Digital PCR Improves Sensitivity and Quantification in Monitoring CAR-T Cells in B Cell Lymphoma Patients

Chimeric antigen receptor T cells (CAR-T) has emerged as a promising therapy, over 60% of patients fail to sustain a long-term response. The underlying factors that leads to the effectiveness of this therapy are not completely understood, CAR-T cell persistence and monitoring seems to be pivotal for ensuring a successful response. Various monitoring methods such as multiparametric flow cytometry (MFC) or quantitative PCR (qPCR) have been applied. Our objective is to develop digital PCR (dPCR) assays for detection and quantification of CAR-T cells, comparing them with MFC and qPCR. Samples taken at different follow-up times from 45 patients treated with CAR-T therapy were analyzed to assess the correlation between the different methodologies. dPCR presented a high correlation with MFC and qPCR (r = 0.97 and r = 0.87, respectively), while offering a higher sensitivity (0.01%) compared to MFC (0.1%) and qPCR (1%). dPCR emerged as an alternative and highly sensitivity method for monitoring CAR-T cell dynamics. This technique is well-suited for implementation in clinical practice as a complementary technique to MFC.

Results of haploidentical transplant in patients with donor-specific antibodies: a survey on behalf of the Spanish Group of Hematopoietic Transplant and Cell Therapy

Background

Donor-specific antibodies (DSAs) are IgG allo-antibodies against mismatched donor HLA molecules and can cause graft failure (GF) in the setting of haploidentical hematopoietic stem cell transplantation (haplo-HSCT). Our aim was to report the experience of the Spanish Group of Hematopoietic Transplant (GETH-TC) in DSA-positive patients who had undergone haplo-HSCT.

Methods

We conducted a survey of patients who underwent haplo-HSCT in GETH-TC centers between 2012 and 2021. Data were collected on the DSA assay used, monitoring strategy, complement fixation, criteria for desensitization, desensitization strategies and transplant outcomes.

Results

Fifteen centers from the GETH-TC responded to the survey. During the study period, 1,454 patients underwent haplo-HSCT. Seventy of the transplants were performed in 69 DSA-positive patients, all of whom lacked a suitable alternative donor; 61 (88%) patients were female (90% with prior pregnancies). All patients received post-transplant cyclophosphamide-based graft-versus-host disease prophylaxis. Regarding baseline DSA intensity, 46 (67%) patients presented mean fluorescence intensity (MFI) >5,000, including 21 (30%) with MFI >10,000 and three (4%) with MFI >20,000. Six patients did not receive desensitization treatment, four of them with MFI <5,000. Of 63 patients receiving desensitization treatment, 48 (76%) were tested after desensitization therapy, and a reduction in intensity was confirmed in 45 (71%). Three patients (5%) experienced an increase in MFI after desensitization, two of whom experienced primary GF. Cumulative incidence of neutrophil engraftment at day 28 was 74% in a median of 18 days (IQR, 15─20); six patients died before engraftment due to toxicity or infection and eight patients had primary GF despite desensitization in seven of them. After a median follow-up of 30 months, two-year overall and event-free survival were 46.5% and 39%, respectively. The two-year cumulative incidence of relapse was 16% and non-relapse mortality (NRM) was 43%. Infection was the most frequent cause of NRM, followed by endothelial toxicity. Multivariate analysis identified baseline MFI >20,000 as an independent risk factor for survival and an increase in titers after infusion as an independent risk factor for GF.

Conclusions

Haplo-HSCT is feasible in DSA-positive patients, with high rates of engraftment after desensitization guided by DSA intensity. Baseline MFI >20,000 and increased intensity after infusion are risk factors for survival and GF.

Poor graft function after haploidentical stem cell transplantation with post-transplant cyclophosphamide

This is a retrospective cohort study of consecutive adult patients who received a haploidentical-SCT (haplo-SCT) with post-transplant cyclophosphamide (PT-Cy) in a single centre. Poor graft function (PGF) was defined as the occurrence of either persistent neutropenia (ANC < 0.5 × 10⁹/µL) with poor response to granulocyte colony-stimulating factors (G-CSF) and/or thrombocytopenia (platelets < 20 × 10⁹/L) with transfusion dependence, with complete donor chimerism and without concurrent severe GVHD or underlying disease relapse, during the first 12 months after transplantation. Forty-four (27.5%) out of 161 patients were diagnosed with PGF. Previous CMV reactivation was significantly more frequent in patients with PGF (88.6% versus 73.5%, p = 0.04) and the number of reactivations was also higher in these patients. Besides, early CMV reactivations in the first 6 months post-SCT were also significantly more frequent among patients with PGF (88.6% versus 71.8% p = 0.025). Thirty-two percent of patients with PGF were treated with increasing doses of thrombopoietin-receptor agonists (TRA) and 7 patients were treated with a donor CD34 + selected boost. In total, 93.2% of patients reached adequate peripheral blood counts in a median time of 101 days (range 11-475) after diagnosis. PGF is a frequent complication after haplo-SCT with PT-Cy. CMV reactivation might be the most relevant factor associated to its development. Even when most patients recover peripheral counts with support therapy, there is a group of patients with persistent cytopenias who can effectively be treated with TRA and/or a boost of CD34 + selective cells.

Association between gene polymorphisms in the cyclophosphamide metabolism pathway with complications after haploidentical hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a curative treatment for patients with hematologic malignances. Haploidentical HSCT (Haplo-HSCT) is an alternative option for patients who do not have an HLA-matched donor. The use of post-transplantation high dose cyclophosphamide (PT-Cy) is commonly employed for graft-versus-host disease (GVHD) prophylaxis in haplo-HSCT. Cyclophosphamide (Cy) is an alkylating agent with antineoplastic and immunosuppressive activity, whose bioactivation requires the activity of polymorphic enzymes in the liver to produce phosphoramide mustard, which is a DNA alkylating agent. To identify polymorphisms in the genes of Cy metabolism and correlate them with post-HSCT complications [GVHD, sinusoidal obstruction syndrome (SOS), hemorrhagic cystitis (HC) and transplant-related mortality (TRM)], we designed a custom next-generation sequencing panel with Cy metabolism enzymes. We analyzed 182 patients treated with haplo-HSCT with PT-Cy from 2007 to 2019, detecting 40 variants in 11 Cy metabolism genes. Polymorphisms in CYP2B6, a major enzyme involved in Cy activation, were associated with decreased activity of this enzyme and a higher risk of Graf-versus-host disease (GVHD). Variants in other activation enzymes (CYP2A6, CYP2C8, CYP2C9, CYP2C19) lead to decreased enzyme activity and were associated with GVHD. Polymorphisms in detoxification genes such as glutathione S-transferases decreased the ability to detoxify cyclophosphamide metabolites due to lower enzyme activity, which leads to increased amounts of toxic metabolites and the development of III-IV acute GVHD. GSMT1*0 a single nucleotide polymorphism previously recognized as a risk factor for SOS was associated with a higher risk of SOS. We conclude that polymorphisms of genes involved in the metabolism of cyclophosphamide in our series are associated with severe grades of GVHD and toxicities (SOS and TRM) after haplo-HSCT and could be used to improve the clinical management of transplanted patients.

