Analysis of maternal Fc gamma receptor IIIb isoantibodies using immunomagnetic negative selected neutrophils.

BACKGROUND AND OBJECTIVES: The isolation of neutrophils and subsequent detection of anti-human neutrophil antigens (HNA) antibodies are crucial in clinical medicine for the diagnosis of autoimmune neutropenia, neonatal alloimmune neutropenia (NAIN) and transfusion-related acute lung injury (TRALI). This study reports two cases of maternal anti-Fc-gamma-receptor-IIIb (FcγRIIIb) isoimmunization without NAIN symptoms and compares the efficiency of immunomagnetic negative selection (IMNS) with traditional dextran/Ficoll for neutrophil isolation in HNA serological assays. MATERIALS AND METHODS: Investigating two cases of maternal anti-FcγRIIIb isoimmunization, neutrophils from three donors were isolated from 8 mL of whole blood using IMNS and dextran/Ficoll. Serological assays included the granulocyte agglutination and immunofluorescence test, monoclonal antibody immobilization of granulocyte antigens and the LABScreen Multi (One Lambda). IMNS and dextran/Ficoll were compared in terms of cell yield, viability, time, cost and purity. RESULTS: Maternal anti-FcγRIIIb isoantibodies with FCGR3B gene deletion were detected in both cases. Newborns and fathers exhibited specific gene combinations: FCGR3B*02/FCGR3B*02 (Case 1) and FCGR3B*02/FCGR3B*03 (Case 2). IMNS outperformed dextran/Ficoll, yielding four times more neutrophils (average neutrophil counts: 18.5 × 103/µL vs. 4.5 × 103/µL), efficiently removing non-neutrophil cells and reducing processing time (30-40 min vs. 70-90 min), although it incurred a higher cost (2.7 times). CONCLUSION: Two cases of maternal anti-FcγRIIIb isoantibodies, unrelated to NAIN, were identified. Although neutropenia has not been described in these cases, we emphasize the importance of identifying asymptomatic cases with the potential for severe neutropenia. Additionally, IMNS is introduced as a rapid, high-yield, high-purity neutrophil isolation technique, beneficial for serological assays detecting anti-HNA antibodies.

HLA-DRB1 molecules and the presentation of anchor peptides from RhD, RhCE, and KEL proteins.

BACKGROUND: Antigens from the Rh and Kell systems are recognized as the most immunogenic in clinical practice. This study evaluated the possible molecular mechanisms involved in the interaction of antigenic peptides with the DRB1 molecules, which help to explain the high frequency of anti-K and association of D + C antibodies in transfusion and incompatible pregnancy. STUDY DESIGN AND METHODS: We included 201 patients with antibodies against antigens from the Rh and Kell systems and compare them with 174,015 controls. HLA-DRB1 genotyping and in silico analysis were performed. The NetMHCIIpan software was used to identify RhD-, RhCE-, and KEL-derived anchor peptides that bind to DRB1 molecules. RESULTS: HLA-DRB1*15 is associated with an increased risk of D, C, E, and K alloimmunization, while the HLA-DRB1*01 and *12 alleles are overrepresented in patients with anti-C and anti-D, respectively. In silico analysis showed that three polymorphic points (60I, 68S, and 103S) common to C and D antigens can be presented by several DRB1 molecules, including DRB1*15:01. The DRB1*09:01 molecule, although not showing statistical significance, was able to interact strongly with almost all five anchor peptides from the sequence containing the polymorphic determinants of E antigen, except 217-WMFWPSVNS-225. CONCLUSION: The DRB1*15 molecule has specific physicochemical characteristics in residues 11P and 13R in the P4 pocket that can favor the response to various antigenic peptides. Anti-K alloimmunization is unrestricted for interaction with specific DRB1 molecules, which suggests that almost all individuals in our population have DRB1 molecules capable of binding to KEL-derived anchor peptides and produce anti-K when stimulated.

Autoimmune pancytopenia after liver transplantation: A case report.

