Machine learning for the development of diagnostic models of decompensated heart failure or exacerbation of chronic obstructive pulmonary disease.

Heart failure (HF) and chronic obstructive pulmonary disease (COPD) are two chronic diseases with the greatest adverse impact on the general population, and early detection of their decompensation is an important objective. However, very few diagnostic models have achieved adequate diagnostic performance. The aim of this trial was to develop diagnostic models of decompensated heart failure or COPD exacerbation with machine learning techniques based on physiological parameters. A total of 135 patients hospitalized for decompensated heart failure and/or COPD exacerbation were recruited. Each patient underwent three evaluations: one in the decompensated phase (during hospital admission) and two more consecutively in the compensated phase (at home, 30 days after discharge). In each evaluation, heart rate (HR) and oxygen saturation (Ox) were recorded continuously (with a pulse oximeter) during a period of walking for 6 min, followed by a recovery period of 4 min. To develop the diagnostic models, predictive characteristics related to HR and Ox were initially selected through classification algorithms. Potential predictors included age, sex and baseline disease (heart failure or COPD). Next, diagnostic classification models (compensated vs. decompensated phase) were developed through different machine learning techniques. The diagnostic performance of the developed models was evaluated according to sensitivity (S), specificity (E) and accuracy (A). Data from 22 patients with decompensated heart failure, 25 with COPD exacerbation and 13 with both decompensated pathologies were included in the analyses. Of the 96 characteristics of HR and Ox initially evaluated, 19 were selected. Age, sex and baseline disease did not provide greater discriminative power to the models. The techniques with S and E values above 80% were the logistic regression (S: 80.83%; E: 86.25%; A: 83.61%) and support vector machine (S: 81.67%; E: 85%; A: 82.78%) techniques. The diagnostic models developed achieved good diagnostic performance for decompensated HF or COPD exacerbation. To our knowledge, this study is the first to report diagnostic models of decompensation potentially applicable to both COPD and HF patients. However, these results are preliminary and warrant further investigation to be confirmed.

Long-term use of somatostatin analogs for chronic gastrointestinal bleeding in hereditary hemorrhagic telangiectasia.

Background: Chronic bleeding due to gastrointestinal (GI) involvement in patients with hemorrhagic hereditary telangiectasia (HHT) can provoke severe anemia with high red blood cells (RBC) transfusion requirements. However, the evidence about how to deal with these patients is scarce. We aimed to assess the long-term efficacy and safety of somatostatin analogs (SA) for anemia management in HHT patients with GI involvement. Methods: This is a prospective observational study including patients with HHT and GI involvement attended at a referral center. SA were considered for those patients with chronic anemia. Anemia-related variables were compared in patients receiving SA before and during treatment. Patients receiving SA were divided into responders (patients with minimal hemoglobin levels improvement >10 g/L and maintaining hemoglobin levels ≥80 g/L during treatment), and non-responders. Adverse effects during follow-up were collected. Results: Among 119 HHT patients with GI involvement, 67 (56.3%) received SA. These patients showed lower minimal hemoglobin levels (73 [60-87] vs. 99 [70.2-122.5], p < 0.001), and more RBC transfusion requirements (61.2% vs. 38.5%, p = 0.014) than patients without SA therapy. Median treatment period was 20.9 ± 15.2 months. During treatment, there was a statistically significant improvement in minimum hemoglobin levels (94.7 ± 29.8 g/L vs. 74.7 ± 19.7, p < 0.001) and a reduction of patients with minimal hemoglobin levels <80 g/L (39 vs. 61%, p = 0.007) and RBC transfusions requirement (33.9% vs. 59.3%, p < 0.001). Sixteen (23.9%) patients showed mild adverse effects, mostly diarrhea or abdominal pain, leading to treatment discontinuation in 12 (17.9%) patients. Fifty-nine patients were eligible for efficacy assessment and 32 (54.2%) of them were considered responders. Age was associated with non-responder patients, OR 95% CI; 1.070 (1.014-1.130), p = 0.015. Conclusion: SA can be considered a long-term effective and safe option for anemia management in HHT patients with GI bleeding. Older age is associated with poorer response.

Catheter-Directed Therapies in Patients with Pulmonary Embolism: Predictive Factors of In-Hospital Mortality and Long-Term Follow-Up.

