Consecutive Liver and Bone Marrow Transplantation for Erythropoietic Protoporphyria: Case Report and Literature Review.

BACKGROUND: Erythropoietic protoporphyria (EPP) is a rare inherited disease of heme biosynthesis resulting in the accumulation of protoporphyrin, characterized by liver failure in a minority of cases. Although liver transplant (LT) is the therapeutic strategy for advanced hepatic disease, it does not correct the primary defect, which leads to recurrence in liver graft. Thus, hematopoietic stem cell transplantation (HSCT) is an approach for treating EPP. METHODS: We aim to describe the first sequential LT and HSCT for EPP performed in Latin America, besides reviewing the present-day literature. RESULTS: The patient, a 13-year-old female with a history of photosensitivity, presented with symptoms of cholestatic and hepatopulmonary syndrome and was diagnosed with EPP. Liver biopsy demonstrated cirrhosis. She was submitted to a successful LT and showed improvement of respiratory symptoms. However, she had disease recurrence on the liver graft. She underwent a myeloablative HSCT using a matched unrelated donor, conditioning with BuCy (busulfan and cyclophosphamide), and GvHD (graft vs. host disease) prophylaxis with ATG (thymoglobulin), tacrolimus and methotrexate. Neutrophil engraftment occurred on D+18. She has presented mixed chimerism, but normalization of PP levels, being 300 days after HSCT, in good state of health and normal liver function. CONCLUSIONS: Consecutive LT and HSCT for EPP is a procedure that has been described in 10 cases in the literature and, even though these patients are a highly diversified population, studies have shown favorable results. This concept of treatment should be considered in patients with established liver disease.

Aspects of laboratory characteristics, analysis of alloimmunization, and searching for predictors related to survival in patients with Autoimmune Hemolytic Anemia.

Autoimmune hemolytic anemia (AIHA) is characterized by hemolysis caused by autoantibodies. However, many patients do not respond to therapies and may have an unfavorable outcome. It has been hypothesized that patients with AIHA and alloantibodies have a lower survival compared to patients with this disease and without alloimmunization. To this end, the clinical and laboratory profile was described and sought to identify features associated with survival in patients with AIHA. This is a single-site retrospective observational study that included patients (children, adolescents, adults and elderly) diagnosed with AIHA from January 2000 to June 2019. Epidemiological data, laboratory tests, treatment response, alloantibody and autoantibody profile, red cell transfusion and clinical course were analyzed. Survival analysis was performed using Kaplan-Meier curves and Cox proportional hazards regression. The study included 138 patients, mostly caucasians and female. The median age at diagnosis was 48.5 years (0.16-88) and 82 (59.4 %) patients had secondary AIHA. In addition, 33 % (25/75) of subjects had alloantibodies at the time of AIHA diagnosis and 40 % (16/40) detected alloantibody emergence later. The overall 10-year survival rate was 51 % (median follow-up was 39 months). Monocytosis, IgM class autoantibody and Direct Antiglobulin Test (DAT) intensity had a significant impact on predicting mortality in this population. On the other hand, alloimmunization at diagnosis and after did not affect survival in this population.

An Experimental Study Comparing the Expansion of Peripheral Blood Natural Killer (NK) Cells Cultured with Artificial Antigen-Presenting Cells, in the Presence or Absence of Bone Marrow Mesenchymal Stem Cells (MSCs).

NK cells have been seen as potential agents in adoptive immunotherapy for cancer. The main challenge for the success of this approach is to obtain a great quantity of activated NK cells for adoptive transfer. The present study had aimed to evaluate the effect of a feeder layer of irradiated MSCs in the in vitro expansion of NK cells. MSCs were obtained from the bone marrow (BM) cells remaining in the bag and filter used in the transplantation of hematopoietic stem cells. NK cells were obtained from peripheral blood (PB) of healthy volunteers. NK expansion and activation were stimulated by culture with artificial antigen-presenting cells (aAPCs) and IL-2, in the presence or absence of BM-MSCs. NK cell proliferation, phenotypic expression and cytotoxic activity were evaluated. Both culture conditions showed high NK purity with predominance of NK CD56brightCD16+ subset post expansion. However, cultures without the presence of MSCs showed higher NK proliferation, expression of activation markers (CD16 and NKG2D) and related cytotoxic activity. In this experimental study, the presence of a feeder layer of irradiated BM-MSCs interfered negatively in the expansion of PB-NKs, limiting their growth and activation. Further investigation is needed to understand the mechanisms of NK-MSC interaction and its implications.

A simple protocol for transfecting human mesenchymal stem cells.

OBJECTIVES AND RESULTS: Mesenchymal stromal cells (MSCs) are potential targets for cell and gene therapy-based approaches against a variety of different diseases. The MSCs from bone marrow are a promising target population as they are capable of differentiating along multiple lineages and have significant expansion capability. These characteristics make them strong candidates for delivering genes and restoring organ systems function. However, as other primary cells, MSCs are difficult to transfect. In order to standardize a simple protocol for transfection of MSCs, we conducted a series of experiments and achieved a protocol that does not require the use of viral particles or specific expensive equipment. CONCLUSION: MSCs transfection at early passages using a ratio lipid/DNA of 3.0 µL/µg with Lipofectamine 3000® yields good transfection efficiencies for human MSCs (up to 26%) and is rapid, simple, and safe.

