Munich, Germany — In a groundbreaking development that could reshape the future of HIV treatment, a 60-year-old man from Germany has been declared at least the seventh person to be free of the HIV virus following a stem-cell transplant.
This case, revealed at the 25th International AIDS Conference in Munich, marks a significant advancement in HIV research, especially because the patient received stem cells from a donor with a less conventional genetic profile.
The Next Berlin Patient
The patient, who has been HIV-free for nearly six years, is being referred to as the “next Berlin patient.”
His case is particularly noteworthy because, unlike previous patients, he did not receive stem cells from a donor with a complete CCR5 gene mutation—a mutation that has been a focal point in HIV cure research.
Instead, the donor had only one copy of the mutated gene, which means the patient’s cells still express the CCR5 receptor, albeit at lower levels.
Ravindra Gupta, a microbiologist from the University of Cambridge who led a team treating a previous HIV-free patient, expressed his surprise at the results. “I am quite surprised that it worked,” Gupta said. “It’s a big deal.”
The “Berlin patient” Timothy Ray Brown was the first person to achieve HIV remission following a bone-marrow transplant to treat blood cancer.
Brown, along with others who have achieved similar outcomes, received stem cells with a complete CCR5 gene mutation. This mutation prevents the HIV virus from entering immune cells, offering a potential pathway to a cure.
A Shift in Paradigm
The latest case challenges the prevailing notion that a complete CCR5 gene mutation is essential for an HIV cure.
The new patient’s stem cells carried only one mutated copy of the CCR5 gene, suggesting that the presence of a single mutated gene may still provide substantial protection against the virus.
Sharon Lewin, an infectious-disease physician and head of The Peter Doherty Institute for Infection and Immunity in Melbourne, Australia, noted that this case illustrates that the quest for an HIV cure may not be solely about targeting CCR5.
“The case sends a clear message that finding a cure for HIV is not all about CCR5,” she said.
The findings from this case could have profound implications for expanding the pool of potential stem-cell donors.
While approximately 1% of people of European descent carry mutations in both copies of the CCR5 gene, around 10% have one mutated copy. This broader donor pool could make stem-cell transplants a more feasible option for patients with HIV.
Journey to Remission
The patient, whose identity remains confidential, was diagnosed with HIV in 2009. In 2015, he developed acute myeloid leukemia, a type of blood and bone-marrow cancer.
Despite a challenging search, doctors were unable to find a matching stem-cell donor with both copies of the CCR5 mutation. Instead, they found a female donor with one mutated copy of the gene, mirroring the patient’s genetic profile.
Following the stem-cell transplant in 2015, the patient’s cancer treatment was successful, and his bone-marrow stem cells were replaced with those from the donor.
By 2018, he stopped taking antiretroviral drugs, which are typically used to suppress HIV. Remarkably, almost six years later, researchers have found no evidence of HIV replication in his system.
Christian Gaebler, a physician-scientist and immunologist at Charité – Berlin University Medicine, presented the results at the conference.
He noted that the rapid replacement of the patient’s bone-marrow stem cells with donor cells might have been crucial in eradicating the virus.
“The cancer treatment went very well,” Gaebler said. “Within a month, the patient’s bone-marrow stem cells had been replaced with the donor’s.”
Exploring New Mechanisms
Previous attempts at curing HIV through stem-cell transplants using regular CCR5 genes have generally seen the virus return after antiretroviral therapy is discontinued.
However, in 2023, the “Geneva patient” was reported to be HIV-free for about 32 months following similar procedures. Researchers are now exploring why these particular cases succeeded where others have failed.
Several theories have been proposed. One possibility is that antiretroviral treatment significantly reduces the amount of virus in the body, while chemotherapy before the stem-cell transplant eliminates many of the host’s immune cells, where residual HIV might reside.
The transplanted donor cells might then target and destroy any remaining host cells and the virus within them.
Another factor could be the partial mutation of the CCR5 gene in both the patient and donor, which might have created an additional barrier to the virus entering cells. This partial mutation could be a significant factor in the success of the treatment.
Implications for Future Treatments
The implications of these findings extend beyond stem-cell transplants. The case has significant ramifications for therapies currently in early-stage clinical trials.
Some of these therapies involve using CRISPR-Cas9 and other gene-editing techniques to remove the CCR5 receptor from a patient’s own cells. Even if these treatments do not reach every cell, they could still impact the virus significantly.
Sara Weibel, a physician-scientist at the University of California, San Diego, emphasized that this case “broadens the horizon of what might be possible” for treating HIV.
With around 40 million people living with HIV globally, these developments offer hope for new avenues of treatment and potentially a broader range of therapeutic options.
As researchers continue to investigate the mechanisms behind these successful cases, the medical community remains hopeful that these breakthroughs will pave the way for more effective and accessible HIV treatments in the future.
Conclusion
The announcement of the German man’s HIV-free status represents a monumental step forward in the fight against HIV. While challenges remain, the success of this case underscores the potential for new treatment strategies and broadens the possibilities for curing HIV.
The scientific community, and indeed millions of people living with HIV worldwide, will be watching closely as researchers continue to unravel the complexities of this promising breakthrough.
This article was created using automation technology and was thoroughly edited and fact-checked by one of our editorial staff members
