Serology-based therapeutic strategy in SARS-CoV-2-infected patients.

SARS-CoV-2 infection can be a life-threatening disease. The optimal treatment of patients is not yet standardized. We use a serology-based therapeutic strategy based on the presence of antibodies against the SARS-CoV-2 virus, in which patients with positive serology receive aggressive anti-inflammatory treatment with high-dose dexamethasone and/or tocilizumab and patients with negative serology receive early convalescent plasma therapy. We also analyze the immunological impact of this therapy in the recovery of T cells, B cells and NK cells during hospitalization in a COVID-19 infectious ward. Our results suggest that aggressive therapy with early administration of convalescent plasma and high-dose dexamethasone may be of benefit in patients with SARS-CoV-2 infection and might avoid progression of lung damage or need of admission in intensive care. This strategy did not impair immune responses against SARS-CoV-2, as 93% of the patients generated antibodies against the virus. Independently of previous immunological status of the patients, serology-guided therapy might benefit even patients with a high CIRS-G score, immunosuppressed or medically debilitated individuals and elderly patients. T cell disturbances were most frequent in patients who required high-dose dexamethasone, and B cell depletion was most frequent in patients who received tocilizumab. Early passive immunotherapy with convalescent plasma does not affect lymphoid recovery.

Maintenance therapy with ex vivo expanded lymphokine-activated killer cells and rituximab in patients with follicular lymphoma is safe and may delay disease progression.

Anti-cluster of differentiation 20 (CD20) monoclonal antibodies (mAbs) have shown promise in follicular lymphoma (FL) as post-induction therapy, by enhancing antibody-dependent cellular cytotoxicity (ADCC). However, cytotoxic cells are reduced after this treatment. We hypothesised that ex vivo expanded lymphokine-activated killer (LAK) cells administered to FL-remission patients are safe and improve anti-CD20 efficacy. This open, prospective, phase II, single-arm study assessed safety and efficacy of ex vivo expanded LAK cells in 20 FL-remission patients following rituximab maintenance. Mononuclear cells were obtained in odd rituximab cycles and stimulated with interleukin 2 (IL-2) for 8 weeks, after which >5 × 108 LAK cells were injected. Patients were followed-up for 5 years. At the end of maintenance, peripheral blood cells phenotype had not changed markedly. Natural killer, LAK and ADCC activities of mononuclear cells increased significantly after recombinant human IL-2 (rhIL-2) stimulation in all cycles. Rituximab significantly enhanced cytotoxic activity. No patients discontinued treatment. There were no treatment-related serious adverse events. Three patients had progressed by the end of follow-up. After a median (interquartile range) follow-up of 59.4 (43.8-70.9) months, 85% of patients remained progression free. No deaths occurred. Quality-of-life improved throughout the study. Post-induction LAK cells with rituximab seem safe in the long term. Larger studies are warranted to confirm efficacy.

Full donor chimerism without graft-versus-host disease: the key factor for maximum benefit of pre-emptive donor lymphocyte infusions (pDLI).

Compared to standard-conditioned regimens, reduced-intensity conditioning and T-cell depletion deliver lower transplant-related mortality and decreased graft-vs-host disease after allogeneic hematopoietic stem-cell transplantation. These advantages may however be mitigated by increased relapse rates and delays in achievement of full donor chimerism (FDC). Pre-emptive donor lymphocyte infusions (pDLI) facilitate the conversion of mixed (MDC) to FDC. However, there is a lack of published data on the risk/benefit analysis of this intervention. We performed a retrospective analysis of 119 patients who received 276 pDLI doses for falling CD3 chimerism, CD3 < 50% or mixed XX/XY karyotype. 71/119(60%) Patients achieved FDC, with only one reverting to MDC. Cumulative incidence (CI) of relapse at 5 years was significantly lower in the FDC group (16.0 vs 41.4%, p < 0.001). Those patients who achieved FDC had improved EFS (p < 0.001) and OS (p < 0.001). Interestingly, patients with FDC who developed DLI-induced graft-vs-host disease (GvHD) showed a similar outcome to those with MDC. The majority of patients who receive pDLI convert to FDC and retain that status. Achievement of FDC after pDLI impacts on survival, and those patients who achieve FDC without GvHD, experience maximum clinical benefit. Strategies to minimise DLI-induced GvHD should be considered to maximise the therapeutic potential of this intervention.

