Antibody, cell-mediated response and infection susceptibility in allogeneic hematopoietic stem cell recipients after COVID-19 mRNA vaccination.

BACKGROUND: Patients undergoing allogeneic stem-cell transplantation (allo-SCT) have reduced responses to vaccines due to immunosuppressive status linked to GvHD prophylaxis and treatment. In our study, we compared humoral responses to anti-SARS-CoV-2 mRNA vaccine, and infection onset, according to patients and transplant features; we also evaluated cellular response in patients without seroconversion. METHODS: We tested antibodies titer after second and third vaccine doses. Antibodies were detected through an immune-enzymatic assay. In a patients' subgroup without seroconversion, we tested cell-mediated responses evaluating interferon-gamma release by T-lymphocytes exposed to virus spike protein. RESULTS: Seroconversion rate increased from 66% at 30 days to 81% at 90 days after the second dose; it was 97% at 150 days after the third dose. We found a significant association between seroconversion after the second dose and two variables: shorter interval between allo-SCT and vaccination; ongoing immunosuppression. Twelve of 19 patients (63%) without antibodies after the second dose did not show cellular responses. Nineteen percent of patients developed SARS-CoV-2 infection after the third dose, with favorable outcome in all cases. Patients within 12 months after allo-SCT showed a significantly higher infection risk. CONCLUSIONS: Our study suggests that an interval shorter than 12 months between allo-SCT and first vaccine dose and/or ongoing immunosuppression were associated with humoral and cellular response deficiency after two doses. Third dose induced an increased and sustained humoral response in the majority of patients. However, patients within 1 year after allo-SCT remained at higher infection risk and may be candidate for prophylaxis with anti-SARS-CoV-2 monoclonal antibodies.

Risk Factors and Outcome of C. difficile Infection after Hematopoietic Stem Cell Transplantation.

Patients who undergo hematopoietic stem cell transplants (HSCT) are at major risk of C. difficile (CD) infection (CDI), the most common cause of nosocomial diarrhea. We conducted a retrospective study, which enrolled 481 patients who underwent autologous (220) or allogeneic HSCT (261) in a 5-year period, with the aim of identifying the incidence, risk factors and outcome of CDI between the start of conditioning and 100 days after HSCT. The overall cumulative incidence of CDI based upon clinical evidence was 5.4% (95% CI, 3.7% to 7.8%), without any significant difference between the two types of procedures. The median time between HSCT and CDI diagnosis was 12 days. Out of 26 patients, 19 (73%) with clinical and symptomatic evidence of CDI were positive also for enzymatic or molecular detection of toxigenic CD; in particular, in 5 out of 26 patients (19%) CD binary toxin was also detected. CDI diagnoses significantly increased in the period 2018-2019, since the introduction in the microbiology lab unit of the two-step diagnostic test based on GDH immunoenzymatic detection and toxin B/binary toxin/027 ribotype detection by real-time PCR. Via multivariate analysis, abdominal surgery within 10 years before HSCT (p = 0.002), antibiotic therapy within two months before HSCT (p = 0.000), HCV infection (p = 0.023) and occurrence of bacterial or fungal infections up to 100 days after HSCT (p = 0.003) were significantly associated with a higher risk of CDI development. The 26 patients were treated with first-line vancomycin (24) or fidaxomicine (2) and only 2 patients needed a second-line treatment, due to the persistence of stool positivity. No significant relationship was identified between CDI and the development of acute graft versus host disease (GVHD) after allogeneic HSCT. At a median follow-up of 25 months (range 1-65), the cumulative incidence of transplant related mortality (TRM) was 16.6% (95% CI 11.7% to 22.4%) and the 3-year overall survival (OS) was 67.0% (95% CI 61.9% to 71.6%). The development of CDI had no significant impact on TRM and OS, which were significantly impaired in the multivariate analysis by gastrointestinal and urogenital comorbidities, severe GVHD, previous infections or hospitalization within two months before HSCT, active disease at transplant and occurrence of infections after HSCT. We conclude that 20% of all episodes of diarrhea occurring up to 100 days after HSCT were related to toxigenic CD infection. Patients with a history of previous abdominal surgery or HCV infection, or those who had received broad spectrum parenteral antibacterial therapy were at major risk for CDI development. CDIs were successfully treated with vancomycin or fidaxomicin after auto-HSCT as well as after allo-HSCT.

