Larissa Barbosa Lopes

Impact of using different laboratory assays to detect human leukocyte antigen antibodies in female blood donors

BACKGROUND: HLA antibodies passively transferred to transfused recipients may cause transfusion reactions such as transfusion‐related acute lung injury (TRALI), but in many of the reported TRALI incidents, no white blood cell antibodies have been identified. We investigated whether a higher number of anti‐HLA would be detected in donors plasma by using a method with potential higher sensitivity rate.

HNA-3 gene frequencies in Brazilians and a new polymerase chain reaction-restriction fragment length polymorphism method for HNA-3a/3b genotyping

HNA‐3 antigens are the result of a rs2288904 single‐nucleotide polymorphism (SNP) in the CTL2, and the HNA‐3a and HNA‐3b variants are encoded by a guanine and adenine at Nucleotide Position 461. Anti‐HNA‐3 are involved in severe transfusion‐related acute lung injury reactions and in neonatal alloimmune neutropenia. Since the distribution of the HNA‐3 system was unknown in South Americans, in this study we determined the frequency of the HNA‐3 alleles in Brazilians.

Lesão pulmonar aguda associada à transfusão

Transfusion-related acute lung injury (TRALI) is a serious clinical syndrome associated with the transfusion of plasma-containing blood components. Recently, TRALI has come to be recognized as the leading cause of transfusion-related death in the United States and United Kingdom. This complication typically presents as shortness of breath, hypoxemia, hypotension, fever and noncardiogeneic pulmonary edema, all occurring during or within 6 h after transfusion. Although the mechanism of TRALI has not been fully elucidated, it has been associated with human leukocyte antigen antibodies (class I, class II or neutrophil alloantigens) and with biologically active mediators in stored cellular blood components. Most of the donors implicated in cases of TRALI are multiparous women. Rarely diagnosed, TRALI can be confused with other causes of acute respiratory failure. Greater knowledge regarding TRALI on the part of clinicians could be crucial in preventing and treating this severe complication of blood transfusion.

Antibodies to human neutrophil antigen HNA-3b implicated in cases of neonatal alloimmune neutropenia: ANTI-HNA-3B IMPLICATED IN CASES OF NAIN

Neonatal alloimmune neutropenia results from maternal alloimmunization to human neutrophil antigens. The alloantibodies involved in neonatal alloimmune neutropenia are against human neutrophil antigens HNA‐1a, HNA‐1b, HNA‐1c, HNA‐1d, HNA‐2, HNA‐3a, HNA‐4a, HNA‐4b, and HNA‐5a; however, to date, antibodies specific to HNA‐3b have not been reported.

Effects of Immunosenescence on the Lower Expression of Surface Molecules in Neutrophils and Lymphocytes

BACKGROUND Immunosenescence is a remodeling of the immune system, caused by aging, with changes in the function of neutrophils, lymphocytes, and Treg cells. OBJECTIVE This study aimed to evaluate the expression of molecules CD11b, CD16 and CD64 (neutrophils), CD154 (T lymphocytes), CD40 (B lymphocytes), and to quantitatively analyze the Treg cell subpopulation. METHODS 49 elderlies (≥60 years) and 49 adults (≤35 years) were studied. Flow cytometry was used to analyze the expression of surface molecules and the subpopulation of Treg cells, and the results between the groups were compared statistically by the t-test. RESULTS There was a decreased significance in the expression of CD11b and CD40 in the elderly. CONCLUSION Decreased CD11b expression can result in susceptibility to infectious diseases, and impairment of phagocytic capacity. Decreased CD40 expression can result in a decline in B lymphocyte activation. The other molecule studied presented alterations not significant, but compatible with the immunological changes in aging.

Distribution of HNA alleles in Brazilians

Dear Editor, The manuscript ‘Neutrophil alloantigens and alloantibodies in different populations’ [1] brings important updates on the subject and conducts a comprehensive review of the allelic frequencies of HNAs, especially in the Asian population. However, in terms of the Brazilian population, some changes should be considered, since the reported HNA frequencies are only representative of isolated native indigenous groups in which inbreeding (endogamy) prevails. We consider that the HNA frequencies that best represent the totality of the Brazilian population are observed in studies including blood donors, which reflect more adequately the high miscegenation rate of our population. In fact, the distribution of HNA alleles in indigenous groups is remarkably different from that reported for blood donors, who have a profile similar to Europeans. In this context, the data from studies involving Brazilian blood donors are compiled in Table 1, expressing more accurately the frequencies of the HNA alleles in Brazilians. Conflict of interests