Christian had been off antiviral drugs for almost a year. It was October in Germany, a time of year when tourists come from all over the world to participate in the festivities of Oktoberfest. Berlin’s streets were crowded with celebration. Christian, on the other hand, was nervous. For months now, he had been going in for blood tests, but today they were going to stick a needle in his lymph nodes to see if HIV was hiding in there.
For Jessen, the last few months had been surreal. Christian had kept all his appointments faithfully, coming in regularly to have his blood drawn. Christian said he felt healthy, he was sure the HIV was gone from his body. Remarkably, this seemed to be true. Despite using PCR tests sensitive enough to detect as little as 500 copies of the virus in his blood, they had been unable to detect any virus at all.
There were other signs that Christian had overcome HIV. In a healthy person, commander and storm trooper T cells are found in roughly equal numbers, in a 1:1 ratio. While a healthy person’s ratio ranges from 1 to 4, in AIDS patients, the number of commander T cells dips dangerously low to ratios below 0.5. This low ratio means the immune system is in trouble. With dwindling numbers of commander T cells, the immune system can’t even recognize which cells are infected with HIV, much less target them for destruction. Physicians often use the ratio of commanders to storm troopers to assess the health of an HIV patient.
On the first day Christian took therapy, in June 1996, his commander-to-storm-trooper ratio was 0.52. Having such a low ratio early in the course of the infection shows that Christian’s immune system was already struggling. Surprisingly, this ratio slowly climbed, even when he stopped his therapy early. Two years after he first started therapy, and a year and a half after he stopped, his ratio was 0.87, completely in the normal range for a healthy person uninfected with HIV. As well as the improved ratio, the sheer number of commander T cells had more than doubled over the same period.
At the same time, the number of naive T cells doubled in Christian’s blood from a low 24 percent to a typical 49 percent. Naive T cells are officers in training. They are the T cells that, fresh from their time maturing in the thymus, are patrolling the body, looking for invaders. Naive T cells stand in contrast to memory T cells, which have encountered a foreign intruder and remember it. These memory cells have been educated by war. They subsequently become “activated,” meaning they’re ready to plan an attack with the other cells of the immune system. The fact that Christian’s body had regained the naive T cell pool was a welcome sign that the virus was no longer dominating his immune system.
When Jessen called Lisziewicz to tell her the virus was still undetectable in Christian months after he stopped therapy, at first she didn’t believe him. She was sure there must be some mistake. Finally, as Jessen’s insistent phone calls increased with intensity, Lisziewicz traveled to Germany. When she looked at Jessen’s data, she remained incredulous. What he was showing her was impossible.
Then, timidly, she said aloud, “Perhaps we have eradicated HIV in this patient.”
Both Jessen and Lisziewicz knew that if they wanted to prove that this one patient was truly cleared of the virus, they would need some heavy-hitting partners. They would need to bring in the big names in HIV that had both the methods and prestige to prove to the world that a patient had been cured. Lisziewicz’s first call was to Bob Siliciano. He is an MD/PhD at Johns Hopkins University School of Medicine who, in 1997, published a highly influential paper in Science. Together with his colleagues, he had developed a new method to detect HIV in resting T cells. Resting T cells are just how they sound: They’re inactive, unlike their dividing counterparts. Roughly 95 percent of the T cells in the blood are resting, awaiting the arrival of an outsider to propel them into action.
Because HIV likes to hide in resting T cells, measuring the amount of virus in these cells is a critical test in assessing the ability of any therapy to cure HIV. This is because clearing the virus from the blood isn’t enough to cure someone of HIV. This became apparent in the mid-1990s when the new antiviral drugs proved themselves incredibly effective. Within a few months of using them, many patients went from high levels of HIV in the blood to none at all. Scientists hoped that the presence of these drugs was enough to wipe out the virus from the body so that patients wouldn’t have to take the drugs forever. Siliciano’s paper in 1997 dashed these hopes. His research showed that despite the fact that antiviral therapy drops HIV to undetectable levels in the blood, the virus is still hiding in resting T cells. These cells are a perfect hiding spot, for they can remain dormant for years, even decades, below the detection of the immune system and beyond the reach of antiviral therapy. The virus, stably inserted within our DNA, is able to bide its time, waiting until therapy is stopped and it can take over the immune system once again. Siliciano’s research showed that the amount of virus hiding in these resting T cells does not decrease in proportion to the amount of time someone is on therapy. So it doesn’t matter how long a person is on antiviral therapy—it can never wipe out the virus. At least not by itself.