Clinical grade production of IL-15 stimulated NK cells for early infusion in adult AML patients undergoing haploidentical stem cell transplantation with post-transplant cyclophosphamide

BACKGROUND

Allogeneic stem cell transplantation is the treatment of choice for acute myeloid leukemia (AML) patients. Unmanipulated haploidentical transplantation (Haplo-HSCT) is commonly used for those AML patients who need a timely transplant and do not have a suitable matched donor, but relapse rates are still high, and improvements are needed. Adoptive immunotherapy using natural killer cells (NK cells) could be a promising tool to improved Haplo-HSCT but, to date, no optimal infusion and manufacturing protocols have been developed.

STUDY DESIGN AND METHODS

In this study, we describe a quick and reproducible protocol for clinical-grade production of haploidentical donor NK cells using double immunomagnetic depletion and enrichment protocol and overnight IL-15 stimulation.

RESULTS

Thus, we have obtained 8 viable and functional NK cell products that have been safely infused to five AML patients undergoing unmanipulated Haplo-HSCT.

DISCUSSION

Our results demonstrate the safety and feasibility of manufactured NK IL15 cells obtained from an adult allogeneic donor in the setting of haploidentical transplantation for AML patients.

Hemophagocytic lymphohistiocytosis/macrophage activation syndrome (HLH/MAS) following treatment with tisagenlecleucel

Chimeric antigen receptor (CAR) T cell-related HLH/MAS is an unusual manifestation of severe cytokine release syndrome (CRS) with poor prognosis and a challenging diagnosis. The establishment of specific diagnosis criteria is essential, and the combination of several techniques for CAR T-cell follow-up, allows a more precise management of this complication.

Implementation of a hospital-at-home (HAH) unit for hematological patients during the COVID-19 pandemic: safety and feasibility

Background

“Hospital-at-home” (HAH) programs have been shown to optimize resource utilization, shorten hospitalization and prevent nosocomial infection.

Methods

We retrospectively analysed data regarding implementation of an HAH unit for caring patients with hematological malignancies in our center, during the COVID-19 pandemic.

Results

Between January and November 2020, 105 patients were treated in the HAH unit for a total of 204 episodes. Nine patients with multiple myeloma (MM) received autologous HSCT (auto-HSCT). Three patients with acute myeloid leukemia (AML) received consolidation therapy, 32 patients underwent clinical and analytical monitoring, 20 were transplant recipients early discharged (5 auto-HSCT and 15 allo-HSCT) and 2 had received CART cells therapy. Azacitidine, bortezomib and carfilzomib were administered at home to 54 patients with AML, myelodysplastic syndrome (MDS) or MM. A median of 17 (IQR 13–19) days of admission per patient and a total of 239 visits to the Hematology day-care hospital were avoided. Overall, 28 patients (14% of all episodes) needed admission to the hospital, 4 of them due to COVID-19.

Conclusions

Implementation of a Hematology HAH unit was feasible and safe, and provided thorough advanced care to a high-risk population. Advanced care-at-home strategies can be crucial during times of COVID-19 to minimize treatment interruptions and reduce the risk of cross-infections.

Management of Donor-Specific Antibodies in Haploidentical Transplant: Multicenter Experience From the Madrid Group of Hematopoietic Transplant

Background

Donor specific antibodies (DSAs) can be responsible for graft failure (GF) in the setting of mismatched hematopoietic stem cell transplantation (HSCT). The aim of our study is to report the experience of the Madrid Group of Hematopoietic Transplant (GMTH) in patients with DSAs undergoing haplo-HSCT.

Methods

Patients undergoing haplo-HSCT in centers from the GMTH from 2012 to 2020 were included in the study. DSAs were analyzed with a solid-phase single-antigen immunoassay; monitoring was performed during desensitization on days -14, -7, 0 and in a weekly basis until neutrophil engraftment. Desensitization strategies varied depending on center experience, immunofluorescence intensity, complement fixation and type of antibodies.

Results

We identified a total of 20 haplo-HSCT in 19 patients performed with DSAs in 5 centers. 10 (53%) patients presented anti-HLA class I DSAs (6 of them with > 5000 mean fluorescence intensity (MFI)), 4 (21%) presented anti-HLA class II (1 with > 5000 MFI) and 5 (26%) presented both anti-HLA class I and II (5 with > 5000 MFI). 90% of patients received at least two treatments as desensitization strategy and all experienced a decrease of MFI after desensitization (mean reduction 74%). Only one patient who developed progressive increase of MFI after infusion developed GF. Desensitization treatments used included rituximab, immunoglobulins, therapeutic plasma exchange, incompatible platelets, buffy coat and immunosuppressors. Seventeen (90%) patients achieved neutrophil engraftment; one patient died before engraftment because of infection and one patient with class I DSAs developed primary GF despite an intensive desensitization. After a median follow-up of 10 months, OS and EFS were 60% and 58%, respectively, cumulative incidence of relapse was 5% and NRM was 32%.

Conclusions

Despite the optimal strategy of DSAs desensitization remains unclear, the use of desensitization treatment guided by DSAs intensity kinetics constitute an effective approach with high rates of engraftment for patients with DSAs in need for an haplo-HSCT lacking an alternative suitable donor.

