Berlin Patient Research Articles

Absence of Detectible HIV-1 Viremia After Treatment Cessation in an Infant.

Until very recently, the only patient “cured” of HIV was the “Berlin patient,” an adult male treated for HIV-associated acute myeloid leukemia with stem cell transplantation from a donor who was intrinsically resistant to HIV. The donor carried homozygous mutations (delta32) in the chemokine receptor 5 gene, which is an essential co-receptor for HIV entry into most target cells. The present study reports on an infant who also may be cured with early, highly active antiretroviral therapy (ART) after documented perinatal infection.A 35-week gestational age infant was born by normal vaginal delivery to an HIV-infected woman who received no prenatal care and who was not taking ART. ART was initiated in the infant at 30 hours of age with zidovudine, lamivudine, and nevirapine. At 1 week of age, this regimen was adjusted to zidovudine, lamivudine, and ritonavir-boosted lopinavir. The infant remained on ART for 18 months and was then lost to follow-up until 23 months of age. ART has been discontinued and, because of results from subsequent studies, has not been restarted.Standard HIV polymerase chain reaction (PCR) assays and HIV antibody testing were used to diagnose and monitor the HIV-exposed infant. Peripheral blood mononuclear cell cultures were analyzed with PCR for virus DNA and with co-culture techniques for replication-competent virus. Lymphocyte subset analysis was conducted with standard flow cytometry, and HIV-specific T-cell responses were evaluated with intracellular cytokine generation assays.During the first month of life and while receiving ART, the infant had elevated quantitative HIV RNA PCR measurements that declined to undetectable levels and remained there. Subsequently, although proviral DNA was detected at the limits of the assay at 26 months of age, plasma viral RNA was undetectable, and replication-competent virus could not be cultured at age 24 months. HIV antibody assays were not detected in the infant at or after 24 months of age, when maternal antibody would not confound the assays, and HIV-specific T-cell responses were not detected at age 28 months. CD4+ T-cell counts remain normal throughout the study.Very early ART therapy in infants born at risk may abort HIV infection.In patients with established HIV infection, effective ART drives the virus to “undetectable” levels, usually defined as <20/copies of viral RNA/mL of plasma. However, viremia persists in such patients at very low levels and as DNA pro-virus in peripheral blood mononuclear cells. Was this infant cured of HIV? According to the Centers for Disease Control and Prevention definition, the infant was “infected”: 2 positive PCR test results on at least 2 different blood specimens. The data presented demonstrated that after unintended discontinuation of therapy, the infant remained free of replication-competent HIV from at least 12 months of age. As the authors conclude, “very early ART in infants may alter the establishment and long term persistence of HIV-infection.” But why might this happen in a newborn when it has not been demonstrated in older patients except under the unique circumstances of the Berlin patient? HIV persistence depends on the establishment of a reservoir of infected cells. Recent studies suggest that this condition involves a specific population of “central memory T cells.” Perhaps very early therapy aborts or inhibits establishment of this reservoir or perhaps these cells have not fully matured to be infected in newborns. In any case, the present report suggests that very early therapy may prevent establishment of HIV in high-risk infants, and certainly this possibility is being studied intensively.

Lymphoid fibrosis occurs in long-term nonprogressors and persists with antiretroviral therapy but may be reversible with curative interventions.

Human immunodeficiency virus (HIV) replication causes lymphoid tissue (LT) fibrosis, which causes CD4(+) T-cell depletion. It is unknown whether people who spontaneously control HIV replication have LT fibrosis. We measured LT fibrosis and CD4(+) T cells in 25 HIV controllers, 10 noncontrollers, 45 HIV-positive individuals receiving therapy, and 10 HIV-negative individuals. Controllers had significant LT fibrosis and CD4(+) T-cell depletion, similar to noncontrollers, but the so-called Berlin patient (in whom HIV infection was cured) had near normal LT. Thus, LT fibrosis occurs in all HIV-infected subjects, and current therapy does not reverse it. Reversal of fibrosis during a curative intervention suggests that ongoing low-level virus production may maintain LT fibrosis.

Targeting CCR5 for anti-HIV research.

