Low utilization of vancomycin in febrile neutropenia: real-world evidence from 4 Brazilian centers.

PURPOSE: The prompt initiation of a betalactam antibiotic in febrile neutropenic patients is considered standard of care, while the empiric use of vancomycin is recommended by guidelines in specific situations, with a low level of evidence. The objective of this study was to assess the utilization of vancomycin in the management of febrile neutropenia within four Brazilian medical centers that implemented more stringent criteria for its administration. METHODS: A comprehensive retrospective analysis was performed encompassing all instances of febrile neutropenia observed during the period from 2013 to 2019. The primary focus was to identify the reasons for initiating vancomycin therapy. RESULTS: A total of 536 consecutive episodes of febrile neutropenia were documented, involving 384 patients with a median age of 52 years (range 18-86). Chemotherapy preceded febrile neutropenia in 59.7% of cases, while 40.3% occurred after hematopoietic stem cell transplantation. The most prevalent underlying diseases were acute myeloid leukemia (26.5%) and non-Hodgkin's lymphoma (22%). According to international guidelines, vancomycin should have been initiated at the onset of fever in 145 episodes (27%); however, it was administered in only 27 cases (5.0%). Three episodes were associated with Staphylococcus aureus bacteremia, two of which were methicillin resistant. The 15-day and 30-day mortality rates were 5.0% and 9.9%, respectively. CONCLUSIONS: The results of this study underscore the notably low utilization rate of vancomycin in cases of febrile neutropenia, despite clear indications outlined in established guidelines. These findings emphasize the importance of carefully implementing guideline recommendations, considering local epidemiological factors, especially when the strength of recommendation is weak.

COVID-19 in HSCT recipients: a collaborative study of the Brazilian Society of Marrow Transplantation (SBTMO).

In the COVID-19 scenario, patients undergoing hematopoietic stem cell transplantation (HSCT) infected with SARS-CoV-2 may have an increased risk of death. Through a national multicenter study, we aimed to describe the impact of COVID-19 on the survival of HSCT recipients in Brazil. Eighty-six patients with a confirmed diagnosis of SARS-CoV-2 (92% by RT-PCR) were included. There were 24 children and 62 adults receiving an autologous (n = 25) and allogeneic (n = 61) HSCT for malignant (n = 72) and non-malignant (n = 14) disorders. Twenty-six patients died, (10 on autologous (38%) and 16 patients (62%) on allogeneic group). The estimated overall survival (OS) at day 40 was 69%. Adults had decreased OS compared to children (66% vs 79%, p = 0.03). The severity of symptoms at the time of diagnosis, ECOG score, laboratory tests (C-reactive protein, urea values) were higher in patients who died (p < 0.05). In conclusion, HSCT recipients infected with SARS-CoV-2 have a high mortality rate mainly in adults and patients with critical initial COVID-19 presentation. These findings show the fragility of HSCT recipients with SARS-CoV-2 infection. Therefore, the importance of adherence to preventive measures is evident, in addition to prioritizing the vaccination of family members and the HSCT team.

Deregulation of Ikaros expression in B-1 cells: New insights in the malignant transformation to chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is a chronic form of leukemia that originates from an abnormal expansion of CD5+ B-1 cells. Deregulation in the BCR signaling is associated with B-cell transformation. Contrariwise to B-2 cells, BCR engagement in B-1 cells results in low proliferation rate and increased apoptosis population, whereas overactivation may be associated with lymphoproliferative disorders. It has been demonstrated that several transcription factors that are involved in the B cell development play a role in the regulation of BCR function. Among them, Ikaros is considered an essential regulator of lymphoid differentiation and activation. Several reports suggest that Ikaros expression is deregulated in different forms of leukemia. Herein, we demonstrated that CLL cells show decreased Ikaros expression and abnormal cytoplasmic cell localization. These alterations were also observed in radioresistant B-1 cells, which present high proliferative activity, suggesting that abnormal localization of Ikaros could determine its loss of function. Furthermore, Ikaros knockdown increased the expression of BCR pathway components in murine B-1 cells, such as Lyn, Blnk, and CD19. Additionally, in the absence of Ikaros, B-1 cells become responsive to BCR stimulus, increasing cell proliferation even in the absence of antigen stimulation. These results suggested that Ikaros is an important controller of B-1 cell proliferation by interfering with the BCR activity. Therefore, altered Ikaros expression in CLL or radioresistant B-1 cells could determine a responsive status of BCR to self-antigens, which would culminate in the clonal expansion of B-1 cells.

