Complete Immune Reconstitution Research Articles

Pattern of Immune Reconstitution Post Allogeneic Stem Cell Transplant: Data From a Resource Constraint Country.

To determine the Pattern of immune reconstitution (IR) post allogeneic stem cell transplant at six months. Prospective observational study. Place and duration of the study: This study was conducted at The Armed Forces Bone Marrow Transplant Centre (AFMBTC) Rawalpindi, Pakistan, from May 2022 to December 2022. After approval from the institutional review board, informed/written consents were taken from patients. All patients (both genders, irrespective of age) undergoing allogeneic hematopoietic stem cell transplant were included in the study. Patients undergoing haplo-identical or autologous bone marrow transplants were excluded from the study. Innate immune reconstitution was checked by complete blood count and adaptive immune reconstitution at six months was checked lymphocyte subset analysis and serum immunoglobulin levels. Data was entered in pre-designed proforma and was analyzed using IBM Corp. Released 2017. IBM SPSS Statistics for Windows, Version 25.0. Armonk, NY: IBM Corp. This study analyzes 43 patients, including 67% (n=29) males. The median age at the time of HSCT was 11.19 years. Cellular and humoral reconstitution at six months after transplant was used to assess immune reconstitution. Innate immune reconstitution was checked by complete blood count for count recovery (Neutrophil engraftment), and adaptive immune reconstitution (cellular/humoral) at six months was checked lymphocyte subset analysis and serum immunoglobulin levels. By using chi-square, significant associations were found as pre-transplant condition regimen with CD4 (PChi= 0.001), GVHD prophylaxis with CD4 (PChi= 0.04), source of stem cells with CD19 (PChi= 0.008), patient-donor gender disparity with CD19 (PChi= 0.05), GVHD treatment low CD19 (PChi= 0.04), patient-donor relationship with IgA(PChi= 0.007), IgG (PChi= 0.001), and IgM (PChi= 0.001), gender of the patient with IgA (PChi= 0.04). Our data suggested thatat post-transplant six months, there was adequate immune reconstitution except for CD4 and CD4:CD8 ratio. Therefore, post-transplant, six months in Allo-HSCT could be considered for immunization.

Circulating GDF-15: a biomarker for metabolic dysregulation and aging in people living with HIV.

Despite effective control of HIV replication by antiretroviral therapy (ART), a significant number of people living with HIV (PLWH) fail to achieve complete immune reconstitution and thus are deemed immune non-responders (INRs). Compared with immune responders (IRs) who have restored their CD4 T cell numbers and functions, CD4 T cells from these INRs exhibit prominent mitochondrial dysfunction and premature aging, which play a major role in increasing the incidence of non-AIDS, non-communicable diseases (NCDs). To date, there are no reliable biomarkers that can be used to typify and manage PLWH, especially INRs with non-AIDS NCDs. Growth differential factor-15 (GDF-15) is a transforming growth factor-β (TGF-β) family member known to regulate several biological processes involved in cell aging and stress responses. Since PLWH exhibit premature aging and metabolic dysregulation, here we measured the plasma levels of GDF-15 by ELISA and metabolic proteins by proteomic array and correlated the results with clinical parameters in ART-controlled PLWH (including INRs and IRs) and healthy subjects (HS). We found that GDF-15 levels were significantly elevated in PLWH compared to HS. GDF-15 levels were positively correlated with age and negatively associated with body mass and LDL cholesterol levels in the study subjects. Also, elevated GDF-15 levels were correlated with differential dysregulation of multiple metabolic proteins in PLWH. These results suggest that GDF-15 protein may serve as a biomarker of metabolic dysregulation and aging, and this biomarker will be useful in clinical trials targeting aging and metabolic disorders in ART-treated PLWH.

Immune reconstitution and influencing factors in HIV infected men who have sex with men with access to antiviral therapy in Guangxi Zhuang Autonomous Region from 2005 to 2021

