19S Proteasome Subunits as Oncogenes and Prognostic Biomarkers in FLT3-Mutated Acute Myeloid Leukemia (AML).

26S proteasome non-ATPase subunits 1 (PSMD1) and 3 (PSMD3) were recently identified as prognostic biomarkers and potential therapeutic targets in chronic myeloid leukemia (CML) and multiple solid tumors. In the present study, we analyzed the expression of 19S proteasome subunits in acute myeloid leukemia (AML) patients with mutations in the FMS-like tyrosine kinase 3 (FLT3) gene and assessed their impact on overall survival (OS). High levels of PSMD3 but not PSMD1 expression correlated with a worse OS in FLT3-mutated AML. Consistent with an oncogenic role for PSMD3 in AML, shRNA-mediated PSMD3 knockdown impaired colony formation of FLT3+ AML cell lines, which correlated with increased OS in xenograft models. While PSMD3 regulated nuclear factor-kappa B (NF-κB) transcriptional activity in CML, we did not observe similar effects in FLT3+ AML cells. Rather, proteomics analyses suggested a role for PSMD3 in neutrophil degranulation and energy metabolism. Finally, we identified additional PSMD subunits that are upregulated in AML patients with mutated versus wild-type FLT3, which correlated with worse outcomes. These findings suggest that different components of the 19S regulatory complex of the 26S proteasome can have indications for OS and may serve as prognostic biomarkers in AML and other types of cancers.

Loss of G0/G1 switch gene 2 (G0S2) promotes disease progression and drug resistance in chronic myeloid leukaemia (CML) by disrupting glycerophospholipid metabolism.

Tyrosine kinase inhibitors (TKIs) targeting BCR::ABL1 have turned chronic myeloid leukaemia (CML) from a fatal disease into a manageable condition for most patients. Despite improved survival, targeting drug-resistant leukaemia stem cells (LSCs) remains a challenge for curative CML therapy. Aberrant lipid metabolism can have a large impact on membrane dynamics, cell survival and therapeutic responses in cancer. While ceramide and sphingolipid levels were previously correlated with TKI response in CML, the role of lipid metabolism in TKI resistance is not well understood. We have identified downregulation of a critical regulator of lipid metabolism, G0/G1 switch gene 2 (G0S2), in multiple scenarios of TKI resistance, including (1) BCR::ABL1 kinase-independent TKI resistance, (2) progression of CML from the chronic to the blast phase of the disease, and (3) in CML versus normal myeloid progenitors. Accordingly, CML patients with low G0S2 expression levels had a worse overall survival. G0S2 downregulation in CML was not a result of promoter hypermethylation or BCR::ABL1 kinase activity, but was rather due to transcriptional repression by MYC. Using CML cell lines, patient samples and G0s2 knockout (G0s2-/- ) mice, we demonstrate a tumour suppressor role for G0S2 in CML and TKI resistance. Our data suggest that reduced G0S2 protein expression in CML disrupts glycerophospholipid metabolism, correlating with a block of differentiation that renders CML cells resistant to therapy. Altogether, our data unravel a new role for G0S2 in regulating myeloid differentiation and TKI response in CML, and suggest that restoring G0S2 may have clinical utility.

26S Proteasome Non-ATPase Regulatory Subunits 1 (PSMD1) and 3 (PSMD3) as Putative Targets for Cancer Prognosis and Therapy.