Diagnosis and treatment of chronic lymphocytic leukemia: recommendations from the Brazilian Group of Chronic Lymphocytic Leukemia

ABSTRACT Chronic lymphocytic leukemia is characterized by clonal proliferation and progressive accumulation of B-cell lymphocytes that typically express CD19+, CD5+ and CD23+. The lymphocytes usually infiltrate the bone marrow, peripheral blood, lymph nodes, and spleen. The diagnosis is established by immunophenotyping circulating B-lymphocytes, and prognosis is defined by two staging systems (Rai and Binet) established by physical examination and blood counts, as well as by several biological and genetic markers. In this update, we present the recommendations from the Brazilian Group of Chronic Lymphocytic Leukemia for the diagnosis and treatment of chronic lymphocytic leukemia. The following recommendations are based on an extensive literature review with the aim of contributing to more uniform patient care in Brazil and possibly in other countries with a similar social-economic profile.

Diagnosis and treatment of chronic lymphocytic leukemia: recommendations from the Brazilian Group of Chronic Lymphocytic Leukemia.

Chronic lymphocytic leukemia is characterized by clonal proliferation and progressive accumulation of B-cell lymphocytes that typically express CD19+, CD5+ and CD23+. The lymphocytes usually infiltrate the bone marrow, peripheral blood, lymph nodes, and spleen. The diagnosis is established by immunophenotyping circulating B-lymphocytes, and prognosis is defined by two staging systems (Rai and Binet) established by physical examination and blood counts, as well as by several biological and genetic markers. In this update, we present the recommendations from the Brazilian Group of Chronic Lymphocytic Leukemia for the diagnosis and treatment of chronic lymphocytic leukemia. The following recommendations are based on an extensive literature review with the aim of contributing to more uniform patient care in Brazil and possibly in other countries with a similar social-economic profile.

Persistence of Yellow Fever vaccine-induced antibodies after cord blood stem cell transplant.

We report the case of a cord blood haematopoietic stem cell transplant recipient who was vaccinated for Yellow Fever (YF) 7 days before initiating chemotherapy and had persistent YF antibodies more than 3 years after vaccination. Since the stem cell donor was never exposed to wild YF or to the YF vaccine, and our patient was not exposed to YF or revaccinated, this finding strongly suggests the persistence of recipient immunity. We briefly discuss potential consequences of incomplete elimination of recipient's leukocytes following existing haematopoietic cancer treatments.

Low Counts of Plasmacytoid Dendritic Cells after Engraftment Are Associated with High Early Mortality after Allogeneic Stem Cell Transplantation.

Dendritic cells (DCs) are antigen-presenting cells that drive immune responses and tolerance and are divided in different subsets: myeloid DCs (mDCs: lineage-; HLA-DR+, 11c+), plasmacytoid dendritic cells (pDCs: HLA-DR+, CD123+), and monocyte-derived DCs (moDC: lineage-, 11c+, 16+). After hematopoietic stem cell transplantation (HSCT), low DC counts in the recipients' peripheral blood (PB) have been associated with worse outcomes, but the relevance of DC graft content remains unclear, and there are few data in the setting of unrelated donor HSCT. We evaluated the DC graft content and monitored DC recovery in PB from 111 HSCT recipients (median age, 17 years; range 1 to 74), who received bone marrow (46%), umbilical cord blood (32%), or PB (22%) from unrelated (81%) or related donors (19%). In 86 patients with sustained allogeneic recovery, patients with higher counts of all DC subsets (pDC, mDC, and moDC) 3 weeks after engraftment had lower incidence of nonrelapse mortality (NMR) and acute graft-versus-host disease (aGVHD) and better survival. pDC counts were associated with more striking results: patients with higher pDC counts had much lower incidences of NRM (3% versus 47%, P < .0001), lower incidence of aGVHD (24% versus 67%, P < .0001), and better overall survival (92% versus 45%, P < .0001). In contrast, higher pDC counts in the graft was associated with an increased risk of aGVHD (55% versus 26%, P = .02). Our results indicate that DC counts are closely correlated with HSCT outcomes and warrant further prospective evaluation and possible early therapeutic interventions to ameliorate severe aGVHD and decrease mortality.

Alternative donor hematopoietic stem cell transplantation for mature lymphoid malignancies after reduced-intensity conditioning regimen: similar outcomes with umbilical cord blood and unrelated donor peripheral blood.

