Haploidentical transplantation in high-risk pediatric leukemia: A retrospective comparative analysis on behalf of the Spanish working Group for bone marrow transplantation in children (GETMON) and the Spanish Grupo for hematopoietic transplantation (GETH)

A total of 192 pediatric patients, median age 8.6 years, with high-risk hematological malignancies, underwent haploidentical stem cell transplantation (haplo-HSCT) using post-transplantation cyclophosphamide (PT-Cy), or ex vivo T cell-depleted (TCD) graft platforms, from January 1999 to December 2016 in 10 centers in Spain. Some 41 patients received an unmanipulated graft followed by PT-Cy for graft-vs-host disease (GvHD) prophylaxis. A total of 151 patients were transplanted with CD3-depleted peripheral blood stem cells (PBSCs) by either CD34⁺ selection, CD3⁺CD19⁺ depletion, TCRαβ⁺CD19⁺ depletion or CD45RA⁺ depletion, added to CD34⁺ selection for GvHD prophylaxis. The PBSCs were the only source in patients following ex vivo TCD haplo-HSCT; bone marrow was the source in 9 of 41 patients following PT-CY haplo-HSCT. Engraftment was achieved in 91.3% of cases. A donor younger than 30 years, and the development of chronic GvHD were positive factors influencing survival, whereas positive minimal residual disease (MRD) before transplant and lymphoid disease were negative factors. The probability of relapse increased with lymphoid malignancies, a donor killer-cell immunoglobulin-like receptor (KIR) haplotype A and positive MRD pretransplant. No difference was found in overall survival, disease-free survival or relapse incidence between the two platforms. Relapse is still of concern in both platforms, and it should be the focus of future efforts. In conclusion, both platforms for haplo-HSCT were effective and could be utilized depending on the comfort level of the center.     

A comparative effectiveness study of lipegfilgrastim in multiple myeloma patients after high dose melphalan and autologous stem cell transplant

G-CSF administration after high-dose chemotherapy and autologous stem cell transplantation (ASCT) has been shown to expedite neutrophil recovery. Several studies comparing filgrastim and pegfilgrastim in the post-ASCT setting concluded that the two are at least equally effective. Lipegfilgrastim (LIP) is a new long-acting, once-per-cycle G-CSF. This multicentric, prospective study aimed to describe the use of LIP in multiple myeloma patients receiving high-dose melphalan and autologous stem cell transplantation (ASCT) and compare LIP with historic controls of patients who received short-acting agent (filgrastim [FIL]). Overall, 125 patients with a median age of 60 years received G-CSF after ASCT (80 patients LIP on day 1 post-ASCT and 45 patients FIL on day 5 post-ASCT). The median duration of grade 4 neutropenia (absolute neutrophil count [ANC] < 0.5 × 10 [9]/L) was 5 days in both LIP and FIL groups, whereas the median number of days to reach ANC ≥ 0.5 × 10 [9]/L was 10% lower in the LIP than in the FIL group (10 vs 11 days), respectively. Male sex was significantly associated with a faster ANC ≥ 0.5 × 10 [9] L response (p = 0.015). The incidence of FN was significantly lower in the LIP than in the FIL group (29% vs 49%, respectively, p = 0.024). The days to discharge after ASCT infusion were greater in patients with FN (p < 0.001). The study indicates that LIP had a shorter time to ANC recovery and is more effective than FIL for the prevention of FN in the ASCT setting.     

The impact of the prevention strategies on the indirect effects of CMV infection in solid organ transplant recipients

Transplant recipients receiving immunosuppressive therapy are at increased risk of active cytomegalovirus (CMV) infection and disease. Without appropriate prophylaxis, as many as 80% of solid organ transplant recipients may experience CMV infection. In addition to the direct effects of CMV, infection may be associated with a range of indirect effects, including an increase in risk of other infections, as well as a higher incidence of rejection, graft loss and death. The indirect effects of CMV infection can vary depending on the transplanted organ. For example, CMV-infected kidney transplant recipients may be at increased risk of cardiovascular disease and diabetes, while CMV infection in liver transplant recipients may potentiate hepatitis C infection and increase the risk of post-transplant lymphoproliferative disease. Indirect effects result from a number of pathological processes, including immune modulation and immunosuppression, generation of cytotoxic, pro-inflammatory responses, and smooth muscle proliferation. Prophylactic treatment with antiviral medication can reduce the risk of CMV disease, thereby improving graft survival and overall outcomes, particularly in kidney and heart transplant recipients. Antiviral prophylaxis should be considered for all patients at risk of CMV infection after solid organ transplantation. In this paper we review the main indirect effects of CMV infection in solid organ transplant recipients, and the impact of CMV prophylaxis on these effects.     