Ever since the ubiquitin proteasome system was characterized, efforts have been made to manipulate its function to abrogate the progression of cancer. As a result, the anti-cancer drugs bortezomib, carfilzomib, and ixazomib targeting the 26S proteasome were developed to treat multiple myeloma, mantle cell lymphoma, and diffuse large B-cell lymphoma, among others. Despite success, adverse side effects and drug resistance are prominent, raising the need for alternative therapeutic options. We recently demonstrated that knockdown of the 19S regulatory components, 26S proteasome non-ATPase subunits 1 (PSMD1) and 3 (PSMD3), resulted in increased apoptosis of chronic myeloid leukemia (CML) cells, but had no effect on normal controls, suggesting they may be good targets for therapy. Therefore, we hypothesized that PSMD1 and PSMD3 are potential targets for anti-cancer therapeutics and that their relevance stretches beyond CML to other types of cancers. In the present study, we analyzed PSMD1 and PSMD3 mRNA and protein expression in cancerous tissue versus normal controls using data from The Cancer Genome Atlas (TCGA) and the Clinical Proteomic Tumor Analysis Consortium (CPTAC), comparing expression with overall survival. Altogether, our data suggest that PSMD1 and PSMD3 may be novel putative targets for cancer prognosis and therapy that are worthy of future investigation.

Proteasome 26S subunit, non-ATPases 1 (PSMD1) and 3 (PSMD3), play an oncogenic role in chronic myeloid leukemia by stabilizing nuclear factor-kappa B.

Tyrosine kinase inhibitors (TKIs) targeting BCR-ABL1 have revolutionized therapy for chronic myeloid leukemia (CML), paving the way for clinical development in other diseases. Despite success, targeting leukemic stem cells and overcoming drug resistance remain challenges for curative cancer therapy. To identify drivers of kinase-independent TKI resistance in CML, we performed genome-wide expression analyses on TKI-resistant versus sensitive CML cell lines, revealing a nuclear factor-kappa B (NF-κB) expression signature. Nucleocytoplasmic fractionation and luciferase reporter assays confirmed increased NF-κB activity in the nucleus of TKI-resistant versus sensitive CML cell lines and CD34+ patient samples. Two genes that were upregulated in TKI-resistant CML cells were proteasome 26S subunit, non-ATPases 1 (PSMD1) and 3 (PSMD3), both members of the 19S regulatory complex in the 26S proteasome. PSMD1 and PSMD3 were also identified as survival-critical genes in a published small hairpin RNA library screen of TKI resistance. We observed markedly higher levels of PSMD1 and PSMD3 mRNA in CML patients who had progressed to the blast phase compared with the chronic phase of the disease. Knockdown of PSMD1 or PSMD3 protein correlated with reduced survival and increased apoptosis in CML cells, but not in normal cord blood CD34+ progenitors. Luciferase reporter assays and immunoblot analyses demonstrated that PSMD1 and PSMD3 promote NF-κB protein expression in CML, and that signal transducer and activator of transcription 3 (STAT3) further activates NF-κB in scenarios of TKI resistance. Our data identify NF-κB as a transcriptional driver in TKI resistance, and implicate PSMD1 and PSMD3 as plausible therapeutic targets worthy of future investigation in CML and possibly other malignancies.

Ethnic and border differences on blood cancer presentation and outcomes: A Texas population-based study.

BACKGROUND: The Texas/Chihuahua (US/Mexico) border is a medically underserved region with many reported barriers for health care access. Although Hispanic ethnicity is associated with health disparities for many different diseases, the population-based estimates of incidence and survival for patients with blood cancer along the border are unknown. The authors hypothesized that Hispanic ethnicity and border proximity is associated with poor blood cancer outcomes. METHODS: Data from the Texas Cancer Registry (1995-2016) were used to investigate the primary exposures of patient ethnicity (Hispanic vs non-Hispanic) and geographic location (border vs non-border). Other confounders and covariates included sex, age, year of diagnosis, rurality, insurance status, poverty indicators, and comorbidities. The Mantel-Haenszel method and Cox regression analyses were used to determine adjusted effects of ethnicity and border proximity on the relative risk (RR) and survival of patients with different blood cancer types. RESULTS: Hispanic patients were diagnosed at a younger age than non-Hispanic patients and presented with increased comorbidities. Whereas non-Hispanics had a higher incidence of developing blood cancer compared with Hispanics overall, Hispanics demonstrated a higher incidence of acute lymphoblastic leukemia (RR, 1.92; 95% CI, 1.79-2.08; P < .001) with worse outcomes. Hispanics from the Texas/Chihuahua border demonstrated a higher incidence of chronic myeloid leukemia (RR, 1.28; 95% CI, 1.07-1.51; P = .02) and acute myeloid leukemia (RR, 1.17; 95% CI, 1.04-1.33; P = .0009) compared with Hispanics living elsewhere in Texas. CONCLUSIONS: Hispanic ethnicity and border proximity were associated with a poor presentation and an adverse prognosis despite the younger age of diagnosis. Future studies should explore differences in disease biology and treatment strategies that could drive these regional disparities.