(1) Background: Catheter-directed therapies (CDT) may be considered for selected patients with pulmonary embolism (PE); (2) Methods: Retrospective observational study including all consecutive patients with acute PE undergoing CDT (mechanical or pharmacomechanical) from January 2010 through December 2020. The aim was to evaluate in-hospital and long-term mortality and its predictive factors; (3) Results: We included 63 patients, 43 (68.3%) with high-risk PE. All patients underwent mechanical CDT and, additionally, 27 (43%) underwent catheter-directed thrombolysis. Twelve (19%) patients received failed systemic thrombolysis (ST) prior to CDT, and an inferior vena cava (IVC) filter was inserted in 28 (44.5%) patients. In-hospital PE-related and all-cause mortality rates were 31.7%; 95% CI 20.6-44.7% and 42.9%; 95% CI 30.5-56%, respectively. In multivariate analysis, age > 70 years and previous ST were strongly associated with PE-related and all-cause mortality, while IVC filter insertion during the CDT was associated with lower mortality rates. After a median follow-up of 40 (12-60) months, 11 more patients died (mortality rate of 60.3%; 95% CI 47.2-72.4%). Long-term survival was significantly higher in patients who received an IVC filter; (4) Conclusions: Age > 70 years and failure of previous ST were associated with mortality in acute PE patients treated with CDT. In-hospital and long-term mortality were lower in patients who received IVC filter insertion.

Non-retrieved inferior vena cava filters: causes and long-term follow-up.

BACKGROUND: Temporary inferior vena cava (IVC) filters are not always retrieved. Information about long-term outcomes of patients with indwelling filters is scarce. Aims of our study were to assess reasons that preclude retrieval of temporary IVC filters and long-term outcomes and causes of death in patients with indwelling filters. MATERIALS AND METHODS: Retrospective observational study including all consecutive patients undergoing IVC filter insertion from January 2009 through December 2018. Patients with permanent filters and those with temporary filters not retrieved were followed from insertion until June 2020. RESULTS: We included 271 patients with a mean age of 63.8 years. The main indication for filter insertion was acute venous thromboembolism and contraindication for anticoagulation (83%). The filter was deemed as permanent in 24.4% of patients and temporary in 75.6%. Sixty six percent of temporary filters were retrieved; the main cause of non-retrieval was lack of planning / follow-up (57.9%). One hundred twelve patients (41.3%) remained with indwelling filters. After follow-up, 54.5% were alive and 45.5% had died, with a median survival time of 6.19 (95% CI, 2.63-9.75) years. The most frequent cause of death during follow-up was cancer (49%). The frequency of anticoagulant therapy was similar in both groups (57.4%% versus 54.9%). CONCLUSIONS: The main preventable cause of non-retrieval of temporary IVC filters was lack of planning / follow-up. Structured follow-up programs should be implemented to increase retrieval rates. In patients with indwelling filters, the main cause of death was cancer and extended anticoagulation was not associated with survival.

Blood test dynamics in hospitalized COVID-19 patients: Potential utility of D-dimer for pulmonary embolism diagnosis.

BACKGROUND: A higher incidence of thrombotic events, mainly pulmonary embolism (PE), has been reported in hospitalized patients with COVID-19. The main objective was to assess clinical and laboratory differences in hospitalized COVID-19 patients according to occurrence of PE. METHODS: This retrospective study included all consecutive patients hospitalized with COVID-19 who underwent a computed tomography (CT) angiography for PE clinical suspicion. Clinical data and median blood test results distributed into weekly periods from COVID-19 symptoms onset, were compared between PE and non-PE patients. RESULTS: Ninety-two patients were included, 29 (32%) had PE. PE patients were younger (63.9 (SD 13.7) vs 69.9 (SD 12.5) years). Clinical symptoms and COVID-19 CT features were similar in both groups. PE was diagnosed after a mean of 20.0 (SD 8.6) days from the onset of COVID-19 symptoms. Corticosteroid boluses were more frequently used in PE patients (62% vs. 43%). No patients met ISTH DIC criteria. Any parameter was statistically significant or clinically relevant except for D-Dimer when comparing both groups. Median values [IQR] of D-dimer in PE vs non-PE patients were: week 2 (2010.7 [770.1-11208.9] vs 626.0 [374.0-2382.2]; p = 0.004); week 3 (3893.1 [1388.2-6694.0] vs 1184.4 [461.8-2447.8]; p = 0.003); and week 4 (2736.3 [1202.1-8514.1] vs 1129.1 [542.5-2834.6]; p = 0.01). Median fold-increase of D-dimer between week 1 and 2 differed between groups (6.64 [3.02-23.05] vs 1.57 [0.64-2.71], p = 0.003); ROC curve AUC was 0.879 (p = 0.003) with a sensitivity and specificity for PE of 86% and 80%, respectively. CONCLUSIONS: Among hospitalized COVID-19 patients, D-dimer levels are higher at weeks 2, 3 and 4 after COVID-19 symptom onset in patients who develop PE. This difference is more pronounced when the fold increase between weeks 1 and 2 is compared.