Clinical Utility of the Detection of the Loss of the Mismatched HLA in Relapsed Hematological Patients After Haploidentical Stem Cell Transplantation With High-Dose Cyclophosphamide

Haploidentical hematopoietic stem cell transplantation (Haplo-HSCT) with high-dose cyclophosphamide (PTCy) has resulted in a low incidence of graft-vs.-host disease (GVHD), graft failure, and non-relapse mortality. However, post-transplantation relapse remains a common cause of treatment failure in high-risk patients. Unraveling the mechanisms of relapse is therefore crucial for designing effective relapse treatment strategies. One of these mechanisms is the loss of the mismatched HLA on the recipient's leukemic cells. To study the incidence and clinical relevance of this phenomenon, we analyzed 181 patients treated with Haplo-HSCT with PTCy (2007–2019), of which 37 relapsed patients after transplantation. According to the kit employed for HLA-loss analysis, among 22 relapsed patients, we identified HLA loss at relapse in 6 of the 22 patients (27%) studied. Based on the results obtained, the genomic loss of HLA was more common in females than males (66 vs. 33%) and HLA-loss relapses occurred later than classical relapses (345 vs. 166 days). Moreover, the patients with HLA-loss had a greater presence of active disease at the time of transplantation and had undergone a larger number of treatment lines than the group with classical relapses (66 vs. 43% and 66 vs. 18%, respectively). Four of these relapses were studied retrospectively, while two were studied prospectively, the results of which could be considered for patient management. Additionally, two relapsed patients analyzed retrospectively had myeloid neoplasms. One patient had not undergone any treatment, and three had undergone donor lymphocyte infusions (DLIs) and chemotherapy. All presented severe GVHD and disease progression. In contrast, the two patients studied prospectively had a lymphoid neoplasm and were not treated with DLIs. One of them was treated with chemotherapy but died from disease progression, and the other patient underwent a second Haplo-HSCT from a different donor and is still alive. We can conclude that the detection of HLA-loss at the onset of relapse after Haplo-HSCT with PTCy could help in clinical practice to select appropriate rescue treatment, thereby avoiding the use of DLIs or a second transplantation from the same donor.

Elafin as a Predictive Biomarker of Acute Skin Graft-Versus-Host Disease After Haploidentical Stem Cell Transplantation Using Post-Transplant High-Dose Cyclophosphamide

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) has shown favorable results in the treatment of hematological malignancies. Despite the use of post-transplant cyclophosphamide (PTCy), graft versus host disease (GVHD) remains as one of the main complications in this setting. Since the skin appears affected in up to 80% of cases of acute GVHD (aGVHD), its prognosis and diagnosis are essential for the correct management of these patients. Plasma concentration of elafin, an elastase inhibitor produced by keratinocytes, has been described elevated at the diagnosis of skin GVHD, correlated with the grade of GVHD, and associated with an increased risk of death. In this study we explored elafin plasma levels in the largest series reported of T cell-replete haplo-HSCT with PTCy. Plasma samples drawn from 87 patients at days +15 and +30 were analyzed ("discovery cohort"). Elafin levels at days +15 were no associated with chronic GVHD, non-relapse mortality, relapse, therapy-resistant GVHD, or overall survival. In our series, elafin levels at day +30 were not associated with post-transplant complications. On the other hand, elafin plasma levels at day +15 were higher in patients with severe skin aGVHD (21,313 vs.14,974 pg/ml; p = 0.01). Of note, patients with higher elafin plasma levels at day +15 presented a higher incidence of stage III-IV skin aGVHD (HR = 18.9; p < 0.001). These results were confirmed (HR = 20.6; p < 0.001) in an independent group of patients (n = 62), i.e. the "validation cohort." These data suggest that measurement of elafin in patients undergoing haplo-HSCT with PTCy might be useful for an early identification of those patients who are at higher risk of suffering severe skin aGVHD and thus, improve their treatment and prognosis.

Genetic biomarkers identify a subgroup of high-risk patients within low-risk NPM1-mutated acute myeloid leukemia

Although acute myeloid leukemia (AML) with NPM1^mut/FLT3-ITD^neg is a low-risk entity, its relapse rate remains high. Out of 333 AML patients, 27 were NPM1^mut, and were analyzed in greater detail in order to find associations between clinical and molecular features and cumulative incidence of relapse. Next-generation sequencing (NGS) was performed on diagnosis and remission samples using two capture-based panels. The presence of the FLT3^D835 variant at diagnosis and a qPCR value of NPM1^mut ≥0.1% after induction chemotherapy were associated with an increased probability of relapse, especially if both conditions are present together. By contrast, patients in which the main clone found at diagnosis harbored NPM1 variant had a lower risk of relapse. Nineteen of the 85 variants found at diagnosis were detected by NGS in remission. AML Subgroup with NPM1^mut/FLT3-ITD^neg is a heterogeneous entity, which can be further risk-stratified based on molecular biomarkers.

Generation, establishment and characterization of a pluripotent stem cell line (CVTTHi001-A) from primary fibroblasts isolated from a patient with activated PI3 kinase delta syndrome (APDS2)

APDS2 is caused by mutations in PIK3R1 gene resulting in constitutive PI3Kδ activation. PI3Kδ is predominantly expressed in leukocytes and plays critical roles in regulating immune responses. Here we first derived fibroblast primary cells from a skin biopsy of a patient carrying a heterozygous single T deletion in intron 11 of the PIK3R1 gene. We next present the derivation of an induced pluripotent stem cell (iPS) line using a non-integrative reprogramming technology. Pluripotent-related hallmarks are further shown, including: iPSCs self-renewal and expression of pluripotent and differentiation markers after in vitro differentiation towards embryonic germ layers, assessed by RT-PCR and immunofluorescence.