INTRODUCTION: Autoimmune hemolytic anemia (AIHA), immune thrombocytopenia (ITP), and autoimmune neutropenia (AIN) are reported in the literature after liver, intestinal, heart, pancreas, and kidney transplants. We report a case of autoimmune pancytopenia (AIHA, AIN and ITP) 9 years after liver transplantation with confirmed erythrocyte and neutrophil auto-antibodies. CASE REPORT: A 49 years old man was admitted to our hospital presented with dysentery and fever, with history of liver transplantation in 2008. Laboratory evaluation demonstrated hemoglobin: 7.2 g/dL, granulocytes: 0.10 × 109/L and platelets: 15 × 109/mm³; indirect bilirubin: 3.62 mg/dL; lactate dehydrogenase: 603 U/L. Direct antiglobulin test revealed a monospecific anti-IgG plus C3 and the acid eluate was reactive to all panel red cells, consistent with an AIHA. Granulocyte immunofluorescence test (GIFT) and agglutination test (GAT) were reactive for granulocytes. Test with Luminex technology for human neutrophil antigen (HNA) antibody detection was strong reactive with beads expressing HNA-1a, -1b, -1c, -2, -4a and -5a antigens. HNA genotyping revealed the presence of the corresponding antigens, confirming the autoantibodies. Test with Luminex technology for human leucocyte antigen (HLA) antibody detection was negative. Monoclonal antibody immobilization of platelet antigens (MAIPA) assay was negative. Viral causes were excluded. The condition was compatible with clinical onset of autoimmune pancytopenia. Prednisone was administered at an initial dose of 1 mg/kg/day and immunosuppressive therapy was adjusted. This treatment resulted in rapid resolution of pancytopenia. CONCLUSION: Combined autoimmune pancytopenia (AIHA, AIN and ITP) is a rare condition that may occur after liver transplantation. Early recognition of this phenomenon permits appropriate treatment.

Exercise-Induced Abnormal Increase of Systolic Pulmonary Artery Pressure in Adult Patients With Sickle Cell Anemia: An Exercise Stress Echocardiography Study.

BACKGROUND: Pulmonary hypertension (PH) at rest is a risk factor for death in patients with sickle cell anemia (SCA). Exercise echocardiography (EE) can detect latent PH. We sought to investigate the occurrence of exercise-induced abnormal response of systolic pulmonary artery pressure (SPAP) in adult patients with SCA and normal SPAP at rest, and to identify the independent predictors of this abnormal response. METHODS AND RESULTS: Forty-four adult patients with SCA and normal SPAP at rest (tricuspid regurgitant jet flow velocity [TRV] <2.5 m/sec) were studied and divided into 2 groups: exhibiting normal SPAP after treadmill EE (TRV ≤ 2.7 m/sec) (G1), and exhibiting abnormal exercise-induced increase of SPAP (TRV > 2.7 m/sec) (G2). TRV cutoff points at rest and during EE were based on data from healthy-matched control subjects. Abnormal response of SPAP with exercise occurred in 57% of the sample (G2), with mean TRV level of 3.39 ± 0.41 m/sec (range 2.8-4.5 m/sec), significantly higher than those of G1 (2.29 ± 0.25 m/sec, range 2.0-2.7 m/sec; P < 0.001). Multivariate analysis identified TRV value in resting conditions ≥2.25 m/sec (P < 0.05), left atrial volume index ≥41 mL/m2 (P < 0.05), and a E/e'-waves ratio ≥6.3 (P < 0.05) as independent predictors of exercise-induced increase of SPAP. CONCLUSION: We concluded that adult patients with SCA and normal SPAP at rest may exhibit abnormal exercise-induced increase in SPAP, which was independently related to resting TRV levels, and indices of diastolic impairment and left ventricular filling pressure.

Molecular Basis of KELnull Phenotype in Brazilians.

BACKGROUND: KELnull (K0) persons can produce clinically significant anti-KEL5 antibody after transfusion and/or pregnancy, requiring K0 blood transfusion when indicated. 37 K0 alleles have been reported in studies over different populations, but none in Amerindian-Caucasian descendants from South America. The aim of this study was to identify the molecular basis of K0 phenotype in Brazilians. METHODS: We investigated three K0 samples from different Brazilian blood banks (Recife, Manaus, and Vila Velha) in women with anti-KEL5. KEL antigen typing was performed by serologic techniques, and the K0 status was confirmed by flow cytometry. PCR-RFLP and DNA sequencing of the KEL coding and exon-intron regions were also performed. RESULTS: RBCs of the 3 patients were phenotyped as KEL:-1,-2,-3,-4,-7. The 3 patients had the same KEL*02/02 genotype and were negative for KEL*02.03 and KEL*02.06 alleles. The Recife K0 patient was homozygous for IVS16 + 1g>a mutation (KEL*02N.31 allele). The flow cytometry with anti-KEL1, anti-KEL2, anti-KEL3, anti-KEL4, and anti-CD238 confirmed the K0 phenotype. In addition, we found the c.10423C>T mutation (KEL*02N.04 allele) in both the Manaus K0 and the Vila Velha K0 patients. CONCLUSION: This report represents the first study of K0 molecular basis performed in Amerindian-Caucasian descendants from South America.