Tratamiento de la telangiectasia hemorrágica hereditaria en el paciente adulto / Medical management of haemorrhagic hereditary telangiectasia in adult patients

La telangiectasia hemorrágica hereditaria es una enfermedad minoritaria con herencia autosómica dominante que ocasiona un crecimiento vascular anómalo de forma sistémica. El abordaje y seguimiento de estos pacientes debería hacerse desde unidades multidisciplinares. Su diagnóstico es clínico según los criterios de Curaçao. Las telangiectasias en la mucosa nasal ocasionan epistaxis recurrentes, principal síntoma de esta enfermedad y de difícil control. Los 3 patrones de afectación hepática, comunicaciones entre arteria hepática y venas suprahepáticas, entre arteria hepática y vena porta o entre vena porta y venas suprahepáticas pueden causar insuficiencia cardiaca por hiperaflujo, hipertensión portal o encefalopatía hepática, respectivamente. Estos tipos de afectación vascular se pueden establecer mediante tomografía computarizada. Se debe realizar un cribado de fístulas arteriovenosas pulmonares a todos los pacientes mediante una ecocardiografía con contraste. Nuestro principal objetivo es realizar una revisión del manejo de las epistaxis, afectación hepática y pulmonar del paciente adulto con telangiectasia hemorrágica hereditaria

Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant inherited Rare Disease that causes a systemic anomalous vascular overgrowth. The approach and follow-up of these patients should be from multidisciplinary units. Its diagnosis is carried out according to Curaçao clinical Criteria. Telangiectasia in the nasal mucosa cause recurrent epistaxis, the main symptom of HHT and difficult to control. The three types of hepatic shunting, hepatic artery to hepatic vein, hepatic artery to portal vein or to portal vein to hepatic vein, can cause high-output heart failure, portal hypertension or porto-systemic encephalopathy, respectively. These types of vascular involvement can be established using computerised tomography. Pulmonary arteriovenous fistula should be screened for all HHT patients by contrast echocardiography. The main objective is to review the management of epistaxis, liver and lung involvement of the adult patient with HHT

Effort Oxygen Saturation and Effort Heart Rate to Detect Exacerbations of Chronic Obstructive Pulmonary Disease or Congestive Heart Failure.

BACKGROUND: current algorithms for the detection of heart failure (HF) and chronic obstructive pulmonary disease (COPD) exacerbations have poor performance. METHODS: this study was designed as a prospective longitudinal trial. Physiological parameters were evaluated at rest and effort (walking) in patients who were in the exacerbation or stable phases of HF or COPD. Parameters with relevant discriminatory power (sensitivity (Sn) or specificity (Sp) ≥ 80%, and Youden index ≥ 0.2) were integrated into diagnostic algorithms. RESULTS: the study included 127 patients (COPD: 56, HF: 54, both: 17). The best algorithm for COPD included: oxygen saturation (SaO2) decrease ≥ 2% in minutes 1 to 3 of effort, end-of-effort heart rate (HR) increase ≥ 10 beats/min and walking distance decrease ≥ 35 m (presence of one criterion showed Sn: 0.90 (95%, CI(confidence interval): 0.75⁻0.97), Sp: 0.89 (95%, CI: 0.72⁻0.96), and area under the curve (AUC): 0.92 (95%, CI: 0.85⁻0.995)); and for HF: SaO2 decrease ≥ 2% in the mean-of-effort, HR increase ≥ 10 beats/min in the mean-of-effort, and walking distance decrease ≥ 40 m (presence of one criterion showed Sn: 0.85 (95%, CI: 0.69⁻0.93), Sp: 0.75 (95%, CI: 0.57⁻0.87) and AUC 0.84 (95%, CI: 0.74⁻0.94)). CONCLUSIONS: effort situations improve the validity of physiological parameters for detection of HF and COPD exacerbation episodes.

Gastrointestinal Bleeding in Patients with Hereditary Hemorrhagic Telangiectasia: Risk Factors and Endoscopic Findings.

