Authors: Martha Powell, Future Science Group
Long-term follow-up of the ‘London patient’, the second patient to ever achieve sustained HIV remission after ceasing antiretroviral treatment, has suggested that there is no active detectable HIV virus remaining.
The study, presented at Conference on Retroviruses and Opportunistic Infections (8–11 March, held online), assessed the second HIV patient to undergo successful stem cell transplantation from donors with a HIV-resistant gene 30 months after they had ceased antiretroviral therapy.
The patient reported in this study underwent one stem cell transplantation and a reduced-intensity chemotherapy regimen, without whole-body irradiation. In August 2019, it was first reported in Nature that the London patient was in remission, and this study provides a close follow-up study of the individual.
Viral load sampling was carried out in the patient’s intestinal tissue, lymphoid tissue and cerebrospinal fluid 29 months after the cessation of antiretroviral therapy, and was carried out in blood samples at 30 months after stopping therapy. CD4 cell counts were also carried out.
The team discovered that there was no active viral infection in the patient’s blood, tissue samples or cerebrospinal fluid; however, remnants of integrated HIV-1 DNA remained in tissue samples. The researchers suggest these are unlikely to be capable of reproducing the virus.
The patient also had a healthy CD4 cell count, with their CD4 cells replaced by those derived from the HIV-resistant stem cell transplant.
Lead author, Ravindra Kumar Gupta (University of Cambridge, UK), commented: “We propose that these results represent the second ever case of a patient to be cured of HIV. Our findings show that the success of stem cell transplantation as a cure for HIV, first reported 9 years ago in the Berlin patient, can be replicated.”
Comparing this London patient with the first ever case of sustained HIV remission, the Berlin patient, the authors suggest that this study represents a step towards a less intensive treatment approach, although they cautioned that the patient will need continued monitoring for re-emergence.
However, this procedure is not a treatment that could be offered widely to patients with HIV, as Gupta explained: “It is important to note that this curative treatment is high-risk, and only used as a last resort for patients with HIV who also have life-threatening haematological malignancies.”
Writing in a linked Comment in The Lancet HIV journal, Professor Sharon R Lewin (University of Melbourne, Australia) who was not involved in the study, concluded: “Given the large number of cells sampled here and the absence of any intact virus, is the London patient truly cured? The additional data provided in this follow up case report is certainly encouraging but unfortunately in the end, only time will tell.”
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Sources: Gupta Rk, Peppa D, Hill AL et al. Evidence for HIV-1 cure after CCR5Δ32/Δ32 allogeneic haemopoietic stem-cell transplantation 30 months post analytical treatment interruption: a case report. Lancet HIV. doi:10.1016/ S2352-3018(20)30069-2 (2020); www.eurekalert.org/emb_releases/2020-03/tl-tlh030920.php