ABCG2 and CD200 define patients at high risk of relapse in ELN favorable subgroup of AML.

OBJECTIVE: Overexpression of ABCG2 and CD200 has been independently associated with poor outcome in acute myeloid leukemia (AML). However, no data are available on the role of these two factors in patients with core-binding factor (CBF)-positive or FLT3-negative/NPM1-mutated cytogenetically normal (CN) AML. METHODS: We analyzed 65 adult AML patients with CBF+ (n=16) or FLT3-/NPM1+ CN (n=49), evaluating clinical and biological factors associated with complete remission attainment, leukemia-free survival (LFS) and overall survival (OS). RESULTS: ABCG2 was expressed in 36 (55%) cases, and CD200 was positive in 33 (51%) cases, six at high levels. Both ABCG2 and CD200 positivity have a negative impact on relapse risk: 3-year LFS was 51% vs 82% in ABCG2+ cases (RR 3.3), 49% vs 82% in CD200+ patients (RR=4.4), and 25% in CD200- high cases (RR=17.1). ABCG2 and CD200 affected also OS with 3-year OS of 39% in ABCG2+ (compared to 71% in ABCG2-; RR=2.6) and CD200+ (compared to 68% in CD200-; RR=2.5) patients. CONCLUSIONS: Our data confirm a negative impact of ABCG2 and CD200 overexpression also in AML patients considered at favorable risk according to ELN cytogenetic/molecular classification.

High CD200 expression is associated with poor prognosis in cytogenetically normal acute myeloid leukemia, even in FlT3-ITD-/NPM1+ patients.

Overexpression of CD200, a trans-membrane protein belonging to the immunoglobulin superfamily, has been associated with poor prognosis in patients with acute myeloid leukemia (AML). As few data are available in the subset of cytogenetically-normal (CN) AML, we retrospectively evaluated the correlations between CD200 expression and response to therapy in a series of 139 adults with CN-AML. CD200 was expressed in 67/139 (48%) cases; 18 of them (28%) expressed CD200 at high intensity. No differences in CD200 expression rate were observed according to age, WBC count, type of leukemia, FLT3 or NMP1 mutation, and CD56 expression. A higher incidence of CD200 expression was observed in CD34+ cases (P<0.0001) and in BCL2+ patients (P=0.04). Complete remission (CR) was evaluable achieved in 98 patients (70%): 56/71 (79%) in CD200- and 47/67 (63%) in CD200+ patients (P=0.03), with a lower CR rate in patients with high CD200 intensity (9/18, 50%). CD200 expression had a negative impact on long-term outcome. CD200 expression, per se, did not impact on disease-free survival (DFS), but cases with high CD200 expression had a lower 3-year DFS compared to CD200-negative and low-expressing ones (0% vs 65% vs 68%, P=0.019). Three-year overall survival (OS) was 51% in CD200- and 27% in CD200+ patients (P=0.01), with a significant difference among cases with low or high CD200 expression (35% vs 0%, P=0.001). CD200 high expression defined a group with very poor DFS and OS also among the 37 FLT3-/NPM1+: 3-year DFS and OS were 88% and 60% in CD200-, 50% and 32% in CD200 low and 0% and 0% in CD200 high patients, respectively (P=0.01 for DFS and P=0.05 for OS). Our data suggest a negative impact of CD200 expression in CN-AML, with a further worsening in high-expressing cases, also in the subset of FLT3-/NPM1+ patients.

Risk Factors and Outcomes of Infections by Multidrug-Resistant Gram-Negative Bacteria in Patients Undergoing Hematopoietic Stem Cell Transplantation.