Objective: To analyze immune reconstitution and influencing factors in HIV infected men who have sex with men (MSM) with access to antiviral therapy (ART) in Guangxi Zhuang Autonomous Region (Guangxi) during 2005-2021. Methods: The data were collected from Chinese Disease Prevention and Control Information System. The study subjects were HIV infected MSM with access to the initial ART for ≥24 weeks in Guangxi from 2005 to 2021 and HIV RNA lower than the detection limit within 24 months. The proportion of infected MSM who had immune reconstitution after ART was calculated. Cox proportional hazard regression model was used to analyze the influencing factors of immune reconstitution. Software SPSS 24.0 was used for statistical analysis. Results: A total of 3 200 HIV infected MSM were enrolled, in whom 15.56 % (498/3 200) had no immune reconstitution, 14.78% (473/3 200) had moderate immune reconstitution, and the rate of complete immune reconstitution was 69.66% (2 229/3 200). The M (Q1, Q3) of ART time for immune reconstitution was 12 (5, 27) months. Multivariate Cox proportional risk regression model analysis results showed that compared with those with initial ART at age ≥30 years, WHO clinical stage Ⅲ/Ⅳ illness, baseline BMI <18.50 kg/m2 and baseline CD4+T lymphocyte (CD4) counts <200 cells/µl, HIV infected MSM with initial ART at age <30 years, WHO clinical stageⅠ/Ⅱ illness, baseline BMI≥24.00 kg/m2 and baseline CD4 counts ≥200 cells/µl were more likely to have complete immune reconstitution. Conclusions: In the HIV infected MSM in Guangxi, failures to achieve moderate and complete immune reconstitution were observed. Surveillance and ART regimen should be improved for key populations, such as those with older age and low baseline CD4 counts.

Recent advances in poor HIV immune reconstitution: what will the future look like?

Combination antiretroviral therapy has demonstrated proved effectiveness in suppressing viral replication and significantly recovering CD4+ T cell count in HIV type-1 (HIV-1)-infected patients, contributing to a dramatic reduction in AIDS morbidity and mortality. However, the factors affecting immune reconstitution are extremely complex. Demographic factors, co-infection, baseline CD4 cell level, abnormal immune activation, and cytokine dysregulation may all affect immune reconstitution. According to report, 10-40% of HIV-1-infected patients fail to restore the normalization of CD4+ T cell count and function. They are referred to as immunological non-responders (INRs) who fail to achieve complete immune reconstitution and have a higher mortality rate and higher risk of developing other non-AIDS diseases compared with those who achieve complete immune reconstitution. Heretofore, the mechanisms underlying incomplete immune reconstitution in HIV remain elusive, and INRs are not effectively treated or mitigated. This review discusses the recent progress of mechanisms and factors responsible for incomplete immune reconstitution in AIDS and summarizes the corresponding therapeutic strategies according to different mechanisms to improve the individual therapy.

Lentiviral Gene Therapy with Low Dose Conditioning for X-Linked SCID Results in Complete Immune Reconstitution and No Evidence of Clonal Expansion

Introduction: Gene therapy (GT) for X-linked severe combined immunodeficiency (SCID-X1) using a gamma (γ) retroviral vector resulted in robust T cell immune reconstitution but also insertional oncogenesis. A multi-institutional trial using a self-inactivating (SIN) γ-retroviral vector resulted in equivalent T cell immune reconstitution but no insertional oncogenesis to date (Hacein-Bey-Abina et al, NEJM 2014). In both trials, conditioning was only rarely used and therefore gene marking in B cells and neutrophils was negligible and reconstitution of NK cells was limited. To improve both the immune reconstitution and safety of GT for SCID-X1, we developed a lentiviral vector (LV) in which a codon optimized IL2RG transgene is driven by the elongation factor 1 alpha short promoter (EFS) and introduced low dose busulfan conditioning to enhance hematopoietic and multilineage expression of IL2RG. An international, multicenter, Phase 1/2 clinical trial (NCT03311503, NCT03601286) is currently underway to evaluate the safety and efficacy of LV mediated gene transfer using this vector. Methods: A total of 14 patients have been enrolled. Two patients were withdrawn due to poor stem cell mobilization and collection and manufacturing are in progress for 3 patients. Nine patients have been infused, 8 receiving mobilized peripheral blood stem cells and 1 receiving bone marrow at an average age of 5.3 months (range 3.2-7.1). Hematopoietic stem cells (CD34+ cells) were transduced with the LV vector (using transduction enhancers in 7 products) and drug products were cryopreserved. Median cell dose was 9.06 x 10e6 CD34+ cells/kg (4.55-17.87) and median vector copy number (VCN) was 0.86 copies/diploid genome(dg) (0.67-2.79). Drug products were thawed and infused after 2 days of busulfan conditioning targeted to an AUC of 30 mg*h/L. All infants tolerated busulfan exposure without any significant toxicity. Results: As of July 2022, all treated patients are alive with robust reconstitution of gene marked T cells with median follow up of 2.2 years (0.2-4.3). T cell reconstitution was rapid with median CD3+ T cell count 552 cells/uL (132-1160) at 3 months. Seven patients evaluable at 1 year had CD3+ (2377-4900 cells/uL) and CD4+ T cell counts (1507-3080 cells/uL) normal for age at 1-year post-GT (Figure 1). Gene marking in T cells was robust averaging 1.55-5.66 copies/dg. Evidence of thymic function includes rising naïve CD4+ T cells and maintenance of a normal CD4/CD8 ratio. Multilineage engraftment of gene modified cells is evident in B cells, neutrophils, and NK cells at last follow-up with stable VCN over time (ranges 0.43-2.05, 0.24-2.11, 1.98-3.61 respectively). In contrast to limited NK cell reconstitution seen in the absence of conditioning in prior trials, NK cell counts have been sustained in 6 of 7 patients with greater than 12 months of follow-up achieving values within the normal range for age (Figure 1). Six of these 7 patients have been able to stop immunoglobulin replacement, 4 of 4 who have completed a primary vaccine series show response, with the results of 2 further patients awaited. Insertion site analysis shows uniformly polyclonal repertoire with no evidence of clonal expansion. Conclusion: In summary, gene therapy using a lentiviral vector and low dose busulfan conditioning resulted in robust and complete immune reconstitution correcting T, NK, and B cell defects characteristic of SCID-X1 with 100% survival and no gene therapy related adverse events. Figure 1 Immune reconstitution in 7 patients treated with >1 year follow-up A) CD3+ T cells. B) CD4+ T cells. C) NK cells. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Age-Related Immune Cell Dynamics Influences Outcomes after Allogeneic Hematopoietic Cell Transplantation