This assay was obviously the one that Jessen and Lisziewicz needed to prove that their patient was different. That the unique therapy he had been given had cleared him of the virus. Siliciano hadn’t had a patient with HIV yet that he couldn’t detect virus in. This would be the ultimate challenge. Jessen sent half a liter of Christian’s blood, about the same volume as a pint of milk, to Siliciano’s lab in Baltimore and waited on tenterhooks.
Siliciano’s group found something completely unprecedented. They couldn’t detect any virus in Christian’s blood. It looked just like the blood of a person who had never been infected with the virus. Of course everyone knew the experiment would have to be repeated and this was just a single result, but still . . . it was a wonder.
Jessen and Lisziewicz next needed to determine if there was any HIV in Christian’s lymph nodes. Lymph nodes are tiny lima-bean-shaped organs distributed throughout our body. When we get a cold, we notice these tiny organs, often under the jaw, as they swell up uncomfortably, a sign that our immune system is up and running, fighting an infection. The lymph nodes act as a filtration system for the body, concentrating foreign particles. Millions of white blood cells are packed into each lymph node, the perfect staging ground for the start of an immune system attack. It’s also the perfect environment for HIV to multiply and destroy. It’s like a sneak attack on the enemy camp. When someone begins taking antiviral therapy, and the virus becomes undetectable in their blood, the virus can still be found lurking in the lymph nodes. Ultimately, because the virus multiplies to such high levels in the lymph nodes, it begins to destroy the organs, replacing the complex native architecture with a swath of scar tissue. This effectively cuts off the organ from the rest of the immune system. Jessen and Lisziewicz knew that if the lymph nodes were still intact, it would help explain the lack of virus in his body. They called Cecil Fox, a researcher, also in Maryland, who had just published an influential paper detecting HIV in lymph nodes. He was the leader in the field.
What Fox found when he examined Christian’s lymph nodes was complicated. The lymph nodes were intact—a victory for the body against a virus skilled at destroying them. However, Fox could detect a “trace of HIV.” While most research methods wouldn’t have been able to detect any HIV in the lymph nodes, Fox, with his sophisticated equipment and extensive experience, was able to see something, although the amount was too low to quantify. Jessen and Lisziewicz, in no position to question an established expert in the field, decided that the best solution was to resample the lymph nodes. At the same time, they sent another half liter of Christian’s blood to Siliciano’s lab to repeat the search for HIV in resting T cells, the known reservoir of the virus.
Given the remarkable initial result, the Siliciano team redesigned their assay to make it five times more sensitive. They could now detect as little as a single infected memory T cell in a sea of 10 billion. The revolutionary technological feat was something of a compliment to Christian’s immune system. This work paid off. Siliciano’s group was able to find virus lurking in Christian’s resting T cells, albeit at a very low frequency. Siliciano found that less than one of every billion cells in Christian harbored HIV. More important, they found that the virus hadn’t changed. The lack of new mutations meant the virus had not been crippled by the immune system. Crippled virus is a phenomenon that would be documented later in HIV controllers, where the immune system put so much pressure on the virus that it mutated wildly to avoid the immune system attack. The heavily mutated viruses found in HIV controllers were no longer able to replicate and make more of themselves. They had effectively mutated themselves into a box, cornered by an immune system that was too smart for them. This wasn’t so in Christian’s case. The virus in him, when cultured in a dish in the incubator, was able to grow normally. So why wasn’t it growing inside him?
