Distinct exhaustion features of T lymphocytes shape the tumor-immune microenvironment with therapeutic implication in patients with non-small-cell lung cancer.

BACKGROUND: Reinvigoration of T-cell exhaustion with antibodies has shown promising efficacy in patients with non-small-cell lung cancer (NSCLC). However, the characteristics of T-cell exhaustion with regard to tumor-infiltrating lymphocytes (TILs) are poorly elucidated in NSCLC. Here, we investigated the exhaustion status of TILs in NSCLC patients at the intraindividual and interindividual levels. METHODS: We obtained paired peripheral blood, normal adjacent tissues, peritumoral tissues, and tumor tissues from 96 NSCLC patients. Features of T-cell exhaustion were analyzed by flow cytometry. T cells were categorized according to their programmed cell death-1 (PD-1) expression (PD-1high, PD-1int, and PD-1neg cells). Patients were classified based on the presence or absence of discrete PD-1high CD8+ TILs. Production of effector cytokines by CD8+ TILs was measured after T-cell stimulation with or without antibodies against immune checkpoint receptors. RESULTS: Progressive T-cell exhaustion with marked expression of exhaustion-related markers and diminished production of effector cytokines was observed in PD-1high CD8+ TILs compared with PD-1int and PD-1neg CD8+ TILs. Patients with distinct PD-1high CD8+ TILs (PD-1high expressers) exhibited characteristics associated with a favorable anti-PD-1 response compared with those without these lymphocytes (non-PD-1high expressers). Combined inhibition of dual immune checkpoint receptors further restored effector cytokine production by CD8+ TILs following T-cell stimulation. PD-1high CD8+ T lymphocyte populations in the peripheral blood and tumors were significantly correlated. CONCLUSIONS: T-cell exhaustion was differentially regulated among individual patients and was prominent in a subgroup of NSCLC patients who may benefit from PD-1 blockade or combined blockade of other immune checkpoint receptors.

Induction therapy with thymoglobulin after heart transplantation: impact of therapy duration on lymphocyte depletion and recovery, rejection, and cytomegalovirus infection rates.

BACKGROUND: This retrospective single-center study compared lymphocyte depletion in 144 heart transplant recipients using 2 different induction protocols with Thymoglobulin (Genzyme Transplant, Cambridge, MA). METHODS: Thymoglobulin (1.5 mg/kg) was given to 105 patients for 7 days (Thymo7) and 39 patients for 5 days (Thymo5). RESULTS: Patient clinical characteristics were similar except that the Thymo7 group had a higher prevalence of women (33% vs 15%, p = 0.04), gender mismatch (35% vs 19%, p = 0.07), donor African American race (19% vs 2%, p = 0.008), older donor age (35 +/- 13 vs 31 +/- 12, p = 0.08), and higher pre-transplant creatinine (1.43 +/- 0.67 vs 1.25 +/- 0.48 mg/dl, p = 0.095). Seventy-five percent of the Thymo7 group reached target (absolute lymphocyte count or=1B) within the first year (7% vs 22%, p = 0.02). No humoral rejection occurred. At 1 year, freedom from rejection was 93% in the Thymo7 group vs 80% in the Thymo5 group (p = 0.007), and cytomegalovirus disease (9% and 5%, p = 0.5) and bacterial infection (26% vs 32%, p = 0.5) were similar. One-year actuarial survival was 92% +/- 3% in the Thymo7 and 100% in the Thymo5 group (p = 0.07), and at 3 years, 85 +/- 4% and 90 +/- 6%, respectively (p = 0.4). CONCLUSIONS: Both Thymoglobulin regimens were well tolerated. The 7-day treatment led to more efficient and prolonged lymphocyte depletion and significantly less rejection at 1 year, without an increase in cytomegalovirus infection rate.

T-cell depletion prevents from bronchiolitis obliterans and bronchiolitis obliterans with organizing pneumonia after allogeneic hematopoietic stem cell transplantation with related donors.

Bronchiolitis obliterans (BO) and bronchiolitis obliterans organizing pneumonia (BOOP) are late-onset non-infectious pulmonary complications (LONIPCs) following allogeneic hematopoietic stem cell transplantation (HSCT). In the present study 10 of 197 conventionally prepared stem cell recipients developed BOOP after 365 days and 6 patients developed BO 333 days post-transplant. No BOOP or BO was diagnosed following T-cell depletion (p<0.05). Chronic GVHD was ascertained in all BOOP patients and appeared significantly (p<0,001) more frequent in the conventional transplant group. The data confirm a strong association between T-cell activity, chronic GVHD, BO and BOOP and point out the impact of T lymphocytes in the pathomechanism of BOOP.