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

BACKGROUND: 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. STUDY DESIGN AND METHODS: DNA of 500 blood donors, 120 Xikrin Amerindians, 74 Japanese individuals, and 124 African Brazilians were genotyped for rs2288904 by a polymerase chain reaction (PCR)-restriction fragment length polymorphism assay. The PCR product was digested with enzyme Taq(α) 1, specific to nucleotide guanine (HNA-3a). RESULTS: The results showed that the frequencies of the HNA-3a/HNA-3b alleles were 0.81/0.19 in blood donors, 1.00/0.00 in Amerindians, 0.63/0.37 in Japanese, and 0.85/0.15 in African Brazilians. All 81 individuals genotyped as HNA-3a/a did not present the SNP c.457T by molecular sequencing. CONCLUSION: The frequencies of HNA-3 genotypes in Brazilian blood donors is similar to that described in Caucasians; however, all Amerindians were HNA-3a/a, African Brazilians showed a lower frequency of HNA-3b/b, and Japanese had a higher prevalence of HNA-3b/b, suggesting that they may be at risk for developing anti-HNA-3a alloantibodies.

Frequency of the DI*A, DI*B and Band 3 Memphis polymorphism among distinct groups in Brazil.

INTRODUCTION: The Band 3 is a red blood cell protein that carries the Dia and Dib antigens from the Diego blood system. The SLC4A1 gene encodes Band 3; Band 3 Memphis is a polymorphism of normal Band 3 and has two variants, but only the variant II carries the Dia antigen. OBJECTIVES: Describe the frequencies of the DI*A and DI*B alleles and the Band 3 Memphis among blood donors, sickle cell disease (SCD) patients and Amazonian Indians. METHODS: A total of 427 blood samples were collected and separated into three groups: 206 unrelated blood donors, 90 patients with SCD and 131 Amazonian Indians. We performed DI*A/B, normal Band 3 and Band 3 Memphis genotyping, using the Polymerase Chain Reaction Restriction Fragment Length Polymorphism (PCR-RFLP). RESULTS: The frequency of the DI*A/DI*A genotype was 0.5% in blood donors and it was not found in other groups. The frequency of the DI*A/DI*B was higher in Amazonian Indians (33.6%) and the frequency of the DI*B/DI*B was highest in blood donors (92.2%). All 105 individuals tested were positive for the presence of normal Band 3 and of these individuals, only 5/105 (4.8%) presented the Band 3 Memphis mutation. CONCLUSION: We observed a higher frequency of the DI*B allele in blood donors and a low frequency of the DI*A/DI*A genotype in all groups studied. The Band 3 Memphis was found in a higher frequency in the blood donor group. Our findings highlight the importance of analyzing different population groups to gain a better understanding of the genetic association of blood group antigens.

Targeting patient blood management's first pillar: A multicentric retrospective study on preoperative anemia.

INTRODUCTION: Anemia is a common issue in surgical patients and has been associated with worse clinical outcomes, such as a higher probability of transfusions and longer hospital stay. Therefore, Patient Blood Management programs are actively aiming to achieve early identification and treatment of anemia, previous to the surgery. METHODS AND MATERIALS: In this study, preoperative hemoglobin within the Blood Order Schedule (BOS) at 16 blood centers in several Brazilian regions were retrospectively evaluated. Data regarding hemoglobin, age, gender and Brazilian regions were further analyzed. RESULTS: From the 20,201 BOSs evaluated, the mean age was 55.65 ± 23.52 years old, with an overall prevalence of preoperative anemia of 60.9%. Women had a lower mean preoperative hemoglobin (11.74 ± 2.84 for women and 12.27 ± 3.06 for men) and higher prevalence of anemia than men (66% of females and 52.2% of males). The individuals over 65 years old and under 18 were the most affected by preoperative anemia. All regions had a high prevalence of preoperative anemia, without any direct association with the Human Development Index. CONCLUSION: In summary, upon evaluating the BOS, our study showed a high prevalence of preoperative anemia in all Brazilian regions, regardless of the gender and age group, but that women and individuals less than 18 or over 65 years old have an even higher prevalence of preoperative anemia. This information can identify the institutions in which preoperative anemia is a critical issue and in which new strategies, such as preoperative screening clinics, might be helpful.