Allogeneic hematopoietic cell transplantation (HCT) holds a pivotal place in the setting of therapeutic algorithms for hematological disorders. Its therapeutic index is principally related to the immunogenic graft-versus-leukemia (GvL) effect that, together with an efficient immune reconstitution ensures the success of the procedure, contributing to disease control and immune competence. Factors influencing recipient immune recovery have been largely investigated across multiple cohorts issuing heterogenous results. Differences in outcomes in adult and pediatric populations suggest an age-related contribution to post-transplant immune reconstitution, however it is unclear how this parameter may affect the dynamics of single immune cells. Here we conducted a monocentric prospective study questioning on the modifications of immune cell recovery in a cohort of 176 patients (58 children and 118 adults) with hematological disorders receiving a HCT between 2015 and 2020 and followed at our institution. Complete flow-based immune reconstitution data on T-CD4, T-CD8, NK and B cell populations were collected at defined time-points (+1, 3, 6 and 12 months post-HCT). After ascertaining the dynamics in adult and pediatric populations of each cell component, the effect of a set of baseline clinico-biological variables on late (>6 months) reconstitution for each cell population was tested through univariable and multivariable linear or logistic regression models. First, we analyzed the linear relationship existing between recipient and donor age and each cell compartment. Interestingly, while donor age did not impact on any of the parameters in study, CD4- T (Adj R2 0.4, p=5.7x 10-15) and, in minor part, B cell post-transplant increments (Adj R2 0.05, p=0.004) were inversely correlated with recipient age, which instead did not influence CD8-T nor NK cell reconstitution. Results of stepwise multivariable analyses showed that CD8-T cell reconstitution was positively impacted by recipient positive CMV serostatus (p=0.00009) while donor CMV serostatus positively influenced CD4-T cell recovery (p=0.017). This effect was likely dependent from the expansion of CMV related T cell clonotypes in case of previous CMV immunity. The inverse correlation between CD4-T cells and recipient age was confirmed in multivariable analysis (p=0.0148). Donor EBV positive serostatus resulted instead to be a negative predictor of B cell recovery (p=0.0442). Interestingly none of the parameters analyzed influenced NK cell recovery. The impact on age mirrored a different kinetics of immune reconstitution in adult and pediatric patients (<18 years). Therefore, while early after HCT immune cell composition was similar in the two groups, with NK cells representing the largest component, followed by CD8-T and CD4-T, and minimal B cell contribution, in later phases we assisted to a faster expansion of CD4-T arm in children whereas CD8-T remained the major contributor of the immune recovery processes in adults still one year after transplant. B cell reconstitution was also faster in children, with a better immunoglobulin levels recuperation (measured on IgM to avoid bias of prophylactic IgG infusions) despite no differences in post-transplant pre-emptive rituximab utilization. When looking at different outcomes of pediatric and adult patients, both overall and event free survival were significantly higher in children (p=0.00062 and p=0.0062). While no difference in acute grade III-IV GvHD, adults experienced a significantly higher cumulative incidence (CI) of chronic GvHD (p=0.0258) and of specific infections, including EBV (p=0.031) and fungi (p=0.007). Although CI of relapse was not different, children experienced later relapses as compared to adults (median of 294 vs. 139 days, p=0.039), indicating a better disease control at least at early post-transplant stages. Here, starting from immune reconstitution data prospectively collected for patients transplanted at our institution, we dissected the effect of age on post-transplant immune cells. A faster CD4-T and B cell recovery in children may be the driver of a better immune competence underpinning superior outcomes in pediatric populations. If age-related thymus involution may reflect suboptimal CD4-T cell differentiation in adults, younger donor selection does not seem to improve recipient post-transplant immune reconstitution.

