Interleukin-10 GCC/GCC haplotype is associated high risk of acute GVHD in patients undergoing allogeneic HSCT in the southern of Brazil.

INTRODUCTION: Hematopoietic Stem Cell Transplant (HSCT) is currently an important curative treatment for many patients with malignant and non-malignant diseases. Graft versus host disease (GVHD) represents a major complication in allogeneic HSCT recipients. Several polymorphisms in cytokine genes have recently been investigated as candidates for risk factors for acute-GVHD (aGVHD) in allogeneic hematopoietic stem cell transplantation (allo-HSCT). OBJECTIVE: In this study, we analyzed specific interleukin (IL)-10 haplotypes polymorphisms, in a cohort of 99 patients and their respective allo-HSCT donors for aGVHD and risk. RESULTS: An association was found between IL-10 promoter haplotype polymorphisms at positions -1082, -819 and - 592 with the occurrence of aGVHD. Patients who have the GCC/GCC haplotype are at increased risk of aGVHD (P = 0.017, HR: 5.42 (95% CI: 1.34-21.84). In the donors group and severity of aGVHD as not found statistical significancy. CONCLUSION: The results obtained show the IL-10 GCC/GCC haplotype can be an important biomarker to identify the greatest risk of aGVHD in the patient undergoing HSCT.

Flow cytometry immunophenotyping of healthy platelets and hospitalized patients with suspected platelet dysfunction: Challenges for establishing a cutoff value.

INTRODUCTION AND OBJECTIVE: Flow Cytometry (FC) is one of the techniques, which allows the identification and characterization of platelets. The detection of absent or reduced expression of the glycoproteins is the main objective of this technique. Abnormalities of glycoproteins lead to hemorrhagic syndromes. Among the main diseases, the Bernard-Soulier syndrome (BSS) and Glanzmann thrombasthenia (GT) stand out. We aimed to show a FC-based platelet assessment test for diagnostic use, which measures the expression of markers in normal patients, and evaluate these markers in patients with platelet disorders. METHODS: We examined a control group of 41 healthy adults to establish reference values and assess the variability of the relative expression of platelet markers and subsequently compared these findings to those of 30 patients with suspected platelet dysfunctions. We determined the mean fluorescent intensity (MFI) of the expressed parameters by FC using CD41, CD42a, CD42b and CD61 and SSC/FSC platelet-gated cells. RESULTS: We determined our baseline panel of markers and compared them to suspected platelet dysfunctions. Patients with suspected BSS presented increased levels of the MFI for the GPIIIa (CD61) and GPIIb (CD41). They showed significantly reduced levels of the GPIb (CD42b) and GPIX (CD42a). Patients with suspected GT showed normal expression of the GPIX (CD42a), increased expression of the GPIb (CD42b) and reduced levels of the GPIIIa (CD61). In this case, with reduced levels of only one marker, the GPIIb (CD41), values showed normal expression. CONCLUSIONS: We describe the FC assay to support the diagnosis of different platelet disorders. Our study made it possible to implement a technique that brought benefits to care.

Evaluation of RET-He values as an early indicator of iron deficiency anemia in pregnant women

Abstract Introduction During pregnancy, women are at an increased risk of developing iron-deficiency anemia. Objective The objective of this study was to assess the diagnostic performance of the reticulocyte hemoglobin equivalent (RET-He) in the early detection of iron-deficiency anemia in a group of pregnant women and to establish a reference range for this parameter in a group of control individuals. Method: A total of 60 patients and 130 control subjects were included in the study. Blood samples collected from the subjects were submitted to a complete blood count and a serum ferritin test and the data were analyzed by comparing the groups and ROC curves. Results The reference range found for the RET-He was between 29.75pg and 38.24pg, with a median of 35pg. The receiver operating characteristic (ROC) curve analysis for the ferritin parameter showed an area under the curve of 0.732 for the RET-He, 0.586 for hemoglobin, 0.551 for the mean corpuscular hemoglobin concentration and 0.482 for the mean corpuscular volume. Conclusion Early diagnosis of iron deficiency anemia in pregnancy is essential to prevent damage to both maternal and fetal health. The RET-He presents an excellent potential as an auxiliary tool for the diagnosis of iron deficiency in pregnant women.

Evaluation of RET-He values as an early indicator of iron deficiency anemia in pregnant women.