BLOOD CELLS PROFILE IN UMBILICAL CORD OF LATE PRETERM AND TERM NEWBORNS.

OBJECTIVE: To describe the hematological profile in cord blood of late preterm and term newborns and compare blood indices according to sex, weight for gestational age and type of delivery. METHODS: Cross-sectional study with late preterm and term newborns in a second-level maternity. Multiple gestation, chorioamnionitis, maternal or fetal hemorrhage, suspected congenital infection, 5-minute Apgar <6, congenital malformations, and Rh hemolytic disease were excluded. Percentiles 3, 5,10, 25, 50, 75, 90, 95 and 97 of blood indices were calculated for both groups. RESULTS: 2,662 newborns were included in the sample, 51.1% males, 7.3% late preterms, 7.8% small for gestational age (SGA) and 81.2% adequate for gestational age (AGA). Mean gestational age was 35.6±1.9 and 39.3±1.0 weeks, respectively, for premature and term neonates. The erythrocytes indices and white blood cells increased from 34-36.9 to 37-41.9 weeks. Basophils and platelets remained constant during gestation. Premature neonates presented lower values ​​of all blood cells, except for lymphocytes and eosinophils. SGA neonates presented higher values ​​of hemoglobin, hematocrit and lower values of leukocytes, neutrophils, bands, segmented, eosinophils, monocytes and platelets. Male neonates presented similar values ​​of erythrocytes and hemoglobin and lower leukocytes, neutrophils, segmented and platelets. Neonates delivered by C-section had lower values ​​of red blood cells and platelets. Chronic or gestational hypertension induced lower number of platelets. CONCLUSIONS: Blood cells increased during gestation, except for platelets and basophils. SGA neonates had higher hemoglobin and hematocrit values and lower leukocytes. Number of platelets was smaller in male SGAs, born by C-section and whose mothers had hypertension.

Frequency of the DI*A, DI*B and Band 3 Memphis polymorphism among distinct groups in Brazil

ABSTRACT Introduction: The Band 3 is a red blood cell protein that carries the Dia and Dib antigens from the Diego blood system. The SLC4A1 gene encodes Band 3; Band 3 Memphis is a polymorphism of normal Band 3 and has two variants, but only the variant II carries the Dia antigen. Objectives: Describe the frequencies of the DI*A and DI*B alleles and the Band 3 Memphis among blood donors, sickle cell disease (SCD) patients and Amazonian Indians. Methods: A total of 427 blood samples were collected and separated into three groups: 206 unrelated blood donors, 90 patients with SCD and 131 Amazonian Indians. We performed DI*A/B, normal Band 3 and Band 3 Memphis genotyping, using the Polymerase Chain Reaction Restriction Fragment Length Polymorphism (PCR-RFLP). Results: The frequency of the DI*A/DI*A genotype was 0.5% in blood donors and it was not found in other groups. The frequency of the DI*A/DI*B was higher in Amazonian Indians (33.6%) and the frequency of the DI*B/DI*B was highest in blood donors (92.2%). All 105 individuals tested were positive for the presence of normal Band 3 and of these individuals, only 5/105 (4.8%) presented the Band 3 Memphis mutation. Conclusion: We observed a higher frequency of the DI*B allele in blood donors and a low frequency of the DI*A/DI*A genotype in all groups studied. The Band 3 Memphis was found in a higher frequency in the blood donor group. Our findings highlight the importance of analyzing different population groups to gain a better understanding of the genetic association of blood group antigens.

Expression of adhesion molecules on CD34+ cells from steady-state bone marrow before and after mobilization and their association with the yield of CD34+ cells.

