Consuelo del Cañizo

Immunomodulatory effect of 5-azacytidine (5-azaC): potential role in the transplantation setting

Cytokine genes are targets of multiple epigenetic mechanisms in T lymphocytes. 5-azacytidine (5-azaC) is a nucleoside-based DNA methyltransferase inhibitor that induces demethylation and gene reactivation. In the current study, we analyzed the effect of 5-azaC in T-cell function and observed that 5-azaC inhibits T-cell proliferation and activation, blocking cell cycle in the G(0) to G(1) phase and decreasing the production of proinflammatory cytokines such as tumor necrosis factor-alpha and interferon-gamma. This effect was not attributable to a proapoptotic effect of the drug but to the down-regulation of genes involved in T-cell cycle progression and activation such as CCNG2, MTCP1, CD58, and ADK and up-regulation of genes that induce cell-growth arrest, such as DCUN1D2, U2AF2, GADD45B, or p53. A longer exposure to the drug leads to demethylation of FOXP3 promoter, overexpression of FOXP3, and expansion of regulatory T cells. Finally, the administration of 5-azaC after transplantation prevented the development of graft-versus-host disease, leading to a significant increase in survival in a fully mismatched bone marrow transplantation mouse model. In conclusion, the current study shows the effect of 5-azaC in T lymphocytes and illustrates its role in the allogeneic transplantation setting as an immunomodulatory drug, describing new pathways that must be explored to prevent graft-versus-host disease.

Chimerism and minimal residual disease monitoring after reduced intensity conditioning (RIC) allogeneic transplantation

Since graft-versus-leukemia (GVL) is the main weapon for disease eradication after reduced intensity conditioning (RIC) allogeneic SCT, the availability of sensitive and specific techniques to monitor changes in tumor load after transplant are especially helpful. These minimal residual disease techniques would allow an early intervention in the event of low tumor burden, for which immunotherapy is highly effective. Some authors have found an association between persistence of MRD, mixed chimerism and risk of relapse. Nevertheless, data from the literature remain contradictory and further correlations should be established, especially in RIC transplants. In this study we have analyzed the impact of MRD and chimerism monitoring on the outcome of 34 patients undergoing RIC allogeneic SCT who were considered poor candidates for conventional transplantation due to advanced age or other concurrent medical conditions. At day +100 25 (75%) patients reached complete remission (CR), there were five (15%) partial responses and three patients progressed. Incidence of grade 2–4 aGVHD and extensive cGVHD were 35% and 58%, respectively. Sixteen percent of patients developing aGVHD relapsed as compared to 47% in those without aGVHD (P = 0.03) and also 10% of patients developing cGVHD relapsed as compared to 50% relapses in those without cGHVD (P = 0.03). Four patients (12%) died due to early (n = 1) and late (n = 3) transplant-related mortality. After a median follow-up of 15 months, 24 out of the 34 patients remain alive. Projected overall survival and disease-free survival at 3 years are 68% and 63%, respectively. Early chimerism analysis showed 67% of patients with complete chimerism (CC) in bone marrow (BM), 86% in peripheral blood (PB), 89% in granulocytes and 68% in T lymphocytes. On day +100, these figures were 68%, 79%, 90% and 73%, respectively, and on day +180 there were 83% patients with CC in BM, 100% in PB, 100% in granulocytes and 100% in T lymphocytes. We observed a trend to a higher incidence of relapse in patients with mixed chimerism (MC) as compared to patients with CC. MRD monitoring by flow cytometry and/or RT-PCR analysis was performed in 23 patients. MRD assessment on days +21 to +56 after transplant allowed identification of patients at risk of relapse. In this sense, seven out of 12 patients (58.3%) who had positive MRD on days +21 to +56 relapsed as compared to none out of 11 patients who had negative MRD (P = 0.002). Of the seven patients with criteria to monitor MRD who relapsed after transplant, all but one remained MRD positive until relapse. By contrast, 10 patients remained MRD negative and all of them are in continuous CR. In nine additional patients, persistence of MRD or mixed chimerism was observed after transplant and withdrawal of cyclosporin with or without DLI was performed. Only two out of these nine patients relapsed. MRD clearance was preceded by CC and GVHD. In conclusion, in our study we found that RIC allogeneic transplantation can be used in patients considered poor candidates for conventional transplantation due to advanced age or other concurrent medical conditions with both low toxicity and low transplant-related mortality. Simultaneous studies of both chimerism and MRD are a useful tool in order to predict risk of relapse in patients undergoing RIC transplants and so can be helpful for individualizing treatment strategies after transplant.