Identification of CD8+ T cell subsets that normalize in early-treated people living with HIV receiving antiretroviral therapy

BackgroundAlthough combined antiretroviral therapy (cART) has decreased the mortality associated with HIV infection, complete immune reconstitution is not achieved despite viral suppression. Alterations of CD8+ T cells and some of their subpopulations, such as interleukin (IL)-17-producing cells, are evidenced in treated individuals and are associated with systemic inflammation and adverse disease outcomes. We sought to evaluate if different CD8+ T cell subsets are differentially normalized during a clinical follow-up of people living with HIV (PLWH) receiving suppressive cART.MethodsWe explored the changes in the frequencies, activation/exhaustion phenotypes (HLA-DR, CD38, PD-1, and TIM-3), and function (total and HIV-specific cells expressing CD107a, perforin, granzyme B, interferon [IFN]-γ and IL-17) of CD8+ T cells from early-treated PLWH receiving cART in a 1-year follow-up, using a multidimensional flow cytometry approach.ResultsDespite continuous cART-induced viral suppression and recovery of CD4+ T cells, after a 1-year follow-up, the CD8+ T cell counts, CD4:CD8 ratio, PD-1 expression, and IL-17 production by CD8+ T cells exhibited incomplete normalization compared with seronegative controls. However, the proportion of CD8+ T cells with an exhausted phenotype (co-expressing PD-1 andTIM-3), and cells co-expressing cytotoxic molecules (Perforin and Granzyme B), reached normalization.ConclusionsAlthough suppressive cART achieves normalization of CD4+ T cell counts, only particular subsets of CD8+ T cells are more rapidly normalized in PLWH receiving cART, which could be routinely used as biomarkers for therapy efficiency in these patients.

Serological Response Following BNT162b2 Anti-Sars-Cov-2 mRNA Vaccination in Hematopoietic Stem Cell Transplantation Patients

Patients with hematological malignancies (HM) undergoing hematopoietic stem cell transplantation (HSCT) have an increased vulnerability to SARS-Cov-2 (Sharma et al, Lancet Haematology 2020; Ljungman et al, Leukemia 2021), the reason why international guidelines strongly support the need for a protective vaccination for these subjects. The most relevant data currently available on the response to a complete anti-SARS-Cov-2 vaccination cycle in HM patients after HSCT refer to 314 patients reported in a Lithuanian national survey (Maneikis et al, Lancet Haematol 2021). In this study, the median titers of antibodies against SARS-Cov-2, determined 7-21 days after the second vaccination, were comparable to that of healthy controls (HC) in both autologous and allogeneic groups, with no patient found below the protective threshold of 50 arbitrary units (AU)/ml. Notably, the large majority of patients had received the transplant more than 1 year before vaccination.In a prospective, cohort study, we compared 114 patients, who had received an autologous or allogeneic HSCT at least three months before the first dose of vaccination, to 107 HC, matched for age and sex. Study population and HC received two doses of BNT162b2 anti-SARS-Cov-2 mRNA vaccine on days 1 and 21, between April and May 2021. Serological tests were performed by a commercially available immunoassay for the quantitative determination of anti-spike IgG antibodies to SARS-Cov-2. The cut-off for defining responders was 50 or greater AU/ml. Patients and HC samples were collected four weeks after the second dose of the vaccine.Table 1 reports the main clinical characteristics of patients and HC. Eighteen of 114 patients (16%) did not respond (24% in the allogeneic group, 6% in autologous recipients). Overall, median antibodies titers did not differ between HC and the entire cohort of transplanted patients, recipients of allogeneic HSCT, all patients responding to the vaccine or responders in the autologous subgroup (Figure 1A). All autologous HSCT recipients had significantly lower titers of antibodies than HC, while higher levels were found in responders who had received allogeneic HSCT (Figure 1A). Responders in the allogeneic subgroup showed antibodies titers significantly higher than responders in the autologous subgroup (Figure 1B).We further stratified patients in three groups, according to the time elapsed from transplant to vaccination: G1:<1 year; G2:1-5 years; G3:>5 years. Higher antibodies titers were observed in HC compared to all transplanted patients in G1 (Figure 1C), including both allogeneic (Figure 1D) and autologous (Figure 1E) HSCT recipients. No differences emerged in G2 between HC and all patients (Figure 1C), allogeneic (Figure 1D) or autologous (Figure 1E) HSCT recipients. Finally, no differences were found in G3 when comparing HC with all patients (Figure 1C) or allogeneic recipients (Figure 1D), whereas patients in the autologous subgroup showed significantly lower titers than HC (Figure 1E).Myeloma patients with controlled disease showed higher titers than patients with active disease (Figure 1F). According to median age, autologous HSCT recipients older than 57 years had significantly lower antibody levels than younger patients (Figure 1G). Autologous vs allogeneic HSCT, age of all patients and of allogeneic HSCT recipients, sex, type of allogeneic HSCT, conditioning regimen, age and sex of donor, occurrence of GVHD, disease type and single vs double autologous HSCT did not significantly impact on antibody levels (data not shown). No relevant side effects were recorded after vaccination. With a median follow up of 12 weeks, no case of COVID19 occurred among vaccinated patients.In our single center study, patients with a previous history of HSCT tolerated well BNT162b2 vaccine and mounted a potentially protective immune response in the majority of cases one month after two doses of vaccine. However, lack of response was not rare, especially in the allogeneic setting. The main factor associated with the quality of response was the time from HSCT, with lower responses within the first year from transplant and differences between autologous and allogeneic groups transplanted more than five years before vaccination. Here, a consolidated, complete immune reconstitution in allogeneic HSCT recipients, as well as age and a still active disease in the autologous setting, could have played opposite pivotal roles. [Display omitted] DisclosuresDelia: Gilead: Consultancy; Amgen: Consultancy; abbvie: Consultancy; Jazz pharmaceuticals: Consultancy.

