus Benjamin Franklin, Berlin, Germany.
In February 2007, the medical team of the Charité Berlin performed an allogeneic haematopoietic stem cell transplantation (HSCT) in an HIV-infected patient with acute myeloid leukaemia (AML) using progenitor cells from a donor, especially selected for homozygosity for the CCR5-delta32 deletion (HIV-resistance gene). Now, more than 3 years after this treatment, the patient is still off antiretroviral medication and without any evidence of viral replication. Furthermore, the patient's CD4 cell count rose to more than 800/μl and all investigated haematopoietic stem cell derivatives, including macrophages of the gut, became CCR5 negative. This case has inspired new hopes that some kind of gene therapy may become the key to an improvement in HIV treatment and hopefully an HIV cure. Nevertheless, it was just a single case and repeating this approach in a small series of patients would be desirable to make further conclusions. Here, we report our efforts to find a second candidate for allogeneic CCR5-delta32 transplantation and the limitations of this undertaking.