Lymphocyte Recovery Research Articles

Efficacy and Safety of Intravenous Cladribine in Patients with Rapidly Evolving or Early Secondary Progressive Multiple Sclerosis.

BackgroundMultiple sclerosis (MS) is an autoimmune and demyelinating inflammatory disease that affects the central nervous system (CNS). The etiology of the disease remains unknown. Multiple theories highlight genetic, environmental, and infectious factors that may a role. MS is considered as the main cause of disability in young people. Cladribine, known chemically as (2-Chloro-2′-deoxyadenosine), is a purine analog chemotherapy used for hairy cell leukemia and other B-cell lymphomas. The goal of this study was to evaluate the safety and efficacy of cladribine in patients with rapidly evolving or early secondary progressive MS.MethodsThis observational, single-center, retrospective chart review at the MS Clinic in the Ottawa General Hospital, Ottawa, Canada. A total of 24 patients (median Expanded Disability Status Scale (EDSS) of 4.5) received cladribine (0.07 mg/kg/day) for four consecutive days every six months for ≥ 2 cycles with further cycles depending on lymphocyte recovery or disease activity to a maximum of eight cycles from 2005 until 2016 were included. Four patients who were already diagnosed with rapidly evolving or early secondary progressive multiple sclerosis (SPMS) were induced with cladribine. We evaluated relapse, EDSS, and magnetic resonance imaging (MRI) results.ResultsOut of 24 patients (ages ranging from 30 - 60), 80% were female. Median follow-up time was seven years. The mean relapse rate in the two years before patients were given cladribine was 1.25. Twenty patients had previously received multiple disease-modifying therapies (DMTs) (≥ 2) prior to receiving cladribine. Following cladribine, eight patients suffered 10 relapses (33.3% of the cohort). Annualized relapse rates (ARRs) were reduced from 1.25 to 0.42, which was statistically significant (p-value = 0.002). There was no mean difference in EDSS (p-value = 0.06): 16% deteriorated, 62% did not change, and 12.5% improved. New MRI activity (new T2 or Gad+ lesions) was noted in only seven of 24 patients. ConclusionParenteral cladribine reduced the relapse rate from 1.25 to 0.42, which was statistically significant (p-value = 0.002). MRI activity in patients with rapidly evolving or early secondary progressive multiple sclerosis had a reasonable safety profile.

Investigating the Relationship between CD34+and CD3+ Cell Doses, One-Year Graft-Versus-Relapse-Free-Survival, Graft-Versus-Host Disease, and Overall Survival in Haploidentical Hematopoietic Stem Cell Transplantation Using Post Transplant Cytoxan: A Single Center Experience

Background Haploidentical hematopoietic cell transplantation (haplo-HCT) is a popular alternative to traditional HLA-matched HCT. The dose of CD34+ cells used during haplo-HCT to ensure favorable outcomes using PTCy has not yet been reported though 2-5.00 × 106 cells/kg is common. The optimal dose of CD3+ cells is also unknown but recent data suggests ≤3.00 × 108 cells/kg may prevent the development of acute GVHD. The importance of studying the impact of CD34+/CD3+ cell dosing may improve outcomes in this setting. Methods We retrospectively analyzed adult patients at USC Norris Cancer Hospital who received haplo-HCT from 2014 to 2019. The primary end-point assessed was 1-year GVHD-free/relapse-free survival (GRFS). Secondary end-points included 1-, 2-, and 3-year relapse-related mortality (RRM) and overall survival (OS) in addition to 1-year transplant related mortality (TRM) and incidence of acute and chronic GVHD. Results 67 adult haplo-HCT recipients were reviewed with 50% (n = 33) male and 49% (n = 32) female. The age range was 21-71 years old (median = 44) and the most common underlying hematologic disorders included AML (40%), ALL (38%), and aplastic anemia (7.7%). 67% received myeloablative conditioning while 33% received reduced intensity. 70% (n = 47) received peripheral blood and 30% (n = 20) received bone marrow stem cells. The mean CD34+ and CD3+ doses were 6.07 × 106 cells/kg and 2.94 × 108 cells/kg. The mean time to recovery of platelets, ANC, and lymphocytes was 25, 18, and 37 days respectively. CD34+ ≥5.00 × 106 cells/kg was associated with shorter time to lymphocyte recovery (p = 0.0265) though recovery less than 30 days was not associated with OS (p = 0.5268). Incidence of 1-year GRFS was 71% (n= 46) and 1-, 2-, and 3-year RRM were 4.6%, 6%, and 7.7% respectively. 1-year TRM was 15.3% with 50% of deaths from acute GVHD. 1-, 2-, and 3-year OS were 80%, 78%, and 77%. 33% (n = 22) and 30% (n = 20) developed acute and chronic GVHD. Subgroup analysis of those who received CD34+ dose ≥7.00 × 106 cells/kg (n = 24) and ≥10 × 106 cells/kg (n = 7) were found to have 1-year OS of 87.5% and 85.7% compared with 77% and 80% in those that received lower doses (p= 0.2229 and p = 1.00). Discussion Our results demonstrate 71% survived 1 year without experiencing at least 1 GRFS event compared with reports of 24-35% and 3-year OS of 77% when compared with 48%. The mean CD34+ dose of our population is higher than the standard which may have lead to improved outcomes however the CD34+/CD3+ dose was not significantly associated with our end-points but significantly associated with shorter time to lymphocyte recovery, a factor that has been reported to be associated with decreased RRM and therefore improved OS. Subgroup analysis of higher CD34+ doses also did show improved 1-year OS though not significant. Further research with a prospective study identifying the optimal CD34+/CD3+ cell dose is warranted to improve haplo-HCT outcomes.