We have reported encouraging results of unrelated cord blood transplantation for patients with lymphoid malignancies. Whether those outcomes are comparable to matched unrelated donor transplants remains to be defined. We studied 645 adult patients with mature lymphoid malignancies who received an allogeneic unrelated donor transplant using umbilical cord blood (n=104) or mobilized peripheral blood stem cells (n=541) after a reduced-intensity conditioning regimen. Unrelated cord blood recipients had more refractory disease. Median follow-up time was 30 months. Neutrophil engraftment (81% vs. 97%, respectively; P<0.0001) and chronic graft-versus-host disease (26% vs. 52%; P=0.0005) were less frequent after unrelated cord blood than after matched unrelated donor, whereas no differences were observed in grade II-IV acute graft-versus-host disease (29% vs. 32%), non-relapse mortality (29% vs. 28%), and relapse or progression (28% vs. 35%) at 36 months. There were also no significant differences in 2-year progression-free survival (43% vs. 58%, respectively) and overall survival (36% vs. 51%) at 36 months. In a multivariate analysis, no differences were observed in the outcomes between the two stem cell sources except for a higher risk of neutrophil engraftment (hazard ratio=2.12; P<0.0001) and chronic graft-versus-host disease (hazard ratio 2.10; P=0.0002) after matched unrelated donor transplant. In conclusion, there was no difference in final outcomes after transplantation between umbilical cord blood and matched unrelated donor transplant. Umbilical cord blood is a valuable alternative for patients with lymphoid malignancies lacking an HLA-matched donor, being associated with lower risk of chronic graft-versus-host disease.

Four hundred thirty consecutive pediatric living donor liver transplants: variables associated with posttransplant patient and graft survival.

The availability of living donors allows transplant teams to indicate living donor liver transplantation (LDLT) early in the course of liver disease before the occurrence of life-threatening complications. Late referral to transplant centers is still a problem and can compromise the success of the procedure. The aim of this study was to examine the perioperative factors associated with patient and graft survival for 430 consecutive pediatric LDLT procedures at Sirio-Libanes Hospital/A. C. Camargo Hospital (São Paulo, Brazil) between October 1995 and April 2011. The studied pretransplant variables included the following: recipient age and body weight, Pediatric End-Stage Liver Disease score, z score for height/age, bilirubin, albumin, international normalized ratio, hemoglobin, sodium, presence of ascites, and previous surgery. The analyzed technical aspects included the graft-to-recipient weight ratio and the use of vascular grafts for portal vein reconstruction. In addition, the occurrence of hepatic artery thrombosis (HAT), portal vein thrombosis (PVT), and biliary complications was also analyzed. The liver grafts included 348 left lateral segments, 5 monosegments, 51 left lobes, and 9 right lobes. In a univariate analysis, an age < 12 months, a low body weight (≤10 kg), malnutrition, hyperbilirubinemia, and HAT were associated with decreased patient and graft survival after LDLT. In a multivariate analysis, a body weight ≤ 10 kg and HAT were significantly associated with decreased patient and graft survival. The use of vascular grafts significantly increased the occurrence of PVT. In conclusion, a low body weight (≤10 kg) and the occurrence of HAT independently determined worse patient and graft survival in this large cohort of pediatric LDLT patients.

The role of transplantation in diffuse large B-cell lymphoma: the impact of rituximab plus chemotherapy in first-line and relapsed settings.

Rituximab has improved the prognosis of patients with diffuse large B-cell lymphoma, but a high proportion of patients with advanced disease will relapse or will fail to achieve a remission with front-line treatment. Salvage chemotherapy, followed by high-dose chemotherapy or radiation therapy and autologous stem cell transplantation, remains the best treatment option for such patients, especially those who retain chemosensitivity. Allogeneic transplantation is under investigation in this setting, often as a treatment for relapse after autologous transplantation. Treatment-related mortality due to graft-versus-host disease, preparative regimen toxicity, and poor immune recovery often limits its benefits. This article reviews the role of hematopoietic stem cell transplantation in the treatment of diffuse large B-cell lymphoma, the incorporation of rituximab, and avenues of clinical investigation in this rapidly evolving field.

Is there an impact of killer cell immunoglobulin-like receptors and KIR-ligand incompatibilities on outcomes after unrelated cord blood stem cell transplantation?

Donor killer cell immunoglobulin-like receptor (KIR) ligand incompatibility in the graft-versus-host direction is associated with decreased relapse incidence and improved disease-free survival after haploidentical and human leucocyte antigen (HLA)-mismatched unrelated, haematopoietic stem cell transplantation. However, review of all published studies of allogeneic HLA-matched or mismatched stem cell transplantation shows that the results on the relationship between donor-recipient KIR(-ligand) (in)compatibility and outcomes are highly variable, ranging from highly beneficial to detrimental. Reasons for these differences may include the methodology to determine KIR(-ligand) incompatibility, the disease distribution and the transplant protocol or donor type. Two retrospective studies on the effects of KIR-ligand incompatibility in unrelated cord blood transplantation (UCBT) for haematological malignancies have resulted in conflicting results. The Eurocord study showed a favourable effect of KIR-ligand mismatching on relapse incidence and leukaemia-free survival, whereas the Minneapolis study showed no effect on these end points and a detrimental effect on incidence of graft-versus-host disease (GvHD). In patients with non-malignant disorders, KIR-ligand (in)compatibility between donor and recipient was not associated with outcomes in a recent Eurocord analysis. Therefore, the role of natural killer (NK) cell alloreactivity in UCBT is far from clear. It is too early to use a donor-recipient KIR(-ligand) algorithm for selection of a cord blood donor.

