Short communication: Immune reconstitution after autologous peripheral blood stem cell transplantation in HIV-infected patients: might be better than expected?

Allogeneic immunity clears latent virus following allogeneic stem cell transplantation in SIV-infected ART-suppressed macaques

Allogeneic hematopoietic stem cell transplantation (alloHSCT) from donors lacking C-C chemokine receptor 5 (CCR5Δ32/Δ32) can cure HIV, yet mechanisms remain speculative. To define how alloHSCT mediates HIV cure, we performed MHC-matched alloHSCT in SIV+, anti-retroviral therapy (ART)-suppressed Mauritian cynomolgus macaques (MCMs) and demonstrated that allogeneic immunity was the major driver of reservoir clearance, occurring first in peripheral blood, then peripheral lymph nodes, and finally in mesenteric lymph nodes draining the gastrointestinal tract. While allogeneic immunity could extirpate the latent viral reservoir and did so in two alloHSCT-recipient MCMs that remained aviremic >2.5 years after stopping ART, in other cases, it was insufficient without protection of engrafting cells afforded by CCR5-deficiency, as CCR5-tropic virus spread to donor CD4+ T cells despite full ART suppression. These data demonstrate the individual contributions of allogeneic immunity and CCR5 deficiency to HIV cure and support defining targets of alloimmunity for curative strategies independent of HSCT.

Postautologous stem cell transplantation long-term outcomes in 26 HIV-positive patients affected by relapsed/refractory lymphoma

OBJECTIVES

To describe survival data, CD4 T-cell long-term dynamics and the correlation between dynamics and events occurrence in 26 HIV-positive patients with refractory lymphoma in complete response after autologous stem cell transplantation (ASCT).

DESIGN

Retrospective single-centre study.

METHODS

Lymphoma relapse, second cancers and opportunistic infections were considered after ASCT. Group A included patients experiencing events after ASCT and group B the remaining patients. Overall survival, progression-free survival and event-free survival probabilities were estimated by Kaplan-Meier method. The comparison of median CD4 T-cell count at cancer diagnosis with matched values was investigated by Wilcoxon signed-rank test and between group A and B by Mann-Whitney U test.

RESULTS

With a median of 6-year follow-up, the overall survival, the progression-free survival and the event-free survival at 10 years were 91, 86 and 36%. Compared with CD4 T-cell count at cancer diagnosis a higher amount was maintained over time after ASCT. Two patients experienced a lymphoma relapse at 4.3 and 3.1 years; five patients had secondary malignancies and nine patients opportunistic infections at a median time of 2.2 and 0.4 years from ASCT. At 6 and 12 months after ASCT, a significant difference in CD4 T-cell count was found between group A and B.

CONCLUSION

ASCT has a dramatic impact on survival of HIV-positive patients with refractory lymphoma. We support surveillance of opportunistic infections early after ASCT and of second cancers or lymphoma relapses later from ASCT. Both opportunistic infections and second malignancies were successfully managed and the only long-term death occurred due to lymphoma relapse. ASCT seems to contribute to immune recovery.

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.

HIV cure research: advances and prospects

Thirty years after the identification of HIV, a cure for HIV infection is still to be achieved. Advances of combined antiretroviral therapy (cART) in recent years have transformed HIV infection into a chronic disease when treatment is available. However, in spite of the favorable outcomes provided by the newer therapies, cART is not curative and patients are at risk of developing HIV-associated disorders. Moreover, universal access to antiretroviral treatment is restricted by financial obstacles. This review discusses the most recent strategies that have been developed in the search for an HIV cure and to improve life quality of people living with HIV.

Genetic modification of hematopoietic stem cells as a therapy for HIV/AIDS

The combination of genetic modification and hematopoietic stem cell (HSC) transplantation may provide the necessary means to develop an alternative treatment option to conventional antiretroviral therapy. As HSCs give rise to all hematopoietic cell types susceptible to HIV infection, modification of HSCs is an ideal strategy for the development of infection-resistant immune cell populations. Although promising results have been obtained in multiple animal models, additional evidence is needed to convincingly demonstrate the feasibility of this approach as a treatment of HIV-1 infected patients. Here, we review the potential of HSC transplantation and the recently identified limitations of this approach. Using the Berlin Patient as a model for a functional cure, we contrast the confines of autologous versus allogeneic transplantation. Finally, we suggest that although autologous, gene-modified HSC-transplantation may significantly reduce plasma viremia, reaching the lower detection limits currently obtainable through daily HAART will remain a challenging endeavor that will require innovative combinatorial therapies.