The objective of this study was to determine risk factors and outcomes of infections by multidrug-resistant gram-negative (MDR GN) bacteria in 241 recipients of hematopoietic stem cell transplantation (HSCT). The cumulative incidence of infections was 10.5% (95% CI, 12.0% to 25.8%), with 57% of infections occurring during the period of severe neutropenia (neutrophil count < .1 × 106/L). In multivariate analysis, allogeneic transplant and colonization with MDR GN bacteria at admission to the transplant unit were significantly associated with an increased risk of infection. Although we observed neither transplant-related mortality (TRM) nor deaths due to infections by MDR GN bacteria after autologous transplant, in the allogeneic setting a significant difference was reported in terms of overall survival (OS) and TRM between patients who developed infections and those who did not (1-year OS, 39% versus 68%; 1-year TRM, 42% versus 19%). In multivariate analysis, refractory disease and development of grades III to IV graft-versus-host disease (GVHD) were factors that affected both TRM and OS, whereas occurrence of infections by MDR GN pathogens significantly reduced OS. We conclude that eligibility to allogeneic HSCT in MDR GN bacteria carriers should be carefully evaluated together with all other factors that independently influence outcome (disease status, donor, and GVHD risk).

ABCG2, Cytogenetics, and Age Predict Relapse after Allogeneic Stem Cell Transplantation for Acute Myeloid Leukemia in Complete Remission.

Recent studies have shown that ABGG2 protein overexpression in acute myeloid leukemia (AML) may be associated with poor response to therapy and increased relapse risk. Few data are available in patients with AML undergoing allogeneic stem cell transplantation (SCT), particularly when in complete remission (CR). We analyzed 105 patients with AML who underwent allogeneic SCT in CR evaluating the role of ABCG2 and other pretransplantation features on subsequent transplantation outcomes. Factors negatively associated with leukemia-free survival (LFS) were unfavorable cytogenetics (3-year LFS 48% versus 80%, P = .0035) and ABCG2 positivity (65% versus 80%, P = .045). Three-year cumulative incidence of relapse (CIR) in the whole population was 20%; a higher incidence of relapse was associated with adverse cytogenetics (41% versus 16%, P = .018), ABCG2 overexpression (29% versus 15%, P = .04), and, marginally, age > 50 years (30% versus 14%, P = .06). We grouped patients according to the combination of these 3 risk factors: no patient relapsed within 3 years from SCT in the group without risk factors, whereas the 3-year CIR was 12% (95% confidence interval [CI], 2% to 25%) in the group with 1 risk factor and 47% (95% CI, 31% to 70%) in patients with 2 or 3 risk factors (P = .00005). In conclusion, allogeneic SCT does not seem to abrogate the negative prognosis associated with ABCG2 overexpression at diagnosis, specifically in terms of a higher relapse risk. ABCG2, age, and cytogenetics can predict AML relapse after SCT in patients who undergo transplantation while in CR.

Clinical impact of CD200 expression in patients with acute myeloid leukemia and correlation with other molecular prognostic factors.

CD200, a protein belonging to the immunoglobulin superfamily, has been associated with a poor prognosis in lymphoproliferative disorders and in acute leukemia. We studied the expression of CD200 in a series of 244 patients with diagnosis of acute myeloid leukemia (AML), to evaluate its impact on outcome and its possible association with other known prognostic factors. CD200 was found in 136/244 (56%) patients, in 41 of whom (30%) with high intensity of expression (MFI ≥ 11). CD200 was more frequent in secondary compared to de novo leukemia (p = 0.0006), in CD34 positive cases (p = 0.00001), in Bcl2 overexpressing cases (p = 0.01), in those wild-type Flt3 (p = 0.004) and with favorable or unfavorable compared to intermediate karyotype (p = 0.0003). CD200+ patients have a two-fold lower probability to attain complete remission, both in univariate (p = 0.006) and multivariate (p = 0.04) analysis. The negative impact of CD200 was found also in overall survival (p = 0.02) and was correlated with the intensity of expression of the molecule (p = 0.024). CD200 has an additive negative impact on survival in patients with unfavorable cytogenetic (p = 0.046) and in secondary leukemia (p = 0.05), and is associate with a worsening of outcome in patients with favorable biological markers, such as mutated NPM (p = 0.02), wild-type Flt3 (p = 0.034), negativity of CD34 (p = 0.03) and of CD56 (p = 0.03). In conclusion, CD200 is emerging as both a prognostic factor and a potential target of novel therapeutic approaches for AML, aiming to reverse the "do not eat me" signal of CD200 or to manipulate the suppressive immune microenvironment induced by CD200 binding to its receptor.