[Paroxysmal nocturnal hemoglobinuria: from physiopathology to treatment]. / Hemoglobinúria paroxística noturna: da fisiopatologia ao tratamento.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disorder, an acquired chronic hemolytic anemia, often associated with recurrent nocturnal exacerbations, recurrent infections, neutropenia, thrombocytopenia, and episodes of venous thrombosis. Its clinical course is highly variable. It frequently arises in association with bone marrow failure, particularly aplastic anemia and myelodysplastic syndrome. It is also an acquired thrombophilia, presenting with a variety of venous thrombosis, mainly manifested with intra-abdominal thrombosis, here the major cause of mortality. The triad of hemolytic anemia, pancytopenia, and thrombosis makes a truly unique clinical syndrome of PNH, which was reclassified from a purely acquired hemolytic anemia to a hematopoietic stem cell mutation defect of the phosphatidyl inositol glycanclass-A gene. This mutation results in an early block in the synthesis of glycosylphosphatidylinositol (GPI) anchors, responsible for binding membrane functional proteins. Among these proteins are the complement inhibitors, especially CD55 and CD59, that play a key role in protecting blood cells from complement cascade attack. Therefore, in PNH occurs an increased susceptibility of red cells to complement, and consequently, hemolysis. We here review PNH physiopathology, clinical course, and treatment options, especially eculizumab, a humanized monoclonal antibody that blocks the activation of terminal complement at C5 and prevents formation of the terminal complement complex, the first effective drug therapy for PNH.

Venous thromboembolism and cancer: a systematic review.

Venous thromboembolism (VTE) is a serious and potentially fatal disorder, which is often associated with a significant impact on the quality of life and on the clinical outcome of cancer patients. The pathophysiology of the association between thrombosis and cancer is complex: malignancy is associated with a baseline hypercoagulable state due to many factors including release of inflammatory cytokines, activation of the clotting system, expression of hemostatic proteins on tumor cells, inhibition of natural anticoagulants, and impaired fibrinolysis. Several risk factors, related to the patient, the disease, and the therapeutic interventions, have been identified as contributing to the occurrence of VTE. There is convincing evidence to recommend the use of heparins or fondaparinux for prevention of VTE in selected cancer patients, and, especially in some particular types of malignancies and cancer treatments. Management of VTE in patients with cancer is more challenging and bleeding complications associated with the use of anticoagulants are significantly higher in cancer patients than in those without malignancy. Important issues that need to be considered in all cases are interference with anticancer therapy, inconvenience of treatment, and impact on quality of life.

Evaluation of hemostasis and endothelial function in patients with paroxysmal nocturnal hemoglobinuria receiving eculizumab.

BACKGROUND: Paroxysmal nocturnal hemoglobinuria (PNH) is associated with an increased risk of thrombosis through unknown mechanisms. DESIGN AND METHODS: We studied 23 patients with PNH, before and after five and 11 weeks of treatment with eculizumab. We examined markers of thrombin generation and reactional fibrinolysis (prothrombin fragment 1+2 (F1+2), D-dimers, and plasmin antiplasmin complexes (P-AP), and endothelial dysfunction tissue plasminogen activator (t-PA), plasminogen activator inhibitor (PAI-1), soluble thrombomodulin (sTM), intercellular adhesion molecule 1 (sICAM-1), vascular cell adhesion molecule (sVCAM-1), endothelial microparticles (EMPs), and tissue factor pathway inhibitor (TFPI). RESULTS: At baseline, vWF, sVCAM-1, the EMP count, and F1+2 and D-dimer levels were significantly elevated in the patients, including those with no history of clinical thrombosis. Treatment with eculizumab was associated with significant decreases in plasma markers of coagulation activation (F1+2, P=0.012, and D-dimers, P=0.01), and reactional fibrinolysis (P-AP, P=0.0002). Eculizumab treatment also significantly reduced plasma markers of endothelial cell activation (t-PA, P=0.0005, sVCAM-1, P<0.0001, and vWF, P=0.0047) and total (P=0.0008) and free (P=0.0013) TFPI plasma levels. CONCLUSIONS: Our results suggest a new understanding of the contribution of endothelial cell activation to the pathogenesis of thrombosis in PNH. The terminal complement inhibitor, eculizumab, induced a significant and sustained decrease in the activation of both the plasma hemostatic system and the vascular endothelium, likely contributing to the protective effect of eculizumab on thrombosis in this setting.