Blood cancer health disparities in the United States Hispanic population.

Cancer is a challenging, multifaceted disease that involves a combination of biological and nonbiological factors. Aside from COVID-19, cancer is the second leading cause of death in the United States and the first among Hispanic Americans. The Hispanic population is the largest minority group in the United States, which is rapidly growing in size. Unfortunately, U.S. Hispanics and other minority groups experience many different health disparities, resulting in poor survival outcomes and a reduced quality of life. Factors such as genomic mutations, lower socioeconomic status, lack of education, reduced access to health care, comorbidities, and environmental factors all contribute to these health-care inequalities. In the context of blood cancer health disparities, Hispanic patients are often diagnosed at a younger age and have worse outcomes compared with non-Hispanic individuals. In this commentary, we highlight the existing knowledge about cancer health disparities in the Hispanic population, with a focus on chronic and acute leukemia. In our experience at the U.S./Mexican border, analysis of several different blood cancers demonstrated that younger Hispanic patients with acute lymphoid or myeloid leukemia have higher incidence rates and worse prognoses. A combined approach, involving improved health-care access and better knowledge of the underlying factors, will allow for more timely diagnoses and the development of intervention strategies aimed at reducing or eliminating the disparities.

Energy metabolism and drug response in myeloid leukaemic stem cells.

Despite significant advances in the treatment of myeloid malignancies, many patients become resistant to therapy and ultimately succumb to their disease. Accumulating evidence over the past several years has suggested that the inadequacy of many leukaemia therapies results from their failure to target the leukaemic stem cell (LSC). For this reason, the LSC population currently represents the most critical target in the treatment of myeloid malignancies. However, while LSCs are ideal targets in the treatment of these diseases, they are also the most difficult population to target. This is due to both their heterogeneity within the LSC population, and also their phenotypic similarities with normal haematopoietic stem cells. This review will highlight the current landscape surrounding LSC biology in myeloid malignancies, with a focus on altered energy metabolism, and how that knowledge is being translated into clinical advances for the treatment of chronic and acute myeloid leukaemia and myelodysplastic syndromes.

Características epidemiológicas e genéticas associadas à gravidade da bronquiolite viral aguda pelo vírus sincicial respiratório / Epidemiological and genetic characteristics associated with the severity of acute viral bronchiolitis by respiratory syncytial virus