INTRODUCTION: During pregnancy, women are at an increased risk of developing iron-deficiency anemia. OBJECTIVE: The objective of this study was to assess the diagnostic performance of the reticulocyte hemoglobin equivalent (RET-He) in the early detection of iron-deficiency anemia in a group of pregnant women and to establish a reference range for this parameter in a group of control individuals. METHOD: A total of 60 patients and 130 control subjects were included in the study. Blood samples collected from the subjects were submitted to a complete blood count and a serum ferritin test and the data were analyzed by comparing the groups and ROC curves. RESULTS: The reference range found for the RET-He was between 29.75pg and 38.24pg, with a median of 35pg. The receiver operating characteristic (ROC) curve analysis for the ferritin parameter showed an area under the curve of 0.732 for the RET-He, 0.586 for hemoglobin, 0.551 for the mean corpuscular hemoglobin concentration and 0.482 for the mean corpuscular volume. CONCLUSION: Early diagnosis of iron deficiency anemia in pregnancy is essential to prevent damage to both maternal and fetal health. The RET-He presents an excellent potential as an auxiliary tool for the diagnosis of iron deficiency in pregnant women.

Comparison of Nonsequencing Techniques for Identification of NPM1 Mutations and Associated Blast Morphology in Patients With Acute Myeloid Leukemia.

CONTEXT.­: Nucleophosmin 1 (NPM1) mutations affect 20% to 30% of all acute myeloid leukemia (AML) patients; several methods are employed to analyze NPM1 mutations, each of them with its advantages and limitations. OBJECTIVE.­: To compare 3 nonsequencing protocols capable of detecting the main NPM1 mutations and to evaluate nuclear morphometric analysis (NMA) as an alternative to cuplike blast detection. DESIGN.­: We selected multiparameter flow cytometry (MFC), amplification refractory mutation system-polymerase chain reaction (ARMS-PCR), and a quantitative PCR (qPCR) kit to identify NPM1 mutations in AML patients at diagnosis. We also evaluated the presence of cuplike blasts and assessed nuclear morphometry using NMA. RESULTS.­: MFC appears as a screening method for NPM1 mutations because of its lower specificity. ARMS-PCR demonstrated specificity similar to that of the qPCR kit, although it was more laborious. qPCR testing, conversely, is relatively fast and easy to standardize. Of these methods, qPCR was the only one capable of identifying the type of NPM1 mutation. With regard to morphology, NMA could be used as an alternative for the evaluation of cuplike blasts in AML smears. CONCLUSIONS.­: qPCR appears to be the best option to identify NPM1 mutations, with ARMS-PCR representing a cheaper alternative. MFC may be used as a screening method, in which results falling within and above the gray zone should be confirmed by molecular testing.

Lymphocytes from B-acute lymphoblastic leukemia patients present differential regulation of the adenosinergic axis depending on risk stratification.

PURPOSE: Although risk-stratified chemotherapy regimens improve B-cell acute lymphoblastic leukemia (B-ALL) clinical outcome, relapse occurs in a significant number of cases. The identification of new therapeutic targets as well as prognostic and diagnostic biomarkers can improve B-ALL patients' clinical outcomes. Purinergic signaling is an important pathway in cancer progression, however the expression of ectonucleotidases and their impact on immune cells in B-ALL lacks exploration. We aimed to analyze the expression of ectonucleotidases in B-ALL patients' lymphocyte subpopulations. METHODS: Peripheral blood samples from 15 patients diagnosed with B-ALL were analyzed. Flow cytometry was used to analyze cellularity, expression level of CD38, CD39, and CD73, and frequency of [Formula: see text], and [Formula: see text] in lymphocyte subpopulations. Plasma was used for cytokines (by CBA kit) and adenine nucleosides/nucleotides detection (by HPLC). RESULTS: Comparing B-ALL patients to health donors, we observed an increase of CD4 + and CD8 + T-cells. In addition, a decrease in CD38 expression in B and Treg subpopulations and an increase in CD39+ CD73+ frequency in Breg and CD8+ T-cells. Analyzing cytokines and adenine nucleosides/nucleotides, we found a decrease in TNF, IL-1ß, and ADO concentrations, together with an increase in AMP in B-ALL patients' plasma. CONCLUSION: As immunomodulators, the expression of ectonucleotidases might be associated with activation states, as well as the abundance of different cellular subsets. We observed a pro-tumor immunity expression profile in B-ALL patients at diagnosis, being associated with cell exhaustion and immune evasion in B-ALL.

NT5E gene and CD38 protein as potential prognostic biomarkers for childhood B-acute lymphoblastic leukemia.