Seven Years of Haplo-Cord Transplantation: Immune Reconstitution and Outcomes Using Anti-Thymocyte Globulin

Introduction Haplo-cord transplantation – the co-infusion of a single cord unit with CD34-selected cells from a haplo-identical donor, provides an alternate stem cell source for patients lacking HLA-matched donors. Anti-thymocyte globulin (ATG) is routinely used in haplo-cord preparative regimens to reduce graft failure, graft vs. host disease (GVHD) and graft vs. graft reactions. However, excessive depletion of cord lymphocytes may compromise immune reconstitution and graft vs. tumor (GVT) effects. Methods We reviewed lymphocyte recovery and outcome data for consecutive patients with hematologic malignancy who underwent haplo-cord transplantation at Weill Cornell Medicine between June 2012 and June 2019. All were conditioned using fludarabine and melphalan with or without total body irradiation (200-600cGy). All received rabbit ATG (Thymoglobulin), initially at a total dose of 6mg/kg (2012-2013) and later at a total dose of 4.5mg/kg (2013 onward). Data was collected as part of study 01810588 registered at clinicaltrials.gov. Probabilities of relapse and non-relapse mortality (NRM) were generated using cumulative incidence estimates to accommodate competing risks. Probabilities of overall survival (OS) and progression-free survival (PFS) were calculated using Kaplan-Meier estimates. Results Our study included 220 haplo-cord transplant recipients with a median age of 58 yrs (Range: 18 – 76 yrs). The majority had myeloid disease (AML – 54%, MDS/MPN – 19.5%, CML – 2%). Conditioning incorporated TBI for 120 patients (55%). ATG was dosed at 6mg/kg for 41 patients (19%). The median absolute lymphocyte count (ALC) at first ATG exposure was 0.4 × 10^9/L (IQR25-75: 0.2-0.7 × 10^9/L). The median patient weight was 75.5kg (IQR25-75: 65.4-89.9kg). Neutrophil and platelet engraftment occurred at a median of 12 days (IQR25-75: 10-16 days) and 22 days (IQR25-75: 17-35 days) respectively. Graft failure was observed in 16 patients (7%). Rapid early recovery of CD19+ lymphocytes, CD56+ natural killer cells and IgG levels was observed. T-cell recovery was delayed, with a gradual increase observed from Day 100 (Figure). Overall PFS and OS at 2 yrs were 30% (CI 24-37%) and 39% (CI 32-46%) respectively. The 2 yr cumulative incidence of NRM was 33% (+/- 3% SEM). The overall 2 yr incidence of relapse was 37% (+/- 3% SEM), however there was a significant difference in relapse incidence between patients treated with 6mg/kg ATG (54%) versus 4.5mg/kg (31.5%) (p=0.009). Conclusion Haplo-cord transplant facilitates early neutrophil engraftment with early normalization of B- and NK-lymphocytes. An observed delay in T-cell recovery may be due to the use of ATG in this platform and higher ATG doses result in a greater incidence of relapse. Our data supports the minimization or replacement of ATG in haplo-cord transplant. An analysis of GVHD incidence and viral reactivation events is ongoing and will be presented.

Lymphocyte reconstitution after DMF discontinuation in clinical trial and real-world patients with MS.

BackgroundDelayed-release dimethyl fumarate (DMF) has demonstrated robust efficacy in treating patients with relapsing-remitting multiple sclerosis. Decreases in absolute lymphocyte count (ALC) are a well-known pharmacodynamic effect of DMF treatment, but lymphocyte recovery dynamics are not well characterized after discontinuation of DMF.MethodsData sources included the Biogen DMF integrated clinical trial data set, a retrospective US chart abstraction study, and data from MSBase. We assessed rate and time course of lymphocyte reconstitution after DMF discontinuation.ResultsThe majority of patients who developed lymphopenia while treated with DMF and subsequently discontinued treatment experienced ALC reconstitution. The median time to reach ALC ≥0.8 × 109/L was 2–4 months after discontinuation for patients treated in real-world data sets; the median time to reach ALC ≥0.91 × 109/L was 2 months after discontinuation in DMF clinical trials. Severity of lymphopenia on treatment and decline in ALC within the first 6 months did not affect the ALC reconstitution rate after DMF discontinuation; rather, on-treatment lymphopenia duration influenced the reconstitution rate. In patients with severe, prolonged lymphopenia for ≥3 years, lymphocyte reconstitution to ≥0.91 × 109/L was 12–18 months vs 2–3 months in patients with lymphopenia persisting <6 months.ConclusionsThe majority of patients who discontinued DMF due to lymphopenia experienced ALC reconstitution within 2–4 months following DMF discontinuation. This may help guide clinicians in managing patients who develop lymphopenia during DMF treatment. Prolonged lymphopenia on DMF treatment is associated with slow lymphocyte recovery after DMF discontinuation.

The Prognostic Value of Eosinophil Recovery in COVID-19: A Multicentre, Retrospective Cohort Study on Patients Hospitalised in Spanish Hospitals

Objectives: A decrease in blood cell counts, especially lymphocytes and eosinophils, has been described in patients with severe SARS-CoV-2 (COVID-19), but there is no knowledge of the potential role of their recovery in these patients’ prognosis. This article aims to analyse the effect of blood cell depletion and blood cell recovery on mortality due to COVID-19. Design: This work is a multicentre, retrospective, cohort study of 9,644 hospitalised patients with confirmed COVID-19 from the Spanish Society of Internal Medicine’s SEMI-COVID-19 Registry. Setting: This study examined patients hospitalised in 147 hospitals throughout Spain. Participants: This work analysed 9,644 patients (57.12% male) out of a cohort of 12,826 patients ≥18 years of age hospitalised with COVID-19 in Spain included in the SEMI-COVID-19 Registry as of 29 May 2020. Main outcome measures: The main outcome measure of this work is the effect of blood cell depletion and blood cell recovery on mortality due to COVID-19. Univariate analysis was performed to determine possible predictors of death and then multivariate analysis was carried out to control for potential confounders. Results: An increase in the eosinophil count on the seventh day of hospitalisation was associated with a better prognosis, including lower mortality rates (5.2% vs 22.6% in non-recoverers, OR 0.234 [95% CI, 0.154 to 0.354]) and lower complication rates, especially regarding to development of acute respiratory distress syndrome (8% vs 20.1%, p=0.000) and ICU admission (5.4% vs 10.8%, p=0.000). Lymphocyte recovery was found to have no effect on prognosis. Treatment with inhaled or systemic glucocorticoids was not found to be a confounding factor. Conclusion: Eosinophil recovery in patients with COVID-19 is a reliable marker of a good prognosis that is independent of prior treatment. This finding could be used to guide discharge decisions.Funding Statement: None.Declaration of Interests: The authors declare that there are no conflicts of interest.Ethics Approval Statement: Data confidentiality and patient anonymity were maintained at all times, in accordance with Spanish regulations on observational studies. This study was carried out in accordance with the Declaration of Helsinki and was approved by the Institutional Research Ethics Committees of each participating hospital.