Genetically modified hematopoietic stem cell transplantation for HIV-1-infected patients: can we achieve a cure?

The cure of a human immunodeficiency virus (HIV)-1-infected patient following allogeneic transplantation from a CCR5-null donor and potential cure of two patients transplanted with CCR5 wild-type hematopoietic stem cells (HSC) have provided renewed optimism that a potential alternative to conventional antiretroviral therapy (ART) is forthcoming. While allogeneic grafts have thus far suggested complete eradication of viral reservoirs, it has yet to be observed following autologous HSC transplantation. Development of curative autologous transplantation strategies would significantly increase the number of treatable patients, eliminating the need for matched donors and reducing the risks of adverse events. Recent studies suggest gene therapy may provide a mechanism for developing curative therapies. Expression of cellular/artificial restriction factors or disruption of CCR5 has been shown to limit viral replication and provide protection of genetically modified cells. However, significant obstacles remain with regards to the depletion of established viral reservoirs in an autologous transplantation setting devoid of the "allo-effect". Here, we discuss results from early-stage clinical trials and recent findings in animal models of gene modified HSC transplantation. Finally, we propose innovative combination therapies that may aid in the reduction and/or elimination of viral reservoirs in HIV-1-infected patients and promote the artificial development of a natural controller phenotype.

Plasma viremia and cellular HIV-1 DNA persist despite autologous hematopoietic stem cell transplantation for HIV-related lymphoma

A cure of HIV-1 has been achieved in one individual through allogeneic stem cell transplantation with a CCR5[INCREMENT]32 homozygous donor. Whether myeloablation and autologous stem cell transplantation for lymphoma in patients on suppressive antiretroviral therapy can eliminate HIV-1 reservoirs is unknown. Low-level plasma viremia and total HIV-1 DNA and 2-LTR circles in blood mononuclear cells were quantified after autologous transplantation in 10 patients on suppressive antiretroviral therapy using quantitative polymerase chain reaction assays capable of single-copy nucleic acid detection. Plasma viremia was detectable in 9 patients, whereas HIV-1 DNA was detectable in all 10 patients, indicating that HIV-1 had not been eliminated.

Use of V(D)J recombination excision circles to identify T- and B-cell defects and to monitor the treatment in primary and acquired immunodeficiencies

T-cell receptor excision circles (TRECs) and kappa-deleting recombination excision circles (KRECs) are circular DNA segments generated in T and B cells during their maturation in the thymus and bone marrow. These circularized DNA elements persist in the cells, are unable to replicate, and are diluted as a result of cell division, thus are considered markers of new lymphocyte output. The quantification of TRECs and KRECs, which can be reliably performed using singleplex or duplex real-time quantitative PCR, provides novel information in the management of T- and B-cell immunity-related diseases. In primary immunodeficiencies, when combined with flow cytometric analysis of T- and B-cell subpopulations, the measure of TRECs and KRECs has contributed to an improved characterization of the diseases, to the identification of patients’ subgroups, and to the monitoring of stem cell transplantation and enzyme replacement therapy. For the same diseases, the TREC and KREC assays, introduced in the newborn screening program, allow early disease identification and may lead to discovery of new genetic defects. TREC and KREC levels can also been used as a surrogate marker of lymphocyte output in acquired immunodeficiencies. The low number of TRECs, which has in fact been extensively documented in untreated HIV-infected subjects, has been shown to increase following antiretroviral therapy. Differently, KREC number, which is in the normal range in these patients, has been shown to decrease following long-lasting therapy. Whether changes of KREC levels have relevance in the biology and in the clinical aspects of primary and acquired immunodeficiencies remains to be firmly established.

Clinical, virologic, and immunologic outcomes in lymphoma survivors and in cancer-free, HIV-1-infected patients: a matched cohort study

BACKGROUND

The objective of this study was to compare immunologic, virologic, and clinical outcomes between living human immunodeficiency virus (HIV)-infected individuals who had a diagnosis of lymphoma versus outcomes in a control group of cancer-free, HIV-infected patients.

METHODS

In this matched cohort study, patients in the case group were survivors of incident lymphomas that occurred between 1997 and June 2010. Controls were living, cancer-free, HIV-infected patients who were matched to cases at a 4:1 ratio by age, sex, nadir CD4 cell count, and year of HIV diagnosis. The date of lymphoma diagnosis served as the baseline in cases and in the corresponding controls.