The risk stratification of B-acute lymphoblastic leukemia (B-ALL) is based on clinical and biological factors. However, B-ALL has significant biological and clinical heterogeneity and 50% of B-ALL patients do not have defined prognostic markers. In this sense, the identification of new prognostic biomarkers is necessary. Considering different cohorts of childhood B-ALL patients, gene (DPP4/CD38/ENTPD1/NT5E) and protein (CD38/CD39/CD73) expressions of ectonucleotidases were analyzed in silico and ex vivo and the association with prognosis was established. In univariate analyses, expression of NT5E was significantly associated with worse progression-free survival (PFS) in bone marrow (BM) samples. In multivariate analyses, Kaplan-Meier analysis, and log-rank test, higher NT5E expression predicted unfavorable PFS in BM samples. Considering minimal residual disease (MRD), higher levels of cellularity were associated with the high NT5E expression at day 8 of induction therapy. In addition, we observed that white blood cells (WBC) of childhood B-ALL patients had more CD38 compared to the same cell population of healthy donors (HD). In fact, MRD > 0.1% patients had higher CD38 protein expression on WBC in comparison to HD. Noteworthy, we observed higher CD38 expression on WBC than blasts in MRD > 0.1% patients. We suggest that NT5E gene and CD38 protein expression, of the ectonucleotidases family, could provide interesting prognostic biomarkers for childhood B-ALL.

HEMOPHAGOCYTOSIS BY BLASTS IN A CHILD WITH ACUTE MONOCYTIC LEUKEMIA AFTER CHEMOTHERAPY.

OBJECTIVE: To describe the case of a child who presented hemophagocytic lymphohistiocytosis (HLH) associated with acute monocytic leukemia after chemotherapy, with hemophagocytosis caused by leukemic cells. CASE DESCRIPTION: In a university hospital in Southern Brazil, a 3-year-old female was diagnosed with acute monocytic leukemia with normal karyotype. The chemotherapy regimen was initiated, and she achieved complete remission six months later, relapsing after four months with a complex karyotype involving chromosomes 8p and 16q. The bone marrow showed vacuolated blasts with a monocytic aspect and evidence of hemophagocytosis. The child presented progressive clinical deterioration and died two months after the relapse. COMMENTS: HLH is a rare and aggressive inflammatory condition characterized by cytopenias, hepatosplenomegaly, fever, and hemophagocytosis in the bone marrow, lymph nodes, spleen, and liver. Although rare, malignancy-associated HLH (M-HLH) is fatal. The patient in this case report met five out of the eight established criteria for HLH. The evolution of the patient's karyotype, regardless of the diagnostic profile, seemed secondary to the treatment for acute monocytic leukemia. In this case, the cytogenetic instability might have influenced the abnormal behavior of leukemic cells. This is a rare case of HLH in a child with acute monocytic leukemia.

Comparison of two techniques for assessing pancreatic islet viability: flow cytometry and fluorescein diacetate/propidium iodine staining

Introduction: The success of islet transplantation for patients with unstable type 1 diabetes mellitus depends, in part, on the number of isolated islets and their quality, which is assessed by functional and viability tests. The test currently employed to evaluate islet viability, used by the Collaborative Islet Transplant Registry to release products for transplantation, is fluorescein diacetate/propidium iodide (FDA/PI) staining. However, the efficacy of this method relies on researcher experience; in this context, a quantitative method may be useful. The aim of this study was to compare islet viability as assessed by flow cytometry and the FDA/PI assay. Methods: Viability was analyzed in islets isolated from 10 male Wistar rats. Upon FDA/PI staining, 50 islets from each animal were analyzed under fluorescence microscopy by two well-trained researchers. For flow cytometry, islets were dispersed and 100 000 single cells were incubated with the 7-amino-actinomycin D (7AAD) fluorophore (dyes necrotic and late apoptotic cells) and the Annexin V-APC antibody (marks early apoptotic cells). Results: A moderate correlation was found between techniques (r = 0.6; p = 0.047). The mean islet viability measured by flow cytometry was higher than that estimated using FDA/PI staining (95.5 ± 1.4% vs 89.5 ± 5.0%; p = 0.002). Conclusions: Although flow cytometry is more expensive and time-consuming than FDA/PI staining, it is a quantitative technique with greater reproducibility that is less subject to inter-observer variability than FDA/PI. Therefore, flow cytometry appears to be the technique of choice when aiming for a more precise determination of islet viability. (AU)