Battle of Thermopylae: 300 Spartans (natural killer cells plus obinutuzumab) versus the immortal warriors (chronic lymphocytic leukemia cells) of Xerxes' army.

AIM: To analyze the effects of subcutaneous or intravenous rituximab + lymphokine-activated killer cells, obinutuzumab or ibrutinib on natural killer (NK) cell levels in chronic lymphocytic leukemia and follicular lymphoma patients. PATIENTS & METHODS: The distribution of peripheral blood NK cells of 31 patients was analyzed by flow cytometry. RESULTS: We detected a decrease of NK cells in peripheral blood below normal range after obinutuzumab treatment. During maintenance treatment with subcutaneous rituximab, an NK cell reduction was less pronounced than after intravenous rituximab treatment, despite lymphokine-activated killer cell infusions. CONCLUSION: After one dose of obinutuzumab, each NK cell in peripheral blood destroys 25 leukemic cells.

Obinutuzumab induces depletion of NK cells in patients with chronic lymphocytic leukemia.

AIM: Obinutuzumab induces NK cell antibody-dependent cell-mediated cytotoxicity. OBJECTIVE: Investigate the effects on the human immune system after obinutuzumab monotherapy treatment in patients with chronic lymphocytic leukemia (CLL). METHOD: To evaluate these effects, we analyzed the distribution of CD4+ and CD8+ T cells, B cells and NK cells in the peripheral blood of eight CLL patients who were treated with obinutuzumab in monotherapy. The distribution of peripheral blood lymphocytes was examined prior to each dose of obinutuzumab and 24-72 h after the first 1000 mg complete dose (cycle 1 day 2). We also repeated measurements 3 months after the last obinutuzumab dose. In total we obtained ten samples of each patient. Analyses were performed by flow cytometry with monoclonal antibodies against CD3, CD4, CD8, CD19 and CD56+. RESULTS: After the first 1000 mg obinutuzumab infusion (cycle 1 day 2), CD4+ T cells and CD8+ T cells were significantly decreased in peripheral blood compared with prior to therapy. This reduction in the CD4+ T cells persisted after six cycles of obinutuzumab (1235 cells/µl basal vs 662 cells/µl after six cycles, p ≤ 0.05), but not in CD8+ T cells (987 cells/µl basal vs 837 cells/µl after six cycles). Interestingly, we also observed significant differences in the NK cell compartment after the first 1000 mg drug infusion (490 cells/µl basal vs 23 cells/µl postinfusion, p ≤ 0.05), and after cycle 6 (490 cells/µl basal vs 149 cells/µl after six cycles, p ≤ 0.05). CONCLUSION: Obinutuzumab induces depletion of NK cells in CLL.

Follicular lymphoma: in vitro effects of combining lymphokine-activated killer (LAK) cell-induced cytotoxicity and rituximab- and obinutuzumab-dependent cellular cytotoxicity (ADCC) activity.

Follicular lymphoma (FL) is a disease of paradoxes-incurable but with a long natural history. We hypothesized that a combination of lymphokine-activated killer (LAK) cells and monoclonal antibodies might provide a robust synergistic treatment and tested this hypothesis in a phase II clinical trial (NCT01329354). In this trial, in addition to R-CHOP, we alternated the administration of only rituximab with rituximab and autologous LAK cells that were expanded ex vivo. Our objective was to determine the in vitro capability of LAK cells generated from FL patients to produce cytotoxicity against tumor cell lines and to determine rituximab- and obinutuzumab-induced cytotoxicity via antibody-dependent cellular cytotoxicity (ADCC) activity. We analyzed the LAK cell-induced cytotoxicity and rituximab (R)- and obinutuzumab (GA101)-induced ADCC activity. We show that LAK cells generated from FL patients induce cytotoxicity against tumor cell lines. R and GA101 enhance cytolysis through ADCC activity of LAK cells. Impaired LAK cell cytotoxicity and ADCC activity were detected in 50 % of patients. Percentage of NK cells in LAK infusions were correlated with the R- and GA101-induced ADCC. Our results indicate that the combination of R or GA101 and LAK cells should be an option as frontline maintenance therapy in patients with FL.