Transjugular Intrahepatic Portosystemic Shunt for Very Severe Veno-Occlusive Disease/Sinusoidal Obstruction Syndrome (VOD/SOS) after Unmanipulated Haploidentical Hematopoietic Stem Cell Transplantation with Post-transplantation Cyclophosphamide

Hepatic veno-occlusive disease or sinusoidal obstruction syndrome (VOD/SOS) is a threatening complication after both autologous and allogeneic hematopoietic stem cell transplantation (HSCT), with high mortality rates despite early medical treatment, including the use of defibrotide (DF). We retrospectively analyzed 185 unmanipulated haploidentical (haplo-) HSCT with post-transplantation cyclophosphamide as graft-versus-host disease prophylaxis performed consecutively between 2011 and June 2019 in a single center. Seventeen patients (9.2%) were diagnosed with VOD/SOS. Based on revised European Society for Blood and Marrow Transplantation severity criteria, the VOD/SOS cases were classified as mild in 2 patients (11.7%), moderate in 2 (11.7%), severe in 2 (11.7%), and very severe in 11 (64.9%). Thirteen patients (76%) were treated with DF, including all patients with severe or very severe VOD/SOS, except 1 patient with CNS hemorrhage. Sixteen patients (94%) were alive at day +100 after HSCT. Seven patients (41%) with very severe VOD/SOS were treated with transjugular intrahepatic portosystemic shunt (TIPS) owing to rapid clinical or analytical deterioration or refractory hepatorenal syndrome despite medical treatment, including DF. TIPS insertion was performed at a median time since VOD/SOS diagnosis of 4 days (range, 1 to 28 days) without technical complications in any case. The median hepatic venous pressure gradient before and after TIPS treatment was 24 mmHg (range, 14 to 29 mmHg) and 7 mmHg (range, 2 to 11 mmHg), respectively, with a median drop of 16 mmHg (range, 9 to 19 mmHg). Following TIPS insertion, all patients showed clinical improvement with hepatomegaly, ascites, and renal failure resolution, and all showed analytical improvement with reduced alanine aminotransferase (ALT), creatinine, and international normalized ratio values, except for patient 2, whose indication for TIPS was refractory hepatorenal syndrome with a normal ALT level. The 6 patients who had initiated DF before TIPS insertion completed 21 days of treatment. All patients met the criteria for complete remission (CR) at a median of 8 days after TIPS insertion (range, 2 to 82 days). The 100-day overall survival was 100%. For patients with rapid progressive VOD/SOS, early TIPS insertion allowed completion of DF therapy. The use of TIPS together with DF resulted in CR and no associated complications with no VOD/SOS-associated mortality despite high severity. In our experience, timely and individualized use of TIPS significantly improves outcomes of very severe VOD/SOS after haplo-HSCT. Therefore, TIPS should be promptly considered in rapidly progressive cases.

Cytokine release syndrome after allogeneic stem cell transplantation with posttransplant cyclophosphamide

Cytokine release syndrome (CRS) is a systemic inflammatory response with aberrant immune activation and immune hyperstimulation, that leads to increased cytokine levels and inflammation. CRS has been described after antibody and cellular-based therapies. The use of posttransplant cyclophosphamide (PTCy) as graft-vs-host disease (GVHD) prophylaxis in haploidentical hematopoietic stem cell transplantation (haplo-HSCT) has led to the extension of allogeneic HSCT to patients without HLA-identical donors. Furthermore, PTCy has also been introduced in matched and unrelated donor HSCT. However, description of incidence and clinical impact of CRS on outcomes in these patients is scarce. We retrospectively analyzed 107 consecutive haplo-HSCT and 39 HLA-identical HSCT with PTCy from 2010 to 2017 in our institution. We used published CRS criteria to identify 76% and 14% of patients who developed CRS after haplo-HSCT and HLA-identical HSCT, respectively. Most patients presented CRS grades 1 and 2. Only one patient from the whole series presented grade 3 CRS and required tocilizumab therapy. The use of peripheral blood stem cells (PBSC), as well as total nucleated cells infused were associated with an increased risk of CRS. Patients who presented CRS developed grade II-IV acute GVHD more frequently than those who did not (60% vs 28.6% respectively, P = .012). The development of CRS was not significantly associated with nonrelapse mortality or overall survival. CRS is a frequent complication after PBSC haploidentical T-repleted HSCT, but significantly less frequent after HLA-identical HSCT. Most cases are mild. Prompt identification allows adequate management of severe forms.

Autologous stem cell transplantation for lymphoma in HIV+ patients: higher rate of infections compared with non-HIV lymphoma

Autologous hematopoietic stem cell transplantation (ASCT) is a well-established treatment strategy in HIV-related lymphoma patients (HIV+ Ly). Nevertheless, current evidence is mainly based on reports from specialized centers, multicentre heterogeneous studies, noncomparative analyses, or registry data-based comparisons. Likewise, the risk of infections reported so far for this population, seems to be similar to that of HIV- patients, and it does not seem to impact on mortality. We report a single-center retrospective comparative analysis of AHCT procedural results, infectious complications and survival in HIV+ Ly matched with a non-HIV comparative cohort. Thirty-three HIV+ patients and 45 matched controls, who underwent ASCT between 2000 and 2016, were included. Transplant-related toxicity, event-free survival, relapse rate, and overall survival were similar in both groups. Engraftment was delayed in HIV+ Ly (neutrophils: 15 vs 12 days (p = 0.0001), and platelets 39 vs 16 days (p = 0.00001)). Bacterial infections during the pre-engraftment period were more frequent in HIV+ Ly (RR 2.24, p = 0.017), as well as viral infections in the postengraftment period (RR 3.22, p = 0.004). CMV reactivation was more frequent in HIV+ Ly (39% vs 15% p = 0.007). In conclusion, ASCT is viable and effective in HIV+ Ly, but it is associated with a higher risk of infection.

Adult peripheral blood and umbilical cord blood NK cells are good sources for effective CAR therapy against CD19 positive leukemic cells

Among hematological cancers, Acute Lymphoblastic Leukemia (ALL) and Chronic Lymphocytic Leukemia (CLL) are the most common leukemia in children and elderly people respectively. Some patients do not respond to chemotherapy treatments and it is necessary to complement it with immunotherapy-based treatments such as chimeric antigen receptor (CAR) therapy, which is one of the newest and more effective treatments against these cancers and B-cell lymphoma. Although complete remission results are promising, CAR T cell therapy presents still some risks for the patients, including cytokine release syndrome (CRS) and neurotoxicity. We proposed a different immune cell source for CAR therapy that might prevent these side effects while efficiently targeting malignant cells. NK cells from different sources are a promising vehicle for CAR therapy, as they do not cause graft versus host disease (GvHD) in allogenic therapies and they are prompt to attack cancer cells without prior sensitization. We studied the efficacy of NK cells from adult peripheral blood (AB) and umbilical cord blood (CB) against different target cells in order to determine the best source for CAR therapy. AB CAR-NK cells are slightly better at killing CD19 presenting target cells and CB NK cells are easier to stimulate and they have more stable number from donor to donor. We conclude that CAR-NK cells from both sources have their advantages to be an alternative and safer candidate for CAR therapy.