ABCG2 overexpression in patients with acute myeloid leukemia: Impact on stem cell transplantation outcome.

ABGG2 protein overexpression in acute myeloid leukemia (AML) has been associated with poor response to conventional chemotherapy and increased relapse risk. No data are available on the role of allogeneic stem cell transplantation (SCT) in reversing its negative prognostic role. We have reviewed the outcome of 142 patients with high risk AML who underwent allogeneic SCT in complete remission (n = 94) or with active disease (n = 48). Patients with ABCG2 overexpression at AML diagnosis have lower leukemia free survival (LFS) and increased cumulative incidence of relapse (CIR) compared with ABCG2- patients (5-year LFS 50% vs. 65%, P = 0.01; 5-year CIR 46% vs. 27%, P = 0.003). Five-year overall survival was not significantly different between ABCG2+ and ABCG2- patients (39% vs. 51%, P = 0.1). However, if we consider only disease-related deaths, ABCG2 maintains its negative role (64% vs. 78%, P = 0.018). The negative impact of ABCG2 overexpression was higher in patients undergoing SCT in CR compared with patients receiving transplant with active disease. Conditioning regimen did not abrogate the effect of ABCG2 overexpression, as CIR was higher in ABCG2+ patients receiving both myeloablative (44% vs. 22%, P = 0.018) or reduced intensity conditioning (50% vs. 32%, P = 0.03). In conclusion, ABCG2 overexpression at AML diagnosis identifies a subset of patients with poor outcome also after allogeneic SCT, mainly in terms of higher relapse rates. Prospective studies employing conditioning drugs or post-transplant strategies able to target ABCG2 are needed to maximize the curative potential of stem cell transplantation.

Donor compatibility and performance status affect outcome of allogeneic haematopoietic stem cell transplant in patients with relapsed or refractory acute myeloid leukaemia.

We retrospectively analysed 78 patients with relapsed (n = 38), primary refractory (n = 34) or untreated (n = 6) acute myeloid leukaemia (AML) who underwent allogeneic HSCT at our Institution between 2002 and 2011, to verify outcome and to identify factors that can affect long-term outcome. Myeloablative conditioning regimens were used in 48 patients (24 siblings, 24 matched unrelated donor (MUD)), while 30 patients (18 siblings, 12 MUD) received reduced-intensity conditioning. Acute graft versus host disease (GVHD) developed in 37 (47 %) patients, while chronic GVHD occurred in 19 of the 65 evaluable patients (29 %). With a median follow-up time of 5 years, 13 of 78 patients (17 %) are alive and in complete remission (CR), while 64 have died. Cause of death was disease recurrence in 37 patients (58 %), infection in ten patients (16 %) and GVHD in six (9 %). One-year non-relapse mortality was 35 %. In multivariate analysis, performance status ≥80 % WHO and a full-matched donor were associated with a better outcome: these two variables allowed for risk stratification, identifying three groups with significantly different survival after transplant (P = 0.0001). Considering post-transplant variables, only CR at recovery and development of cGVHD were correlated with a longer survival. Our data confirm the capacity of allogeneic transplant to prolong survival in a significant proportion of extremely high-risk AML patients.

Concomitant ABCG2 overexpression and FLT3-ITD mutation identify a subset of acute myeloid leukemia patients at high risk of relapse.

