Predictive value of HIV type 1 DNA levels on overall survival in HIV-related lymphoma Patients treated with high-dose chemotherapy (HDC) plus autologous stem cell transplantation (ASCT)

Reconstitution of HIV-1 reservoir following high-dose chemotherapy/autologous stem cell transplantation for lymphoma

OBJECTIVES

Autologous stem cell transplantation following high-dose chemotherapy (HDC/ASCT) is the prime model to study the impact of HDC in HIV-1-infected participants. We analyzed the impact of HDC/ASCT on the resurgent reservoir composition and origin.

DESIGN

We included retrospectively a homogenous group of HIV-1-infected patients treated for high-risk lymphoma in a reference center with similar chemotherapy regimens.

METHODS

Thirteen participants treated with HDC/ASCT from 2012 to 2015 were included. A median seven longitudinal blood samples per participant were available. Total HIV-1 DNA levels in peripheral blood mononuclear cells (PBMCs) were quantified by quantitative PCR. In six participants with sustained viral suppression, the highly variable C2V3 viral region was subjected to next-generation sequencing. Maximum-likelihood phylogeny trees were generated from the reconstructed viral haplotypes. Lymphocyte subsets were studied by flow cytometry.

RESULTS

PBMC-associated HIV-1 DNA levels were stable over time. Viral diversity decreased along lymphoma treatment, but increased promptly back to prechemotherapy numbers after HDC/ASCT. Blood viral populations from all time-points were intermingled in phylogeny trees: the resurgent reservoir was similar to pre-HDC circulating proviruses. Memory subsets were the main contributor to the early restoration of the CD4+ T-cell pool, with a delayed increase in naïve cell counts.

CONCLUSIONS

The characterization of HIV-1 reservoir in blood revealed a fast and consistent replenishment from memory CD4+ T cells after HDC/ASCT. As HDC/ASCT is increasingly involved in HIV cure trials with gene-modified hematopoietic stem cells, the management of infected T cells in HIV-positive autologous transplants will be critical.

Total HIV-1 DNA, a Marker of Viral Reservoir Dynamics with Clinical Implications

HIV-1 DNA persists in infected cells despite combined antiretroviral therapy (cART), forming viral reservoirs. Recent trials of strategies targeting latent HIV reservoirs have rekindled hopes of curing HIV infection, and reliable markers are thus needed to evaluate viral reservoirs. Total HIV DNA quantification is simple, standardized, sensitive, and reproducible. Total HIV DNA load influences the course of the infection and is therefore clinically relevant. In particular, it is predictive of progression to AIDS and death, independently of HIV RNA load and the CD4 cell count. Baseline total HIV DNA load is predictive of the response to cART. It declines during cART but remains quantifiable, at a level that reflects both the history of infection (HIV RNA zenith, CD4 cell count nadir) and treatment efficacy (residual viremia, cumulative viremia, immune restoration, immune cell activation). Total HIV DNA load in blood is also predictive of the presence and severity of some HIV-1-associated end-organ disorders. It can be useful to guide individual treatment, notably, therapeutic de-escalation. Although it does not distinguish between replication-competent and -defective latent viruses, the total HIV DNA load in blood, tissues, and cells provides insights into HIV pathogenesis, probably because all viral forms participate in host cell activation and HIV pathogenesis. Total HIV DNA is thus a biomarker of HIV reservoirs, which can be defined as all infected cells and tissues containing all forms of HIV persistence that participate in pathogenesis. This participation may occur through the production of new virions, creating new cycles of infection and disseminating infected cells; maintenance or amplification of reservoirs by homeostatic cell proliferation; and viral transcription and synthesis of viral proteins without new virion production. These proteins can induce immune activation, thus participating in the vicious circle of HIV pathogenesis.

γ-Herpesvirus load as surrogate marker of early death in HIV-1 lymphoma patients submitted to high dose chemotherapy and autologous peripheral blood stem cell transplantation

Autologous stem cell transplantation (ASCT) is a feasible procedure for human immunodeficiency virus-1 (HIV-1) lymphoma patients, whose underlying disease and intrinsic HIV-1- and ASCT-associated immunodeficiency might increase the risk for γ-herpesvirus load persistence and/or reactivation. We evaluated this hypothesis by investigating the levels of Epstein-Barr virus (EBV)- and Kaposi sarcoma-associated herpesvirus (KSHV)-DNA levels in the peripheral blood of 22 HIV-1-associated lymphoma patients during ASCT, highlighting their relationship with γ-herpesvirus lymphoma status, immunological parameters, and clinical events. EBV-DNA was detected in the pre-treatment plasma and peripheral blood mononuclear cells (PBMCs) of 12 (median 12135 copies/mL) and 18 patients (median 417 copies/10⁶ PBMCs), respectively; the values in the two compartments were correlated (r = 0.77, p = 0.0001). Only EBV-positive lymphomas showed detectable levels of plasma EBV-DNA. After debulking chemotherapy, plasma EBV-DNA was associated with lymphoma chemosensitivity (p = 0.03) and a significant higher mortality risk by multivariate Cox analysis adjusted for EBV-lymphoma status (HR, 10.46, 95% CI, 1.11–98.32, p = 0.04). After infusion, EBV-DNA was detectable in five EBV-positive lymphoma patients who died within six months. KSHV-DNA load was positive in only one patient, who died from primary effusion lymphoma. Fluctuations in levels of KSHV-DNA reflected the patient’s therapy and evolution of his underlying lymphoma. Other γ-herpesvirus-associated malignancies, such as multicentric Castleman disease and Kaposi sarcoma, or end-organ complications after salvage treatment were not found. Overall, these findings suggest a prognostic and predictive value of EBV-DNA and KSHV-DNA, the monitoring of which could be a simple, complementary tool for the management of γ-herpesvirus-positive lymphomas in HIV-1 patients submitted to ASCT.

