Saturday, July 30, 2011
Novel gene therapy for HIV(Bone marrow transplant 'cures HIV patient' )
Novel gene therapy for HIV(Bone marrow transplant 'cures HIV patient' )
Muhammed Ishad*,Megha.M, Nayanathara P.S, Dilip.C, P.N. Krishnan, Junise.V
Al shifa college of pharmacy, poonthavanam, perinthalmanna,kerala.
Abstract
The "Berlin Patient" -- now known to be Timothy Ray Brown -- remains free of any detectable HIV in his blood, gut tissue, and other reservoir sites 4 years after receiving a bone marrow transplant containing stem cells from a donor with the CCR5-delta32 mutation, according to a report in the December 8, 2010 advance online edition of Blood. These findings, his doctors say, "strongly suggest that cure of HIV has been achieved in this patient."
INTRODUCTION
Two million people die of Aids every year and HIV is estimated to have infected 33 million people worldwide. [1] Doctors in Germany say a patient (42-year-old patient was an American living in Berlin) appears to have been cured of HIV by a bone marrow transplant from a donor who had a genetic resistance to the virus [2]. The researchers in Berlin said the man, who suffered from leukaemia and HIV, had shown no sign of either disease since the transplant two years ago.HIV requires one of 2 co-receptors, CCR5 or CXCR4, to enter human cells. Individuals with a natural genetic mutation known as CCR5-delta32, who do not express CCR5 on their CD4 T-cells, are resistant to HIV infection.[3] Those who do become infected may be "elite controllers" who maintain very low viral load without antiretroviral therapy (ART).
CASE STUDY
A berlin HIV +ve Patient underwent leukemia treatment that involves using potent chemotherapy to kill off immune cells -- which eliminates the cancer -- and reconstituting the immune system with donated hematopoietic stem cells, which differentiate into all the different types of blood cells, including T-cells.After the first transplant, researchers were unable to find any evidence of HIV, even though the patient stopped taking ART. He then received a second transplant from the same donor due to a relapse of leukemia. He had been infected with the human immunodeficiency virus, that causes Aids, for more than a decade and also had leukaemia. The clinic said since the transplant was carried out 20 months ago, tests on the patient's bone marrow, blood and other organ tissues have all been clear.
RESULT
"Results demonstrate successful CD4+ T-cell reconstitution at the systemic level as well as in the largest immunologic organ [the gut] following CCR5-delta32/delta32 stem cell transplant, and additionally provide evidence for the reduction in the size of the potential HIV reservoir over time," they elaborated in their discussion.
The Berlin Patient, however, shows no evidence of residual HIV and has not experienced disease progression.
His immune system was successfully reconstituted, and now contains HIV-resistant CCR5-delta32 cells, like those of the donor.
Furthermore, the researchers noted, "We found evidence for the replacement of long-lived host tissue cells with donor-derived cells indicating that the size of the viral reservoir has been reduced over time."
CONCLUSION
Although the recovered CD4+ T-cells are susceptible to infection with [CXCR4] HIV infection, the patient remains without any evidence for HIV infection since more than 3.5 years after discontinuation of ART," the researchers concluded. "From these results, it is reasonable to conclude that cure of HIV infection has been achieved in this patient."
References.
1) Fauci AS,Lane HC.Human immune deficiency virus disease: AIDS and related disorders.In: Kasper,Braunwald,Fauci,Hauser,Longo,Jameson,Harrisons principle of internal medicine 17th ed. Newyork Mc Graw-Hill; 2005.p.1137-1148
2) Shelburne SA,Visnegarwala F,Darcourt J,Graviss EA,Giordano TP,White AC Jr,
et al. Incidence and risk factors for immune reconstitution inflammatory syndrome during highly active antiretroviral therapy.AIDS 2005,19:399-406
Muhammed Ishad,
M Pharm 1st year
Alshifa college of pharmacy,
Dilip.c
Associate prof
Alshifa college of pharmacy
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