Do you discover a cure for HIV?

• April 24, 2024

Two HIV-positive patients show no signs of the virus after receiving chemotherapy and stem cell transplants as a treatment for lymphoma, according to new research.

Patients have become the second and third known cases of the "sterilizing cure", in which a medical treatment eliminates all the vestiges of HIV, the virus that causes AIDS, of the organism. They have remained free of the virus although doctors stopped taking drugs for months.

"We have not been able to detect the virus either in the blood cells or in the plasma of these patients," said lead researcher Dr. Timothy Henrich of the Faculty of Medicine of the Harvard University and Brigham and Women's Hospital, Boston.

"We also did a biopsy of the intestinal tissue of one of our patients, and we were not able to detect HIV in those cells, essentially we do not have any evidence of viral recovery."

The findings will be presented at the International AIDS Society Conference in Kuala Lumpur, Malaysia.

The patients had been receiving long-term antiretroviral therapy for HIV when they developed lymphoma, a type of blood cancer that has to do with white blood cells, Henrich said.

Both underwent chemotherapy followed by bone marrow transplants to cure the lymphoma. Subsequently, Henrich could not detect any infection with HIV in their organisms.

Henrich presented some preliminary findings of the research at the International AIDS Conference. Since then, he and his researchers withdrew antiretroviral therapy from patients to see how completely anticancer treatment for HIV had been discarded. One patient has been without treatment and without detectable viruses for 15 weeks, and the other for seven.

Henrich warned that it is too early to declare that patients are completely cured. "Although we can not detect HIV, it may be present, but in extremely low amounts," he said. "We're going to wait and watch, and see what happens with these patients."

Unfortunately, this type of cure is not something that can be practiced widely in all people infected with the virus. "Transplants are not an extensible, affordable and even safe treatment for HIV patients," Henrich said.

The so-called "Berlin patient", Timothy Brown, is the first documented case of a sterilizing cure for HIV. Brown is an American man who lived in Germany and who received a bone marrow transplant to treat leukemia.

Brown has remained free of HIV even after leaving antiretroviral therapy. The transplanted bone marrow cells provided a donor carrying a rare genetic mutation that increases immunity to the most common form of the virus, and researchers believe that helped protect Brown from re-infection.

Henrich's findings are significant because his two patients did not receive bone marrow cell transplants with the genetic mutation that helped Brown. They also did not receive the intense chemotherapy or whole body radiation that preceded the Brown stem cell transplant.

His stem cell transplants seem to have been protected by ongoing antiretroviral therapy from the patients themselves, which continued while receiving cancer treatment.

"In bone marrow transplants, the donated cells actually remove and replace the recipient's blood cells," Henrich explained. "Antiretroviral therapy allowed the donor cells to replace the recipient's cells without becoming infected."

By comparing Brown to the two new patients, researchers hope to better understand the immune responses that have protected all three, said Rowena Johnston, vice president and research director of amfAR (Foundation for AIDS Research), which sponsors Henrich's research.

"At that time it was not at all clear how the cure had occurred," Johnston said of Brown's case. "One way in which Henrich's findings are significant is that they allowed us to differentiate between the factors that could have been key in Timothy Brown's cure."

"We currently imagine that curing people on a large scale through stem cell transplants would pose many serious problems, but researchers in gene therapy are working on ways that maybe one day may be possible," Johnston said.

The findings presented at meetings should be considered preliminary until they are published in a medical journal reviewed by professionals.
 

Video Medicine: A potential cure for HIV | The Economist (April 2024).