Autograft HIV-DNA load predicts HIV-1 peripheral reservoir after stem cell transplantation for AIDS-related lymphoma patients

Autologous stem cell transplantation (ASCT) is a widely used procedure for AIDS-related lymphomas, and it represents an opportunity to evaluate strategies curing HIV-1 infection. The association of autograft HIV-DNA load with peripheral blood HIV-1 reservoir before ASCT and its contribution in predicting HIV-1 reservoir size and stability during combination antiretroviral therapy (cART) after transplantation are unknown. Aiming to obtain information suggesting new functional cure strategies by ASCT, we retrospectively evaluated HIV-DNA load in autograft and in peripheral blood before and after transplantation in 13 cART-treated HIV-1 relapse/refractoring lymphoma patients. Among them seven discontinued cART after autograft infusion. HIV-DNA was evaluated by a sensitive quantitative real-time polymerase chain reaction (PCR). After debulking chemotherapy/mobilization, the autograft HIV-1 reservoir was higher than and not associated with the peripheral HIV-1 reservoir at baseline [median 215 HIV-DNA copies/10(6) autograft mononuclear cells, range 13-706 vs. 82 HIV-DNA copies/10(6) peripheral blood mononuclear cells (PBMCs), range 13-479, p = 0.03]. After high dose chemotherapy and autograft infusion, HIV-DNA levels reached a plateau between month 6 and 12 of follow-up. No association was found between peripheral HIV-DNA levels at baseline and after infusion in both cART interrupting and not interrupting patients. Only in the last subgroup, a stable significant linear association between autograft and peripheral blood HIV-1 reservoir emerged from month 1 (R(2) = 0.84, p = 0.01) to month 12 follow-up (R(2) = 0.99, p = 0.0005). In summary, autograft HIV-1 reservoir size could be influenced by the mobilization phase and predicts posttransplant peripheral HIV-1 reservoir size in patients on continuous cART. These findings could promote new research on strategies reducing the HIV-1 reservoir by using the ASCT procedure.

A new prognostic score for AIDS-related lymphomas in the rituximab-era

While the International Prognostic Index is commonly used to predict outcomes in immunocompetent patients with aggressive B-cell non-Hodgkin lymphomas, HIV-infection is an important competing risk for death in patients with AIDS-related lymphomas. We investigated whether a newly created prognostic score (AIDS-related lymphoma International Prognostic Index) could better assess risk of death in patients with AIDS-related lymphomas. We randomly divided a dataset of 487 patients newly diagnosed with AIDS-related lymphomas and treated with rituximab-containing chemoimmunotherapy into a training (n=244) and validation (n=243) set. We examined the association of HIV-related and other known risk factors with overall survival in both sets independently. We defined a new score (AIDS-related lymphoma International Prognostic Index) by assigning weights to each significant predictor [age-adjusted International Prognostic Index, extranodal sites, HIV-score (composed of CD4 count, viral load, and prior history of AIDS)] with three risk categories similar to the age-adjusted International Prognostic Index (low, intermediate and high risk). We compared the prognostic value for overall survival between AIDS-related lymphoma International Prognostic Index and age-adjusted International Prognostic Index in the validation set and found that the AIDS-related lymphoma International Prognostic Index performed significantly better in predicting risk of death than the age-adjusted International Prognostic Index (P=0.004) and better discriminated risk of death between each risk category (P=0.015 vs. P=0.13). Twenty-eight percent of patients were defined as low risk by the ARL-IPI and had an estimated 5-year overall survival (OS) of 78% (52% intermediate risk, 5-year OS 60%; 20% high risk, 5-year OS 50%).

Assessment of immunovirological features in HIV related non-Hodgkin lymphoma patients and their impact on outcome

BACKGROUND

Despite the era of highly active antiretroviral therapy, non-Hodgkin lymphoma (NHL) remains one of the main causes of death in HIV-infected patients, with a wide variation on the outcome.

OBJECTIVES

We investigated immunological status and EBV, HHV8, HIV viral load in a group of HIV-infected patients at diagnosis of NHL to evaluate their prognostic significance.

STUDY DESIGN

Eighty-one consecutive HIV+ NHL patients were studied. CD4 and CD8 cell counts, HHV8 DNA, EBV DNA, HIV RNA and HIV DNA were assessed at diagnosis and at 3 months after chemotherapy initiation. Hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) of disease free survival (DFS) and overall survival (OS) were computed according to CD4 and CD8 cell counts, EBV DNA, HIV RNA and HIV DNA. HRs were, thereafter, computed also for continuous variation of CD4, CD8 cell counts and EBV DNA.

RESULTS

In the multivariate analysis, CD4<160 and CD8<590 cell/μl and EBV DNA≥300 c/ml were independently associated to DFS (HR=2.98; 95%CI: 1.26-7.03; HR=2.65, 95%CI: 1.13-6.19; HR=4.01; 95%CI: 1.81-8.91) and OS (HR=3.32; 95%CI: 1.41-7.83; HR=4.62, 95%CI: 1.91-11.19; HR=3.11, 95%CI: 1.42-6.80). HRs for DFS and OS decreased continuously with increasing CD4 and CD8 cell counts, while they increased continuously with increasing EBV DNA levels.

CONCLUSIONS

The association with survival of low CD4 and CD8 cell counts and detectable EBV viremia, measured at lymphoma's diagnosis, identified three independent prognostic biomarkers that might help in the management of NHL HIV+ patients, offering complementary information in the ascertainment of their outcome.