Conventional versus reduced-intensity conditioning regimen for allogeneic stem cell transplantation in patients with hematological malignancies.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (HSCT) from human leukocyte antigen (HLA)-compatible sibling donors is a potential curative treatment for hematological and non-hematological malignancies. Nevertheless, high mortality rates may be associated with this therapy, especially in older patients, those with other comorbidities or who receive a second HSCT. PATIENTS AND METHODS: We analyzed the factors associated with transplant-related mortality (TRM) and overall survival in 157 consecutive adult patients (104 males and 53 females) who received a HSCT [29 bone marrow (BM) transplantation and 128 peripheral blood (PB) transplantation] from a HLA-identical sibling between January 1995 and March 2002 in our institution. One hundred patients received a standard conditioning prior to HSCT (STAND) and 57 patients received a reduced-intensity conditioning (RIC) HSCT. Fifty-eight patients were in an early phase at transplant and 99 in a non-early phase. Median age was 46 yr (16-66), and 90 patients (57%) were >45 yr of age. RESULTS: Patients in the RIC group were older than those in the STAND group, and had a higher proportion of non-early disease phases including a prior autologous HSCT in 39%. Median follow-up for survivors was 28 and 15 months in the STAND and RIC groups (P < 0,001), respectively. Cumulative incidence of TRM at 2 yr was 30% [95% confidence interval (CI) 22-41%] for the STAND group and 22% (95% CI 13-37%) for the RIC group [non-significant (NS)]. Factors associated with a higher TRM in multivariate analysis were: STAND vs. RIC conditioning regimen [relative risk (RR) 5.4; 95% CI 2.3-12.8; P < 0.001]; age > or =45 yr vs. <45 yr (RR 5; 95% CI 2.4-10.8, P < 0.001); second vs. first HSCT (RR 2.8, 95% CI 1.3-6.3, P = 0.01) and non-T-cell-depleted vs. T-cell-depleted graft (RR 2.7, 95% CI 1.3-5.8, P = 0.009). Overall survival (OS) at 2 yr was 52.5 +/- 10.4% for STAND group and 59 +/- 16.8% in RIC group. Factors associated with poorer OS in multivariate analysis were: STAND vs. RIC conditioning regimen (RR 3.4, 95% CI 1.7-6.9, P = 0.001); age > or =45 vs <45 yr (RR 2.5, 95% CI 1.4-4.5, P = 0.002) and diagnosis [other than chronic myeloid leukemia (CML) vs. CML] (RR 2.6, 95% CI 1.2-5.7 P = 0.02). CONCLUSIONS: Our results indicate that the introduction of RIC allogeneic HSCT for patients at high risk for TRM (advanced age, prior HSCT and non-T-cell depletion) leads to a reduction in the TRM and improvement in the OS.

Correlation of early lymphocyte recovery and progression-free survival after autologous stem-cell transplant in patients with Hodgkin's and non-Hodgkin's Lymphoma.

The importance of the association between early lymphocyte recovery and outcome has not been well studied in autologous stem cell transplantation (ASCT). In this retrospective study, we analyzed 90 consecutive patients with non-Hodgkin's and Hodgkin's lymphoma who underwent ASCT. Patients were divided into two groups: group 1 with absolute lymphocyte count (ALC) on day +15 below the median of 667/mm(3), and group 2 with ALC >or=667/mm(3). The median progression-free survival (PFS), but not overall survival (OS), was significantly longer in group 2 when compared to group 1 (16 months vs not reached P=0.02). Group 2 patients also had significantly shorter hospital stay, received higher CD34(+) cell dose, and had shorter time to neutrophil recovery. Multivariate analysis demonstrated day +15 ALC to be an independent prognostic indicator for PFS, but not OS, while CD34(+) cell dose and the number of pretransplant treatments were better predictors for both PFS and OS. We conclude that higher day +15 ALC may independently predict better PFS after ASCT for lymphoma patients; however, whether this merely reflects faster overall recovery caused by higher infused CD34(+) cell dose and less pretransplant therapy needs further investigation.

T-cell depletion of allogeneic peripheral blood stem cells.

The high content of immunocompetent T-cells in apheresis products may expose recipients of allogeneic peripheral blood stem cells (PBSC) to an elevated risk of acute and chronic graft-versus-host disease (GvHD). Thus, the use of an appropriate T-cell reduction or depletion technique might reduce this risk. The hazards of rejection and of a higher relapse rate should be avoided by maintaining a portion of the T-cells in the graft or by increasing the number of transplanted stem cells. The positive selection of CD34+ cells from peripheral blood preparations simultaneously provides an approximately 1,000-fold reduction of T-cells. Purified CD34+ cells containing committed and pluripotent stem cells are suitable for allogeneic transplantation. In transplantation from HLA-mismatched or three HLA-loci different family donors the amount of stem cells can be increased for reducing the incidence of rejection without increasing the T-cell number. In cases of poor marrow graft function a 'boost' with stem cells from the same family donor can be given. The risk of GvHD in transplantation from volunteer-matched unrelated donors might be reduced by T-cell depletion. If T-cells are used for enhancing the graft-versus-leukaemia effect, CD34+ enriched cells can be given for haematopoietic engraftment.