The role of BCL11A and HMIP-2 polymorphisms on endogenous and hydroxyurea induced levels of fetal hemoglobin in sickle cell anemia patients from southern Brazil.

High levels of fetal hemoglobin (HbF) reduce sickle cell anemia (SCA) morbidity and mortality. HbF levels vary considerably and there is a strong genetic component that influences HbF production. Genetic polymorphisms at three quantitative trait loci (QTL): Xmn1-HBG2, HMIP-2 and BCL11A, have been shown to influence HbF levels and disease severity in SCA. Hydroxyurea (HU) is a drug that increases HbF. We investigated the influence of single nucleotide polymorphisms (SNPs) at the Xmn1-HBG2 (rs7482144); BCL11A (rs1427407, rs4671393 and rs11886868); and HMIP-2 (rs9399137 and rs9402686) loci on baseline and HU-induced HbF levels in 111 HbSS patients. We found that both BCL11A and HMIP-2 were associated with increased endogenous levels of HbF. Interestingly, we also found that BCL11A was associated with higher induction of HbF with HU. This effect was independent of the effect of BCL11A on baseline HbF levels. Additional studies will be needed to validate these findings and explain the ample inter-individual variations in HbF levels at baseline and HU-induced in patients with SCA.

DNA damage in blood leukocytes of individuals with sickle cell disease treated with hydroxyurea.

Hydroxyurea (HU) plays an important role in the treatment of patients with sickle cell disease (SCD). Although HU has been associated with an increased risk of leukemia in some patients with myeloproliferative disorders, the mutagenic and carcinogenic potential of HU has not been established. This study investigated levels of DNA damage using the alkaline (pH>13) comet assay to analyze peripheral blood leukocytes sampled from 28 patients with SCD treated with HU (SCHU) and from 28 normal individuals. The damage index (DI) in the SCHU group was significantly higher than in controls (p<0.05). Gender, smoking or age were not associated with DNA damage in controls or SCHU individuals. In the group of SCHU individuals, mean HU dose and DI were positively correlated, and individuals who received a mean dose of >20 mg/kg HU (DI=24.9+/-5.5) showed significantly more DNA damage than those who received < or =20 mg/kg HU (DI=14.6+/-1.8) (p<0.05). Individuals treated for > or =42 months (DI=23.1+/-4.2) showed significantly greater DNA damage than those treated for <42 months (13.6+/-1.9) (p<0.05). DI was inversely correlated with body mass index in the SCHU group.

Lack of association between cardiac troponin T and D-dimer in the evaluation of myocardial damage.

Acute myocardial infarction (AMI) disrupts cardiac cell membranes, releasing intracellular cardiac proteins into the vascular system. Some of these proteins, including the cardiac troponin subunits T and I, have proven useful for diagnosing myocardial damage. Intracoronary thrombosis plays a key role in the pathogenesis of AMI, and the formation of an occlusive thrombus usually precedes the development of myocardial damage. To evaluate whether there is an association between the size of intracoronary thrombosis and myocardial damage, we analyzed D-dimer and cTnT levels in blood samples from patients suspected to have myocardial damage. We investigated 102 patients who were admitted to emergency service for suspected myocardial damage. D-dimer was assessed with the use of the immunoassay Liatest D-dimer, and cTnT levels were measured with an electrochemiluminescence immunoassay (Troponin T STAT). D-dimer levels were lower in patients with cTnT < 0.01 than in patients presenting cTnT > 0.01 ng/mL. We investigated the relationship between D-dimer and cTnT levels in the patients with cTnT > 0.01 ng/mL (0.40 +/- 0.10 ng/mL), and no significant agreement (r = 0.20, P > 0.05) was observed. The levels of D-dimer were not associated with the levels of cTnT in patients with cTnT > 0.01 ng/mL.

Interaction between normal and CML hematopoietic progenitors and stroma influences abnormal hematopoietic development.

Several studies have shown defective progenitor-stromal interactions in chronic myeloid leukemia (CML), and adhesive defects induced by BCR/ABL have been described. However, controversial results have been reported, and the role of the stroma in abnormal development of the hematopoietic system is not clear. In this study, CML hematopoietic and irradiated stromal cells were co-cultured in different combinations for 10 or 21 days. Maintenance of viable cells was dependent both on the sources of hematopoietic progenitors and stromal adherent layers, with normal cells performing better than their leukemic counterparts. The frequency of CD34(+) CD38(-) cells in the non-adherent fraction was more related to the source of hematopoietic cells than of stroma, and hematopoietic cells from normal subjects showed better performance. The simultaneous analysis of different combinations of normal and leukemic precursor cells and stromal layers, as done in the present work, suggests that the outcome of the interaction depends on characteristics of both compartments. This hematopoietic system development is influenced by intrinsic qualities of both hematopoietic stem cells and the supportive stroma.