BACKGROUND: Cell adhesion molecules (CAMs) expressed on hematopoietic progenitor cells (HPCs), endothelial cells, and stromal cells play a pivotal role in the mobilization of CD34+ cells. Herein, we conducted a non-randomized peripheral blood stem cell (PBSC) mobilization study aimed to compare the potential differences in the expressions of several CAMs and chemokines on CD34+ cells obtained from bone marrow aspirate before and after HPC mobilization from patients with hematologic malignancies and healthy donors. METHODS: Three-color cytofluorometric analysis was used to compare the expressions of CAMs and chemokines in the bone marrow before and after mobilization. RESULTS: For all studied groups, CAM expression among those with good and poor yields of CD34+ cells was significantly correlated with VCAM-1 (P=0.007), CD44 (P=0.027), and VLA-4 (P=0.014) expressions. VCAM-1 (P=0.001), FLT-3 (P=0.001), CD44 (P=0.011), VLA-4 (P=0.001), and LFA-1 (P=0.001) expressions were higher before HPC mobilization than after HPC mobilization. By contrast, the expression of CXCR4 significantly varied before and after mobilization only among those with successful PBSC mobilization (P=0.002). CONCLUSION: We attempted to identify particular aspects of CAMs involved in CD34+ cell mobilization, which is a highly complex mechanism that involves adhesion molecules and matrix metalloproteases. The mechanism by which CD34+ cell mobilization is activated through proteolytic enzymes is not fully understood. We believe that CXCR4, VLA-4, CD44, and VCAM-1 are the most important molecules implicated in HPC mobilization, particularly because they show a correlation with the yield of CD34+ cells collected via large volume leukapheresis.

Targeting patient blood management's first pillar: A multicentric retrospective study on preoperative anemia

ABSTRACT Introduction: Anemia is a common issue in surgical patients and has been associated with worse clinical outcomes, such as a higher probability of transfusions and longer hospital stay. Therefore, Patient Blood Management programs are actively aiming to achieve early identification and treatment of anemia, previous to the surgery. Methods and materials: In this study, preoperative hemoglobin within the Blood Order Schedule (BOS) at 16 blood centers in several Brazilian regions were retrospectively evaluated. Data regarding hemoglobin, age, gender and Brazilian regions were further analyzed. Results: From the 20,201 BOSs evaluated, the mean age was 55.65 ± 23.52 years old, with an overall prevalence of preoperative anemia of 60.9%. Women had a lower mean preoperative hemoglobin (11.74 ± 2.84 for women and 12.27 ± 3.06 for men) and higher prevalence of anemia than men (66% of females and 52.2% of males). The individuals over 65 years old and under 18 were the most affected by preoperative anemia. All regions had a high prevalence of preoperative anemia, without any direct association with the Human Development Index. Conclusion: In summary, upon evaluating the BOS, our study showed a high prevalence of preoperative anemia in all Brazilian regions, regardless of the gender and age group, but that women and individuals less than 18 or over 65 years old have an even higher prevalence of preoperative anemia. This information can identify the institutions in which preoperative anemia is a critical issue and in which new strategies, such as preoperative screening clinics, might be helpful.

p16 gene methylation lacks correlation with angiogenesis and prognosis in multiple myeloma.

Methylation of p16 gene is a relatively frequent molecular finding in multiple myeloma (MM), but its clinical implication is disputable. Cell cycle regulators are now recognized as active in the control of angiogenesis, which is an integral component of pathogenesis and a target for new treatment modalities of this disease. On such background, we focused on determining whether loss of p16 function by methylation could be associated with increased angiogenesis and VEGF expression, and the prognostic relevance of p16 methylation in 50 untreated, newly diagnosed MM patients. Thirty-one percent (13/42) of 42 patients assessable for p16 gene methylation showed to be methylation-positive. High-angiogenesis was present in 73% of cases, but methylation of the p16 gene did not associate with angiogenesis or with VEGF expression. Also, p16 methylation did not show prognostic relevance or correlation with the clinical and laboratory parameters of prognostic significance in univariate analysis. P16 immunoexpression presented only a faint agreement with the molecular study. Therefore, p16 methylation seems to have no correlation with angiogenesis and VEGF expression, neither with overall and event-free survival in MM patients. Besides, P16 immunohistochemistry seems inadequate to substitute the molecular study of methylation in this type of tumor cells. Additional studies are needed to clarify the correspondence between the epigenetic alteration of the p16 gene and its protein immunexpression, and the clinical relevance of p16 methylation in MM patients.

Large-volume leukapheresis for peripheral blood progenitor cell collection in low body weight pediatric patients: a single center experience.