Detection of Anatoxin-a and Three Analogs in Anabaena spp. Cultures: New Fluorescence Polarization Assay and Toxin Profile by LC-MS/MS

Anatoxin-a (ATX) is a potent neurotoxin produced by several species of Anabaena spp. Cyanobacteria blooms around the world have been increasing in recent years; therefore, it is urgent to develop sensitive techniques that unequivocally confirm the presence of these toxins in fresh water and cyanobacterial samples. In addition, the identification of different ATX analogues is essential to later determine its toxicity. In this paper we designed a fluorescent polarization (FP) method to detect ATXs in water samples. A nicotinic acetylcholine receptor (nAChR) labeled with a fluorescein derivative was used to develop this assay. Data showed a direct relationship between the amount of toxin in a sample and the changes in the polarization degree of the emitted light by the labeled nAChR, indicating an interaction between the two molecules. This method was used to measure the amount of ATX in three Anabaena spp. cultures. Results indicate that it is a good method to show ATXs presence in algal samples. In order to check the toxin profile of Anabaena cultures a LC-MS/MS method was also developed. Within this new method, ATX-a, retention time (RT) 5 min, and three other molecules with a mass m/z 180.1 eluting at 4.14 min, 5.90 min and 7.14 min with MS/MS spectra characteristic of ATX toxin group not previously identified were detected in the Anabaena spp. cultures. These ATX analogues may have an important role in the toxicity of the sample.     

Marcadores pronósticos en pacientes con gammapatía monoclonal de significado incierto

Objective

The assessment of prognostic biomarkers in monoclonal gammopathies of uncertain significance (MGUS) requires using large cohorts and long follow-ups, due to the low rate of conversion to multiple myeloma (MM). The aim of this article is to develop a model that allows smaller cohorts and shorter follow-ups to be used with high reliability.

Patients and methods

A total of 64 MGUS patients were studied and followed-up prospectively for 6 ± 0.24 years. Patients were classified as evolving or non-evolving, depending on whether the monoclonal protein levels increased or not over time. The risk of conversion to MM was tested based on these phenotypes, and whether the factors that predict conversion to MM are also associated with the appearance of an evolving phenotype.

Results

Eleven patients showed an evolving phenotype, and 53 a non-evolving one. All patients who converted to MM previously showed evolving phenotype (P = .003). At diagnosis, evolving phenotype associated with monoclonal gammopathies of IgA isotype (27 vs. 9%), monoclonal IgG levels above 1,500 mg/dl (P = .007, OR 9.8) and altered kappa/lambda ratios (P = .001, OR 11.7).

Conclusions

Risk factors for developing an evolving phenotype in MGUS patients are the same as those already described for the development of MM. These data show the validity of the evolving/non-evolving model to study markers to predict the outcome of MGUS patients, and confirm the role of the levels of monoclonal IgG and the light chains ratio in the prognosis of this disease.     

Systems Medicine: from molecular features and models to the clinic in COPD

Background and hypothesis

Chronic Obstructive Pulmonary Disease (COPD) patients are characterized by heterogeneous clinical manifestations and patterns of disease progression. Two major factors that can be used to identify COPD subtypes are muscle dysfunction/wasting and co-morbidity patterns. We hypothesized that COPD heterogeneity is in part the result of complex interactions between several genes and pathways. We explored the possibility of using a Systems Medicine approach to identify such pathways, as well as to generate predictive computational models that may be used in clinic practice.

Objective and method

Our overarching goal is to generate clinically applicable predictive models that characterize COPD heterogeneity through a Systems Medicine approach. To this end we have developed a general framework, consisting of three steps/objectives: (1) feature identification, (2) model generation and statistical validation, and (3) application and validation of the predictive models in the clinical scenario. We used muscle dysfunction and co-morbidity as test cases for this framework.

Results

In the study of muscle wasting we identified relevant features (genes) by a network analysis and generated predictive models that integrate mechanistic and probabilistic models. This allowed us to characterize muscle wasting as a general de-regulation of pathway interactions. In the co-morbidity analysis we identified relevant features (genes/pathways) by the integration of gene-disease and disease-disease associations. We further present a detailed characterization of co-morbidities in COPD patients that was implemented into a predictive model. In both use cases we were able to achieve predictive modeling but we also identified several key challenges, the most pressing being the validation and implementation into actual clinical practice.

Conclusions

The results confirm the potential of the Systems Medicine approach to study complex diseases and generate clinically relevant predictive models. Our study also highlights important obstacles and bottlenecks for such approaches (e.g. data availability and normalization of frameworks among others) and suggests specific proposals to overcome them.