Hematopoietic Stem Cell Transplantation for Progressive Combined Immunodeficiency and Lymphoproliferation in Patients With Activated Phosphatidylinositol–3–OH Kinase δ Syndrome Type 1

To examine clinical features, laboratory findings, treatment, and outcomes of patients with activated phosphatidylinositol-OH-3 kinase δ syndrome type 1 (APDS1) and evaluate hematopoietic stem cell transplant (HSCT) as a potential treatment option.This study included 23 patients with confirmed PIK3CD mutations. Nine of these patients underwent HSCT.This was a retrospective study to characterize clinical characteristics, laboratory findings, treatment, and outcomes of patients with APDS1. Patients were identified by patient registry, physician referral, or having been previously reported in literature. Data were obtained by review of medical records and physician questionnaires.Common clinical features of patients with APDS1 included recurrent infections, lymphoproliferation, and enteropathy, with a median age at symptoms onset of 11 years old. The majority (65%) of patients received immunoglobulin replacement, and some additionally had prophylactic antimicrobial agents. Eleven transplantations were performed for recurrent infections or treatment refractory disease among 9 total patients. Fludarabine-based reduced-intensity conditioning regimens were used in all transplants (90–180 mg/m2), and 55% used human leukocyte antigen–mismatched donors. All but 1 patient ultimately achieved engraftment, but 36.4% had initial graft failure and required retransplantation, boosts of peripheral blood stem cells, or growth hormone administration for delayed T lymphocyte recovery. More than 90% of transplanted patients had an adverse complication, most commonly mild graft-versus-host disease. Despite this, most symptoms were improved post-HSCT, and no patients required ongoing immunoglobulin replacement by day 100 post-HSCT. The 30-year overall survival was 86.1%, and event-free survival was 39.6%.HSCT should be considered in patients with APDS1 and recurrent infections and/or treatment refractory lymphoproliferation. Clinical symptoms improved posttransplantation, although adverse complications and graft failure were frequent.Patients with APDS1 are at increased risk for recurrent infections, bronchiectasis, lymphoproliferation, chronic viral infections, and lymphoma. This article highlights the role that HSCT may play in the future management of patients with APDS1. Although not without its own risks, early HSCT can improve clinical symptoms and reduce the lifetime risk for potentially fatal complications in this disease. Investigators in this study closely examine HSCT regimens for APDS1 patients among various international medical centers, which serves as the first critical step toward improving event-free and overall survival for these patients.

Low Lymphocyte Count at Day 30 after Single Cord Blood Transplantation Had Negative Impact on Survival, Because of Higher NRM Rate

&amp;lt;Introduction&amp;gt; Delayed immune reconstitution after allogeneic transplantation increases the risk of treatment-related mortality, and chronic GVHD. Previous reports showed that absolute lymphocyte count at day 30 (ALC30) was a significant prognostic factor of transplantation, and lower numbers of total CD4+ T cells and naïve CD4+ T cells in particular were associated significantly with higher mortality. However, there is little knowledge about the factors associated with low lymphocyte recovery, especially in cord blood transplantation (CBT). The cut-off value of lymphocyte recovery for statistical significance has not been determined yet. &amp;lt;Methods&amp;gt; We retrospectively analyzed the outcome of 579 consecutive patients who underwent single cord blood transplantation (CBT) for the first time at Toranomon Hospital between January 2011 and 2018. Patients with active infection at transplantation (n=40), in poor ECOG PS (3 or more) (n=36), or lacked information about CT before CBT (n=1) were excluded from this study. &amp;lt;Results&amp;gt; Five hundred and two patients (n=317 male; n=185 female) were included in this study. The median age at transplantation was 57 years (range, 16-77), with a median HCT-CI score of 2 (0-10). Underlying diseases were AML (307), MDS (43), MPN (20), ALL (50), mature lymphoid malignancies (54), and others (28). Median spleen index (SI) before transplantation was 60.2 (16.5-319.7). Three hundred and ninety eight patients (79%) were not in remission at transplant. MAC regimens were selected in 400 (80%). TAC alone was used in 132 (26%) as GVHD prophylaxis. Median number of TNC and CD34+ cells infused were 2.62 (1.57-6.85) x 107/kg and 0.86 (0.29-3.77) x 105/kg, respectively. 194 (39%) were positive for anti-HLA antibodies, but none had donor-specific. With a median follow-up of 32 (range, 3-99) months, cumulative incidence of neutrophil engraftment (NE), the 3-year probabilities of overall survival (OS), relapse rate (RR) and non-relapse mortality (NRM) for entire population were 92.8%, 40.6%, 23.5%, and 35.3%, respectively. Underlying disease (myeloid malignancy), disease status at SCT (non-CR), poor PS (PS=2), GVHD prophylaxis (TAC+MMF), low CD34-positive cell dose (&amp;lt;0.8 x 105/kg), and splenomegary (SI ≥ 40) were significantly associated with inferior NE in multivariate analysis. Disease status at SCT (non-CR), poor PS (PS=2), Higher HCT-CI (PS ≥ 3), and GVHD prophylaxis (TAC+MMF) were significantly associated with higher NRM in multivariate analysis. We analyzed the relationship between ALC30 and transplantation outcome. Median number of ALC30 was 231 (3.5-1503), and the 25th percentile was 144. We divided the cohort into two groups, ALC30 low group (&amp;lt;150, n=123), ALC30 high group (≥150, n=346). High number of ALC30 (≥150) was associated with better survival (48.1% vs. 29.5%, p &amp;lt; 0.01) and lower NRM (26.9% vs. 41.9%, p &amp;lt; 0.01) due to reduced incidence of lethal infection (7.1% and 23.4% of total death in ALC30 high and low, respectively, p &amp;lt; 0.01), but was not associated with RR (25.5% vs. 25.1%, p = 0.59). High ALC30 (≥150), as well as younger age (&amp;lt;60), underlying disease (myeloid malignancy), better PS (0-1), and disease status at SCT (CR) showed a superior OS in multivariate analysis. We then assessed factors associated with ALC30, and higher infused dose of CD34-positive cells was the only factor associated with high ALC30, (p=0.03, t-test). Other factors, such as infused TNC dose, type of conditioning, or GVHD prophylaxis did not show significant association with ALC30. &amp;lt;Conclusion&amp;gt; This retrospective study demonstrated that low ALC30 after CBT had negative impact on survival because of higher NRM rate. High CD34-positive cell dose was the only factor associated with high ALC30. Not CD34-positive cell dose, but ALC30 had significant impact on OS in multivariate analysis, so we need to take lymphocyte recovery into account, in an attempt to improve transplantation outcome. Figure Disclosures No relevant conflicts of interest to declare.