BACKGROUND: ABCG2 protein overexpression and FLT3 internal tandem duplication (ITD) correlate with higher relapse rate and shorter disease-free survival (DFS) in acute myeloid leukemia (AML), but no data are available on the possible effect of concomitant presence of these 2 factors. METHODS: The authors analyzed the outcome of 166 cases of adult AML patients who were homogeneously treated with a fludarabine-based induction therapy. RESULTS: ABCG2 overexpression and FLT3-ITD were detected in 83 (50%) and 47 (28%) patients, respectively. A significant correlation was found between ABCG2 positivity and FLT3 mutation, with 33 (40%) ITD in 83 ABCG2-positive patients compared with 14 (17%) ITD in 83 ABCG2-negative patients (P = .002). Complete remission (CR) after induction therapy was achieved in 95 (57%) patients. Neither ABCG2 overexpression nor FLT3-ITD had any impact on achievement of CR. Relapse occurred in 42 of 95 (44%) patients at a median time of 28 months. Time to relapse was shortened in patients overexpressing ABCG2 (P = .0004). DFS was not affected by FLT3-ITD alone, but FLT3 mutation significantly worsened long-term outcome of ABCG2-positive patients. DFS at 1 and 3 years in patients with overexpression of both ABCG2 and FLT3-ITD was only 36% and 28%, respectively; in ABCG2-positive/FLT3-negative patients, DFS at 1 and 3 years was 65% and 48%, respectively; and in ABCG2-negative cases (regardless of FLT3 status), DFS at 1 and 3 years was greater than 85% and 75%. CONCLUSIONS: Concomitant overexpression of ABCG2 and FLT3-ITD is relatively frequent and identifies a subgroup of AML patients with a significantly worse prognosis. The possible interactions between these 2 prognostic factors need to be defined.

Fludarabine-based induction therapy does not overcome the negative effect of ABCG2 (BCRP) over-expression in adult acute myeloid leukemia patients.

Over-expression of multidrug resistance (MDR) proteins PGP and BCRP has a negative prognostic impact in acute myeloid leukemia (AML) patients. Inclusion of fludarabine in induction chemotherapy increases remission rate in PGP over-expressing cases. We investigated the role of BCRP in 138 adult AML patients receiving induction therapy with fludarabine. None of the MDR-related proteins influenced complete remission attainment. Conversely, high levels of BCRP significantly affected disease-free survival, as higher relapse rates (48.5% vs 28.5%) and earlier relapse occurred in BCRP+ patients. Also overall survival was affected by BCRP positivity, and survival significantly worsened in case of concomitant PGP and BCRP over-expression.

Case-control study of multidrug resistance phenotype and response to induction treatment including or not fludarabine in newly diagnosed acute myeloid leukaemia patients.

One hundred and six patients aged /= 6) vs. 75% among the MDR-Pgp-negative (neg(ve)) ones (MFI < 6) (P = 0.16). Conversely, in the controls, the CR rate was 44% among the MDR-Pgp-pos(ve) patients vs. 67% among the MDR-Pgp-neg(ve) ones (P = 0.02). The 4-year disease-free survival (DFS) and overall survival (OS) of MDR-Pgp-pos(ve) cases were significantly longer than those of MDR-Pgp-pos(ve) controls (DFS, 28.1% vs. 6.5%, P = 0.004; OS, 33.5% vs. 9.6%, P = 0.01). This difference was not found among the MDR-Pgp-neg(ve) patients. By univariate (P = 0.007) and multivariate (P = 0.007) analysis, the MDR-Pgp-pos(ve) phenotype was negatively correlated with CR and it emerged as the most important independent negative prognostic factor, after cytogenetics. Our study confirms the prognostic impact of the MDR phenotype in AML and strongly suggests fludarabine-based induction treatments as a promising strategy for MDR-Pgp-pos(ve) AML patients. In this setting of patients, large prospective randomised studies should be planned.

Effect on survival of the development of late-onset non-infectious pulmonary complications after stem cell transplantation.

We evaluated the incidence, risk factors, and clinical outcome of late-onset non-infectious pulmonary complications (LONIPC) in 599 patients who underwent hematopoietic allogeneic stem cell transplantation (HSCT). The 2-year cumulative incidence of LONIPC was 10% among the 438 patients surviving more than 3 months after HSCT. Transplants from an unrelated donor and occurrence of extensive chronic graft-versus-host disease were the variables significantly associated with the development of LONIPC. The 5-year overall survival was significantly worse among patients with LONIPC than among those without (34% vs 65%, p=0.009). Causes of death were respiratory failure and infections. The relapse rate was similar in the two groups.

