Bartonella henselae AS A PUTATIVE CAUSE OF CONGENITAL CHOLESTASIS.

Severe anemia and cholestatic hepatitis are associated with bartonella infections. A putative vertical Bartonella henselae infection was defined on the basis of ultrastructural and molecular analyses in a three-year-old child with anemia, jaundice and hepatosplenomegaly since birth. Physicians should consider bartonellosis in patients with anemia and hepatitis of unknown origin.

First Complete Genome Sequence of Zika Virus (Flaviviridae, Flavivirus) from an Autochthonous Transmission in Brazil.

We report here the genome sequence of Zika virus, strain ZikaSPH2015, containing all structural and nonstructural proteins flanked by the 5' and 3' untranslated region. It was isolated in São Paulo state, Brazil, in 2015, from a patient who received a blood transfusion from an asymptomatic donor at the time of donation.

Bartonella clarridgeiae bacteremia detected in an asymptomatic blood donor.

Human exposure to Bartonella clarridgeiae has been reported only on the basis of antibody detection. We report for the first time an asymptomatic human blood donor infected with B. clarridgeiae, as documented by enrichment blood culture, PCR, and DNA sequencing.

Platelet antibody detection by flow cytometry: an effective method to evaluate and give transfusional support in platelet refractoriness.

BACKGROUND: Immune platelet refractoriness is mainly caused by human leukocyte antigen antibodies (80-90% of cases) and, to a lesser extent, by human platelet antigen antibodies. Refractoriness can be diagnosed by laboratory tests and patients should receive compatible platelet transfusions. A fast, effective and low cost antibody-screening method which detects platelet human leukocyte/platelet antigen antibodies is essential in the management of immune platelet refractoriness. OBJECTIVE: The aim of this study was to evaluate the efficiency of the flow cytometry platelet immunofluorescence test to screen for immune platelet refractoriness. METHODS: A group of prospective hematologic patients with clinically suspected platelet refractoriness treated in a referral center in Campinas, SP during July 2006 and July 2011 was enrolled in this study. Platelet antibodies were screened using the flow cytometry platelet immunofluorescence test. Anti-human leukocyte antigen antibodies were detected by commercially available methods. The sensitivity, specificity and predictive values of the immunofluorescence test were determined taking into account that the majority of antiplatelet antibodies presented human leukocyte antigen specificity. RESULTS: Seventy-six samples from 32 female and 38 male patients with a median age of 43.5 years (range: 5-84 years) were analyzed. The sensitivity of the test was 86.11% and specificity 75.00% with a positive predictive value of 75.61% and a negative predictive value of 85.71%. The accuracy of the method was 80.26%. CONCLUSION: This study shows that the flow cytometry platelet immunofluorescence test has a high correlation with the anti-human leukocyte antigen antibodies. Despite a few limitations, the method seems to be efficient, fast and feasible as the initial screening for platelet antibody detection and a useful tool to crossmatch platelets for the transfusional support of patients with immune platelet refractoriness.

Platelet antibody detection by flow cytometry: an effective method to evaluate and give transfusional support in platelet refractoriness

BACKGROUND:Immune platelet refractoriness is mainly caused by human leukocyte antigen antibodies (80-90% of cases) and, to a lesser extent, by human platelet antigen antibodies. Refractoriness can be diagnosed by laboratory tests and patients should receive compatible platelet transfusions. A fast, effective and low cost antibody-screening method which detects platelet human leukocyte/platelet antigen antibodies is essential in the management of immune platelet refractoriness. OBJECTIVE: The aim of this study was to evaluate the efficiency of the flow cytometry platelet immunofluorescence test to screen for immune platelet refractoriness. METHODS: A group of prospective hematologic patients with clinically suspected platelet refractoriness treated in a referral center in Campinas, SP during July 2006 and July 2011 was enrolled in this study. Platelet antibodies were screened using the flow cytometry platelet immunofluorescence test. Anti-human leukocyte antigen antibodies were detected by commercially available methods. The sensitivity, specificity and predictive values of the immunofluorescence test were determined taking into account that the majority of antiplatelet antibodies presented human leukocyte antigen specificity. RESULTS: Seventy-six samples from 32 female and 38 male patients with a median age of 43.5 years (range: 5-84 years) were analyzed. The sensitivity of the test was 86.11% and specificity 75.00% with a positive predictive value of 75.61% ...