Highly active antiretroviral therapy (HAART) is the only approach for human immunodeficiency virus (HIV) infection treatment at present. Although HAART is effective in controlling the progression of infection, it is impossible to eradicate the virus from patients. The patients have to live with the virus. Alternative ways for the cure of HIV infection have been investigated. As the major co-receptor for HIV-1 infection, C-C motif chemokine receptor 5 (CCR5) is naturally an ideal target for anti-HIV research. The first CCR5 antagonist, maraviroc, has been approved for the treatment of HIV infection. Several other CCR5 antagonists are in clinical trials. CCR5 delta32 is a natural genotype, conferring resistance to CCR5 using HIV-1 strains. Gene therapy research targeting this mutant has been conducted for HIV infection treatment. A Berlin patient has been cured of HIV infection by the transplantation of stem cells from a CCR5 delta32 genotype donor. The infusion of an engineered zinc finger nuclease (ZFN)-modified autologous cluster of differentiation 4 (CD4) T cells has been proved to be a promising direction recently. In this study, the anti-HIV research targeting CCR5 is summarized, including CCR5 antagonist development, stem cell transplantation, and gene therapy.

Is ART suspension never a good idea? - Cons

In the mid ‘90s tremendous progress has marked the pharmacological approach to HIV-1 disease, resulting in the almost complete reversal of the “death sentence” that was associated with the diagnosis of HIV infection and AIDS. However, the terrific advantages of combination antiretroviral therapy (cART) are not available homogeneously on a global scale, with the number of individuals becoming infected still outscoring that of infected people starting treatment. Even restricting the analysis to those countries, including Europe, where cART is largely available, there are several considerations supporting the concept that therapy suspension could still be considered in specific settings, and not only for facing the management of accumulation of multidrug resistant viral species or therapy-related side effects. In fact, some of the most novel and exciting novelties in the field of HIV research have arisen from examples of either casual or programmed therapy suspension. In the case of the so-called “Mississippi Baby”, a newborn (from a mother with undiagnosed AIDS until the time of delivery) was treated with cART shortly after delivery; nonetheless, she became unequivocally infected, but seroreverted after a few weeks. Later, cART was suspended for unknown reasons, surprisingly resulting in the lack of virus rebound and HIV detectability by multiple testing, leading to the hypothesis that she might represent the second case of “cure” after Tymothy Ray Brown, the “Berlin patient” .I n a second example, adult French patients who started their antiretroviral regimens very early after primary HIV infection, underwent therapy suspension after a few years resulting in an unexpected high frequency of spontaneous control of HIV-1 viremia and disease progression (Post-therapy controllers, or VISCONTI cohort). The likelihood that they might represent conventional spontaneous controllers of disease progression, such as LTNP or Elite controllers, is minimal in that their genetic profile is enriched in the BW35 MHC allele that is counterselected in these categories. In summary, without these and other example of cART suspension our current understanding of the potential opportunities to tilt the balance in favor of the host rather than of the virus would be more limited and perhaps would prevent future strategic approaches to achieve long-term control of HIV infection with minimal side effects related to cART.

Dependence on the CCR5 Coreceptor for Viral Replication Explains the Lack of Rebound of CXCR4-Predicted HIV Variants in the Berlin Patient

The "Berlin patient" is the first patient cured of HIV-1 infection after allogeneic transplantation with nonfunctional CCR5 coreceptor stem cells. We demonstrate that CXCR4-predicted minority viruses present prior to transplantation were unable to rebound after transplantation due to their dependence on CCR5 for replication and high genetic barrier toward CXCR4 usage.

The transient HIV remission in the Mississippi baby: why is this good news?