Flow cytometry as a diagnostic tool in childhood solid tumors / Citometria de fluxo como ferramenta diagnóstica em tumores sólidos da infância

RESUMEN Los tumores sólidos infantiles representan aproximadamente el 30% de todos los cánceres pediátricos. En los últimos años se ha incrementado el uso de la citometría de flujo (CF) en el diagnóstico y seguimiento de estas patologías, ya que es un método que permite obtener resultados rápidos y precisos, posibilitando un manejo más precoz. Realizamos esta revisión sistemática para la búsqueda bibliográfica de los siguientes términos en las plataformas de datos Lilacs, PubMed y Scielo: neoplasma, oncología, pediatría, inmunofenotipificación y citometría de flujo. Así, describimos los principales hallazgos hasta la fecha sobre el uso de CF en el diagnóstico diferencial de los cinco principales tumores de células pequeñas, redondas y azules de la infancia: neuroblastoma, sarcoma de Ewing, tumor neuroectodérmico primitivo, tumor de Wilms y rabdomiosarcoma. Además, describimos las principales ventajas y desventajas del método y paneles que se proponen en el diagnóstico diferencial de estas patologías a través de la literatura internacional. A través de esta revisión, observamos que el uso de CF en el diagnóstico de tumores sólidos puede ser útil para la identificación rápida y precisa de la efermedade, así como para el inicio más temprano del tratamiento.

Hemophagocytosis by blasts in a child with acute monocytic leukemia after chemotherapy / Hemofagocitose por células blásticas em paciente pediátrico com leucemia monocítica aguda após quimioterapia

ABSTRACT Objective: To describe the case of a child who presented hemophagocytic lymphohistiocytosis (HLH) associated with acute monocytic leukemia after chemotherapy, with hemophagocytosis caused by leukemic cells. Case description: In a university hospital in Southern Brazil, a 3-year-old female was diagnosed with acute monocytic leukemia with normal karyotype. The chemotherapy regimen was initiated, and she achieved complete remission six months later, relapsing after four months with a complex karyotype involving chromosomes 8p and 16q. The bone marrow showed vacuolated blasts with a monocytic aspect and evidence of hemophagocytosis. The child presented progressive clinical deterioration and died two months after the relapse. Comments: HLH is a rare and aggressive inflammatory condition characterized by cytopenias, hepatosplenomegaly, fever, and hemophagocytosis in the bone marrow, lymph nodes, spleen, and liver. Although rare, malignancy-associated HLH (M-HLH) is fatal. The patient in this case report met five out of the eight established criteria for HLH. The evolution of the patient's karyotype, regardless of the diagnostic profile, seemed secondary to the treatment for acute monocytic leukemia. In this case, the cytogenetic instability might have influenced the abnormal behavior of leukemic cells. This is a rare case of HLH in a child with acute monocytic leukemia.

RESUMO Objetivo: Descrever um caso de um paciente pediátrico que apresentou linfo-histiocitose hemofagocítica (LHH) associada à leucemia monocítica aguda pós-quimioterapia, com hemofagocitose causada pelas próprias células leucêmicas. Descrição do caso: Em um hospital universitário do Sul do Brasil, uma menina de três anos foi diagnosticada com leucemia monocítica aguda com cariótipo normal. Após receber protocolo quimioterápico, atingiu remissão seis meses depois do início do tratamento, recaíndo quatro meses após com um cariótipo complexo envolvendo ambos os cromossomos, 8p e 16q. A medula óssea mostrava-se infiltrada por células blásticas vacuolizadas com aspecto monocítico, com evidências de hemofagocitose. A criança apresentou um declínio clínico progressivo e dois meses após a recaída foi a óbito. Comentários: A LHH é uma condição inflamatória rara e agressiva caracterizada por citopenias, hepatoesplenomegalia, febre e hemofagocitose na medula óssea, linfonodos, baço e fígado. A LHH associada a doenças malignas, embora seja uma condição rara, é potencialmente fatal. A paciente deste caso apresentou cinco dos oito critérios estabelecidos para o diagnóstico de LHH. A evolução do cariótipo do paciente, independentemente do perfil do diagnóstico, pareceu ser secundária ao tratamento da leucemia monocítica aguda, sendo que a instabilidade citogenética pode ter influenciado o comportamento atípico observado nas células leucêmicas. Este é um dos raros casos de LHH em uma criança com leucemia monocítica aguda.