ST2 and REG3α as Predictive Biomarkers After Haploidentical Stem Cell Transplantation Using Post-transplantation High-Dose Cyclophosphamide

Allogenic hematopoietic stem cell transplantation (allo-HSCT) is a curative procedure for several hematological malignancies. Haploidentical HSCT (haplo-HSCT) using high-dose post-transplantation cyclophosphamide (PTCy) makes transplantation possible for patients with no HLA-matched sibling donor. However, this treatment can cause complications, mainly infection, graft-vs.-host disease (GVHD), and conditioning-related toxicity. In recent years, different biomarkers in the form of tissue-specific proteins have been investigated; these may help us to predict complications of allo-HSCT. In this study we explored two such biomarkers, suppression of tumorigenicity 2 (ST2) and regenerating islet-derived 3α (REG3α), in the largest series reported of T cell–replete haplo-HSCT with PTCy. Plasma samples drawn from 87 patients at days +15 and +30 were analyzed. ST2 and REG3α levels at day +15 were not associated with post-transplant complications. ST2 levels at day +30 were higher in patients with grade II-IV acute GVHD, mainly those who received reduced intensity conditioning (RIC; median 2,503 vs. 1,830 ng/ml; p = 0.04). Of note, patients with higher plasma ST2 levels at day +30 also presented a higher incidence of non-relapse mortality (HR, 7.9; p = 0.004) and lower 2-year overall survival (25 vs. 44 months; p = 0.02) than patients with lower levels. Patients with REG3α levels higher than 1,989 pg/ml at day +30 presented a higher incidence of acute gastrointestinal GVHD in the whole cohort (HR, 8.37; p = 0.003) and in the RIC cohort (HR 6.59; p = 0.01). These data suggest that measurement of ST2 and REG3α might be useful for the prognosis and prediction of complications in patients undergoing haplo-HSCT with PTCy.

Successful Treatment of Severe Aspergillosis with Isavuconazole Therapy after Allogeneic Stem Cell Transplantation

Invasive fungal infections are one of the main infectious complications in allogeneic stem cell transplantation (SCT). Triazoles (voriconazole, posaconazole) are the main prophylactic and therapeutic options for the treatment of invasive aspergillosis. However, pharmacological interactions and hepatotoxicity limit its use. Isavuconazole (ISV) is a recently approved azole with a promising interaction and safety profile. We present a case with invasive aspergillosis in the post-allogeneic SCT setting in a critically ill patient with severe multiorgan failure due to veno-occlusive disease. The patient was treated with ISV and B amphotericin during severe kidney and liver failure and multiple immunosuppressants, without significant drug-related toxicity and with favorable outcome. The interaction and safety profile of ISV is discussed along the reported experience. ISV can be an effective salvage therapy even in complex clinical situations with multiple potential interactions.

Transient hemolysis due to anti-D and anti-A1 produced by engrafted donor's lymphocytes after allogeneic unmanipulated haploidentical hematopoietic stem cell transplantation

BACKGROUND

Development of de novo alloantibodies against recipient's red blood cell (RBC) antigens by engrafted donor's lymphocytes is a known phenomenon in the setting of allogeneic hematopoietic stem cell transplantation (HSCT). This situation is usually clinically insignificant. We report a case of early clinically relevant hemolytic anemia in a blood group A₁ D+ patient, due to a limited production of anti-D and anti-A₁ produced by nonpreviously sensitized newly engrafted donor's immune system.

CASE REPORT

A 31-year-old Caucasian woman, blood group A₁ , D+, with Hodgkin's lymphoma, received an unmanipulated haploidentical allogeneic peripheral blood HSCT after a nonmyeloablative conditioning regimen. Donor blood group was A₂ B, D-. The patient had an uneventful course until Day +34, when she developed clinically significant hemolytic anemia with a positive direct antiglobulin test. Anti-D and anti-A₁ produced by the donor-engrafted lymphocytes were detected both in serum and in eluate. The hemolysis produced an accelerated group change, turning the patient's ABO group into A₂ B 2 weeks after the detection of the alloantibodies. As the residual patient's RBCs progressively disappeared, anti-D and anti-A₁ production decreased and were not detected in serum by Day +41.

CONCLUSION

This case illustrates that de novo alloantibody production against ABO and D antigens by the newly engrafted donor's lymphocytes can occasionally cause clinically significant anemia. To our knowledge, this is the first case reported of clinically significant hemolytic anemia due to a transient anti-D anti-A₁ alloimmunization after T-cell-repleted haploidentical HSCT.

Inhibitory killer cell immunoglobulin-like receptor (iKIR) mismatches improve survival after T-cell-repleted haploidentical transplantation

Alloreactivity triggered by interaction between killer cell immunoglobulin-like receptors (KIRs) and natural killer (NK) cells plays a role in the graft-versus-tumor effect after hematopoietic stem cell transplantation (SCT). Our aim in this study was to evaluate this role in the setting of T-cell-repleted haploidentical SCT with postinfusion high-dose cyclophosphamide (PT-Cy). We included 33 patients. Among patient-donor pairs with at least 1 inhibitory KIR (iKIR) gene mismatch, event-free survival (EFS) and cumulative incidence of relapse 1 year after transplant were significantly better (85% vs. 37% [P = 0.008] and 18% vs. 46% [P = 0.041], respectively). A subanalysis in 12 patients with Hodgkin's lymphoma (HL) showed an improvement in EFS 1 year after transplant in those patients with KIR ligand mismatch (100% vs. 25%, P = 0.012), although overall survival (OS) was not affected (85% vs. 80%, P = 0.2). Eight of 12 patient-donors pairs presented iKIR mismatches. Of note, this outcome was better in the small subgroup, both for EFS (100% vs. 25%, P = 0.012) and for OS (100% vs. 37%, P = 0.004). Our data suggest that in the setting of T-cell-repleted haploidentical SCT with PT-Cy, iKIR mismatch is associated with improved survival, with particularly good results for both iKIR and KIR ligand mismatches in patients with HL.

