Veronica Valle

Polymorphism of the complement receptor 1 gene correlates with the hematologic response to eculizumab in patients with paroxysmal nocturnal hemoglobinuria

Complement blockade by eculizumab is clinically effective in hemolytic paroxysmal nocturnal hemoglobinuria. However, the response is variable and some patients remain dependent on red blood cell transfusions. In 72 patients with hemolytic paroxysmal nocturnal hemoglobinuria on eculizumab we tested the hypothesis that response may depend on genetic polymorphisms of complement-related genes. We found no correlation between the complement component C3 genotypes and the need for blood transfusions. On the other hand, we found a significant correlation with the HindIII polymorphism of a complement regulatory gene, the complement receptor 1 (CR1) gene. At this locus two co-dominant alleles are known, of which H (common) is associated with high expression, whereas L (rare) is associated with low expression of CR1 on red blood cells. Patients who still needed blood transfusion on eculizumab accounted for 18% of the H/H homozygotes, 33% of the H/L heterozygotes and 68% of the L/L homozygotes (P=0.016). Thus, patients with paroxysmal nocturnal hemoglobinuria who have the L/L genotype are seven times more likely to be sub-optimal responders to eculizumab. Both in vitro and in vivo we found that the CR1 HindIII genotype correlates with the abundance of paroxysmal nocturnal hemoglobinuria red cells that have bound C3, and with the kinetics of C3 binding. These results are consistent with the notion that by affecting C3 binding the CR1 genotype influences the response to eculizumab treatment, and this emerges as a novel example of pharmacogenetics.

Second-generation tyrosine kinase inhibitors before allogeneic stem cell transplantation in patients with chronic myeloid leukemia resistant to imatinib.

Philadelphia-positive chronic myeloid leukemia (Ph+ CML) patients who are resistant to imatinib are commonly treated with second-generation tyrosine kinase inhibitors (TKIs). Limited data exist on the possible effects of these drugs on subsequent allogeneic hematopoietic stem cell transplantation (allo-HSCT).The outcome of 12 imatinib-resistant CML patients treated with dasatinib or nilotinib or both before allo-HSCT, was retrospectively analyzed. Patients were treated with second-generation TKIs for 1-17 months (median, 8). At the time of transplant, 3 patients were in complete cytogenetic response (CCgR), 3 patients in partial cytogenetic response (PCgR) and 6 patients were in less than PCgR. Donors were HLA-matched related in 4 cases and unrelated in 8 cases. Stem cell source was peripheral blood, bone marrow or cord blood in 6, 5 and 1 cases, respectively. All patients engrafted successfully and all but one achieved a full donor chimerism. Three patients experienced acute and chronic graft-versus-host disease. No cases of transplant-related mortality were recorded. Best response to allo-HSCT was complete molecular response (CMR) in 9 patients, major molecular response (MMR) in 1 patient and CCgR in 2 patients. Median follow-up was 16.5 months. At the last evaluation, 9 patients were in continuous CMR and 1 patient was in MMR; 2 patients had died of disease progression. Second-generation TKIs given before allo-HSCT do not negatively affect transplant engraftment and response rate, nor increases transplant-related toxicity.

B-Cell Concentration in the Apheretic Product Predicts Acute Graft-Versus-Host Disease and Treatment-Related Mortality of Allogeneic Peripheral Blood Stem Cell Transplantation

Background. The influence of the graft composition on the clinical outcome after allogeneic peripheral blood stem cell (PBSC) transplantation is not well established. Methods. The cellular composition of the apheretic products obtained from 63 human leukocyte antigen–identical siblings was prospectively correlated with the outcome of patients with hematological malignancies undergoing an allogeneic PBSC transplant after myeloablative conditioning. The concentration of nuclear, mononuclear, CD34+, T-cell subsets, B cells, and natural killer cells in the graft has been analyzed. Results. In univariate analysis, acute graft-versus-host disease (GVHD) correlated with the disease (P=0.002), with the phase of disease at transplant (P=0.01), and with the number of CD20+ cells infused (P=0.05). In multivariate analysis, a dose of CD20+ cells in the graft higher than the median dose remained the only factor negatively affecting the incidence of acute GVHD (P=0.01; 95% confidence interval [CI]: 0.12–0.78). In univariate analysis, treatment-related mortality (TRM) correlated with the disease (P=0.04) and was negatively affected by a dose of infused B cells greater than the median value (28% versus 50%; P=0.02). In multivariate analysis, TRM was close to statistical correlation with the dose of CD20+ cells (P=0.06; 95% CI: 0.02–1.05). No other clinical parameter was influenced by the composition of the graft. Conclusions. Our results suggest that the concentration of B cells in the apheretic product may predict the incidence of acute GVHD and TRM in patients undergoing an allogeneic PBSC transplantation and open the way to the new preventive and therapeutic strategies for the management of GVHD.