Finding the best haematopoietic stem cell transplant regimen for GATA2 haploinsufficiency: how close are we?

Finding the best haematopoietic stem cell transplant regimen for GATA2 haploinsufficiency: how close are we?

Mitochondrial Functions Are Compromised in CD4 T Cells From ART-Controlled PLHIV.

The hallmark of HIV/AIDS is a gradual depletion of CD4 T cells. Despite effective control by antiretroviral therapy (ART), a significant subgroup of people living with HIV (PLHIV) fails to achieve complete immune reconstitution, deemed as immune non-responders (INRs). The mechanisms underlying incomplete CD4 T cell recovery in PLHIV remain unclear. In this study, CD4 T cells from PLHIV were phenotyped and functionally characterized, focusing on their mitochondrial functions. The results show that while total CD4 T cells are diminished, cycling cells are expanded in PLHIV, especially in INRs. HIV-INR CD4 T cells are more activated, displaying exhausted and senescent phenotypes with compromised mitochondrial functions. Transcriptional profiling and flow cytometry analysis showed remarkable repression of mitochondrial transcription factor A (mtTFA) in CD4 T cells from PLHIV, leading to abnormal mitochondrial and T cell homeostasis. These results demonstrate a sequential cellular paradigm of T cell over-activation, proliferation, exhaustion, senescence, apoptosis, and depletion, which correlates with compromised mitochondrial functions. Therefore, reconstituting the mtTFA pathway may provide an adjunctive immunological approach to revitalizing CD4 T cells in ART-treated PLHIV, especially in INRs.

Switch from sequestering to anti-CD20 depleting treatment: disease activity outcomes during wash-out and in the first 6 months of ocrelizumab therapy

Objectives: Switching between treatments is an opportunity for patients with multiple sclerosis (MS) to ameliorate disease control or safety. The aim of this study was to investigate the impact of switching from fingolimod (FTY) or natalizumab (NTZ) to ocrelizumab (OCR) on disease activity. Methods: We retrospectively enrolled 165 patients treated with OCR from 11 MS centres. We assessed the association of demographic and clinical characteristics on relapse rate (RR) and activity on magnetic resonance imaging (MRI) during wash-out and after 6 months of treatment with OCR through univariable and multivariable negative binomial regression models. Results: We registered a total of 35 relapses during the wash-out period. Previous treatment with FTY, relapses in the previous year, and relapsing-remitting course were associated with higher RR. In the first 6 months of OCR, 12 patients had clinical or MRI disease activity. Higher Expanded Disability Status Scale (EDSS) and higher lymphocyte count at OCR start were associated with a reduced probability of relapse. Discussion and Conclusion: This study confirms that withdrawal from sequestering agents as FTY increases the risk of relapses in the wash-out period. Nevertheless, starting OCR before achieving complete immune reconstitution could limit its effectiveness in the first 6 months probably because trapped lymphocytes escape the CD20-mediated depletion.