Minimal number of circulating CD34+ cells to ensure successful leukapheresis and engraftment in autologous peripheral blood progenitor cell transplantation

BACKGROUND: The number of peripheral blood (PB) CD34+ cells has been widely used to monitor the timing of leukapheresis for autologous transplantation. However, no cutoff value for CD34+ cells in PB has been defined as a guideline for the identification of patients in whom the harvest would be effective and those in whom there was a high probability of failure.

Reduced-intensity conditioning allogeneic transplantation is associated with a high incidence of extramedullary relapses in multiple myeloma patients

Reduced-intensity conditioning allogeneic transplantation is associated with a high incidence of extramedullary relapses in multiple myeloma patients

Prognostic Factors of Chronic Graft-versus-Host Disease Following Allogeneic Peripheral Blood Stem Cell Transplantation: The National Institutes Health Scale Plus the Type of Onset Can Predict Survival Rates and the Duration of Immunosuppressive Therapy

Several grading systems have been developed in the bone marrow transplantation setting in attempts to predict survival in patients with chronic graft-versus-host disease (cGVHD). In this study, we evaluated the prognostic value of the National Institutes of Health (NIH) scoring system and investigated for any additional prognostic factors in a series of 171 patients undergoing peripheral blood stem cell transplantation (PBSCT) from matched related donors. The cumulative incidence of cGVHD was 70%; cumulative incidences of mild, moderate, and severe cGVHD were 29%, 42% and 28%, respectively. Overall, 68% of patients were free from immunosuppression 5 years after transplantation. Absence of previous acute GVHD (aGVHD; hazard ratio [HR] = 2; P = .004) and mild cGVHD (HR = 4.2; P = .007) increased the probability of being off immunosuppressive treatment by the last follow-up. Overall survival (OS) at 5 years was 52%. Severe cGVHD, according to the NIH scoring system (HR = 13.27; P = .001) adversely influenced outcome, whereas de novo onset (HR = 0.094; P = .003) had a more favorable impact on survival. The combination of both variables allowed us to identify 4 different subgroups of patients with OS of 82%, 70%, 50%, and 25%. Our findings indicate that the NIH scoring system has some prognostic value in patients undergoing PBSCT and, together with the type of onset, must be considered to predict the possible outcome of patients who develop cGVHD.

Cidofovir treatment of human polyomavirus-associated acute haemorrhagic cystitis

Abstract: We report the case of an 18‐year‐old patient who received an allogeneic bone marrow transplant from an HLA‐identical unrelated donor for a Ph+ acute lymphoblastic leukemia, in his third complete remission. Cyclophosphamide and busulfan were used as conditioning treatment. Acute graft‐versus‐host disease developed on day +9, and the response to adequate treatment (steroids) was favourable. On day +45 the patient developed an acute severe haemorhragic cystitis, and BK polyomavirus was demonstrated in urine samples using electron microscopy and polymerase chain reaction. Urinary symptoms did not improve in spite of palliative treatment, but a response was evident after 2 weeks of cidofovir treatment.

Antibiotic prophylaxis with meropenem after allogeneic stem cell transplantation

Summary:In the present study, we analyze the efficacy of prophylaxis with meropenem in patients receiving a matched related donor allogeneic transplant. In total, 38 patients were sequentially treated with meropenem starting on the day of the first febrile episode (n=17, group A) vs prophylactic meropenem starting on the first day with <500/mm3 granulocytes (n=21, group B), and maintained until resolution of fever or after granulocyte count >500/mm3. Of these, 16 (94%) patients in group A developed fever as compared to 16 (76%) in group B (P=0.02). While only one patient in group A did not require first-line antibiotherapy, there were seven (33%) in group B who did not require it (P=0.01) since fever lasted less than 72 h. In addition, 52% patients in group B did not require second-line antibiotics as compared to 11% among patients in group A (P=0.04). In multivariate analysis prophylaxis with meropenem (HR=2.83, 95% CI (1–8.02); P=0.04) and disease status at transplant (HR for early stage=0.15, 95% CI (0.04–0.62); P=0.04) significantly influenced the development of fever. In conclusion, the current pilot study suggests that the use of prophylaxis with meropenem during the period of neutropenia in patients undergoing allogeneic transplantation favorably affects the morbidity of the procedure by reducing febrile episodes.