OBJETIVO: avaliar os fatores epidemiológicos e genéticos associados à gravidade da Bronquiolite Viral Aguda (BVA) pelo Vírus Sincicial Respiratório (VSR). FONTE DOS DADOS: foram utilizados descritores "bronchiolitis", "risk factor", "genetics" e "respiratory syncytial virus" e todas as combinações entre eles, nas bases de dados PubMed, SciELO e Lilacs publicados após o ano de 2000 e que incluíram indivíduos menores de dois anos de idade. SÍNTESE DOS DADOS: foram encontrados 1.259 artigos e lidos seus respectivos resumos. Destes foram selecionados 81 que avaliaram fatores de risco para a gravidade da BVA para leitura na íntegra, e foram incluídos os 60 estudos mais relevantes. Os fatores epidemiológicos associados com a gravidade da BVA pelo VSR foram: prematuridade, tabagismo passivo, baixa idade, ausência de aleitamento materno, doença pulmonar crônica, cardiopatia congênita, sexo masculino, etnia, coinfecção viral, baixo peso na admissão hospitalar, tabagismo materno na gestação, dermatite atópica, ventilação mecânica no período neonatal, antecedente materno de atopia e/ou asma na gestação, estação do nascimento, baixo nível socioeconômico, síndrome de Down, poluição ambiental, morar em altitude acima de 2.500 metros do nível do mar e parto cesariana. Em contrapartida, algumas crianças com BVA grave não apresentam nenhum desses fatores de risco. Neste sentido, estudos recentes têm verificado a influência de fatores genéticos relacionados à gravidade da BVA pelo VSR. Polimorfismos dos genes TLRs, RANTES, JUN, IFNA5, NOS2, CX3CR1, ILs e VDR têm-se mostrado associados com a evolução mais grave da BVA pelo VSR. CONCLUSÃO: a gravidade da BVA pelo VSR é um fenômeno dependente da interação entre variáveis epidemiológicas, ambientais e genéticas em seus diferentes graus de interação.

OBJECTIVE: to assess the epidemiological and genetic factors associated with severity of acute viral bronchiolitis (AVB) by respiratory syncytial virus (RSV). DATA SOURCE: the key words ''bronchiolitis'', ''risk factor'', ''genetics'' and ''respiratory syn-cytial virus'', and all combinations among them were used to perform a search in the PubMed,SciELO, and Lilacs databases, of articles published after the year 2000 that included individualsyounger than 2 years of age. DATA SYNTHESIS: a total of 1,259 articles were found, and their respective summaries were read. Of these, 81 were selected, which assessed risk factors for the severity of AVB, and were read in full; the 60 most relevant studies were included. The epidemiologic factors associated with AVB severity by RSV were prematurity, passive smoking, young age, lack of breastfeeding, chronic lung disease, congenital heart disease, male gender, ethnicity, viral coinfection, low weight at admission, maternal smoking during pregnancy, atopic dermatitis, mechanical ventilation in the neonatal period, maternal history of atopy and/or asthma during pregnancy, season of birth, low socioeconomic status, Down syndrome, environmental pollution, living at an altitude > 2,500 meters above sea level, and cesarean section birth. Conversely, some children with severe AVB did not present any of these risk factors. In this regard, recent studies have verified the influence of genetic factors on the severity of AVB by RSV. Polymorphisms of the TLRs, RANTES, JUN, IFNA5, NOS2, CX3CR1, ILs, and VDR genes have been shown to be associated with more severe evolution of AVB by RSV. CONCLUSION: the severity of AVB by RSV is a phenomenon that depends on the varying degrees of interaction among epidemiological, environmental, and genetic variables.

Recommendations for long-term home oxygen therapy in children and adolescents.

OBJECTIVE: To advise pediatricians, neonatologists, pulmonologists, pediatric pulmonologists, and other professionals in the area on the main indications and characteristics of long-term home oxygen therapy in children and adolescents. DATA SOURCE: A literature search was carried out in the MEDLINE/PubMed database (1990 to 2011). Additionally, references from selected studies were included. As consistent scientific evidence does not exist for many aspects, some of the recommendations were based on clinical experience. DATA SYNTHESIS: Long-term home oxygen therapy has been a growing practice in pediatric patients and is indicated in bronchopulmonary dysplasia, cystic fibrosis, bronchiolitis obliterans, interstitial lung diseases, and pulmonary hypertension, among others. The benefits are: decrease in hospitalizations, optimization of physical growth and neurological development, improvement of exercise tolerance and quality of sleep, and prevention of pulmonary hypertension/cor pulmonale. The levels of oxygen saturation indicative for oxygen therapy differ from those established for adults with chronic obstructive pulmonary disease, and vary according to age and disease. Pulse oximetry is used to evaluate oxygen saturation; arterial blood gas is unnecessary. There are three available sources of oxygen: gas cylinders, liquid oxygen, and oxygen concentrators. The flows used are usually smaller, as are the number of hours/day needed when compared to the use in adults. Some diseases show improvement and oxygen therapy discontinuation is possible. CONCLUSIONS: Long-term home oxygen therapy is increasingly common in pediatrics and has many indications. There are relevant particularities when compared to its use in adults, regarding indications, directions for use, and monitoring.