The immune reconstitution after an allogeneic stem cell transplant correlates with the risk of graft-versus-host disease and cytomegalovirus infection

Aim of the study was to correlate the clinical outcome of eighteen patients who have undergone an allogeneic stem cell transplant (SCT) with the concentration in the peripheral blood (PB) of lymphocyte subpopulations evaluated at 1 year from transplant. The occurrence of acute GVHD and CMV infection correlated with the concentration of Tregs in the PB; CMV infection also correlated with the content of NK cells. The obtained results document that the concentration of Tregs in the PB after an allogeneic SCT may protect from GVHD and from CMV infection; the potential anti-viral role of NK cells is confirmed.

Early onset of posterior reversible encephalopathy syndrome (PRES) during Cyclosporine-A infusion.

Posterior reversible encephalopathy syndrome (PRES) is an ncommon but distinctive clinico-radiologic entity characterized y headache, seizures, visual disturbance and altered mental funcion associated with reversible white matter edema affecting the osterior parietal and occipital lobes of the brain [1,2]. Etioloies of PRES include hypertension, cytotoxic medications, sepsis, reeclampsia or eclampsia and multiple organ dysfunction [3]. In he context of allogeneic stem cell transplantation (HSCT), severe eurotoxicity is reported in a substantial number of patients, being yclosporine-A (CSA) most frequently indicated as the medication esponsible for the neurological alterations [4–6].

Management of the 2009 A/H1N1 Influenza Pandemic in Patients with Hematologic Diseases: A Prospective Experience at an Italian Center

Data derived from epidemiologic surveillance adopted at our center in hematologic and stem cell transplant patients during the 2009 influenza A (H1N1)v pandemic are reported. Of the 52 patients with influenza-like disease we observed, 37 underwent a real-time PCR evaluation and 21 had a confirmed diagnosis. Of the RT-PCR-confirmed cases, 23.8% were children (age <18 years) and 9.5% were >65 years; 47.6% presented with a pulmonary infiltrate and 33.3% with respiratory failure. Pulmonary involvement was observed more frequently in patients with comorbidities. All patients received a course of oseltamivir therapy starting an average of 1 day (range <1–2) after the onset of symptoms. No patient was transferred to the intensive care unit. The viral disease had a generally favorable outcome despite the high frequency of pulmonary involvement. A prompt clinical evaluation with an early antiviral and supportive therapy may have played a beneficial role in the outcome.

Clinical responses in allografted acute leukaemia patients with resistant disease using a combined chemo‐immunotherapeutic treatment strategy

Induction of a graft-versus-leukaemia (GVL) immunological response is the key element for the success of the allogeneic haematopoietic stem cell transplant (SCT) procedure. This was first shown by the durable remissions induced by donor lymphocyte infusion (DLI) in relapsed chronic myeloid leukaemia (CML) patients (Kolb et al, 1995). For patients affected by non-CML haematological malignancies, however, this immunological approach is not always successful (Collins et al, 1997; Dermime et al, 1997). Different strategies have been conceived to overcome tumour resistance to donor lymphocytes. Chemotherapy is particularly attractive for both its cytoreductive and immune-potentiating activities (Emens et al, 2001), including provision of lymphoid space, elimination of host anti-donor immune reactivity, suppression of regulatory T cells and induction of activating cytokines (Klebanoff et al, 2005; Rapoport et al, 2005). Animal models of tumour-bearing mice demonstrated that the serum peak concentrations of activating cytokines and growth factors was reached 48 h after a cyclophosphamide-based treatment (Proietti et al, 1998; Bracci et al, 2007). In humans, it has been reported that a fully lymphodepleting chemotherapeutic treatment prior to DLI induces a significant increment of high grade acute graft-versushost disease (GVHD) (Miller et al, 2007), suggesting the possibility of enhancing the anti-tumour efficacy of donor lymphocytes. The present study aimed to analyse the immunological and clinical effects of a chemo-immunotherapeutic treatment strategy consisting of chemotherapy followed 48 h later by DLI in allografted acute leukaemia patients. Four patients with acute myeloid leukaemia (AML) that evolved from a myelodysplastic syndrome (MDS) and two