Classical Monocyte Deficiency Calculated By the Mono-Index Can Predict Mortality in Allogeneic Hematopoietic Stem Cell Transplantation Patients

Background: Most studies in immune reconstitution after allogeneic hematologic stem cell transplantation (alloHSCT) focus on adaptive immunity, particularly in lymphocyte recovery. Classical monocytes (cMo) are part of the innate immunity, playing an important role in the defense against fungal and bacterial infections. The innate and adaptive immunity are closely related, and non-classical monocytes (ncMo) participate in this connection, regulating T cell response. However, the role of these cells in the graft versus tumor effect and graft versus host disease (GVHD) is still unclear. Objectives: The aim of the study was to investigate cMo and ncMo reconstitution after alloHSCT and a possible impact of these cells subsets on acute and chronic GVHD, relapse, non-relapse related mortality (NRM) and overall survival (OS). Patients and Methods: This is a retrospective analysis of 77 patients who underwent alloHSCT in 4 different transplant centers in Brazil. Peripheral blood samples were collected from patients at neutrophil engraftment (NE) and 3, 7, 14, 21, and 42 days after NE. The cMo (DR+, CD11c+, CD14+, CD16-) and ncMo (DR+, CD11c+, CD14-, CD16+) were classified and analyzed by 8-color multiparametric flow cytometry (FACSCanto II). In order to analyze the possible impact of duration and severity of monocytopenia after transplant, we calculated then the 'mono-index' and the 'ncMo-index', based on the area over the curve (AOC) of absolute cMO counts (AMC) and absolute ncMo counts, respectively, considering a horizontal line of AMC 0.5x10e9/L as cut-off value for both subpopulations. Results: The medium follow up was 82 months. Out of 77 patients, 46 (60%) were male, and the median age was 17 years (range: 1-74). The stem cell source was bone marrow in 36 (47%), cord blood in 23 (30%), and peripheral blood in 18 (23%); and donors were matched unrelated in 61 (79%), and matched related in 16 (21%) cases. Most patients received myeloablative conditioning (n=47, 61%); and acute leukemia was the most common diagnosis (72%). A total of 40 (52%) patients received total body irradiation (TBI), and 27 (35%) patients received antithymocyte globulin (ATG). We calculated the possible impact of cMo at all timepoints and found no differences in the main outcomes between patients with lower or higher counts. We then analyzed the AOC of all cMo counts (the mono-index). A higher index represents a more severe deficiency of cMo. We then used the receiver operating characteristic (ROC) curve to define the cut-off value of 14234.4 cells/days x mm3 to discriminate patients as cMo deficient (n=31, 40%) or non-deficient (n=46, 60%). Non relapse mortality (NRM) at 6 years was higher in cMo deficient patients calculated by the mono-index (40% vs. 16% for non-deficient, p=0.02, Figure 1). Deficient patients also had worse OS at 6 years (58% vs. 37% for non-deficient, p=0.03, Figure 2). In multivariate analyses, cMo deficiency calculated by the mono-index remained significantly associated with NRM (hazard ratio 3.07, 95% confidence interval) and OS (HR 2.05, 95%CI 1.20-7.85). We observed no impact of mono-index on acute or chronic GVHD or relapse. We observed no impact of the ncMo counts at all timepoints or the ncMo-index in any of the analyzed outcomes. Conclusion: cMo deficiency calculated by the mono-index can predict mortality in alloHSCT. Mono-Index is an inexpensive, accessible and easy to perform tool that might help clinicians in predicting unfavorable outcomes. Further studies are needed to confirm these findings and to test how different transplant strategies or therapeutic changes might interfere with monocytes recovery in alloHSCT. Disclosures No relevant conflicts of interest to declare.

Investigating the Relationship between CD34+and CD3+ Cell Doses, One-Year Graft-Versus-Relapse-Free-Survival, Graft-Versus-Host Disease, and Overall Survival in Haploidentical Hematopoietic Stem Cell Transplantation: A Single Center Experience