Cerebral toxoplasmosis and Guillain-Barré syndrome after allogeneic peripheral stem cell transplantation.

We report an unusual case of cerebral toxoplasmosis associated with Guillain‐Barré syndrome ( GBS) in a 25‐year‐old patient diagnosed with chronic myelogenous leukaemia ( CML), who underwent a mismatched allogeneic peripheral stem cell transplantation ( PSCT). On day +83 he started with fever, and 7 days later tremor, muscular weakness, diplopia, dysarthria, respiratory difficulty, and universal arreflexia appeared, compatible with GBS. As the patient had a positive cytomegalovirus ( CMV) antigenemia, this was the aetiology suspected for his neurologic findings, but specific treatment failed to improve his clinical situation, and he died on day +123. Necropsy demonstrated cerebral toxoplasmosis and axonal degeneration of nerve roots compatible with the axonal form of GBS. Interestingly, the polymerase chain reaction ( PCR) signal for Toxoplasma gondii in two different cerebrospinal fluid ( CSF) samples had been negative. In addition, this case showed unique magnetic resonance imaging ( MRI) abnormalities. We conclude that a negative PCR on CSF cannot exclude toxoplasmosis in a transplant patient, and we emphasise the importance of considering Toxoplasma as an aetiology of fever and neurological symptoms in the transplant setting.

Allogeneic peripheral stem cell transplantation in a case of hereditary sideroblastic anaemia

We report on a case of pyridoxine refractory hereditary sideroblastic anaemia (HSA) in a 19‐year‐old man who underwent peripheral blood stem cell transplantation (PBSCT) from his HLA‐identical brother. By using short tandem repeat polymorphism, 100% donor cells were observed in peripheral blood on day +21; bone marrow showed mixed chimaerism from day +21 to day +221, when 100% cells of donor origin were observed. The patient developed extensive chronic graft‐versus‐host disease with favourable response to treatment. When the haemoglobin range was normal, a programme of phlebotomies reduced serum ferritin levels. Three years after transplantation, the patient has an ECOG rating of 0, with completely normal haemoglobin values (15 g/dl). To our knowledge, this is the first PBSCT reported in a case of hereditary sideroblastic anaemia.

The novel combination of sirolimus and bortezomib prevents graft-versus-host disease but maintains the graft-versus-leukemia effect after allogeneic transplantation.

Background We have previously shown that bortezomib induces a depletion of alloreactive T cells and allows the expansion of T cells with suppressive properties. In the current study, we analyzed the potential synergistic effect of bortezomib in conjunction with sirolimus in order to reduce-graft-versus-host disease without hampering graft-versus-leukemia effect in the allogeneic transplant setting. Design and Methods We evaluated the effect of sirolimus, bortezomib or the combination of both in the proliferation and activation of in vitro stimulated T lymphocytes. Pathways involved in this synergy were also analyzed using Western blot assays. Finally, BALB/c mice receiving C57BL/6 allogeneic donor bone marrow with splenocytes were used to measure in vivo the effect of this novel combination on the risk of graft-versus-host disease. Results The combination of both drugs synergistically inhibited both activation and proliferation of stimulated T cells. Also, the production of Th1 cytokines (IFN γ, IL-2 and TNF) was significantly inhibited. This effect was due, at least in part, to the inhibition of Erk and Akt phosphorylation. In vivo, the combination reduced the risk of graft-versus-host disease without hampering graft-versus-leukemia effect, as shown in mice receiving graft-versus-host disease prophylaxis with sirolimus plus bortezomib being infused with tumor WEHI cells plus C57BL/6 donor BM and splenocytes. Conclusions The current study reveals a synergistic effect of the combination sirolimus and bortezomib to prevent graft-versus-host disease while maintaining the graft-versus-leukemia effect.