The prognostic value of P-glycoprotein (ABCB) and breast cancer resistance protein (ABCG2) in adults with de novo acute myeloid leukemia with normal karyotype.

Multidrug resistance is a major cause of treatment failure in acute myeloid leukemia (AML). P-glycoprotein (PGP) over-expression has an unfavorable prognostic significance, while the role of breast cancer resistance protein (BCRP) is less clear, especially in AML patients with a normal karyotype. We studied 73 consecutive AML patients with a normal karyotype. BCRP was over-expressed in 24 patients (33%) and was significantly co-expressed with PGP (13/24 vs 11/49, p=0.006) and with CD56. Only PGP, along with age and CD34, affected the achievement of complete remission (p=0.02), while BCRP-positive cases showed an increased risk of relapse (p=0.005) and a shorter disease-free survival (p=0.027). BCRP over-expression did not influence the achievement of remission, but significantly affected the duration of complete remissions. BCRP may, therefore, be regarded as a prognostic factor in patients with normal karyotype AML, for the design of risk-adapted post-remission therapy.

The development of autoantibodies after allogeneic stem cell transplantation is related with chronic graft-vs-host disease and immune recovery.

OBJECTIVE: Chronic graft-vs-host disease (GVHD) has certain similarities with autoimmune diseases and is associated with the development of various autoantibodies in some patients. In this study, we analyzed the occurrence of autoantibodies in 63 patients surviving longer than 3 months after an allogeneic haematopoietic stem cell transplantation (HSCT), with the aim of detecting a possible association between occurrence of autoantibodies and development of chronic GVHD and immune recovery after HSCT. PATIENTS AND METHODS: The patients were screened every 3 months for the occurrence of the following autoantibodies: anti-nuclear (ANA), anti-mitochondrial (AMA), anti-smooth muscle (ASMA), anti-cardiolipin (ACLA), anti-liver-kidney microsomal (LKM), anti-DNA, anti-neutrophil cytoplasmatic (ANCA), and anti-thyroid antibodies. Peripheral blood immunophenotyping with anti-CD3, CD4, CD8, CD19, CD20, CD16, and CD56 antibodies was evaluated at the same intervals. RESULTS: Autoantibodies were not found in 18 patients (29%), at least in one screening in 29 patients (46%), and in all screenings in 16 patients (25%). ANA were found in 41 patients (65%), AMA in 4 (6%), ASMA in 4 (6%), ANCA in 7 (11%), ACLA in 1 (2%), anti-thyroid antibodies in 3 (5%), and anti-DNA in 2 (3%). More than one antibody occurred in 16/63 (25%) positive patients. ANA was significantly more frequent in patients with chronic GVHD and, among these, in those with the extensive form. The nucleolar pattern of immunofluorescence of ANA but not its titer was correlated with the extension of chronic GVHD. Patients who developed autoantibodies had higher CD20(+) cell blood counts than negative patients in the third month (p=0.006), ninth month (p=0.061), and twelfth month (p=0.043). CONCLUSION: We conclude that patients with chronic GVHD, particularly those with an extensive involvement, were likely to develop autoantibodies and have a faster B-cell recovery, suggesting a role of B cells in the pathogenesis of chronic GVHD.

Sclerodermatous chronic graft-versus-host disease after allogeneic hematopoietic stem cell transplantation: incidence, predictors and outcome.

Scleroderma may be one of the most severe forms of chronic graft-versus-host disease (GVHD). We retrospectively evaluated its incidence, predictor variables and outcome in 133 patients who survived at least 4 months after allogeneic hematopoietic stem cell transplantation. The 5-year cumulative incidence was 15.5% in patients with chronic GVHD. The generalized form had a progressive course despite immunosuppressive therapy. Eosinophilia, autoimmune markers, and previous skin involvement by chronic GVHD with disorders of pigmentation were significantly associated with an increased probability of developing scleroderma.