Long-term immune reconstitution and outcome after HLA-nonidentical T-cell-depleted bone marrow transplantation for severe combined immunodeficiency: a European retrospective study of 116 patients.

We have performed a retrospective analysis of the development of T- and B-cell functions after HLA-nonidentical T-cell-depleted bone marrow transplantation (BMT) performed in 193 patients with severe combined immunodeficiency (SCID) at 18 European centers between December 1982 and December 31, 1993. One hundred sixteen of 193 patients were alive with evidence of engraftment 6 months after BMT. Development of T-cell function occurred earlier than B-cell function and was achieved more frequently up to the time of last follow-up. The median time to achieve normal T-cell function was 8.7 months, whereas the median time to achieve normal B-cell function was 14.9 months. Twenty-four patients died later than 6 months post-BMT, mainly due to chronic graft-versus-host disease (cGVHD) and/or viral infection. Absence of T-cell reconstitution 6 months after BMT, unlike absence of B-cell reconstitution, was associated with a poor outcome. Two additional factors were associated with a poor outcome: presence of cGVHD 6 months after BMT and B- SCID versus B+ SCID. However, two of these three factors remained as significant prognostic factors in a multivariate analysis: the absence of T-cell function and the presence of cGVHD 6 months after BMT. Analysis of the factors influencing the development of immune reconstitution showed that T- and B-cell functions occurred earlier and more frequently in B+ SCID versus B- SCID patients. Acute GVHD was associated with a slower development of T-cell function at 6 months, and cGVHD had a negative influence on the development of T-cell function afterwards, but neither acute nor chronic GVHD was found to influence the development of B-cell function. Once engraftment occurred, whether patients had or had not received Busulfan in the conditioning regimen did not influence the kinetics and quality of T-cell function development. In a multivariate study, two factors were found to influence the T-cell function 6 months after BMT: type of SCID and acute GVHD. The results of this retrospective analysis should lead to new protocols adapted to SCID disease, considering that disease-related as well as BMT-related parameters influence the development of immune function and thereby long-term outcome after HLA-nonidentical T-cell-depleted BMT.

Comparison of T cell depletion strategies from bone marrow, umbilical cord and peripheral blood using five separation systems.

The development of bone marrow transplantation in mismatched or matched unrelated donor situations, the recent use of peripheral blood stem cells for allogeneic transplants, the standardization and respect of good methodology practices highlight the need to evaluate new safe methods of T cell depletion (TCD). We have performed 79 in vitro TCD using five techniques: rabbit complement cytotoxicity, CD2-CD7 immunomagnetic depletion, CD5-CD8 panning system, CD34 positive purging and counterflow centrifugation elutriation (CCE). We analyzed these different approaches with regard to the degree of T and B depletion, recovery of progenitors and NK cells. In our hands, the 5 systems evaluated showed a TCD of between 1.3 and 3 log. The CCE, immunomagnetic, complement and panning methods all give similar a TCD of around 2 log. In contrast, we obtained a TCD of approximately 3 log with CD34 positive purging. The progenitor yield was around 50% regardless of the technique used. However, the degree of B and NK cell depletion was dependent on the method: specific TCD resulted in low BCD (under 0.5 log), whereas CCE or CD34 positive purging gave a BCD of greater than 1 log. Moreover, CD34 positive selection resulted in a virtually complete elimination of NK cells. CCE was the only technique allowing isolation of the small lymphocyte population which can be useful for adoptive therapy. To obtain TCD over three logarithms, double purging techniques are necessary. Because specific roles of T cells subsets in engraftment, graft versus host disease, Epstein Barr virus associated B cell lymphoproliferative disorders and disease relapse have not yet been completely elucidated, new techniques such as CD34 positive purging and double purging methods (positive and negative purging) need to be clinically evaluated, especially with respect to peripheral blood stem cells.

ISHAGE bone marrow processing survey: report on an international information gathering process. International Society for Hematotherapy Graft Engineering.

Significant amounts of information are currently available within the database generated by the responses to the Bone Marrow Processing Survey. As additional Surveys are returned, the data will continue to be entered into a Lotus spreadsheet, until a more sophisticated database with a programmed interface becomes available. The readership is encouraged to enter or edit the databank by returning a completed or amended Survey to the Society. Copies of the form are available from the Society or can be found in the first issue of the Journal of Hematotherapy.