As researchers, clinicians and community advocates gathered for the 20th International AIDS Society meeting in Melbourne in July of this year, the announcement of resumption of viremia in the Mississippi baby came as an unwelcome surprise. The case had previously stirred excitement that a cure was possible without the extreme measure of bone marrow transplantation as in the Berlin patient [ 1 ]. When this was no longer true, conversations about the end of our quest for a HIV cure ensued. (Published: 20 November 2014) Ananworanich J and Robb ML. Journal of the International AIDS Society 2014, 17 :19859 http://www.jiasociety.org/index.php/jias/article/view/19859 | http://dx.doi.org/10.7448/IAS.17.1.19859

CCR5 as a Natural and Modulated Target for Inhibition of HIV

Human immunodeficiency virus type 1 (HIV-1) infection of target cells requires CD4 and a co-receptor, predominantly the chemokine receptor CCR5. CCR5-delta32 homozygosity results in a truncated protein providing natural protection against HIV infection—this without detrimental effects to the host—and transplantation of CCR5-delta32 stem cells in a patient with HIV (“Berlin patient”) achieved viral eradication. As a more feasible approach gene-modification strategies are being developed to engineer cellular resistance to HIV using autologous cells. We have developed a dual therapeutic anti-HIV lentiviral vector (LVsh5/C46) that down-regulates CCR5 and inhibits HIV-1 fusion via cell surface expression of the gp41-derived peptide, C46. This construct, effective against multiple strains of both R5- and X4-tropic HIV-1, is being tested in Phase I/II trials by engineering HIV-resistant hematopoietic cells.

Newer Gene Editing Technologies toward HIV Gene Therapy

Despite the great success of highly active antiretroviral therapy (HAART) in ameliorating the course of HIV infection, alternative therapeutic approaches are being pursued because of practical problems associated with life-long therapy. The eradication of HIV in the so-called “Berlin patient” who received a bone marrow transplant from a CCR5-negative donor has rekindled interest in genome engineering strategies to achieve the same effect. Precise gene editing within the cells is now a realistic possibility with recent advances in understanding the DNA repair mechanisms, DNA interaction with transcription factors and bacterial defense mechanisms. Within the past few years, four novel technologies have emerged that can be engineered for recognition of specific DNA target sequences to enable site-specific gene editing: Homing Endonuclease, ZFN, TALEN, and CRISPR/Cas9 system. The most recent CRISPR/Cas9 system uses a short stretch of complementary RNA bound to Cas9 nuclease to recognize and cleave target DNA, as opposed to the previous technologies that use DNA binding motifs of either zinc finger proteins or transcription activator-like effector molecules fused to an endonuclease to mediate sequence-specific DNA cleavage. Unlike RNA interference, which requires the continued presence of effector moieties to maintain gene silencing, the newer technologies allow permanent disruption of the targeted gene after a single treatment. Here, we review the applications, limitations and future prospects of novel gene-editing strategies for use as HIV therapy.

Mesenchymal stem cell therapy in HIV-infected HAART-treated nonimmune responders restores immune competence

Mesenchymal stem cell therapy in HIV-infected HAART-treated nonimmune responders restores immune competence

Targeted gene disruption to cure HIV

Recent clinical research suggests that an HIV-infected patient with lymphoma who was transplanted with bone marrow homozygous for a disrupted mutant CCR5 allele has no remaining HIV replication and is effectively cured of HIV. Here, we discuss the approaches of disrupting host and viral genes involved in HIV replication and pathogenesis with the aim of curing patients with HIV. Data from the 'Berlin patient' suggest that targeted gene disruption can lead to an HIV cure. This review discusses the recent advances in the field of gene disruption toward the development of an anti-HIV therapy. We will introduce the strategies to disrupt host and viral genes using precise disruptions, imprecise disruptions, or site-specific recombination. Furthermore, the production of engineered rare-cutting endonucleases (zinc finger nucleases, TAL effector nucleases, and homing endonucleases) and recombinases that can recognize specific DNA target sequences and facilitate gene disruption will be discussed. The discovery of a gene disruption approach that would cure or efficiently confine HIV infection could have broad implications for the treatment of millions of people infected with HIV. An efficient 'one-shot' curative therapy not only would give infected patients hope of a drug-free or treatment-free future, but also could reduce the huge financial burden faced by many countries because of widespread administration of highly active antiretroviral therapy.