BACKGROUND: We aimed to describe risk factors for gastrointestinal (GI) bleeding and endoscopic findings in patients with hereditary hemorrhagic telangiectasia (HHT). METHODS: This is a prospective study from a referral HHT unit. Endoscopic tests were performed when there was suspicion of GI bleeding, and patients were divided as follows: with, without, and with unsuspected GI involvement. RESULTS: 67 (27.9%) patients with, 28 (11.7%) patients without, and 145 (60.4%) with unsuspected GI involvement were included. Age, tobacco use, endoglin (ENG) mutation, and hemoglobin were associated with GI involvement. Telangiectases were mostly in the stomach and duodenum, but 18.5% of patients with normal esophagogastroduodenoscopy (EGD) had GI involvement in video capsule endoscopy (VCE). Telangiectases ≤ 3 mm and ≤10 per location were most common. Among patients with GI disease, those with hemoglobin < 8 g/dL or transfusion requirements (65.7%) were older and had higher epistaxis severity score (ESS) and larger telangiectases (>3 mm). After a mean follow-up of 34.2 months, patients with GI involvement required more transfusions and more emergency department and hospital admissions, with no differences in mortality. CONCLUSIONS: Risk factors for GI involvement have been identified. Patients with GI involvement and severe anemia had larger telangiectases and higher ESS. VCE should be considered in patients with suspicion of GI bleeding, even if EGD is normal.

Medical management of haemorrhagic hereditary telangiectasia in adult patients. / Tratamiento de la telangiectasia hemorrágica hereditaria en el paciente adulto.

Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant inherited Rare Disease that causes a systemic anomalous vascular overgrowth. The approach and follow-up of these patients should be from multidisciplinary units. Its diagnosis is carried out according to Curaçao clinical Criteria. Telangiectasia in the nasal mucosa cause recurrent epistaxis, the main symptom of HHT and difficult to control. The three types of hepatic shunting, hepatic artery to hepatic vein, hepatic artery to portal vein or to portal vein to hepatic vein, can cause high-output heart failure, portal hypertension or porto-systemic encephalopathy, respectively. These types of vascular involvement can be established using computerised tomography. Pulmonary arteriovenous fistula should be screened for all HHT patients by contrast echocardiography. The main objective is to review the management of epistaxis, liver and lung involvement of the adult patient with HHT.

High Prevalence of Left Ventricle Diastolic Dysfunction in Severe COPD Associated with A Low Exercise Capacity: A Cross-Sectional Study.

BACKGROUND: A subclinical left ventricle diastolic dysfunction (LVDD) has been described in patients with chronic obstructive pulmonary disease (COPD). OBJECTIVES: To evaluate the prevalence of LVDD in stable severe COPD patients, to analyze its relationship with exercise capacity and to look for its possible causes (lung hyperinflation, ventricular interdependence or inflammatory mechanisms). METHODS: We evaluated 106 consecutive outpatients with severe COPD (FEV1 between 30-50%). Thirty-three (31%) were excluded because of previous heart disease. A pulmonary function test, a 6-minute walking test (6MWT), a Doppler echocardiography test, including diastolic dysfunction parameters, and an analysis of arterial blood gases, NT-proBNP and serum inflammatory markers (CRP, leucocytes), were performed in all patients. RESULTS: The prevalence of LVDD in severe stable COPD patients was 90% (80% type I, n=57, and 10% type II, n=7). A significant association between a lower E/A ratio (higher LVDD type I) and a lower exercise tolerance (6-minute walked distance (6MWD)) was found (r=0.29, p<0.05). The fully adjusted multivariable linear regression model demonstrated that a lower E/A ratio, a DLCO in the quartile 4(th) and a higher tobacco consumption were associated with a lower 6MWD (76, 57 and 0.7 metres, respectively, p<0.05). A significant correlation between E/A ratio and PaO2 was observed (r=0.26, p<0.05), but not with static lung hyperinflation, inflammation or right ventricle overload parameters. CONCLUSION: In stable severe COPD patients, the prevalence of LVDD is high and this condition might contribute in their lower exercise tolerance. Hypoxemia could have a concomitant role in their pathogenesis.

Effects of inhaled nitric oxide at rest and during exercise in idiopathic pulmonary fibrosis.