Stepwise methodology for processing marrow products from matched siblings for possible T-cell depletion in patients with fanconi anemia

Background & Aim Post-transplant GvHD risk is increased in patients with aplastic anemia and Fanconi anemia (FA). T-cell depletion (TCD) is considered the most efficient GvHD prophylaxis. in hematopoietic stem cell transplantation (HCT). Overall risk of GvHD is less than 10% at our center using grafts from unrelated or mismatched, related donors for HCT to treat FA. Grafts with higher cell numbers (e.g. adults to children) are often used, providing increased cell numbers. For HCT in HLA matched siblings, most centers use unmodified grafts since TCD is problematic in young, comparably sized donors. Red blood cell (RBC) depletion due to ABO mismatch results in further loss. We studied the feasibility of TCD in a stepwise manner for the processing of marrow products from matched siblings in 2 patients with Fanconi anemia and aplastic anemia, both with a minor ABO mismatch requiring RBC depletion. Methods, Results & Conclusion At HCT, the first patient was 10.5 years old (22.1kg ( 90th%tile for age)). The second patient was 8.7 years old (24.4kg (10th%tile for age)). His sibling was 9.9 years of age (55kg (>90th %tile for age)). Volumes after collection, heparin addition, and stepwise processing are provided in table 1. Initial cell doses were above the threshold for proceeding to TCD (≥5.2 × 106). Products were RBC depleted (CD34+ recovery in table 1). The decision to proceed to TCD was made at this point with the aim for final doses of 2-4 × 106 CD34 cells/kg likely to occur post CD34 selection, even with moderate recovery using a threshold of ≥4.3 × 108 TNC/Kg. We would have proceeded to added GvHD prophylaxis and unmodified grafts should the CD34 cell doses have been lower post RBC depletion. TCD was performed using CliniMACS columns (Miltenyi) (table 1 shows CD34 recovery). The final CD3 cell doses of the two grafts were 3.6 and 0.9 × 103 CD3 cell doses/kg respectively (4.2 and 4.7 log reductions). Both patients engrafted with neutrophil engraftment (day +13), and platelet count of 50,000 (day +32). Patients are alive and disease free approx. 1 yr. post-transplant with complete hematologic and immune reconstitution and chimerism showing 100% myeloid donor engraftment. Careful, stepwise processing can be done in TCD of marrow for HCT in patients using HLA matched sibling donors. (1) Adequate and safe volume must be collected from donors. (2) Cell doses post RBC depletion must be assessed prior to proceeding with unmodified or TCD grafts.

Thymosin alpha 1 and HIV-1: recent advances and future perspectives.

In spite of the consistent benefits for HIV-1 infected patients undergoing antiretroviral therapy, a complete immune reconstitution is usually not achieved. Actually, antiretroviral therapy may be frequently accompanied by immunological unresponsiveness, persistent inflammatory conditions and inefficient cytotoxic T-cell response. Thymosin alpha 1 is a thymic peptide that demonstrates a peculiar ability to restore immune system homeostasis in different physiological and pathological conditions (i.e., infections, cancer, immunodeficiency, vaccination and aging) acting as multitasking protein depending on the host state of inflammation or immune dysfunction. This review reports the present knowledge on the in vitro and in vivo studies concerning the use of thymosin alpha 1 in HIV-1 infection. Recent findings and future perspectives of therapeutic intervention are discussed.

Baseline Naive CD4+ T-cell Level Predicting Immune Reconstitution in Treated HIV-infected Late Presenters.

Background:Among HIV-infected patients initiating antiretroviral therapy (ART), early changes in CD4+ T-cell subsets are well described. However, HIV-infected late presenters initiating treatment present with a suboptimal CD4+ T-cell reconstitution and remain at a higher risk for AIDS and non-AIDS events. Therefore, factors associated with CD4+ T-cell reconstitution need to be determined in this population, which will allow designing effective immunotherapeutic strategies.Methods:Thirty-one adult patients with baseline CD4+ T-cell count <350 cells/mm3 exhibiting viral suppression after ART initiation were followed in the HIV/AIDS research center of Peking Union Medical College Hospital in Beijing, China, from October 2002 to September 2013. Changes in T-cell subsets and associated determinants were measured.Results:Median baseline CD4+ T-cell count was 70 cells/mm3. We found a biphasic reconstitution of T-cell subsets and immune activation: a rapid change during the first 6 months followed by a more gradual change over the subsequent 8 years. Baseline CD4+ T-cell count >200 cells/mm3 in comparison to CD4+ T-cell count ≤200 cells/mm3 was associated with more complete immune Reconstitution (77.8% vs. 27.3% respectively; P = 0.017) and normalized CD4/CD8 ratio. We showed that the baseline percentage of naive CD4+ T-cell was a predictive marker for complete immune reconstitution (area under receiver operating characteristic curve 0.907), and 12.4% as cutoff value had a sensitivity of 84.6% and a specificity of 88.2%.Conclusions:Baseline naive CD4+ T-cell percentage may serve as a predictive marker for optimal immune reconstitution during long-term therapy. Such study findings suggest that increasing thymic output should represent an avenue to improve patients who are diagnosed late in the course of infection.