Background: Haploidentical hematopoietic cell transplantation (haplo-HCT) has emerged as a popular alternative to traditional HLA-matched hematopoietic cell transplant. As the number of haplo-HCT's rises, investigating the factors that may affect outcomes is necessary in order to improve overall survival and reduce transplant-related mortality. The optimal dose of CD34+ cells used during haplo-HCT to ensure favorable outcomes using PTCy has not yet been reported though a range of 2 to 5.00x106 cells/kg is commonly used.Furthermore, the optimal dose of CD3+ cells is unknown however recent data has suggested less than 3.00x108 cells/kg may prevent the development of acute GVHD. The importance of studying the impact of CD34+/CD3+ cell dosing may help to improve outcomes in this setting. Methods: We retrospectively analyzed adult patients at USC Norris Cancer Hospital (age ≥ 21) who received haplo-HCT from 2014 to 2019. The primary end-point assessed was 1-year GVHD-free/relapse-free survival (GRFS) defined as grade 3-4 acute GVHD, systemic therapy-requiring chronic GVHD, relapse, or death in the first post-HCT year. Secondary end-points included 1-, 2-, and 3-year relapse-related mortality (RRM) and overall survival (OS) in addition to 1-year transplant related mortality (TRM) and incidence of both acute and chronic GVHD. Results: A total of 67 adult haplo-HCT recipients were reviewed. Of the patients evaluated, approximately 50% (n = 33) were male and 49% (n = 32) were female. The age range was 21-71 years old (median = 44), and the most common underlying hematologic disorders included AML (40%), ALL (38%), aplastic anemia (7.7%), and others (MDS, lymphoma, myelofibrosis, and HLH) (13.8%). 67% of patients received myeloablative conditioning regimens while 33% received reduced intensity regimens. 70% (n = 47) of patients received peripheral blood as a stem cell source with 30% (n = 20) receiving bone marrow. The mean CD34+ dose infused was 6.07x106 cells/kg and the mean CD3+ dose was 2.94x108 cells/kg. The mean time to recovery of platelets, neutrophils, and lymphocytes was 25, 18, and 37 days respectively. CD34+ stem cells ≥5.00x106 cells/kg was significantly associated with shorter time to lymphocyte recovery (p = 0.0265) though recovery less than 30 days was not significantly associated with OS (p = 0.5268). Incidence of 1-year GRFS was 71% (n= 46) and 1-, 2-, and 3-year RRM were 4.6%, 6%, and 7.7% respectively. 1-year TRM was 15.3% with 50% of deaths from acute GVHD. 1-, 2-, and 3-year OS were 80%, 78%, and 77% respectively. Factors significantly associated with increased mortality included use of RIC regimen (p = 0.004) and disease status at time of transplant (p = 0.04). Cumulative incidence of GVHD was 63% (n = 42) with 33% (n = 22) and 30% of patients (n = 20) with acute and chronic GVHD respectively. Lack of mild chronic GVHD was associated with increased mortality (p = 0.0029) and use of a myeloablative regimen (p = 0.0029) was significantly associated with GVHD. Subgroup analysis of those who received CD34+ dose ≥7.00x106 cells/kg (n = 24) and ≥10x106 cells/kg (n = 7) were found to have 1-year OS of 87.5% and 85.7% compared with 77% and 80% in those that received lower doses (p= 0.2229 and p = 1.00) respectively however this was not found to be significantly associated with increased incidence of GVHD, relapse, or mortality. Discussion: Our results demonstrate improved outcomes specifically 71% survived 1 year without experiencing at least 1 GRFS event compared with 24-35% reported by CIBMTR, Holtan et al 2015, and Solh et al 2016 with 3-year OS of 77% when compared with a previously reported 48%. The mean CD34+ cell dose of our population is higher than the standard range which may account for the improved outcomes however the dosing of CD34+/CD3+ cells were not significantly associated with our primary and secondary end-points. It was significantly associated, however, with shorter time to lymphocyte recovery, a factor that has been reported to be associated with decreased RRM and therefore improved OS. Furthermore, subgroup analysis of higher CD34+ dose did show a better 1-year OS though this was not statistically significant. Limitations of this study include small sample size and short follow-up period. Further research with a prospective study identifying the optimal CD34+/CD3+ cell dose in addition to comprehensive evaluation of immune recovery is warranted in order to improve haplo-HCT outcomes. Figure Disclosures Yaghmour: Jazz Pharmaceutical company: Consultancy, Speakers Bureau; Astella company: Speakers Bureau; Takeda: Speakers Bureau.

Oral calcitriol in hematopoietic recovery and survival after autologous stem cell transplantation: a randomized clinical trial.

Calcitriol, the active metabolite of vitamin D, is an essential regulator in the hematopoiesis and immunity. However, knowledge revealing its influence on the immune and hematologic reconstitution after hematopoietic stem cell transplantation (HSCT) in clinical trials is very limited. The effects of calcitriol on short-term and long-term hematopoietic recovery, relapse-free survival (RFS) and overall survival (OS) in multiple myeloma, Hodgkin's and non-Hodgkin's lymphoma following autologous peripheral blood HSCT were assessed. Eighty patients (age: 18-68years) in complete remission were allocated 1:1 to two groups by balanced block randomization. Calcitriol 0.25μg or placebo capsule was administered three times daily from transplantation to day 30. Absolute neutrophil count (ANC), absolute lymphocyte count (ALC), and platelet count (PC) were determined daily from transplantation to day 30. White blood cell count (WBC), PC, and hemoglobin concentration (HC) of days 180 and 365 were extracted from clinic files. A thorough examination for oral mucositis (OM) was completed daily during hospital stay. Adverse drug reactions (ADRs) as well as two-year RFS and OS were evaluated. Median time to ANC engraftment (≥0.5 × 103/μl: 10.0 vs. 11.0days; P = 0.98) and PC engraftment (≥20.0 × 103/μl: both 14.0days; P = 0.58) was similar between groups. However, the median time to ALC recovery was significantly shorter in the calcitriol group (≥0.5 × 103/μl: 13.0 vs. 20.0days; P < 0.001). Moreover, ALC recovery rates on day 15 (≥0.5 × 103/μl: 82.1% vs. 42.5%; P < 0.001) and on day 30 (≥1.0 × 103/μl: 91.7% vs. 57.5%; P = 0.001) was significantly higher with calcitriol. WBC, PC, and HC on days 180 and 365 were not significantly different between groups. None of the OM indices were modulated by calcitriol. All the ADRs were non-serious and mild, possibly or unlikely related to the intervention. In a median of 29months follow-up, RFS was significantly better in the calcitriol group (77.0%, SE = 7.0% vs. 59.0%, SE = 8.0%; P = 0.03), albeit the OS was not affected (87.0%, SE = 5.0% vs. 92.0%, SE = 4.0%; P = 0.72). Calcitriol could improve ALC recovery and RFS as a safe option post-HSCT. Graphical abstract Oral calcitriol 0.25 µg three times daily from transplantation to day 30 improved lymphocytes recovery and two-year relapse-free survival as a safe option in 80 patients of autologous hematopoietic stem cell transplantation in comparison with placebo.

Lack of Lymphocyte Recovery After Esophagectomy Predicts Overall and Recurrence-Free Survival

BackgroundLymphocytes have become the target of cancer interventions through engineering or immune checkpoint antibodies. We previously found decreased lymphocyte counts to be a predictor of mortality and complications in trauma and cardiac surgery patients. We hypothesized lack of lymphocyte count recovery postoperatively would predict outcomes in esophagectomy patients. MethodsA retrospective review of all patients undergoing esophagectomy for adenocarcinoma performed over 13 y at our center by a single surgeon after institutional review board approval was performed. Patients were grouped by postoperative lymphocytes counts: never low, low with recovery, and low without recovery. Resolution of lymphopenia was assessed by day 4. Primary end points were overall and recurrence-free survival. ResultsIn total, 198 patients were included with a minimum 6-mo follow-up. Collectively the 5-y recurrence and overall survival rates were 36% and 50%, respectively. Recurrence was significantly higher at 5 y in patients with persistent lymphopenia (43%) compared with those who recovered (14% P = 0.0017) and those who never dropped (0% P = 0.0009). The persistent lymphopenia group had significantly lower survival (45%) compared with the two other groups (67% P = 0.0232). ConclusionsThere is a significant decrease in the overall and recurrence-free survival in those patients whose lymphocyte count drops without recovery after their esophagectomy. These data imply differences in immune responses to the stress of surgery that can be measured with routine postoperative laboratory values and are indicative of overall outcomes.