The Cure of HIV with Hematopoietic Cell Transplantation

Hematopoietic cell transplantation (HCT) has produced the only known cure of HIV infection in a patient. The patient had AML and HIV infection and was transplanted in 2007 using peripheral blood stem cells from an adult CCR5-delta32/delta32 donor. The patient, now known as “The Berlin Patient”, does not require antiretroviral drug therapy and, in the analysis of peripheral blood cells and numerous tissue samples, no proviral DNA can be detected. However, this successful HCT has not been repeated because the frequency of CCR5-delta32/delta32 is less than 1% in Caucasians and much less in other ethnic groups, and patients in need of an HCT generally have only a few potential donors. Moreover, a very close HLA match between donor and patient is required when an adult donor is used. In marked contrast, cord blood HCT requires a significantly less stringent HLA match between donor and patient making it much more feasible to find an appropriate unit for an HIV infected patient. We have tested more than 18,000 cord blood samples from our cord blood bank and collaborating cord blood banks, and have identified 121 cryopreserved CCR5-delta 32/delta32 units that are available for HCT. An adequate cord blood cell dose need be only 1 x 10(7) TNC/kg if a combined haploidentical/cord blood transplant is performed. Projections of HLA match rates for an inventory of 300 homozygous units indicates a probability of finding an adequately matched cord blood unit with an adequate cell dose 82.1% of the time for Caucasian adults and for 85.6% for Caucasian pediatric patients. For adult African-Americans, Mexican-Americans and Chinese-Americans the potential HLA match rates are 31.6%, 48.9% and 13.9%, respectively. Patients who have an indication for an HCT for a hematologic malignancy or other disorder, and who are infected with HIV should be considered for transplantation with a CCR5-delta32/delta32 cord blood unit.

Attacking the HIV Reservoir from the Immune and Viral Perspective

Upon HIV infection, a subset of latently infected cells carrying transcriptionally inactive integrated proviral DNA (the HIV-1 reservoir) is rapidly established. These cells are the main force behind HIV persistence under highly active antiretroviral therapy (HAART), which only impacts on actively replicating viruses and it is therefore unable to eradicate the infection. However, the case of Timothy Brown, also known as the Berlin patient, demonstrates that eradication is possible, and recent data support the idea that latency may be reverted in vivo, suggesting that it is possible to perturb the HIV-1 reservoir. This may be achieved by implementing both pharmacological and immunological strategies to reactivate HIV-1 from latently infected cells. Nevertheless, reactivation might not be sufficient to eradicate the virus. Reinforcing HIV-1-specific immune responses and blocking potential new events of viral replication will probably help reaching the final goal of eradication or the alternative objective of a functional cure for HIV-1.

HIV infection

At a satellite meeting prior to the International AIDS Meeting in Washington DC in July, a great deal of discussion was focused on finding a “cure” for HIV infection [1]. While this objective has been discussed at various times over the past decade, the real incentive for this goal comes from the encouraging findings with Timothy Brown, also known as the “Berlin patient.” This HIV-infected man received hematopoietic stem cells from an HLA-matched donor whose genome naturally lacked CCR5, the major receptor for HIV. Five years after two transplants, Mr. Brown appears to be cured of HIV as well as leukemia [2]. Although potentially infected with both a virus that requires CCR5 for entry and a small population of viruses that can infect cells by another receptor, no infectious virus can be recovered from his blood and other tissues. This finding includes biopsies from the brain, bowel, and lymph nodes. Certainly his “cure” encourages approaches that could mimic this achievement in all HIV-infected individuals.

Controversies in HIV cure research.

BackgroundAntiretroviral therapy significantly reduces HIV viral burden and prolongs life, but does not cure HIV infection. The major scientific barrier to a cure is thought to be the persistence of the virus in cellular and/or anatomical reservoirs.DiscussionMost efforts to date, including pharmaco, immuno or gene therapy, have failed to cure patients, with the notable exception of a stem cell transplant recipient commonly known as the Berlin patient. This case has revived interest in the potential to cure HIV infection and has highlighted the need to resolve critical questions in the basic, pre-clinical and clinical research spheres as they pertain specifically to efforts to eradicate HIV from the body of an infected person (a sterilizing cure) or at least render the need for lifelong antiretroviral therapy obsolete (functional cure). This paper describes ongoing debates in each of these research spheres as they were presented and discussed at a satellite session that took place at the 6th International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention in Rome in July 2011.SummaryThe resolution of these debates may have important implications for the search for a cure, the most efficient ways to identify and test promising interventions, and ultimately the availability of such a cure to diverse groups of HIV patients around the world.