Influence of minimal residual disease by multiparametric flow cytometry at day 15 of induction in risk stratification of children with B-cell acute lymphoblastic leukemia treated at a referral hospital in southern Brazil

ABSTRACT Background: The minimal residual disease (MRD) is the most important prognostic factor for acute lymphoblastic leukemia (ALL) in children. This study aimed to investigate the influence of detecting the MRD by the multiparametric flow cytometry (MFC) at day 15 (D15) of the induction on the analysis of the risk group classifications of the different childhood ALL treatment protocols used in a referral hospital in southern Brazil. Method: We retrospectively reviewed the medical records of patients with B-cell ALL, aged 1 to 18 years, treated at a hospital from January 2013 to April 2017. Main results: Seventy-five patients were analyzed. Regarding the MRD by the MFC at D15, the analyses showed statistical significance when the MRD was grouped into three categories, < 0.1%, 0.1-10%, and > 10%, with the following distribution: 30.7%, 52.0%, and 17.3%, respectively. There was a significant association between D15 MRD-MFC < 0.1% and the likelihood of dying or relapsing and between D15 MRD-MFC > 10% and the likelihood of dying or relapsing. The cumulative hazard ratio for the relapse of patients with D15 MRD-MFC < 0.1%, 0.1-10%, and > 10% was 19.2%, 59.8%, and 80.1%, respectively. Conclusion: Our analysis suggests D15 MRD-MFC < 0.1% as a cut-off point for patients with more favorable outcomes and that the MRD at D15 in risk classifications is particularly useful for the stratification of patients with a more favorable prognosis.

Influence of minimal residual disease by multiparametric flow cytometry at day 15 of induction in risk stratification of children with B-cell acute lymphoblastic leukemia treated at a referral hospital in southern Brazil.

BACKGROUND: The minimal residual disease (MRD) is the most important prognostic factor for acute lymphoblastic leukemia (ALL) in children. This study aimed to investigate the influence of detecting the MRD by the multiparametric flow cytometry (MFC) at day 15 (D15) of the induction on the analysis of the risk group classifications of the different childhood ALL treatment protocols used in a referral hospital in southern Brazil. METHOD: We retrospectively reviewed the medical records of patients with B-cell ALL, aged 1 to 18 years, treated at a hospital from January 2013 to April 2017. MAIN RESULTS: Seventy-five patients were analyzed. Regarding the MRD by the MFC at D15, the analyses showed statistical significance when the MRD was grouped into three categories, < 0.1%, 0.1-10%, and > 10%, with the following distribution: 30.7%, 52.0%, and 17.3%, respectively. There was a significant association between D15 MRD-MFC < 0.1% and the likelihood of dying or relapsing and between D15 MRD-MFC > 10% and the likelihood of dying or relapsing. The cumulative hazard ratio for the relapse of patients with D15 MRD-MFC < 0.1%, 0.1-10%, and > 10% was 19.2%, 59.8%, and 80.1%, respectively. CONCLUSION: Our analysis suggests D15 MRD-MFC < 0.1% as a cut-off point for patients with more favorable outcomes and that the MRD at D15 in risk classifications is particularly useful for the stratification of patients with a more favorable prognosis.

Quantification of peripheral blood CD34+ cells prior to stem cell harvesting by leukapheresis: a single center experience

ABSTRACT Background: Due to laboratory logistic issues, our center has traditionally scheduled peripheral blood stem cell harvests based on timing from the start of mobilization. This has proved to be useful in some cases, but also resulted in many fruitless harvests due to poor mobilization. In order to improve the efficiency of collections and compare the effectiveness of peripheral blood CD34+ cells as a predictor with data from other reports, this study analyzed the implementation of this routine. Methods: Peripheral blood and leukapheresis samples were quantified by flow cytometry and the association between these parameters was assessed. Results: Sixty-six consecutive leukapheresis samples were collected from 34 patients after the collection of peripheral blood samples for CD34+ quantification. A moderate positive correlation was observed between peripheral blood CD34+ cell count and total CD34+ cell count/kg (r = 0.596; p-value < 0.001). A multivariable regression model also confirmed this association and allowed the estimation that for every increase in five CD34+ cells/µL in the peripheral blood, a mean increase of 0.38 × 106 CD34+ cells/kg could be predicted. Demographic characteristics, baseline comorbidities and mobilization regimen did not influence final CD34+ cell count in this sample. Conclusions: As observed in other centers, quantification of peripheral blood CD34+ progenitor cells is a strong predictor of effectiveness to guide stem cell harvesting. Due to the results of this study, a modification in the peripheral blood stem cell harvesting logistics was implemented at our center in order to incorporate this routine.