Patients with idiopathic pulmonary fibrosis (IPF) usually develop hypoxemia and pulmonary hypertension when exercising. To what extent endothelium-derived vasodilating agents modify these changes is unknown. The study was aimed to investigate in patients with IPF whether exercise induces changes in plasma levels of endothelium-derived signaling mediators, and to assess the acute effects of inhaled nitric oxide (NO) on pulmonary hemodynamics and gas exchange, at rest and during exercise. We evaluated seven patients with IPF (6 men/1 woman; 57 ± 11 yr; forced vital capacity, 60 ± 13% predicted; carbon monoxide diffusing capacity, 52 ± 10% predicted). Levels of endothelin, 6-keto-prostaglandin-F(1α), thromboxane B(2), and nitrates were measured at rest and during submaximal exercise. Pulmonary hemodynamics and gas exchange, including ventilation-perfusion relationships, were assessed breathing ambient air and 40 ppm NO, both at rest and during submaximal exercise. The concentration of thromboxane B(2) increased during exercise (P = 0.046), whereas levels of other mediators did not change. The change in 6-keto-prostaglandin-F(1α) correlated with that of mean pulmonary arterial pressure (r = 0.94; P < 0.005). Inhaled NO reduced mean pulmonary arterial pressure at rest (-4.6 ± 2.1 mmHg) and during exercise (-11.7 ± 7.1 mmHg) (P = 0.001 and P = 0.004, respectively), without altering arterial oxygenation or ventilation-perfusion distributions in any of the study conditions. Alveolar-to-capillary oxygen diffusion limitation, which accounted for the decrease of arterial Po(2) during exercise, was not modified by NO administration. We conclude that, in IPF, some endothelium-derived signaling molecules may modulate the development of pulmonary hypertension during exercise, and that the administration of inhaled NO reduces pulmonary vascular resistance without disturbing gas exchange.

[State of public pneumology in Catalonia (Spain): 1993 versus 2003]. / Estado de la neumología pública en Cataluña: estudio comparativo entre 1993 y 2003.

The aim of this study was to perform a descriptive analysis of the state of public pneumology in Catalonia (Spain) in 2003 and to compare the results with data from 1993. A questionnaire was sent to all hospitals of the public hospitals network in Catalonia requesting information on the number of pulmonologists. To determine the number of pulmonologists working in primary care, we also contacted all the primary care services (PCS) in Catalonia. All the hospitals and PCS contacted responded. Eighty-three percent of the public network hospitals had a pneumology service. From 1993-2003, the proportion of hospitals with this specialty increased. The rate of pulmonologists per 100,000 persons for the whole of Catalonia was 3.15. The degree of implantation of pneumology in the public hospitals network of Catalonia significantly improved in the decade between 1993 and 2003.

Estado de la neumología pública en Cataluña: estudio comparativo entre 1993 y 2003 / State of public pneumology in Catalonia [Spain]: 1993 versus 2003

El objetivo de este estudio era realizar un análisis descriptivo de la situación de la neumología pública en Cataluña en el año 2003 y comparar los resultados con datos de 1993. Se remitió un cuestionario a todos los hospitales de la red pública de Cataluña (XHUP) solicitando información sobre el número de neumólogos. También se contactó con los servicios de atención primaria (SAP) de Cataluña para conocer el número de neumólogos que trabajan en atención primaria. Se ha obtenido respuesta del 100% de los hospitales y SAPcontactados. El 83% de los hospitales de la XHUP disponende servicio de neumología, y se observa un incremento significativo en la proporción de hospitales que disponen de la especialidad respecto a 1993. La tasa de neumólogos por 100.000 habitantes para toda Cataluña es de 3,15.El grado de implantación de la neumología en la XHUP hamejorado significativamente en el decenio 1993-2003

The aim of this study was to perform a descriptive analysis of the state of public pneumology in Catalonia (Spain) in 2003 and to compare the results with data from 1993.A questionnaire was sent to all hospitals of the public hospitals network in Catalonia requesting information on the number of pulmonologists. To determine the number of pulmonologists working in primary care, we also contacted all the primary care services (PCS) in Catalonia.All the hospitals and PCS contacted responded. Eighty-three percent of the public network hospitals had a pneumology service. From 1993-2003, the proportion of hospitals with this specialty increased. The rate of pulmonologists per 100,000 persons for the whole of Catalonia was 3.15.The degree of implantation of pneumology in the public hospitals network of Catalonia significantly improved in the decade between 1993 and 2003

[Prevalence and prognostic significance of myeloid markers in adults with high-risk acute lymphoblastic leukemia]. / Prevalencia y significado pronóstico de los marcadores mieloides en adultos con leucemia aguda linfoblástica de alto riesgo.