Current Progress and Challenges in HIV Gene Therapy

HIV-1 causes AIDS, a syndrome that affects millions of people globally. Existing HAART is efficient in slowing down disease progression but cannot eradicate the virus. Furthermore the severity of the side effects and the emergence of drug-resistant mutants call for better therapy. Gene therapy serves as an attractive alternative as it reconstitutes the immune system with HIV-resistant cells and could thereby provide a potential cure. The feasibility of this approach was first demonstrated with the 'Berlin patient', who was functionally cured from HIV/AIDS with undetectable HIV-1 viral load after transplantation of bone marrow harboring a naturally occurring CCR5 mutation that blocks viral entry. Here, we give an overview of the current status of HIV gene therapy and remaining challenges and obstacles.

Characteristics and Predictors of Obstructive Sleep Apnea in Patients With Systemic Hypertension

Obstructive sleep apnea (OSA) is a secondary cause of hypertension and independently associated with target-organ damage in hypertensive patients. However, OSA remains largely underdiagnosed and undertreated. The aim of the present study was to evaluate the characteristics and clinical predictors of OSA in a consecutive series of patients followed up in a hypertension unit. A total of 99 patients (age 46 + or - 11 years, body mass index 28.8 kg/m(2), range 25.1 to 32.9) underwent polysomnography. The clinical parameters included age, gender, obesity, daytime sleepiness, snoring, Berlin Questionnaire, resistant hypertension, and metabolic syndrome. Of the 99 patients, 55 (56%) had OSA (apnea-hypopnea index >5 events/hour). Patients with OSA were older and more obese, had greater levels of blood pressure, and presented with more diabetes, dyslipidemia, resistant hypertension, and metabolic syndrome than the patients without OSA. Of the patients with OSA, 51% had no excessive daytime sleepiness. The Berlin Questionnaire and patient age revealed a high sensitivity (0.93 and 0.91, respectively) but low specificity (0.59 and 0.48, respectively), and obesity and resistant hypertension revealed a low sensitivity (0.58 and 0.44, respectively) but high specificity (0.75 and 0.91, respectively) for OSA. Metabolic syndrome was associated with high sensitivity and specificity for OSA (0.86 and 0.85, respectively). Multiple regression analysis showed that age of 40 to 70 years (odds ratio 1.09, 95% confidence interval 1.03 to 1.16), a high risk of OSA on the Berlin Questionnaire (odds ratio 8.36, 95% confidence interval 1.67 to 41.85), and metabolic syndrome (odds ratio 19.04, 95% confidence interval 5.25 to 69.03) were independent variables associated with OSA. In conclusion, more important than the typical clinical features that characterize OSA, including snoring and excessive daytime sleepiness, the presence of the metabolic syndrome is as an important marker of OSA among patients with hypertension.

Stopping HAART temporarily in the absence of virus rebound: exploring new HIV treatment options

To examine the literature in search of data supporting (stopping highly active antiretroviral therapy (HAART) temporarily in the absence of virus rebound) to expand HIV treatment options. We proposed investigating HAART interruptions after the 'Berlin patient' had discontinued HAART while keeping HIV suppressed. The idea of inducing immune control of HIV by treatment interruptions has been largely abandoned and with clinicians have mainly investigated whether treatment withdrawal can reduce toxicity, improve the quality of patients' lives, and save costs. Some data suggest that treatment interruptions remain a feasible strategy and the benefits outweigh the costs; others warn against several pitfalls: onset of resistance, HIV transmission and increased toxicity. Researchers have also found, however, that the viral set point can be lowered by treatment interruptions during chronic infection, similar to (but to a lesser extent than) acute infection. Preliminary studies suggest that immunomodulators and therapeutic vaccines may further improve immune control of HIV replication. Exposure to HIV leads to excessive immune activation and exhaustion. Viral rebounds should be contained to obtain therapeutic benefits and decrease virus transmission. Temporary interruptions of HAART in combination with therapeutic vaccinations and immune modulators, such as antiproliferative drugs, may suppress HIV for extended periods of time.