Lymphocyte subset at time of Epstein-Barr viremia post-allogeneic hematopoietic stem cell transplantation in children may predict development of post-transplant lymphoproliferative disease: CD8:CD20 ratio as a sensitive predictor.

EBV-associated PTLD following allogeneic HSCT is a serious complication associated with significant mortality. In this retrospective study, we evaluated whether lymphocyte subset numbers and CD8:CD20 ratio at time of EBV viremia in children undergoing allogeneic HSCT could predict development of PTLD. Absolute lymphocyte count, lymphocyte subsets, and CD8:CD20 ratio at the time of EBV viremia were analyzed. Patients who were treated preemptively with rituximab for high blood EBV viral load were excluded. Out of 266 patients transplanted during the study period, 26 patients were included in the analysis. Patients were divided into two cohorts; cohort 1 included patients with EBV-associated PTLD (n=5; four with proven, one with probable PTLD). Cohort 2 included patients with EBV viremia without PTLD (n=21). Lymphocyte recovery was slower in the PTLD group. CD8:CD20 ratio was significantly lower in the PTLD group (median 0.15) compared to the non-PTLD group (median 2.4, P=.012). Using the ROC curve and 1 as the cutoff value, CD8:CD20 ratios were analyzed. In the PTLD group, 4/5 patients (80%) had a ratio <1 whereas in the non-PTLD group, all 21 patients had a ratio >1. Sensitivity and specificity were 80% and 100%, respectively. Negative and PPVs were 95% and 100%, respectively. Profoundly low T-cell count and CD8:CD20 ratio may be used to predict development of PTLD in the context of EBV viremia in children post-allogeneic HSCT. Further studies are needed to validate this finding.

Genetic and clinical predictors of CD4 lymphocyte recovery during suppressive antiretroviral therapy: Whole exome sequencing and antiretroviral therapy response phenotypes.

Increase of peripheral blood CD4 lymphocyte counts is a key goal of combined antiretroviral therapy (cART); most, but not all, recipients respond adequately and promptly. A small number of studies have examined specific genetic factors associated with the extent of CD4 recovery. We report a genome-wide examination of factors that predict CD4 recovery in HIV-infected women. We identified women in in a cohort study who were on cART with viral load below 400 copies, and drew racially and ethnically matched samples of those with good CD4 response over 2 years or poor response. We analyzed the exomes of those women employing next generation sequencing for genes associated with CD4 recovery after controlling for non-genetic factors identified through forward stepwise selection as important. We studied 48 women with good CD4 recovery and 42 with poor CD4 recovery during virologically-suppressive cART. Stepwise logistic regression selected only age as a statistically significant (p<0.05) non-genetic predictor of response type (each additional year of age reduced the odds of good recovery by 11% (OR = 0.89, CI = 0.84–0.96, p = 0.0009). After adjustment for age and genomic estimates of race and ethnicity, 41 genes harbored variations associated with CD4 recovery group (p≤0.001); 5 of these have been previously reported to be associated with HIV infection, 4 genes would likely influence CD4 homeostasis, and 13 genes either had known functions or were members of product families that had functions for which interactions with HIV or effects on lymphocyte homeostasis were biologically plausible. Greater age was the strongest acquired factor that predicted poor CD4 cell recovery. Sequence variations spanning 41 genes were independently predictive of CD4 recovery. Many of these genes have functions that impact the cell cycle, apoptosis, lymphocyte migration, or have known interactions with HIV. These findings may help inform new hypotheses related to responses to HIV therapy and CD4 lymphocyte homeostasis.

Prognostic significance of lymphocyte recovery in children with standard and high-risk precursor B acute lymphoblastic leukemia

BackgroundThe primary aim of this study was to determine if absolute lymphocyte count (ALC) at end of induction is an independent prognostic marker of event free survival (EFS) in children with precursor B-ALL. Material & MethodsThis is a retrospective analysis of children (aged 1–18 years) diagnosed with standard and high-risk precursor B ALL. At day 29 of induction ALC (ALC29) ≥ 1.5 × 109/L was considered high and <1.5 × 109/L was considered low. ResultsTotal 260 children with (183 standard risk and 77 high risk) Precursor B ALL were included. The mean age of the study cohort was 5.2 ± 4.0 years. Fourteen patients had an event (12 relapse, 4 deaths). Mean follow-up duration was 41 months ± 20 months (median 41 months).Overall survival (OS) of the entire study cohort was 98.5% (standard risk 99.4%, high risk 96.1%, p = 0.045). EFS of the entire study cohort was 94.6% (standard risk 96.1%, high risk 90.9%, p = 0.072).ALC at any of the studied time points did not correlate with relapse. MRD at day 29 was the strongest predictor of both death (p = 0.00) and relapse (0.034). ALC29 did not differentiate EFS among MRD negative patients.However, once patients relapsed, the OS was 100% for those who had ALC>1.5 × 109/L at day 29 of initial induction chemotherapy vs 40% for those with ALC <1.5 × 109/L (p = 0.01). ConclusionWe conclude that ALC29 cannot be used to risk stratify children with pre B ALL.