Achievement of early complete donor chimerism in CD25+-activated leukocytes is a strong predictor of the development of graft-versus-host-disease after stem cell transplantation

Chimerism dynamics in bone marrow, peripheral blood (PB), and T lymphocytes (TL) has been associated with the development of various complications after allogeneic stem-cell transplantation (allo-SCT). In the present study, the usefulness of chimerism monitoring in CD25(+)-activated leukocytes (AL), together with that in bone marrow, PB, and TL, for the anticipation of complications after allo-SCT, has been analyzed in 68 patients. In AL, we observed a slower dynamics toward complete chimerism (CC) than in PB (p = 0.042), while no significant differences were found between TL and PB (p = 0.12). Complete chimerism achievement in AL at day +30 has shown to be an independent risk factor for the development of grade II-IV acute graft-versus-host disease (aGvHD; hazard ratio [95% confidence interval]: 11.9 [1.5-91.7]; p = 0.017). Moreover, among patients achieving CC in TL and AL at different time-points after SCT (n = 17/68), the incidence of grade II-IV aGvHD was significantly higher in patients who achieved CC earlier in AL (5/5) than in those who achieved CC earlier in TL (1/11; p = 0.001). Therefore, achievement of early complete donor chimerism in CD25(+) AL is a strong predictor for the development of aGvHD. Prospective analysis of chimerism in AL could improve the post-SCT management of immunosuppressive therapy in transplanted patients.

Early peripheral blood and T-cell chimerism dynamics after umbilical cord blood transplantation supported with haploidentical cells

Single-unit umbilical cord blood (CB) SCT is limited by low total nucleated cell (TNC) dose. Co-infusion of CD34+ cells from a third party HLA-mismatched donor, known as dual or haplo-cord transplant, reduces the period of post-transplant neutropenia and related complications. The aim of this study was to analyze the value of early post-transplant peripheral blood (PB) and T cell chimerism after 28 dual transplants regarding CB engraftment. Cumulative incidence of myeloid engraftment at 30 days was 93% with a median time to engraftment of 14 days (10-29). Patients who developed CB graft failure (n=5) showed very low percentages of CB cells on days +14, +21 and +28 with decreasing dynamics. On the other hand, percentages of CB cells in patients who achieved CB engraftment increased over time. Interestingly, such patients showed two distinct chimerism dynamics in PB, but all of them showed a predominance of CB T cells early after SCT with increasing dynamics over time. Early post-transplant chimerism dynamics in PB and T cells predicts CB graft failure enabling rapid therapeutic measures to be applied. On the other hand, early increasing percentages of CB T cells correlates with ultimate CB engraftment.

Graft-versus-tumor effect after allogeneic stem cell transplantation in HIV-positive patients with high-risk hematologic malignancies

Allogeneic hematopoietic stem cell transplantation (Allo-HSCT) is a well-established therapeutic option for hematological malignancies. Combination antiretroviral therapy (cART) has enabled the treatment of medical conditions in patients infected with the human immunodeficiency virus (HIV) in the same way as in the general population. Moreover, improvements in supportive care have allowed HIV-infected patients with life-threatening hematological disorders to be treated with Allo-HSCT. We report on four HIV-infected patients with hematological malignancies receiving an Allo-HSCT in our institution, and on the use of donor lymphocyte infusions to successfully treat post-Allo-HSCT relapse. Of note, one of them is the first HIV(+) patient to receive a "dual transplant" (unrelated umbilical cord blood stem cells combined with mobilized T cell-depleted CD34(+) stem cells from a mismatched third party donor). cART drugs interactions were satisfactorily managed. This approach provided long-term control of the hematological disease. Nevertheless, despite adequate immune reconstitution, infections were the main cause of morbidity and mortality after Allo-HSCT.

Single cord blood combined with HLA-mismatched third party donor cells: comparable results to matched unrelated donor transplantation in high-risk patients with hematologic disorders

Matched unrelated donor (MUD) transplantation is the first alternative in the absence of a matched sibling donor. For patients without a suitable adult donor, we have adopted the dual stem cell transplantation protocol consisting of cord blood (CB) in combination with CD34(+) cells from a third party HLA-mismatched donor. We analyzed the outcomes of patients undergoing both procedures in a single center. Starting in 2004, a total of 20 patients with high-risk disease underwent 22 dual transplants and 25 patients underwent myeloablative MUD transplantation. The 30-day cumulative incidence of neutrophil engraftment was similar in both groups (91% and 95%), with a median time to engraftment of 14 and 16 days, respectively. Grade II-IV acute graft-versus-host disease was more frequent in the MUD group (40% versus 5%). Except for a tendency toward a higher incidence of viral hemorrhagic cystitis in the dual transplantation group, posttransplantation infectious events were comparable in the 2 groups. The 3-year cumulative incidence rates of relapse (41% versus 44%) and nonrelapse mortality (30% versus 25%) were similar in the MUD and dual transplantation cohorts. Estimated 3-year overall survival and disease-free survival were 47% and 41%, respectively, with no survival advantage for either group. In our experience, dual transplantation offers survival rates comparable to those from myeloablative MUD transplantation with similar nonrelapse mortality rates.

False-positive Aspergillus antigenemia due to blood product conditioning fluids

The presence of Aspergillus antigens in blood transfusion components from different manufacturers was analyzed. Galacomannans were found in transfused patients, pooled platelet concentrates, fresh frozen plasma, and packed red cells collected using Fresenius Kabi bags. Galacomannans were also found in blood collection anticoagulant and platelet additive solution from this manufacturer.

Evaluation of minimal residual disease by real-time quantitative PCR of Wilms' tumor 1 expression in patients with acute myelogenous leukemia after allogeneic stem cell transplantation: correlation with flow cytometry and chimerism

Relapse remains the main cause of treatment failure in patients with acute myelogenous leukemia (AML) after allogeneic hemopoietic stem cell transplantation (SCT). The Wilms' tumor 1 gene (WT1) is reportedly overexpressed in >90% of patients with AML and thus can be useful for minimal residual disease (MRD) monitoring. The aim of this study was to evaluate the usefulness of WT1 expression as a relapse predictor marker in patients with AML after SCT and compare it with flow cytometry (FC) and chimerism studies. WT1 expression was assessed retrospectively using quantitative RT-PCR in bone marrow and peripheral blood from 21 patients. Patients were classified according to WT1 dynamics posttransplantation. Eleven of the 21 patients had low and stable WT1 levels. All of these 11 patients showed complete chimerism and negative MRD by FC and remained in complete remission with a median follow-up of 27 months (range, 18-98 months). In contrast, 10 of 21 patients showed WT1 overexpression after SCT, and 9 of these 10 patients relapsed. The incidence of relapse differed significantly between the 2 groups of patients according to WT1 expression post-SCT (P = .00003). Relapse in the 9 patients occurred at a median of 314 days (range, 50-560 days). Interestingly, in these patients, relapse was first predicted by WT1 (with negative FC and complete chimerism) in 7 patients. WT1 overexpression was correlated with disease burden in patients with AML before and after allogeneic SCT. In patients who relapsed, both medullary and extramedullary relapse were better anticipated by WT1 overexpression compared with FC and chimerism.