Recomendações para oxigenoterapia domiciliar prolongada em crianças e adolescentes / Recommendations for long-term home oxygen therapy in children and adolescents

OBJETIVO: Orientar pediatras, neonatologistas, pneumologistas, pneumologistas pediátricos e outros profissionais envolvidos na área sobre as principais indicações e as particularidades da oxigenoterapia domiciliar prolongada em crianças e adolescentes. FONTES DOS DADOS: Pesquisa bibliográfica na base de dados MEDLINE/PubMed (1990 a 2011). Adicionalmente, referências de estudos selecionados foram incluídas. Como para muitos dos aspectos não existem evidências científicas consistentes, algumas recomendações citadas foram feitas com base em experiência clínica. SÍNTESE DOS DADOS: Oxigenoterapia domiciliar prolongada tem sido uma prática crescente nos pacientes pediátricos e se encontra indicada em casos de displasia broncopulmonar, fibrose cística, bronquiolite obliterante, pneumopatias intersticiais, hipertensão pulmonar, etc. Ressaltam-se como benefícios: redução de internações, otimização do crescimento físico e do desenvolvimento neurológico, melhora da tolerância ao exercício e da qualidade do sono e prevenção da hipertensão pulmonar/. Os níveis de saturação de oxigênio indicativos para a oxigenoterapia diferem dos estabelecidos para adultos com doença pulmonar obstrutiva crônica e variam de acordo com a doença e faixa etária. Para a avaliação da saturação de oxigênio, utiliza-se a oximetria de pulso, sendo a gasometria arterial dispensável. Há três fontes de oxigênio disponíveis: cilindros gasosos, oxigênio líquido e concentradores de oxigênio. Os fluxos utilizados costumam ser menores, assim como o número de horas/dia necessários, quando comparados ao uso em adultos. Em algumas doenças há melhora, e a suspensão do oxigênio é possível. CONCLUSÕES: Oxigenoterapia domiciliar prolongada é uma terapêutica cada vez mais comum em pediatria e suas indicações são numerosas. Há particularidades relevantes quando comparada aos adultos em relação às indicações, modo de uso e monitorização.

OBJECTIVE: To advise pediatricians, neonatologists, pulmonologists, pediatric pulmonologists, and other professionals in the area on the main indications and characteristics of long-term home oxygen therapy in children and adolescents. DATA SOURCE: A literature search was carried out in the MEDLINE/PubMed database (1990 to 2011). Additionally, references from selected studies were included. As consistent scientific evidence does not exist for many aspects, some of the recommendations were based on clinical experience. DATA SYNTHESIS: Long-term home oxygen therapy has been a growing practice in pediatric patients and is indicated in bronchopulmonary dysplasia, cystic fibrosis, bronchiolitis obliterans, interstitial lung diseases, and pulmonary hypertension, among others. The benefits are: decrease in hospitalizations, optimization of physical growth and neurological development, improvement of exercise tolerance and quality of sleep, and prevention of pulmonary hypertension/cor pulmonale. The levels of oxygen saturation indicative for oxygen therapy differ from those established for adults with chronic obstructive pulmonary disease, and vary according to age and disease. Pulse oximetry is used to evaluate oxygen saturation; arterial blood gas is unnecessary. There are three available sources of oxygen: gas cylinders, liquid oxygen, and oxygen concentrators. The flows used are usually smaller, as are the number of hours/day needed when compared to the use in adults. Some diseases show improvement and oxygen therapy discontinuation is possible. CONCLUSIONS: Long-term home oxygen therapy is increasingly common in pediatrics and has many indications. There are relevant particularities when compared to its use in adults, regarding indications, directions for use, and monitoring.

