Carolina Costa-Lima

A high angiopoietin-2/angiopoietin-1 ratio is associated with a high risk of septic shock in patients with febrile neutropenia

IntroductionEndothelial barrier breakdown is a hallmark of septic shock, and proteins that physiologically regulate endothelial barrier integrity are emerging as promising biomarkers of septic shock development. Patients with cancer and febrile neutropenia (FN) present a higher risk of sepsis complications, such as septic shock. Nonetheless, these patients are normally excluded or under-represented in sepsis biomarker studies. The aim of our study was to validate the measurement of a panel of microvascular permeability modulators as biomarkers of septic shock development in cancer patients with chemotherapy-associated FN.MethodsThis was a prospective study of diagnostic accuracy, performed in two distinct in-patient units of a university hospital. Levels of vascular endothelial growth factor A (VEGF-A), soluble fms-like tyrosine kinase-1 (sFlt-1) and angiopoietin (Ang) 1 and 2 were measured after the onset of neutropenic fever, in conditions designed to mimic the real-world use of a sepsis biomarker, based on our local practice. Patients were categorized based on the development of septic shock by 28 days as an outcome.ResultsA total of 99 consecutive patients were evaluated in the study, of which 20 developed septic shock and 79 were classified as non-complicated FN. VEGF-A and sFlt-1 levels were similar between both outcome groups. In contrast, Ang-2 concentrations were increased in patients with septic shock, whereas an inverse finding was observed for Ang-1, resulting in a higher Ang-2/Ang-1 ratio in patients with septic shock (5.29, range 0.58 to 57.14) compared to non-complicated FN (1.99, range 0.06 to 64.62; P = 0.01). After multivariate analysis, the Ang-2/Ang-1 ratio remained an independent factor for septic shock development and 28-day mortality.ConclusionsA high Ang-2/Ang-1 ratio can predict the development of septic shock in cancer patients with febrile neutropenia.

The utility of International Society on Thrombosis and Haemostasis-Bleeding Assessment Tool and other bleeding questionnaires in assessing the bleeding phenotype in two platelet function defects.

The main objective of this study is to investigate the utility of International Society on Thrombosis and Haemostasis-Bleeding Assessment Tool (ISTH-BAT) in comparison with the condensed form of Molecular and Clinical Markers for the Diagnosis and Management of type 1 and WHO BATs, in assessing bleeding in two well known and clinically significant platelet function defects. Thirty-eight patients previously diagnosed with Glanzmanns thrombasthenia and 10 with Bernard–Soulier syndrome (BSS) were analyzed. Bleeding scores were significantly higher than that of controls using both electronic bleeding questionnaire (eBQ) and ISTH-BAT with no significant difference between both tools. ISTH-BAT had a sensitivity, specificity, positive predictive value and negative predictive value of 100%, 76.2%, 0.9 and 1. This was closely similar to eBQ. Both ISTH-BAT and eBQ are efficient in BSS and Glanzmanns thrombasthenia. However, given the ISTH recommendation, ISTH-BAT should be adopted. Larger study including other platelet defects will enhance its utility and support the integration of bleeding scores with standardized laboratory testing to allow for a universal diagnostic approach to patients with suspected bleeding disorders.

Evaluation of the immature platelet fraction contribute to the differential diagnosis of hereditary, immune and other acquired thrombocytopenias

The differential diagnosis of immune (ITP) and hereditary macrothrombocytopenia (HM) is key to patient management. The immature platelet fraction (IPF) represents the subset of circulating platelets with higher RNA content, and has been shown to distinguish hypo- from hyperproliferative thrombocytopenias. Here we evaluated the diagnostic accuracy of IPF in the differential diagnosis between HM and other thrombocytopenias in a population of patients with post-chemotherapy thrombocytopenia (n = 56), bone marrow failure (n = 22), ITP (n = 105) and HM (n = 27). TPO levels were also measured in HM and ITP matched for platelet counts. Platelet counts were similar in all patient groups. Higher IPF values were observed in both ITP (12.3%; 2.4–65.6%) and HM (29.8%; 4.6–65.9%) compared to hypoproliferative thrombocytopenias. IPF values were also higher in HM compared to ITP, yielding a diagnostic accuracy of 0.80 (95%CI 0.70–0.90; P < 0.0001) to distinguish these two conditions. Intra- and inter-assays reproducibility of IPF in HM patients revealed that this is a stable parameter. In conclusion, IPF is increased in HM compared to both ITP and other thrombocytopenias and contributes to the differentiation between ITP and HM. Further studies are warranted to understand the biological rationale of these findings and to its incorporation in diagnostic algorithms of HM.

Thalidomide for the treatment of gastrointestinal bleeding due to angiodysplasia in a patient with Glanzmann’s thrombasthenia

Angiodysplasia is a frequent cause of persistent gastrointestinal (GI) hemorrhage in elderly patients. Although GI bleeding isn’t the most common manifestation in patients with bleeding disorders, when present, it represents a challenging complication. We describe a 62-year-old patient with Glanzmann’s thrombasthenia, who used thalidomide for severe and recurrent GI bleeding. For 6 months, the patient experienced temporary control of GI bleeding with thalidomide in a daily oral dose of 100 mg. The anti-angiogenic effects of thalidomide have recently been explored by several groups, particularly in the management of bleeding from angiodysplasia, including cases with von Willebrand disease. Here, we review the relevant descriptions of the use of thalidomide in this situation, and also discuss potential reasons why we observed only a temporary control of the GI bleeding in our patient, such as the use of low-dose regimen due to limitations posed by thalidomide side effects.

Risk of Zika virus transmission by blood donations in Brazil

Background Zika, a disease caused by Zika virus infections, has recently emerged and caused outbreaks in many parts of the world. The clinical manifestations of Zika are usually mild, mostly presenting as an exanthematic febrile disease, but on some occasions, it might be associated with microcephaly after intrauterine infection, and Guillain-Barré Syndrome. Zika virus is primarily transmitted by mosquito bites, but other means of transmission have been described, and potential risk for blood transmission has been reported in French Polynesia and Brazil. Methods To investigate the risk of Zika virus infection after a blood transfusion in an area of Brazil where a possible transmission by a platelet concentrate has been described. Using a mini-pool format, 1857 blood donations were evaluated by real-time reverse transcriptase polymerase chain reaction designed to detect Zika virus RNA. Results After testing samples individually from positive mini-pools, the prevalence of Zika virus RNA was only 0.16%, a result probably associated to the low circulation of this virus in the study area. In addition, it was evident that the implementation of post-surveillance programs is important to detect Zika virus infections in blood donors, as the post-donation surveillance program detected two blood donors with the disease in this study. Conclusion This study shows that the risk for Zika virus transmission by blood transfusion is real, even in regions with a low circulation of the disease, but the combination of the detection of Zika virus RNA by polymerase chain reaction and post-donation surveillance might reduce the risk of transmission by blood transfusions.

'Leaky gut' in hematological malignancies

In humans, the intestinal epithelium is a single layer of cellsthat constitutes one of the most important barriers betweeninternal and external environments. The so-called ‘intesti-nal barrier’ (IB) is a dynamic structure composed of differenttypes of cellular junctions that can be regulated by physio-logical and pathological stimuli, and act as a selective barrierto antigens and pathogens. Physiological mechanisms thatregulate IB function are important for nutrient absorptionand antigen permeation, with potential roles in the regula-tion of tolerance to non-self antigens.