Quantification of peripheral blood CD34+ cells prior to stem cell harvesting by leukapheresis: a single center experience.

BACKGROUND: Due to laboratory logistic issues, our center has traditionally scheduled peripheral blood stem cell harvests based on timing from the start of mobilization. This has proved to be useful in some cases, but also resulted in many fruitless harvests due to poor mobilization. In order to improve the efficiency of collections and compare the effectiveness of peripheral blood CD34+ cells as a predictor with data from other reports, this study analyzed the implementation of this routine. METHODS: Peripheral blood and leukapheresis samples were quantified by flow cytometry and the association between these parameters was assessed. RESULTS: Sixty-six consecutive leukapheresis samples were collected from 34 patients after the collection of peripheral blood samples for CD34+ quantification. A moderate positive correlation was observed between peripheral blood CD34+ cell count and total CD34+ cell count/kg (r = 0.596; p-value < 0.001). A multivariable regression model also confirmed this association and allowed the estimation that for every increase in five CD34+ cells/µL in the peripheral blood, a mean increase of 0.38 × 106 CD34+ cells/kg could be predicted. Demographic characteristics, baseline comorbidities and mobilization regimen did not influence final CD34+ cell count in this sample. CONCLUSIONS: As observed in other centers, quantification of peripheral blood CD34+ progenitor cells is a strong predictor of effectiveness to guide stem cell harvesting. Due to the results of this study, a modification in the peripheral blood stem cell harvesting logistics was implemented at our center in order to incorporate this routine.

Cut-off value for absolute lymphocytes as an alternative for the immunophenotypic analysis of CD3+ T cells in the monitoring of immunosuppressive therapy with thymoglobulin.

INTRODUCTION: Immunosuppression of T lymphocytes is required for preventing acute rejection after transplantation and for the treatment of chronic autoimmune and inflammatory diseases. The laboratory monitoring for this therapy is the measurement of T cells by immunophenotyping, aiming the target value of less than 20 cells per µL. OBJECTIVE: To establish a cut-off point for the total number of lymphocytes in the automated blood cell count that reflects less than twenty T cells µL by immunophenotyping. METHODS: We studied and evaluated 242 kidney transplant patients that had results of automated blood cell count and quantification of T cells by immunophenotyping technique. The patients were divided into two groups, depending on the T lymphocyte immunophenotyping rates established by lower and higher than 20 cells per µL. After, we evaluated the cut-off point for lymphocytes in the blood cell count with a specificity of 100% to exclude patients with high levels of T lymphocytes. RESULTS: We found that the cut-off point of 70 lymphocytes per µL obtained by automated blood cell count showed 100% of specificity to exclude patients with T-cell counts higher than 20 cells per µL by immunophenotyping. CONCLUSION: The results found in this study may be helpful to monitor the immunosuppressive therapy in kidney transplant patients in places where a flow cytometer is not available, or when this equipment is not present in the full routine.

Do Alpha Thalassemia, Fetal Hemoglobin, and the UGT1A1 Polymorphism have an Influence on Serum Bilirubin Levels and Cholelithiasis in Patients with Sickle Cell Disease?

BACKGROUND: Increased destruction of erythrocytes in patients with sickle cell disease results in chronic hyperbilirubinemia and leads to the formation of gallstones. OBJECTIVES: The objective of this study was to determine the combined influence of alpha thalassemia, fetal hemoglobin, and the UGT1A1 polymorphism on serum bilirubin levels and cholelithiasis in patients with sickle cell disease. METHODS: We analyzed 72 patients treated in the outpatient hematology unit of the Clinical Hospital of Porto Alegre. The alpha thalassemia trait was determined by multiplex polymerase chain reaction and the polymorphisms of UGT1A1 by capillary electrophoresis with tagged primers. RESULTS: Total and indirect bilirubin levels differed significantly between genotypes TA7/TA7 and TA6/TA6 (p < 0.05). Bilirubin levels were influenced by the UGT1A1 polymorphism but not by alpha thalassemia and fetal hemoglobin. There was no association between cholelithiasis and any of the variables studied. CONCLUSION: These preliminary findings suggest that the UGT1A1 gene can influence serum bilirubin levels in sickle cell anemia and serve as a tool to differentiate an acute hemolytic condition from a pre-existing condition of hyperbilirubinemia.