[Association between alpha 1 antitrypsin deficiency and cystic fibrosis severity]. / Associação entre deficiência de alfa-1-antitripsina e a gravidade da fibrose cística.

OBJECTIVE: To ascertain the distribution of alpha 1 antitrypsin genotypes and correlate it with the severity of pulmonary disease in patients with cystic fibrosis. METHOD: A clinical and laboratory cross sectional study of 70 patients at the Universidade Estadual de Campinas teaching hospital. Cystic fibrosis diagnoses was confirmed by both clinical and laboratory methods. The severity of cystic fibrosis was evaluated by Shwachman score. All the patients were tested for the presence of S and Z alleles for alpha 1 antitrypsin deficiency using polymerase chain reaction. RESULTS: Nine (12.8%) patients were heterozygous for S or Z alleles or the heterozygote compound (SZ). No significant differences were found in clinical severity of Cystic fibrosis between genotypes of alpha 1 antitrypsin. No significant differences were found when the patients were divided according to the presence or absence of the DeltaF508 mutation. CONCLUSION: In this study, the first undertaken in Brazil into the association of alpha 1 antitrypsin deficiency and cystic fibrosis, we did not find an association between the deficiency and cystic fibrosis severity.

[Cystic fibrosis at a Brazilian center of excellence: clinical and laboratory characteristics of 104 patients and their association with genotype and disease severity]. / Fibrose cística em um centro de referência no Brasil: características clínicas e laboratoriais de 104 pacientes e sua associação com o genótipo e a gravidade da doença.

OBJECTIVE: To identify the clinical, laboratory and radiographic characteristics of the cystic fibrosis patients under care at Universidade Estadual de Campinas (UNICAMP) in the last decade of the twentieth century, and to investigate the association of these characteristics with genotype and severity of the disease as measured by the Shwachman score. METHODS: Descriptive, retrospective and cross-sectional study of the patients assisted at UNICAMP hospital's Cystic Fibrosis Clinic from July 1990 to July 2000. RESULTS: One hundred and four patients were studied; 53.8% male; 93.3% Caucasian; 89.4% presented with respiratory symptoms; 59.6% presented with digestive symptoms; 5.8% had meconium ileus; 4.8% had diabetes. The mean age at onset of symptoms was 3 months, and the mean age at diagnosis was 2 years and 4 months. At diagnosis, 69.9 and 56.6% of the patients had weight and height below 10th percentile, respectively; in 10.6%, sweat chloride was < 60 mEq/l. Staphylococcus aureus was found in 80.2%, Pseudomonas aeruginosa in 76%, and Burkholderia cepacia in 5.2%. DeltaF508 homozygosis was observed in 18.75%, whereas 62.50% of the patients were DeltaF508 heterozygous. A moderate/severe Shwachman score was found in 15.7%. Eighteen patients died in that period (17.3%). The mean age at death was 7 years and 8 months; median survival after diagnosis was 18 years and 4 months. Patients who have at least one DeltaF508 mutation have more frequent alterations in fecal fat levels when compared to patients who do not have this mutation (p < 0.05). There were no differences in any parameter between DeltaF508 homozygous and heterozygous patients. CONCLUSIONS: The clinical and laboratory characteristics of the 104 patients studied were similar to the characteristics described for patients in other countries. Exceptions are the higher age at diagnosis and lower survival. Our results support the recommendation for early diagnosis and the need for more treatment opportunities in the population of cystic fibrosis patients.