Suppression of the noninvolved pair of the myeloma isotype correlates with poor survival in newly diagnosed and relapsed/refractory patients with myeloma.

Heavy light chain (HLC) assays allow precise measurement of the monoclonal and of the noninvolved polyclonal immunoglobulins of the same isotype as the M‐protein (e.g., monoclonal IgAκ and polyclonal IgAλ in case of an IgAκ myeloma), which was not possible before. The noninvolved polyclonal immunoglobulin is termed ‘HLC‐matched pair’. We investigated the impact of the suppression of the HLC‐matched pair on outcome in 203 patients with multiple myeloma, a phenomenon that likely reflects the host's attempt to control the myeloma clone. Severe (>50%) HLC‐matched pair suppression was identified in 54.5% of the 156 newly diagnosed patients and was associated with significantly shorter survival (45.4 vs. 71.9 months, P = 0.019). This correlation was statistically significant in IgG patients (46.4 vs. 105.1 months, P = 0.017), but not in patients with IgA myelomas (32.9 vs. 54.1 months, P = 0.498). At best response, HLC‐matched pair suppression improved only in patients with ≥VGPR, indicating partial or complete humoral immune reconstitution during remission in those with excellent response. Severe HLC‐matched pair suppression retained its prognostic impact also during follow‐up after first response. In the 47 pretreated patients with relapsed/refractory disease, a similar correlation between severe HLC suppression and survival was noted (22.8 vs. not reached, P = 0.028). Suppression of the polyclonal immunoglobulins of the other isotypes than the myeloma protein correlated neither with HLC‐matched pair suppression, nor with outcome. Multivariate analysis identified severe HLC‐matched pair suppression as independent risk factor for shorter survival, highlighting the impact of isotype specific immune dysregulation on outcome in multiple myeloma. Am. J. Hematol. 91:295–301, 2016. © 2015 The Authors. American Journal of Hematology Published by Wiley Periodicals, Inc.

Bringing the End in Sight: Consensus Regarding HIV Screening Strategies

The updated U.S. Preventive Services Task Force recommendations on screening for HIV infection converge with those from the Centers for Disease Control and Prevention. The editorialists comment on ...

CCR5-Targeted Hematopoietic Stem Cell Gene Approaches for HIV Disease: Current Progress and Future Prospects

Despite substantial progress that has been made in understanding many aspects regarding biology and pathogenesis of human immunodeficiency virus type 1 (HIV-1), there is currently no vaccine or curative treatment available. HIV-1 continues to be a major global health problem. In this regard, new strategies are required for promoting a complete immune reconstitution and eradicating the virus from the body. The rationale for the use of hematopoietic stem cell (HSC)-based gene therapy against HIV infection is that, after transplantation, genetically modified HSCs carrying anti-HIV transgenes would engraft, divide and differentiate into large numbers of mature myeloid and lymphoid cells that express antiviral genes and thus are protected from HIV invasion or productive replication. HIV-1 attachment to susceptible cells involves binding of gp120 to CD4 receptor and subsequently to a HIV co-receptor, either CCR5 or CXCR4. The pivotal role of CCR5 in HIV-1 acquisition and disease progression has been established by the discovery of a naturally occurring 32-bp deletion in CCR5 (CCR5Δ 32) which generates a nonfunctional gene product. Homozygosity for CCR5Δ32 confers profound resistance against HIV infection, and heterozygous mutation that induces a decrease in CCR5 surface expression is associated with lower plasma viral load and delayed progression to acquired immune deficiency syndrome (AIDS). This, together with the fact of R5 dominance during the acute and asymptomatic phase, suggests that CCR5 is an attractive target for HIV gene therapeutics. The present review addresses recent advances of CCR5-targeted HSC gene approaches to treat HIV infection, discusses the future prospects and postulates potential strategies in the field.