Electrical properties of the red blood cell membrane and immunohematological investigation.

Hemagglutination is widely used in transfusion medicine and depends on several factors including antigens, antibodies, electrical properties of red blood cells and the environment of the reaction. Intermolecular forces are involved in agglutination with cell clumping occurring when the aggregation force is greater than the force of repulsion. Repulsive force is generated by negative charges on the red blood cell surface that occur due to the presence of the carboxyl group of sialic acids in the cell membrane; these charges create a repulsive electric zeta potential between cells. In transfusion services, specific solutions are used to improve hemagglutination, including enzymes that reduce the negative charge of red blood cells, LISS which improves the binding of antibodies to antigens and macromolecules that decrease the distance between erythrocytes. The specificity and sensitivity of immunohematological reactions depend directly on the appropriate use of these solutions. Knowledge of the electrical properties of red blood cells and of the action of enhancement solutions can contribute to the immunohematology practice in transfusion services.

Electrical properties of the red blood cell membrane and immunohematological investigation

Hemagglutination is widely used in transfusion medicine and depends on several factors including antigens, antibodies, electrical properties of red blood cells and the environment of the reaction. Intermolecular forces are involved in agglutination with cell clumping occurring when the aggregation force is greater than the force of repulsion. Repulsive force is generated by negative charges on the red blood cell surface that occur due to the presence of the carboxyl group of sialic acids in the cell membrane; these charges create a repulsive electric zeta potential between cells. In transfusion services, specific solutions are used to improve hemagglutination, including enzymes that reduce the negative charge of red blood cells, LISS which improves the binding of antibodies to antigens and macromolecules that decrease the distance between erythrocytes. The specificity and sensitivity of immunohematological reactions depend directly on the appropriate use of these solutions. Knowledge of the electrical properties of red blood cells and of the action of enhancement solutions can contribute to the immunohematology practice in transfusion services.

The role of glucocorticoid in SIRP alpha and SHP-1 gene expression in AIHA patients.

The aim of this work was to evaluate the regulation of SIRP alpha, an inhibitory phagocyte receptor, and the phosphatase SHP-1 in monocytes of patients with autoimmune hemolytic anemia, and the role of dexamethasone on SIRP alpha and SHP-1 gene expression and erythrophagocytosis in vitro. SIRP alpha and SHP-1 expression was higher in monocytes from AIHA patients compared with normal, returning to normal after glucocorticoid therapy. SIRP alpha and SHP-1 mRNA expression was upregulated in healthy monocytes treated with dexamethasone compared with basal; however, the erythrophagocytic ability was not altered. Our results point to a minor role of SIRP alpha and SHP-1 in determining AIHA.

The influence of storage and leukocyte depletion on the antigen densities of FY1, FY2, MNS3 and MNS4 measured by flow cytometry.

Red blood cell (RBC) antigens may present changes in density during storage and leukocyte reduction. We evaluated the influence of these variables on FY1, FY2, MNS3 and MNS4 antigens using quantitative flow cytometry (FCM). Forty-eight RBC units were divided into two sub-units each immediately after collection. One of them was leukocyte reduced before storage. Antigen expression was analyzed on days 1 and 35 of storage by gel-centrifugation and FCM. Three RBC samples were submitted to papain and bromelin treatment. The gel-centrifugation test could not detect any influence of storage or leukocyte reduction. However, by FCM, a wide variation of antigen density among the donors was found. Leukocyte depletion did not change the antigen density but after storage, expression of FY1 and MNS4 showed a slight decrease. Median antigenic density of FY1 was 11,332 in FY1,2 and 23,436 in FY1,-2 donors. FY2 presented 7204 and 7868, respectively. MNS4 had 100,589 and 214,340 sites in donors MNS3,4 and MNS-3,4, respectively, and MNS3 had 10,389 and 21,122 sites, respectively. After enzyme treatments none of the antigens could be detected. FCM was a reproducible technique, suitable for the quantification of the antigens studied in RBC concentrates stored and leukocyte reduced in conditions normally used for blood transfusion.