Structured treatment interruptions in chronic HIV management: where next?

In 1999, researchers reported the ‘Berlin patient’, the first instance of successfully controlling HIV viremia after interruption of antiretroviral treatment (ART) [1]. This case report raised the possibility that intermittent ART might have a place in the management of HIV infection. Since then, structured treatment interruptions (STIs) as an experimental alternative strategy in the management of HIV infection have been investigated in a variety of settings [2]. STI is defined as an experimental strategy investigating effects of predetermined interruptions of ART for a variable or fixed duration in selected HIV-infected participants, guided by CD4 or HIV-RNA levels in controlled clinical trial settings. Fixed-cycle STIs refer to interruptions in therapy that are of a set duration (i.e., 1–3 months) cycled with reintroduction of therapy of similar duration’ [3]. CD4-guided STIs are strategies in which interruptions in ART are attempted at CD4 levels above 350 cells/ml with reintroduction of ART at variable levels of CD4 cell count (250–350 cells/ml). STIs in controlled trial settings have been attempted in three categories of HIV-infected patients:

Structured treatment interruption in patients infected with HIV: a new approach to therapy.

Current antiretroviral regimens are limited by issues of potency, adherence, toxicity, resistance and cost. With these limitations and the realisation that eradication of HIV infection currently is not possible, there is enthusiasm for strategies that allow discontinuation of medications, such as the structured treatment interruption (STI). STI is hypothesised to have benefits in three distinct clinical scenarios: acute treated infection, chronic treated infection with controlled viraemia, and chronic treated infection without controlled viraemia (salvage therapy). In patients with acute treated HIV infection, STI may preserve or enhance cellular immune responses to allow continued virological suppression in the absence of ongoing treatment. The Berlin patient presented with acute HIV infection prior to seroconversion and received antiretroviral therapy. After two treatment interruptions (for intercurrent infections), he permanently discontinued therapy and remained virologically suppressed for 2 years. Investigators from Massachusetts General Hospital described eight patients with acute or early HIV infection who received treatment and then underwent one or two STI. After the STIs, five of eight patients showed enhanced cellular immune responses and continued with virological suppression off treatment for a median of 2.7 years. In patients with chronic treated infection with controlled viraemia, STI may enhance immune responses as in the case of acute infection, or may allow decreased drug exposure and toxicity. Investigators from the National Institutes of Health enrolled 18 patients with chronic HIV infection and virological suppression while taking antiretroviral regimens. With a single STI, all patients rebounded, although one (6%) ultimately continued off therapy with virological suppression. The largest study of STI is the Spanish Swiss Intermittent Treatment Trial in which 128 patients with chronic suppressed HIV infection on antiretroviral therapy underwent four cycles of STI. At 52 weeks, 17% had suppressed viral load levels of <5000 copies/ml in the absence of therapy. In patients with chronic treated infection without controlled viraemia (salvage therapy), STI promotes a shift from resistant to wild-type (i.e. no mutations) virus. In the Hamburg cohort, the shift to wild-type virus was seen in 28 of 45 heavily treatment-experienced patients after an STI. Seventy-two percent of these patients experienced a virological response on a subsequent regimen, although many ultimately experienced virological rebound. In the San Francisco cohort, a shift to wild-type virus was seen in 15 of 17 protease inhibitor-experienced patients and six of these patients achieved virological suppression to <200 copies/ml on a new regimen. Risks associated with STI include increases in viral load levels with the risk of loss of virological control (i.e. failure to resuppress on therapy), repopulation of viral reservoirs and antiretroviral resistance, and decreases in CD4+ cell counts with the risk of loss or dysregulation of immune function and the occurrence of clinical events. Other risks include acute retroviral syndrome and the recurrence of short-term adverse effects. Currently, STI cannot be recommended as part of routine clinical care. Prospective studies are needed to assess the risks and benefits of this strategy in all clinical settings.