The mystery deepened. A few months later, after the second set of Christian’s lymph nodes was sampled, Fox found that only 3 of 4.4 billion cells harbored HIV. How was it that Christian had these tiny, hardly quantifiable pockets of virus in hidden cells, but the virus hadn’t surged back into his blood? Lisziewicz knew it must be due to some kind of immune response. She decided to make a call to the man best known for characterizing immune responses to HIV: Bruce Walker.
Walker was the researcher who, back in 1996, had published several papers looking at how storm trooper T cells target and destroy HIV-infected cells. He also had a small group of people who were infected with HIV but had no symptoms. Inside this small group of HIV controllers, he found something remarkable: Their storm trooper T cells were highly active against HIV. Walker developed an assay to measure the strength and specificity of these storm trooper cells against HIV. Lisziewicz knew this novel assay was the perfect tool for understanding how Christian was keeping the virus under control. If his body hadn’t crippled the virus through a coordinated attack mediated by a genetic advantage, then perhaps the answer to this mystery lay in the unique therapy he had been given. Jessen and Lisziewicz hypothesized that giving Christian an intense, early therapy had beaten down the virus enough to let his immune system mount a proper attack.
When Walker got the call from Lisziewicz, he was shocked. This was just the case he had been waiting for. He believed that early, aggressive therapy was the answer, that it represented a path to eliminating the virus. He was simply waiting for the right clinical case to back up his theory and pave the way to new clinical trials. HIV researchers hardly ever use the word cure, a word that carries such import, it would be reckless to throw it around. Yet how else could one describe Christian’s experience? He had been infected with HIV, given an early, highly aggressive therapy, and no longer needed to take therapy. For all intents and purposes, the virus was cleared from his body. After speaking with Lisziewicz, Walker sent off a dozen e-mails to friends and collaborators. He was so excited about this fresh example of the power of HIV therapy, he couldn’t wait to get ahold of some of Christian’s storm trooper T cells, fresh from Berlin.
At the time, no company would risk shipping HIV-positive samples. Instead, Walker sent someone to fly to Berlin and pick up the precious cells. He sent Alicja Piechocka-Trocha, a technician who would work beside him his entire independent research career and who still manages the lab like clockwork. Returning the cells to Boston, Piechocka-Trocha prepared the assay Walker had developed when he was still in training, the enzyme-linked immunosorbent spot assay, nicknamed ELISPOT. ELISPOT, like the ELISA, is an HIV test that measures the ability of the immune system to recognize HIV and make antibodies against the virus. In this assay, instead of looking at antibodies, we measure the ability of the storm troopers to recognize and kill specific pieces of HIV. A clear plastic plate dimpled with ninety-six tiny wells was filled with tiny pieces of HIV, taken from each part of the virus. Christian’s storm trooper T cells in varying concentrations were added to each well. Each condition was repeated several times. The storm trooper T cells kicked into action when coming into contact with a part of the gag gene, a key structural component of the virus that keeps the inner compartment of the virus intact. The cells released interferon-γ, or IFN-γ, a small protein called a cytokine. This humble protein is able to communicate with other cells, and it is a potent antiviral agent. IFN-γ is able to specifically recognize the double-stranded RNA of a virus and then draw in all the molecules and pathways needed to kill the infected cell. When Christian’s cells released IFN-γ in response to a specific piece of the virus, it combined with a secondary antibody on the ELISPOT plate and turned the cells releasing the cytokine a bluish-purple. Each of these special wells became a polka-dot explosion, the number of purple dots indicating the intensity of the HIV-driven immune response. Piechocka-Trocha then put that plate in a reader that looks at each well individually and counts each tiny purple dot. For the part of HIV called gag, more than 2,000 cells released IFN-γ. It was a spectacularly vigorous response to the virus.