Lack of Fluoroquinolone Resistance in Non-Typhoidal Salmonella Bacteremia in HIV-Infected Patients in an Urban US Setting

Non-typhoidal salmonella (NTS) bacteremia is a significant cause of morbidity and mortality in HIV-infected individuals worldwide. Recent reports have noted increasing resistance of NTS isolates to fluoroquinolones, the recommended first-line therapy for NTS bacteremia. The outcomes and risk factors for NTS bacteremia in HIV-infected patients in an urban US setting were evaluated. From January 2002 to December 2006, 26 episodes of NTS bacteremia were identified in 16 patients. The risk factors for NTS bacteremia were low CD4 count, high viral load, and lack of antiretroviral therapy (ART). Recurrences appeared related to lack of immune reconstitution in patients not on ART. Unlike reports from Asia, no fluoroquinolone resistance was identified in any of the Salmonella strains isolated in this setting. Optimal treatment of NTS in the HIV-infected patient in the United States should include therapy with fluoroquinolones as well as attaining complete viral suppression and immune reconstitution with ART.

Lymphocyte reconstitution in multiple myeloma patients after allogeneic G-CSF-mobilized hematopoietic progenitor cells transplantation from HLA-identical siblings

7098 Background: Allogeneic transplantation of G-CSF-mobilized hematopoietic progenitor cells (HPC) results in rapid and complete engraftment in a large proportion of patients and in relatively fast immune recovery. Methods : We have analyzed by flow cytometry the immune reconstitution in 19 patients (pts) affected by multiple myeloma undergone to allogeneic HPC transplant from HLA-identical related donors after nonmyeloablative conditioning regimen with fludarabine 90 mg/m2 and cyclophosphamide 900 mg/m2. In each patient a comparable number of mononuclear cells, CD3+ T lymphocytes and CD34+ progenitor cells was infused. To evaluate the kinetics of the immune reconstitution, the overall number of total lymphocytes, T, B and NK cells of each patient were assessed before and 1, 2, 3, 6, 12, 18, 24, 30, 36 months after allogeneic HPC transplant. Results: Overall T cell reconstitution was in all the pts at 3 months, since at that time the CD3+ T cell median number was 880 cells/microl (r. 589–1,357). However, in all pts high numbers of CD3+ T cells were achieved at 12 months after transplant (median 1,326 cells/microl, r. 850–2,309). The CD4+ T cell median number was 281 cells/microl (r. 185–433) at 6 months, 391 cells/microl (r. 303–505) at 12 months, 603 cells/microl (r. 433–736) at 18 months. The CD8+ T cell median number was increased from the transplant to 18 months in which it was 1,489 cells/microl (r. 760–1,976). The decrease of CD8+ T cells with the normalization of CD4+/CD8+ ratio was observed at 30 months when CD4+ T cells were 650 cells/microl (r. 370–989) and CD8+ T cells were 690 cells/microl (r. 445–1,743). B cells recovery was observed at 18 months with a median number of 194 cells/microl (r. 40–404). The faster reconstitution was documented for NK cells with a median number of 314 cells/microl (r. 61–647) at 2 months. Conclusions: the complete immune reconstitution in our pts was achieved at 30 months after transplant. Our objective is to evaluate if this slow immune recovery is associated with a high incidence of infectious diseases and a low incidence of chronic GVHD. No significant financial relationships to disclose.

Immunological Evaluation after Haematopoietic Stem Cell Transplantation for B–Thalassemia Major

Background: Haematopoietic stem cell transplantation (HSCT) remains the only curative option for patients with thalassemia. After HSCT is particularly important to recover a complete immune reconstitution for prevention of opportunistic infections.Methods: The immunological phenotype of peripheral blood mononuclear cells in 110 consecutively subjects after HLA identical HSCT performed for b thalassemia were studied. CD3+CD4+, CD3+CD8+, CD3−CD19+, CD3−CD16+CD56+ were evaluated by Flow Cytometry at 6 and 12 months after HSCT in 70 patients followed. In a part of patients CD4 naïve T cells was also evaluated at 12 months after HSCT.Results: at 6 months after HSCT we observed reduction of the mean of CD4 T cell percentage in patients respect normal value: in mean 17, 5 % ± 9 vs 45 % ± 10 respectively. After 1 year the rate of CD4+ T-cell population progressively increase: 24 ± 9 at 12 months vs 17, 5 % ± 9 at 6 months, but the mean of CD4+ T-cell count was persistently lower than in controls. The mean of CD8 T cell is stable during the follow up and the CD4/C8 ratio decreased. The mean of the CD19 increase during the follow up (4, 5 % at 6 months vs 17% at 12 months). At 1 year after HSCT the percentage of NK (CD3−CD16+CD56+) was normalized. At 1 year after HSCT reduction of naïve CD4 T cell we observed.Discussion. At 1 year after HSCT the immunological reconstitution is not still complete. The time and the extent of immune reconstitution depend on several factors. It is very important to continue the immune surveillance after HSTC and to evaluate other immunological parameters (i.e. thymic output) for to prevent infectious complications and elaborate an appropriate therapeutic strategy.