Nanostructuring of ultra-thin HfO2 layers for high-k/III-V device application

We report on the nanopatterning by electron beam lithography (EBL) and reactive ion etching (RIE) in a SF6/Ar+ plasma of ultra-thin HfO2 films deposited on GaAs (001) substrates for gate oxide application in next generation III-V metal-oxide-semiconductor field effect transistors (MOSFETs). Characterization of the HfO2/GaAs nanostructured samples by atomic force microscopy (AFM), high-resolution scanning electron microscopy (HRSEM), energy-dispersive X-ray spectroscopy microanalysis (EDX) and transmission electron microscopy (TEM) has shown the formation of well defined HfO2 patterns with nanometre-scale linewidth control and anisotropic profiles. In addition, atomically smooth, stoichiometric and residue-free bottom GaAs etched lines with a lateral dimension of approximately 50 nm have been demonstrated.

[Donor lymphocyte infusions after allogeneic stem cell transplantation: single center clinical experience]

BACKGROUND AND OBJECTIVE

Donor lymphocyte infusions (DLI) have proven to be useful for the treatment of relapse after allogenic stem cell transplantation (SCT) and for the conversion of mixed chimerism (MC) into complete chimerism. The objective of the present study is to analyze the results of DLI used in both scenarios in a single centre.

PATIENTS AND METHOD

Twenty five patients were retrospectively analyzed: DLI was used for relapse treatment in 18 cases and for conversion of mixed chimerism in 7.

RESULTS

Six patients from the first group (35%) showed response in a median of 137 days (23-250). After a median follow-up of 12 months (7 months-8 years), 5 patients remained in complete remission. Additionally, one patient recieved prophylactic DLI with good results. Six of the 7 patients (85%) who received DLI for MC showed response. After a median follow-up of 7 years (6-8), 4 patients (57%) remained in remission.

CONCLUSIONS

In our experience, DLI showed clinical benefit in the management of mixed chimerism, although it was less useful in the management of relapse. Novel strategies should be considered in high risk patients.

Molecular Cloning of the Tryptophan Operon from an Aeromonas hydrophila Freshwater Isolate

A genomic library of Aeromonas hydrophila F9 was constructed by using pBR322 as a vector. From that, two DNA fragments (5.8 and 11.6 kb) were isolated containing genetic information to complement trpA and trpB defects (5.8-kb fragment) and to complement trpA, trpB, trpC, trpD, and trpE defects (11.6-kb fragment) in Escherichia coli mutants. Evidence of the existence of a secondary promoter is given.

Impaired anti-pneumococcal polysaccharide antibody production and invasive pneumococcal infection following heart transplantation

An increased risk of invasive pneumococcal infection has been described among adult heart transplant (HT) recipients. Vaccination has been recommended before HT but the appropriate time for revaccination is not known. In a preliminary analysis of a prospective study involving a cohort of 32 HT recipients receiving daclizumab and triple immunosuppresion therapy, a progressive decline in pneumococcal polysaccharide antibody (anti-PPS) levels was observed during the first year after HT. One of the patients who was found to have a decrease in the levels of anti-PPS developed severe pneumococcal meningitis 20 months after HT. Before HT he had received non-conjugated 23-valent pneumococcal vaccine and showed a normal post-immunization anti-PPS production. The data suggest that long-term immunologic monitoring might be useful to recognize impairment of antibody responses under immunosuppressive therapy in HT.

High-dose chemotherapy and autologous peripheral blood stem cell rescue (Auto-SCT) in multiple myeloma (MM) patients: Busulfan + melphalan-140 (BuMel) versus (vs) melphalan-200 (Mel-200) as conditioning regimens

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Background: Auto-SCT is the preferred treatment modality for MM. From the results of IFM 9502 (Moreau et al. Blood, 2002) melphalan 200 mg/m2 was considered the new standard as conditioning regimen due to its lower toxicity. However, many chemotherapy regimens have been tested. We present our results with two cohorts of consecutive patients (pts) diagnosed of MM and treated with Auto-SCT between 1996 and 2005 in our BMT Unit. Methods: Following induction chemotherapy (median of 6 courses) 20 pts were conditioning with busulfan 16 mg/kg + melphalan 140 mg/m2 (BuMel) and 23 (since September-2002) with melphalan 200 mg/m2 (Mel-200). Clinical features: median age (BuMel vs Mel-200) 55 vs 58 (p=0.5); female sex 10 vs 10; Bence-Jones MM 5 vs 5; renal failure (B) 2/20 (10%) vs 7/23 (30%)(p=0.48); previous treatment with local irradiation 6/20 vs 3/23; status previous Auto-SCT (complete remission, CR) 7/20 (35%) vs 6/23 (26%), p=0.5. A median of 4.8 vs 4.4 x 10e6/kg CD34+ cells were infused, respectively (p=0.15). Results: Four toxic deaths: 2 pts by hemorrhagic cystitis-enterocolitis (at day +84 and +96), 1 pt with disseminated candidiasis (day +7), and 1 pt by pulmonary fibrosis (day +452). At 3 months following Auto-SCT, 13/19 (68%) treated with BuMel and 12/23 (52%) of those treated with Mel-200 achieved CR (p=0.28). At 24 months, probability of remaining disease free was 87% for BuMel group and 55% for Mel-200 (p=0.08). Conclusions: 1) Conditioning regimen BuMel was associated with a higher toxicity than Mel-200, as well as a higher mortality treatment related. 2) However, a trend for higher CR rates and probability of disease free progression were shown in BuMel group without statistical significance

[Table: see text]

No significant financial relationships to disclose.