PB1905 PREDICTIVE VALUE OF PERIPHERAL LYMPHOCYTES SUBPOPULATIONS ON BCR INHIBITORS ACTIVITY IN HIGH‐RISK CHRONIC LYMPHOCYTIC LEUKEMIA

Background:BCR inhibitors (ibrutinib and idelalisib) have dramatically changed clinical scenario of High Risk CLL patients (del17p13, early relapsed or refractory disease), with prolonged responses observed in more than 50% of cases. Both these molecules have immunomodulating properties, with ibrutinib inducing a Th1 phenotype through inhibition of IL2‐inducible kinase (ITK) in Th2 cells and idelalisib promoting autoimmunity in presence of lower T‐regulatory cells (Tregs) levels. Importantly, CLL is characterized by high levels of circulating Tregs, which in turn represents a plausible mechanism of immune‐tolerance. Although several reports indicate that BCR inhibitors‐activity results in the recovery of anti‐cancer immunity, the impact of pre‐treatment lymphocytes subpopulations on these drugs activity has not been investigated yet.Aims:In this study we investigate the role of T and NK Cell compartment in peripheral blood in mediating biological activity of novel BCR inhibitors.Methods:We analysed 50 CLL consecutive pts treated with ibrutinib‐ or idelalisib‐ based regimens from 2015 to 2018 at our centre. Among these patients, we identified 10 (8 treated with ibrutinib and 2 with idelalisib) characterized by high unfavourable biological risk profile according to 2018 iwCLL criteria (del17p13 and/or relapse within 24‐36 months and/or refractory disease): 5 treatment‐naïve pts showed 17p13 deletion, 4 pts relapsed within 24 months from the last treatment and 1 presented a combination of del17p13 and early relapse. An unmutated IgHV status characterized 5 out of 10 pts (50%). All patients have not been treated within the last 12 months and showed adequate lymphocyte recovery at time of analysis. All selected pts received BCR inhibitors treatment at least for 6 consecutive months and no occurrence of toxicity/intolerance were reported. Patients achieving less than partial remission (PR), were considered non‐responders (NRs) based on iwCLL criteria. Absolute number of lymphocytes subpopulations (CD3+ T cells, CD19+ B cells, CD16+ CD56+ CD3‐ NK cells, CD3+ CD4+ T cells and CD3+ CD8+ T cells) was evaluated by flow‐cytometry before starting treatment; T and NK cells compartments were compared to the leukemic monoclonal B‐cells (MBC) defining a T/MBC and NK/MBC ratio.Results:Six patients achieved at least a PR within 6 months of starting treatment, whilst 4 were considered NRs. At baseline, NRs exhibited higher levels of T (median, responders vs NRs: 1875 vs 2261) and NK (median, responders vs NRs: 379 vs 500) circulating lymphocytes than responders. In detail, among T cell compartment, high CD8 positive cells were observed in not responders (median, responders vs NRs: 864 vs 1296) with no significant difference in CD4 positive T cells count (median, responders vs NRs: 1073 vs 927). Further analysis on ibrutinib‐treated pts, revealed that such differences were more pronounced: NRs exhibited a 2‐fold increased levels of circulating T cells (median, responders vs NRs: 1767 vs 3526), NK cells (median, responders vs NRs: 317 vs 756) and circulating CD4 positive cells (median, responders vs NRs: 976 vs 1385) than responders. Moreover, higher T/MBC and NK/MBC ratios were observed among the former.Summary/Conclusion:Higher levels of circulating lymphocytes have been reported to be associated with CLL, probably reflecting a tumour‐permissive status. In this study, although the small size of analysis, our data suggest an hypothetical enhanced activity of BCR inhibitors in CLL patients carrying a normal lymphocytes subpopulation, thus supporting the immunomodulating activity of these molecules.

The use of corticosteroids does not influence CD4+ lymphocyte recovery in HIV-infected patients with advanced immunodeficiency

ABSTRACTCorticosteroids inhibit HIV-related immune activation and seem to have a mild favorable effect on immunological recovery in patients with CD4+ counts ≥200 cells/mm3. Data in patients with advanced immunodeficiency are lacking. We analyzed whether corticosteroids negatively influence the short-term CD4+ lymphocyte recovery in patients with CD4+ cell counts <200 cells/mm3 started on combination antiretroviral therapy (cART). We performed a retrospective cohort analysis including all HIV-infected patients under follow-up in our hospital with a documented episode of Pneumocystis Jirovecii Pneumonia (PJP) in the cART era. CD4+ lymphocyte recovery was assessed at three months after the episode of PJP and subsequent start of cART, comparing patients that received adjunctive corticosteroids (AC) versus patients that did not receive corticosteroids (standard care (SC)). In total, 66 patients with an episode of PJP were identified with 38 patients in the AC-group versus 28 patients in the SC-group. Almost all baseline characteristics were similar, including mean CD4+ lymphocyte counts. After three months, the mean CD4+ cell count did not differ; 222 cells/mm3 for the SC-group versus 259 cells/mm3 for the AC-group (p = .29). The use of corticosteroids does not alter CD4+ lymphocyte recovery in HIV-infected patients with advanced immunodeficiency in the first months of antiretroviral therapy.

Predictive effects of body mass index on immune reconstitution among HIV-infected HAART users in China

BackgroundBody mass index (BMI) may contribute somewhat to drug metabolism, and thus affecting the efficacy of highly active antiretroviral therapy (HAART). This study aimed to determine the frequencies of underweight, normal and overweight/obesity at pre-HAART in a large cohort of HIV-infected Chinese patients, and investigate the prospective effects of BMI on immune reconstitution after HAART initiation.MethodsA longitudinal cohort study was performed to analyze the effects of BMI on immune reconstitution in HIV-infected patients treated with HAART. Multiple linear regression was used to evaluate the relationship between baseline BMI and increased CD4+ T lymphocyte levels at 12 and 30 months after initiating HAART. In addition, Cox proportional hazard model was used to assess the relationship between BMI and time to achieve immunologic reconstitution (CD4+ T lymphocytes>500cells/μL) during the follow-up period.ResultsAmong the 1612 enrolled patients, 283 (17.6%) were overweight/obese (BMI ≥ 25 kg/m2), 173 (10.7%) were underweight (BMI < 18.5 kg/m2) and the remaining were normal weight. Prior to HAART initiating, overweight HIV-infected patients were mostly males, older ages, exhibited higher CD4+ T lymphocytes and lower viral loads (p < 0.01 for all). Patients with higher baseline BMI had an independently positive effect on 30-month CD4+ T lymphocyte recovery (p = 0.028), but not 12-month CD4+ T lymphocyte gain (p = 0.104). In addition, a Cox proportional hazard model with baseline BMI as an independent variable indicated that BMI was correlated with an increased likelihood of achieving immunologic reconstitution over time (hazard ratios [HR] 1.03; 95% confidence intervals [CI] 1.01–1.06; p = 0.011), after adjusting for baseline age, gender, CD4+ T lymphocytes, CD4/CD8 ratio, viral load and WHO stage.ConclusionsHigher baseline BMI could predict better immune reconstitution in HIV-infected patients after HAART initiating.