Fibrose cística em um centro de referência no Brasil: características clínicas e laboratoriais de 104 pacientes e sua associação com o genótipo e a gravidade da doença / Cystic fibrosis at a Brazilian center of excellence: clinical and laboratory characteristics of 104 patients and their association with genotype and disease severity

OBJETIVO: Estudar as características clínicas, laboratoriais e radiográficas de pacientes fibrocísticos acompanhados na última década do século 20 na UNICAMP e verificar se existe associação com o genótipo e a gravidade da doença medida pelo escore de Shwachman. MÉTODOS: Estudo descritivo, retrospectivo e de corte transversal dos pacientes fibrocísticos acompanhados na UNICAMP, que tiveram atendimento entre julho de 1990 e julho de 2000. RESULTADOS: Foram estudados 104 pacientes: sexo masculino - 53,8 por cento; raça caucasóide - 93,3 por cento; comprometimento pulmonar - 89,4 por cento, comprometimento digestivo - 59,6 por cento; íleo meconial - 5,8 por cento; diabetes melito - 4,8 por cento; mediana da idade de início dos sintomas - 3 meses; mediana da idade no diagnóstico - 2 anos e 4 meses; 69,9 e 56,6 por cento apresentavam peso e estatura abaixo do percentil 10, respectivamente, na época do diagnóstico; dosagem de cloro no suor < 60 mEq/l - 10,6 por cento; colonização: S. aureus - 80,2 por cento, P. aeruginosa - 76,0 por cento, B. cepacia - 5,2 por cento; delta F508 homozigoto - 18,75 por cento, deltaF508 heterozigoto - 62,5 por cento; escore de Shwachman moderado/grave - 15,7 por cento. Foram a óbito 18 pacientes (17,3 por cento); mediana de idade do óbito de 7 anos e 8 meses; sobrevida mediana após o diagnóstico no término do estudo de 18 anos e 4 meses. Os pacientes com a mutação deltaF508 apresentaram balanço de gordura nas fezes alterado com maior freqüência que os pacientes sem essa mutação (p < 0,05). Quando comparados os pacientes que apresentavam uma ou duas mutações deltaF508, nenhum parâmetro apresentou diferença estatisticamente significativa. CONCLUSÕES: As características clínicas e laboratoriais dos pacientes estudados foram semelhantes às descritas na população fibrocística de outros países, com algumas exceções, dentre as quais destacamos maior idade no diagnóstico e menor sobrevida. Desta forma, nossos dados permitem inferir que esforços para um diagnóstico precoce e maior oportunidade de tratamento necessitam ser dirigidos aos pacientes fibrocísticos.

Abernethy malformation: one of the etiologies of hepatopulmonary syndrome.

Hepatopulmonary syndrome (HPS) is the clinical relationship between hepatic disease and the existence of pulmonary vascular dilatations, which can result in a range of arterial oxygenation abnormalities. It is probably caused by an alteration in the synthesis or metabolism of vasoactive pulmonary substances at a hepatic level, leading to vasodilatation of pulmonary vessels and diffusion perfusion defects. The Abernethy malformation is characterized by the congenital diversion of portal blood away from the liver, by either end-to-side or side-to-side shunt. Here, we report on a 5-year-and-11-month-old-boy who had started cyanosis at age 4 years and 11 months, and did not have any other pulmonary or cardiac signs or symptoms. In the investigation, arterial blood gases revealed a PaO(2) of 41.4 mm Hg. The chest x-ray film and echo Doppler cardiography were normal. Nuclear scanning with Technetium 99m-labeled macroaggregated albumin showed the presence of arteriovenous shunt, at 47%. Abdominal echography revealed Abernethy malformation with an absence of portal vein. We concluded that the patient had HPS caused by Abernethy malformation. The possible mechanism is that in this malformation, there is a deviation in the blood that comes from the spleen to the vena cava without passing through the liver, so there is no metabolism of some substances which can be responsible for the imbalance between the vasodilatation and the vasoconstriction of the pulmonary circulation. Abernethy malformation must be included as one of the etiologies of hepatopulmonary syndrome. This is the first case described in the literature with this form of presentation.