The top ten clues to understand the origin of chronic lymphocytic leukemia (CLL).

The fundamental task of the immune system is to protect the individual from infectious organisms without serious injury to self. The essence of acquired immunity is molecular self/non self discrimination. Chronic lymphocytic leukemia is characterized by a global failure of immune system that begins with the failure of immunological tolerance mechanisms (autoimmunity) and finish with the incapacity to response to non-self antigens (immunodeficiency). Immunological tolerance mechanisms are involved in chronic lymphocytic leukemia (CLL) development. During B cell development some self-reactive B cells acquire a special BCR that recognize their own BCR. This self-autoantibody-self BCR interaction promotes survival, differentiation and proliferation of self-reactive B cells. Continuous self-autoantibody-self BCR interaction cross-linking induces an increased rate of surface BCR elimination, CD5+ expression, receptor editing and anergy. Unfortunately, some times this mechanisms increase genomic instability and promote additional genetic damage that immortalize self-reactive B cells and convert them into CLL like clones with the capability of clonal evolution and transformed CLL B cells. This review summarizes the immunological effects of continuous self-autoantibody-self BCR interaction cross-linking in the surface of self-reactive B cells and their role in CLL development.

[Venous thromboembolism in patients with cancer]. / Tromboembolia venosa en pacientes con cáncer.

The association between neoplastic diseases and venous thromboembolism (VTE) is known since long time ago. The nature of this association is bidirectional. On one hand, cancer increases the incidence of venous thrombosis and, on the other hand, the hemostatic system does play a key role in the tumorigenesis process. However, despite recent advances in the field, prophylaxis and treatment of VTE in cancer patients is still a challenge, due to the complexity of this type of patients. This review is focused on some important points regarding management of VTE in cancer patients such as physiopathology, epidemiology, search for hidden malignancy, prognostic impact, prophylaxis in the medical and surgical setting, or initial and long-term treatment.

[New strategies in the secondary prevention of relapsing venous thromboembolism]. / Nuevas estrategias en la prevención secundaria de la recurrencia de la tromboembolia venosa.

Treatment of venous thromboembolism includes an acute phase treatment, followed by a secondary prophylaxis period. Oral anticoagulants have been the usual treatment for secondary prophylaxis of VTE. However, some issues regarding oral anticoagulant treatment (OAT), such as length or intensity are controversial. The appropriate duration of OAT depends on the individual risk of both, thrombotic recurrence and hemorrhagic complications. Recent studies suggest that full-dose OAT is more effective and as safe as low-dose OAT. On the other hand, low-molecular-weight heparins are an alternative for the secondary prophylaxis of VTE, being the treatment of choice in patients with cancer or during pregnancy. Probably, new antithrombotic drugs such as idraparinux or ximelagatran, will be considered as another therapeutic alternative in a near future.

[Decreased transfusion requirements in acquired severe bleeding with recombinant activated factor VII]. / Reducción de las necesidades transfusionales en hemorragias adquiridas graves mediante factor VII activo recombinante.

BACKGROUND AND OBJECTIVE: Patients with severe and persistent bleeding have high mortality rates despite standard therapy, including blood transfusion support. The aim of the study was to evaluate the role of rFVIIa in the management of severe bleeding, refractory to other treatments. PATIENTS AND METHODS: All cases with severe bleeding and failure of previous treatments who received rFVIIa (n = 21) at one single center were retrospectively included in the study. RESULTS: A response after the administration of rFVIIa was reported in 16 of 21 patients (76.2%). Hemorrhage was completely halted in 14 cases, and 12 patients (57.1%) were alive 30 days after treatment. The use of rFVIIa was associated with a normalization of coagulation tests, especially the prothrombin time (p = 0.001). A marked reduction in blood requirements, red cell units (p = 0.003), fresh frozen plasma (p = 0.009) and platelets (p = 0.017) was also observed. CONCLUSIONS: rFVIIa may have an important role in the achievement of an adequate hemostasis and reduces blood requirements in patients with severe bleeding, emerging as an alternative to blood transfusion.