RESULTS

In total, 62 patients (cases) who had lymphoma (20 with Hodgkin disease [HD] and 42 with non-Hodgkin lymphoma [NHL]) were compared with 211 controls. The overall median follow-up was 4.8 years (interquartile range, 2.0-7.9 years). The CD4 cell count at baseline was 278 cells/mm³ (interquartile range, 122-419 cells/mm³) in cases versus 421 cells/mm³ (interquartile range, 222-574 cells/mm³) in controls (P = .003). At the last available visit, the CD4 cell count was 412 cells/mm³ (range, 269-694 cells/mm³) in cases versus 518 cells/mm³ (interquartile range, 350-661 cells/mm³) in controls (P = .087). The proportion of patients who achieved virologic success increased from 30% at baseline to 74% at the last available visit in cases (P = .008) and from 51% to 81% in controls (P = .0286). Patients with HD reached higher CD4 cell counts at their last visit than patients with NHL (589 cells/mm³ [range, 400-841 cells/mm³] vs 332 cells/mm³ [interquartile range, 220-530 cells/mm³], respectively; P = .003). Virologic success was similar between patients with HD and patients with NHL at the last visit. Forty cases (65%) and 76 controls (36%) experienced at least 1 clinical event after baseline (P < .0001); cases were associated with a shorter time to occurrence of the first clinical event compared with controls (P < .0001).

CONCLUSIONS

HIV-infected lymphoma survivors experienced more clinical events than controls, especially during the first year of follow-up, but they reached similar long-term immunologic and virologic outcomes.

Stem Cell Transplantation for Lymphoma Patients with HIV Infection

The advent of Highly Active Antiretroviral Therapy (HAART) has radically changed incidence characteristics and prognosis of HIV-positive patients affected by lymphomas. At this time there is consensus in the literature that, in first line, HIV-positive patients should always be treated with curative intent preferentially following the same approach used in the HIV-negative counterpart. On the contrary, an approach of salvage therapy in HIV-positive lymphomas is still a matter of debate given that for a wide range of relapsed or resistant HIV-negative Hodgkin's disease (HD) and non-Hodgkin lymphoma (NHL) patients, autologous peripheral or allogeneic stem cell transplantation are among the established options. In the pre-HAART era, therapeutic options derived from pioneering experiences gave only anecdotal success, either when transplantation was used to cure lymphomas or to improve HIV infection itself. Concerns relating to the entity, quality, and kinetics of early and late immune reconstitutions and the possible worsening of underlying viroimmunological conditions were additional obstacles. Currently, around 100 relapsed or resistant HIV-positive lymphomas have been treated with an autologous peripheral stem cell transplantation (APSCT) in the HAART era. Published data compared favorably with any previous salvage attempt showing a percentage of complete remission ranging from 48% to 90%, and overall survival ranging from 36% to 85% at median follow-up approaching 3 years. However, experiences are still limited and have given somewhat confounding indications, especially concerning timing and patients' selection for APSCT and feasibility and outcome for allogeneic stem cell transplant. Moreover, little data exist on the kinetics of immunological reconstitution after APSCT or relevant to the outcome of HIV infection. The aim of this review is to discuss current knowledge of the role of allogeneic and autologous stem cell transplantation as a modality in the cure of HIV and hemopoietic cancer patients. Several topics dealing with practical aspects concerning the management of APSCT in HIV-positive patients, including patient selection, timing of transplant, conditioning regimen, and relapse or nonrelapse mortality, are discussed. Data relating to the effects of mobilization and transplantation on virological parameters and pre- and posttransplant immune reconstitution are reviewed. Finally, in this review, we examine several ethical and legal issues relative to banking infected or potentially infected peripheral blood stem cells and we describe our experience and strategies to protect positive and negative donors/recipients and the health of caretakers.

Case of relapsed AIDS-related plasmablastic lymphoma treated with autologous stem cell transplantation and highly active antiretroviral therapy

Plasmablastic lymphoma is a rare and aggressive malignancy strongly associated with HIV infection. The refractory/relapsed disease rate is high, and the survival rate is characteristically poor. There are no satisfactory salvage regimens for relapsed cases. We successfully performed autologous stem cell transplantation using a regimen consisting of MCNU (ranimustine), etoposide, cytarabine, and melphalan in a Japanese patient with relapsed AIDS-related plasmablastic lymphoma of the oral cavity. Highly active antiretroviral therapy continued during the therapy. Therapy-related toxicity was tolerable, and a total of 40 Gy of irradiation was administered after autologous stem cell transplantation. The patient has remained in complete remission for 16 months since transplantation.