Banco de sangre

We describe the consequences of the mass arrival of victims and donors on our blood bank. Changes in the organization, interventions and activity related to transfusions and donations are presented. In the conclusion, we critically analyze our experience and discuss ideas that could be applied in future similar situations.

Comparative study of the expression of proteins involved in the cell cycle in renal secondary hyperparathyroidism

BACKGROUND

In renal hyperparathyroidism, parathyroid cell proliferation seems to play a key role in the progression of the disease. Therefore, G1/S transition, a main cell cycle regulatory step, could be deregulated in these patients.

METHODS

One hundred and one parathyroid glands, taken from parathyroidectomies performed on 41 patients on hemodialysis (HD), and 15 glands, taken from 7 patients with post-transplantation persistent hyperparathyroidism (HPT), were studied. Twelve normal parathyroid (PT) glands were used as the control. Biochemical data, immunohistochemical (IHC) profiles of G1/S transition regulators belonging to the two main pathways (cyclin D1/p16INK4A/pRb and p14ARF/p53/MDM2), and proliferation rate (Ki67) were correlated.

RESULTS

All of the other proteins differed from normal IHC profiles in both groups that showed significant higher proliferating rates, decreases in p27KIP1, pRb, and cyclin D1, as well as increases in p16INK4A, p53, MDM2, and p21WAF1 levels, in comparison with normal PT glands, with the exception of cyclin D3. Contrary to patients with HPT who were on hemodialysis, in post-transplantation HPT, consistent correlations between biochemical data and IHC profiles were obtained.

CONCLUSION

In both groups IHC profiles of proteins involved in G1/S transition regulation significantly differed from normal PT glands. The results support partial reversion to normal IHC profile in post-transplantation HPT.

Exploitation of interleukin-8-induced neutrophil chemotaxis by the agent of human granulocytic ehrlichiosis

The agent of human granulocytic ehrlichiosis (HGE) is an obligate intracellular bacterium with a tropism for neutrophils; however, the mechanisms of bacterial dissemination are not yet understood. Interleukin-8 (IL-8) is a chemokine that induces neutrophil migration to sites of infection for host defense against pathogens. We now show that HGE bacteria, and the HGE-44 protein, induce IL-8 secretion in a promyelocytic (HL-60) cell line that has been differentiated along the neutrophil lineage with retinoic acid and in neutrophils. Infected HL-60 cells also demonstrate upregulation of CXCR2, an IL-8 receptor, but not CXCR1. Human neutrophils migrate towards Ehrlichia sp.-infected cells in a chemotaxis chamber assay, and this movement can be blocked with antibodies to IL-8. Finally, immunocompetent and severe combined immunodeficient mice administered CXCR2 antisera, and CXCR2(-/-) mice that lack the human IL-8 receptor homologue, are much less susceptible to granulocytic ehrlichiosis than are control animals. These results demonstrate that HGE bacteria induce IL-8 production by host cells and, paradoxically, appear to exploit this chemokine to enhance infection.

Dissociation of infectivity and pathogenicity in Borrelia burgdorferi

Clonal Borrelia burgdorferi N40 (cN40) passaged 75 times in vitro (N40-75) infects mice but does not cause disease. N40-75 passaged 45 times further in vitro (N40-120) was no longer infectious and lacked genes encoded on linear plasmids 38 and 28-1, among other differences. These data suggest that B. burgdorferi cN40, N40-75, and N40-120 have distinct phenotypes that can be used to dissect the genetic elements responsible for pathogenicity and infectivity.

Coinfection with Borrelia burgdorferi and the agent of human granulocytic ehrlichiosis alters murine immune responses, pathogen burden, and severity of Lyme arthritis

Lyme disease and human granulocytic ehrlichiosis (HGE) are tick-borne illnesses caused by Borrelia burgdorferi and the agent of HGE, respectively. We investigated the influence of dual infection with B. burgdorferi and the HGE agent on the course of murine Lyme arthritis and granulocytic ehrlichiosis. Coinfection resulted in increased levels of both pathogens and more severe Lyme arthritis compared with those in mice infected with B. burgdorferi alone. The increase in bacterial burden during dual infection was associated with enhanced acquisition of both organisms by larval ticks that were allowed to engorge upon infected mice. Coinfection also resulted in diminished interleukin-12 (IL-12), gamma interferon (IFN-gamma), and tumor necrosis factor alpha levels and elevated IL-6 levels in murine sera. During dual infection, IFN-gamma receptor expression on macrophages was also reduced, implying a decrease in phagocyte activation. These results suggest that coinfection of mice with B. burgdorferi and the HGE agent modulates host immune responses, resulting in increased bacterial burden, Lyme arthritis, and pathogen transmission to the vector.

Inhibition of Th1 differentiation by IL-6 is mediated by SOCS1

Interleukin 6 (IL-6) is a cytokine produced by immune and nonimmune cells and exhibits functional pleiotropy and redundancy. IL-6 plays an important role in the differentiation of several cell types. Here, we describe a novel function of IL-6: the negative regulation of CD4+ Th1 cell differentiation. While IL-6-directed CD4+ Th2 differentiation is mediated by IL-4, inhibition of Th1 differentiation by IL-6 is independent of IL-4. IL-6 upregulates suppressor of cytokine signaling 1 (SOCS1) expression in activated CD4+ T cells, thereby interfering with signal transducer and activator of transcription 1 (STAT1) phosphorylation induced by interferon gamma (IFNgamma). Inhibition of IFNgamma receptor-mediated signals by IL-6 prevents autoregulation of IFNgamma gene expression by IFNgamma during CD4+ T cell activation, thereby preventing Th1 differentiation. Thus, IL-6 promotes CD4+ Th2 differentiation and inhibits Th1 differentiation by two independent molecular mechanisms.

Blastoschizomyces capitatus infection in acute leukemia patients

Blastoschizomyces capitatus (BC), a filamentous fungus of genus Trichosporum, is as an important opportunistic pathogen in the compromised host. Within the past 10 years, 47 cases of BC infection have been published. Most of the patients had acute leukemia (AL) or related disorders and had received chemotherapy treatment. Due to BC's resistance to currently used antifungal agents, this infection represents a therapeutic challenge and serious complication in the treatment of hematology malignancies. Here we report our experience with BC infection in four patients with acute leukemia or related disorders.