Finally, Jessen had an explanation for his seemingly miraculous patient. Christian’s storm trooper T cells were able to mount an unusually powerful attack. It finally made sense how Christian could still harbor virus but the virus couldn’t gain a foothold in his body. His immune system was able to keep the virus in check. Walker was elated at the news. This patient given early therapy now had an immune system that looked like one of his elite controllers. When talking to Lisziewicz about the data, he wasn’t sure exactly what to call this Berlin patient. His name had never been given to Walker, to protect Christian’s privacy. Instead, Walker decided to stay with “Berlin patient.” It was a name that would stick, percolating down to scientists, to HIV support groups, and eventually to the press.
It’s important to note that the ELISPOT assay is, like almost all assays, imperfect. It’s impossible to replicate something as intricate as the human immune system in a well that holds less than a tenth of a teaspoon of liquid. You’ll notice that nowhere in the description of the assay are mentioned a key player: the commanders. We also can’t be sure how important IFN-γ is to the immune response to HIV. But despite these reservations, ELISPOT remains a powerful and frequently used tool to assess the strength of a patient’s immune response to the virus. Clearly, this assay showed that, for Christian, his storm trooper T cells were able to recognize and respond to HIV infection in ways that most people can’t.
Armed with a titillating case study, powerful data, and an all-star cast of HIV researchers, Jessen began to prepare the paper. He collected the data from the multiple collaborators as well as his own data from treating Christian. He wrote up a short paper and sent it off with the article to Lisziewicz, assuming he would be listed as first author. It was a reasonable assumption. After all, Christian was his patient, he was the one who decided to perform a small trial of the experimental medication inspired by Andrew, and he collated the data and wrote up the article.
In science, authorship is a precious and valued prize. The first author on a paper is usually the one who has done most of the work. The first author is typically the person who came up with the project idea, designed the experiments, and performed them. The first author nurtures the project like a baby, growing what was once only an idea into a real set of experiments, into a dataset that’s analyzed, and into a paper that’s published and finally read by scientists and journalists around the world. The last author, or senior author, is typically the person who funds the project. The senior author usually assists in interpreting the results and helps edit the paper. Between the first and senior authors is everyone else who worked on the project: technicians, graduate students, and collaborators. Even these names have a hierarchy, stretching down from those who put in the most effort to the least, with a special place reserved for “next to last” author, who often plays a significant senior-author-like role in the paper. These roles can shift; sometimes first and senior authors do more work and sometimes less. The hierarchy, however, is important. How many first- and senior-author papers a scientist has to his or her credit determines the ability to get faculty positions, to get tenure at a university, and to get grant money.
Everyone wants first author. For this paper, the situation was no different. Since it was being submitted to The New England Journal of Medicine, the competition was especially fierce. Being first author was already a big deal, but to be first author in such an important journal was a special opportunity. Immediately, the claws came out; everyone wanted first author: Lisziewicz, Walker, and, of course, Jessen. Remembering the fight that ensued over authorship, Lisziewicz calls it “sad.” For her part, she felt she deserved first authorship at the time. She had coordinated the collaborators, bringing on the people needed to figure out what was going on in Christian’s body. She was also the reason Jessen tested hydroxyurea in the first place. Walker feels bad about authorship on the paper as well, although his memory of the negotiations is limited.
Ultimately, Jessen was pushed out of the first-author position. It was given to Lisziewicz, and Jessen was shoved all the way down to fourth author. A surprising position for the scientist who decided to start a risky trial, recruited the patient, performed key experiments, and wrote up the paper. Some of those involved believe that putting Jessen as fourth author on the paper was blatantly unfair. One potential reason for his position on the paper is that Jessen was primarily a physician, not a scientist. Because of this, it was easier to claim that authorship was not as important to Jessen as it was to the other scientists involved. His salary comes from patients and insurance, not precious grant money.
Authorship settled, Christian’s story was published in The New England Journal of Medicine in May 1999. The first line of the paper reads, “A patient, who has become known as ‘the Berlin patient,’ was treated soon after acute HIV infection.” With those words, the tale of the Berlin patient would spread, seeping into research labs worldwide and fueling the imaginations of many living with the virus.