Study supports claim of HIV cure in a second
patient. No rebound of HIV in the London Patient who has stopped antiretroviral
therapy after a successful stem cell transplantation to treat his hematological
disease.
The so-called London Patient (IciStem patient #36) underwent
a stem cell transplantation as part of his cancer treatment. The transplanted
donor cells had a gene defect (CCR5delta32mutant), which renders these donor
cells resistant against most HIV variants. Now, our study shows that 30 months
after stopping antiretroviral therapy, no viral rebound has been observed in
the London Patient.
This is the longest HIV remission after stem cell
transplantation since the Berlin patient, who was the first person cured of HIV.
Although traces of HIV were found in the Berlin Patient, HIV never rebounded
and he is now celebrating his 13th anniversary of being cured. The transplanted
cells from a CCR5delta32 donor most likely protected his immune system. He also
received aggressive chemotherapy, total body irradiation and two stem cell transplants.
For over a decade, the HIV field has been puzzled regarding which of these factors were essential for his cure.
Professor Ravi Gupta of the University College London
and the University of Cambridge, published a late-breaker abstract at CROI and an
article on the London Patient in The Lancet HIV. In absence of a viral rebound
30 months after treatment interruption, several blood, semen, cerebrospinal
fluid and tissue samples, including gut, lymph node and rectal tissue, were
assessed. Using an arsenal of ultrasensitive techniques low levels of HIV DNA
could be detected in lymph node tissue and blood cells, whereas HIV was
undetectable in all other samples. Importantly, we demonstrated that the low
levels of DNA that could be detected did not represent intact replication competent
virus. The HIV DNA traces were also found in the first patient to be cured, the
Berlin Patient. Scientists suggest that these remains can be considered as
“fossils”, since they are incapable of reproducing the virus.
Dr. Björn Jensen of the Heinrich Heine University in
Dusseldorf presented another HIV-infected patient (IciStem patient #19) who
received a stem cell transplantation with these special donor cells
(CCR5delta32mutant). The Dusseldorf patient interrupted his antiretroviral
therapy 14 months ago and no viral rebound has been detected ever since. At
CROI, it was demonstrated that no HIV DNA could be detected in blood T-cell
subsets and gut biopsies (duodenum, ileum and rectum). In lymph node and gastrointestinal tract
tissues traces of HIV DNA were shown using DNA scope. Since all functional
assays were negative, it is likely that these traces do not represent
replication competent virus. These
results are compatible with sustained remission of HIV.