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)

The kinetics and predictive value of HIV-1 DNA (HIV DNA) levels in relapsed or refractory HIV lymphoma patients, treated with high-dose chemotherapy (HDC) followed by autologous stem cell transplantation (ASCT), were investigated. HIV DNA was measured by real-time PCR in the peripheral blood mononuclear cells (PBMCs) of 22 patients observed for a median follow-up of 31.0 months. At baseline, HIV DNA was found to be correlated with HIV-1 RNA (HIV RNA) (r = 0.56), but not with CD4(+) counts (r = -0.10). HIV RNA load was under control for the entire follow-up, while HIV DNA levels were almost always detectable (baseline levels vs. 1 year from ASCT levels, p > 0.05). Baseline HIV DNA levels were significantly different between alive and deceased patients (p = 0.03), and the overall survival (OS) analysis showed that for patients with higher HIV DNA levels at baseline there was a higher and nearly significant risk of death if compared to patients with lower levels (HR, 8.33, 95% CI, 0.99-70.06, p = 0.05). Our study demonstrated that high HIV DNA levels at baseline could predict overall survival after ASCT in one of the largest cohorts of HIV lymphoma patients treated with salvage therapy.

High-dose therapy and autologous peripheral blood stem cell transplantation as salvage treatment for AIDS-related lymphoma: long-term results of the Italian Cooperative Group on AIDS and Tumors (GICAT) study with analysis of prognostic factors

After the introduction of highly active antiretroviral therapy (HAART), intensive treatment, including high-dose therapy (HDT) and peripheral blood stem cell transplantation (PBSCT), has become feasible in HIV-positive patients with Hodgkin (HL) and non-Hodgkin (NHL) lymphoma. Herein, we report the long-term results, on an intention-to-treat basis, of a prospective study on HDT and PBSCT in 50 HIV-positive HAART-responding patients with refractory/relapsed lymphoma. After debulking therapy, 2 patients had early toxic deaths, 10 had chemoresistant disease, 6 failed stem cell mobilization, 1 refused collection, and 4 progressed soon after PBSC harvest. Twenty-seven actually received transplant. Twenty-one patients are alive and disease-free after a median follow-up of 44 months (OS, 74.6%; PFS, 75.9%). Only lymphoma response significantly affected OS after transplantation. In multivariate analyses both lymphoma stage and low CD4 count negatively influenced the possibility to receive transplant. Median OS of all 50 eligible patients was 33 months (OS, 49.8%; PFS, 48.9%). Low CD4 count, marrow involvement, and poor performance status independently affected survival. PBSCT is a highly effective salvage treatment for chemosensitive AIDS-related lymphoma. It seems rational to explore its use earlier during the course of lymphoma to increase the proportion of patients who can actually receive transplant.

Autologous Stem-Cell Transplantation in Patients With HIV-Related Lymphoma

Purpose

Peripheral-blood autologous stem-cell transplantation (ASCT) in patients with HIV-related lymphoma (HIV-Ly) has been reported as a safe and useful procedure. Herein we report the European Group for Blood and Marrow Transplantation experience on patients with HIV-Ly undergoing ASCT.

Patients and Methods

This was a retrospective, multicentric, registry-based analysis.

Results

Since 1999, 68 patients from 20 institutions (median age, 41 years; range, 29 to 62 years) were included, diagnosed with non-Hodgkin's lymphoma (NHL; n = 50) or Hodgkin's lymphoma (n = 18). At the time of ASCT, 16 patients were in first complete remission (CR1); 44 patients were in CR more than 1, partial remission, or chemotherapy-sensitive relapse (chemo-S); and eight patients had chemotherapy-resistant disease. The median number of CD34+cells infused was 4.5 × 106/kg (range, 1.6 to 21.2 × 106/kg). Median time to neutrophil and platelet engraftment were 11 days (range, 8 to 36 days) and 14 days (range, 6 to 455 days), respectively, with a cumulative incidence (CI) at 1 year of 95.6% and 87%, respectively. CI of nonrelapse mortality (NRM) was 7.5% at 12 months after ASCT, mainly because of bacterial infections. CI of relapse was 30.4% at 24 months, statistically related with not being in CR at ASCT (relative risk [RR] = 3.6), NHL histology other than diffuse large B-cell lymphoma (RR = 3.4), and use of more than two previous treatment lines (RR = 3). At a median follow-up of 32 months (range, 2 to 81 months), progression-free survival (PFS) was 56%. Patients not in CR or with refractory disease at ASCT had poorer PFS (RR = 2.4 and 4.8, respectively).

Conclusion

Similarly to HIV-negative patients with lymphoma, ASCT is a useful treatment for patients with HIV-Ly and is associated with low NRM, mainly when performed in early stages and chemo-S disease.