Biological variation of peripheral blood T-lymphocytes

BackgroundFlow cytometric analysis of the lymphocyte subsets has become one of the most commonly used techniques in the routine clinical laboratory. It is frequently used in monitoring lymphocyte recovery after hematopoietic stem cell transplantation (HSCT), as well as diagnosis and treatment of acquired immunodeficiency syndrome (AIDS). Reliable biological variation (BV) data is needed for safe clinical application of these tests. In this study, similar preanalytical and analytical protocols to the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) checklist were followed and a stringent statistical approach was applied to define BV of T-lymphocytes. MethodsDuring the 10 weeks study period, weekly blood samples were obtained from 30 healthy individuals (20 females, 10 males) and analyzed with Facs Canto (BD Biosciences, San Jose, CA, USA) analyzer using 4-colour BD Multitest CD3/CD8/CD45/CD4 reagents. Data were assessed in terms of normality, tendencies, outliers and variance homogeneity prior to applying coefficient of variance (CV)- analysis of variance (ANOVA) test. Sex-stratified within-individual (CVI) and between-individual (CVG) BV estimates of CD3+, CD3 + CD4+, CD3 + CD8+, and CD3 + CD4 + CD8+ T lymphocytes were calculated. ResultsNo difference was found between males and females. Except for the CD3 + CD4 + CD8+ subset, stable BV was found for CD3+, CD3 + CD4+, and CD3 + CD8+ subsets. ConclussionInstead of using the conventional reference ranges of CD3+, CD3 + CD4+ and CD3 + CD8+ counts for monitoring HIV positive or post-HSCT patients, RCV should be used. Because individualityis characteristic of lymphocytes subsets RCVs should be used instead of RIs for patient monitoring.

Association between adenovirus viral load and mortality in pediatric allo-HCT recipients: the multinational AdVance study

This multivariable analysis from the AdVance multicenter observational study assessed adenovirus (AdV) viremia peak, duration, and overall AdV viral burden—measured as time-averaged area under the viremia curve over 16 weeks (AAUC0-16)—as predictors of all-cause mortality in pediatric allo-HCT recipients with AdV viremia. In the 6 months following allo-HCT, 241 patients had AdV viremia ≥ 1000 copies/ml. Among these, 18% (43/241) died within 6 months of first AdV ≥ 1000 copies/ml. Measures of AdV viral peak, duration, and overall burden of infection consistently correlate with all-cause mortality. In multivariable analyses, controlling for lymphocyte recovery, patients with AdV AAUC0-16 in the highest quartile had a hazard ratio of 11.1 versus the lowest quartile (confidence interval 5.3–23.6); for peak AdV viremia, the hazard ratio was 2.2 for the highest versus lowest quartile. Both the peak level and duration of AdV viremia were correlated with short-term mortality, independent of other known risk factors for AdV-related mortality, such as lymphocyte recovery. AdV AAUC0-16, which assesses both peak and duration of AdV viremia, is highly correlated with mortality under the current standard of care. New therapeutic agents that decrease AdV AAUC0-16 have the potential of reducing mortality in this at-risk patient population.

Lower Risk of One-Year Non-Relapse Mortality, Rapid Engraftment and Better NK Cell Recovery with GvHD Prophylaxis Based in Post-Transplant Cyclophosphamide/Bendamustine in Pediatric Hematopoietic Stem Cell Transplantation

Background Post-transplant cyclophosphamide (Pt-Cy) was a breakthrough in achieving immune tolerance after HSCT. Nevertheless, time to engraftment, GvHD, GvL effect, toxicity, and immune reconstitution are not yet optimal and can be improved. Evidence suggests that post-transplant bendamustine (Pt-Ben) can decrease GvHD and preserve GvL effect. Here we compare two GvHD prophylaxis platforms related to engraftment, GvHD, viral infections, lymphocyte recovery, and one-year non-relapse mortality (1y-NRM) in pediatric HSCT. Methods On Sept/2016 we introduced Pt-Ben to our standard Pt-Cy 50mg/kg/dose; days +3 and +4/Sirolimus aGvHD prophylaxis. The new protocol included Pt-Cy 50mg/kg/dose; day +3, Pt-Ben 200mg/m2/dose; day +4, and CSA starting on day +5. In both cohorts, we used low-dose methotrexate (MTX) in a subgroup of patients. We started G-CSF at day +10, and used rATG mainly for RIC transplants. We preferred PBSC as the cell source for donors >10 years of age. We compared Pt-Cy/Ben/csa cohort (39 cases; Sept/2016-June/2018) with Pt-Cy/sirolimus historical cohort (63 cases; Jan/2013-Aug/2016). We included all patients receiving one of the two protocols, except for Fanconi anemia patients (6 cases). We use non-parametric statistics to compare the median time of cell recovery. We used cumulative hazards to estimate 1y-NRM. We carried-out Cox's multivariate regression models (clustered by number of transplants/subject) to adjust hazard ratios (HR) by the following covariates: recipients age, sex, diagnosis, CMV status, MTX, ATG, TBI, conditioning intensity, infused CD34+ and total nucleated cells, haploidentical graft, donors age, and sex. Results Table 1 presents recipients, graft and donors characteristics by group. Table 2 shows frequencies of GvHD, viral infections, the median time to engraftment, and +30-day lymphocyte recovery. Acute GvHD II-IV was more frequent in the Pt-Cy/Ben/csa group, but III-IV was the same in both groups. The frequency of hemorrhagic cystitis was about half in the Pt-Cy/Ben/csa group compared to the other. Median time to blood cell recovery was faster in the Pt-Cy/Ben/csa group, particularly of platelet counts (11 vs. 20 days; P Conclusions GvHD prophylaxis with Pt-Cy/Ben/csa decreased by 3-times 1y-NRM, proved superior to Pt-Cy/sirolimus in engraftment and NK cell 30-day recovery. Although the historical cohort comparison is not absent of various biases, the association was robust after adjusting for many potential confounders. We consider that this novel strategy deserves further research in larger and better-designed studies.