Peripheral blood progenitor cells (PBPC) have became the preferred source of stem cells for autologous transplantation because of easier accessibility, rapid engraftment, and lower tumor cell contamination. In pediatric patients is very important to optimize peripheral blood stem cells (PBSC) harvesting to obtain a sufficient number of cells with a reduced number of leukapheresis. In this study we prospectively analyzed data on 43 large volume leukapheresis (LVL) from 20 consecutive low body weight pediatric patients with various malignancies. Patients' mean body weight was 16.6 kg (range, 8.9-32.0 kg), and the median age was 4 years (range, 1-10 y ears). Instead of saline, it was used irradiated and leukoreduced red blood cell (RBC) units to prime the machine in 15 patients weighting 25 kg or less. The median number of LVL was 2 (range, 1-4) and a mean of 5.2 patient's blood volume was processed per session lasting 165 min (range, 118-239). The mean number of CD34+ cells, one day before leukapheresis was 49 mm(-3) (range, 9-219). The PBPC collection yielded 24.7 x 10(8) total nucleated cells/kg (range, 6.2-74.0), 10.7 x 10(6) kg(-1) CD34+ cells (range, 3.6-53.7); 49.8 x 10(4) CFU-GM/kg (range, 6.4-198.1), and 65.6 x 10(4) BFU-E/kg (range, 7.6-198.1). The platelet count decreased significantly after each procedure 39.8 +/- 9.1 x 10(9) mm(-3) (range, 18.000-76.000) (p < 0.001). In conclusion, our data show that LVL for collection of PBPC in low weight pediatric patients is a safe and efficient procedure, but it may expose the patient to the risk of thrombocytopenia.

[Evaluation of fetomaternal hemorrhage in postpartum patients with indication for administration of anti-D immunoglobulin]. / Avaliação da hemorragia feto-materna em puérperas com indicação para ministração de imunoglobulina anti-D.

This study evaluated fetomaternal hemorrhage (FMH) in 343 postpartum patients who required prophylaxis of Rh alloimmunization with anti-D immunoglobulin. The rosette test was applied to screen for patients needing quantitative determination of fetal blood transferred from the maternal circulation, which was then measured by the Kleihauer-Betke test (K-B). The rosette test was positive in 22 cases (6.4%). In five of these cases, K-B did not show fetomaternal hemorrhage (a 1.45% false-positive rate for the rosette test), and in one case the test was inconclusive. There were 8 cases with FMH < 10 ml (2.3%), 6 cases with FMH from 10 to 30 ml (1.7%), and two cases with FMH > 30 ml (0.58%), requiring a supplementary dose of anti-D. The study concludes that following the rosette test, additional evaluation of FMH using a quantitative test was unnecessary in 93.6% of the cases.

Clinical and epidemiological profile of female blood donors with positive serology for viral hepatitis B.

INTRODUCTION: Since women are frequently the minority among blood donors worldwide, studies evaluating this population usually reflect male features. We assessed the features of female blood donors with positive serology for HBV and compared them with those of men.METHODS The study comprised consecutive blood donors referred to a specialized liver disease center to be evaluated due to HBsAg- and/or anti-HBc-positive tests. RESULTS: The study encompassed 1,273 individuals, 219 (17.2%) of whom were referred due to positive HBsAg test and 1,054 (82.8%) due to reactive anti-HBc test. Subjects' mean age was 36.8±10.9 years, and 28.7% were women. Female blood donors referred for positive HBsAg screening tests demonstrated higher prevalence of healthcare workers (9.3% vs 2.5%) and lower prevalence of sexual risk behaviors (15.1% vs 41.1%) and alcohol abuse (1.9% vs 19.8%) compared to men. Women had lower ALT (0.6 vs 0.8×ULN), AST (0.6 vs 0.8×ULN), direct bilirubin (0.2 vs 0.3mg/dL), and alkaline phosphatase (0.5 vs 0.6×ULN) levels and higher platelet count (223,380±50,293 vs 195,020±53,060/mm3). Women also had a higher prevalence of false-positive results (29.6% vs 17.0%). No differences were observed with respect to liver biopsies. Female blood donors referenced for reactive anti-HBc screening tests presented similar clinical, epidemiological, and biochemical characteristics to those reported for positive HBsAg screening tests and similarly had a higher prevalence of false-reactive results. CONCLUSIONS: Compared to men, female blood donors with positive HBsAg and/or anti-HBc screening tests demonstrated higher prevalence of professional risk and false-positive results and reduced alteration of liver chemistry.