BACKGROUND AND OBJECTIVE: The prognostic value of myeloid antigen expression in adult acute lymphoblastic leukemia (ALL) is controversial. The objective of this study was to evaluate the frequency and prognostic significance of myeloid antigen expression in adults with high risk ALL. PATIENTS AND METHOD: Between June 1993 and July 2002, 222 adults patients with high-risk ALL were treated according to the PETHEMA LAL 93 protocol. The frequency of myeloid antigen expression, its association with other clinical and biologic variables and the prognostic significance in terms of complete remission (CR) rate, event free survival (EFS) and overall survival (OS) were analyzed. RESULTS: Myeloid antigen expression was present in 96 out of 222 patients (43%). No association was observed between myeloid antigen expression and the main clinical and biologic characteristics of ALL. Response to treatment was slower in patients expressing myeloid antigens, but no differences were found in CR achievement, EFS or OS. The probability of EFS at 10 years for ALL patients without and with myeloid antigen expression was 35% and 34%, respectively, while the probability of OS at 10 years was 30% and 33%, respectively. This absence of differences in EFS and OS probabilities was also observed when only slow responding patients were analyzed. CONCLUSIONS: In this study, myeloid antigen expression did not have prognostic influence in adult patients with high risk ALL.

Prevalencia y significado pronóstico de los marcadores mieloides en adultos con leucemia aguda linfoblástica de alto riesgo / Prevalence and prognostic significance of myeloid markers in adults with high-risk acute lymphoblastic leukemia

Fundamento y objetivo: El valor pronóstico de los marcadores mieloides en la leucemia aguda linfoblástica (LAL) del adulto es controvertido. El objetivo de este estudio fue evaluar la frecuencia y el significado pronóstico de los marcadores mieloides en adultos con LAL de alto riesgo. Pacientes y método: Entre junio de 1993 y julio de 2002, 222 pacientes adultos con LAL de alto riesgo se trataron según el protocolo PETHEMA LAL 93. Se analizó la frecuencia de los marcadores mieloides, su asociación con otras variables clínico-biológicas de la LAL y el significado pronóstico expresado como la probabilidad de obtención de la remisión completa (RC), supervivencia libre de evento (SLE) y supervivencia global (SG). Resultados: La presencia de marcadores mieloides se constató en 96 de los 222 pacientes (43%). No se observó ninguna relación entre la presencia de marcadores mieloides y las principales características clínico-biológicas de la LAL. La rapidez de la respuesta al tratamiento fue menor en los pacientes con marcadores mieloides, pero no se hallaron diferencias en la tasa de obtención de la RC, la SLE y la SG. La probabilidad de SLE a los 10 años fue, respectivamente, del 35 y del 34% para las LAL con marcadores mieloides y sin ellos. La probabilidad de SG a los 10 años fue del 33% para las LAL con marcadores mieloides y del 30% para las que no los presentaban. Cuando se estudiaron de manera aislada los pacientes con respuesta lenta al tratamiento, tampoco se hallaron diferencias en términos de SLE y SG entre ambos tipos de LAL. Conclusiones: En este estudio los marcadores mieloides no tuvieron significado pronóstico en los pacientes adultos con LAL de alto riesgo

Background and objective: The prognostic value of myeloid antigen expression in adult acute lymphoblastic leukemia (ALL) is controversial. The objective of this study was to evaluate the frequency and prognostic significance of myeloid antigen expression in adults with high risk ALL. Patients and method: Between June 1993 and July 2002, 222 adults patients with high-risk ALL were treated according to the PETHEMA LAL 93 protocol. The frequency of myeloid antigen expression, its association with other clinical and biologic variables and the prognostic significance in terms of complete remission (CR) rate, event free survival (EFS) and overall survival (OS) were analyzed. Results: Myeloid antigen expression was present in 96 out of 222 patients (43%). No association was observed between myeloid antigen expression and the main clinical and biologic characteristics of ALL. Response to treatment was slower in patients expressing myeloid antigens, but no differences were found in CR achievement, EFS or OS. The probability of EFS at 10 years for ALL patients without and with myeloid antigen expression was 35% and 34%, respectively, while the probability of OS at 10 years was 30% and 33%, respectively. This absence of differences in EFS and OS probabilities was also observed when only slow responding patients were analyzed. Conclusions: In this study, myeloid antigen expression did not have prognostic influence in adult patients with high risk ALL