José Oyhamburu

Frequent False‐positive results of lupus anticoagulant tests in plasmas of patients receiving the new oral anticoagulants and enoxaparin

Oral direct thrombin and Xa inhibitors are worldwide distributed for prevention and treatment of thrombosis. It is important to recognize their effects on lupus anticoagulant (LA) testing. The aim of the study is to describe the rate of false‐positive results of LA tests on plasmas of patients with previous negative LA tests results that receive dabigatran etexilate (DAB) 110 mg/twice a day, rivaroxaban (RIV) 10 mg/day or 15 mg/twice a day, or enoxaparin 40 mg/day.

Déficit de alfa 1 antitripsina en pacientes con EPOC: estudio de corte transversal

INTRODUCTION Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder associated with early onset chronic obstructive pulmonary disease (COPD) and liver disease. It is also a highly under-diagnosed condition. As early diagnosis could prompt specific interventions such as smoking cessation, testing of family members, genetic counselling and use of replacement therapy, screening programs are needed to identify affected patients. OBJECTIVE To estimate the prevalence of severe AATD in COPD patients by routine dried blood spot testing and subsequent genotyping in patients with alpha-1 antitrypsin (AAT) levels below an established threshold. MATERIALS AND METHODS Cross-sectional study of adult COPD patients attending the Hospital Dr. Antonio Cetrángolo (Buenos Aires, Argentina) between 2009 and 2012. The study consisted of capillary blood collection via finger stick to determine AAT levels, clinical evaluation and lung function tests. Genotype was determined in AAT-deficient patients. RESULTS A total of 1,002 patients were evaluated, of whom 785 (78.34%) had normal AAT levels, while low AAT levels were found in 217 (21.66%). Subsequent genotyping of the latter sub-group found: 15 (1.5%, 95% CI 0.75-2.25) patients with a genotype associated with severe AATD, of whom 12 were ZZ (1.2%, 95% CI 0.52-1.87) and 3 SZ (0.3%, 95% CI 0-0.64). The remaining 202 patients were classified as: 29 Z heterozygotes (2.89%, 95% CI 1.86-3.93), 25 S heterozygotes (2.5%, 95% CI 1.53-3.46) and 4 SS (0.4%, 95% CI 0.01-0.79). A definitive diagnosis could not be reached in 144 patients (14.37%, 95% CI 12.2-16.54). CONCLUSION The strategy using an initial serum AAT level obtained by dried blood spot testing and subsequent genotyping was a satisfactory initial approach to a screening program for severe AAT, as a definitive diagnosis was achieved in 87% of patients. However, results were not obtained for logistical reasons in the remaining 13%. This major obstacle may be overcome by the use of dried blood spot phenotyping techniques. We believe this approach for detecting AATD in COPD patients, in compliance with national and international guidelines, is supported by our results.

Effect of therapy with deflazacort on dyslipoproteinemia after pediatric renal transplantation.

Deflazacort is an oxazolone compound derived from prednisolone, with similar immunosuppressive action but fewer side effects. Kidney function, weight/height ratio, serum triglycerides, cholesterol, high-density lipoprotein (HDL) cholesterol, very-low-density lipoprotein cholesterol, low-density lipoprotein (LDL) cholesterol, apolipoprotein A, apolipoprotein B, and lipoprotein (a) were studied before and 6 months after substitution of deflazacort (mean +/- SEM, 0.3 +/- 0.1 mg/kg per day) for methylprednisone (0.2 +/- 0.1 mg/kg per day) in 14 patients treated with cyclosporine, aged 3.1 to 20.3 years, 3 years after renal transplantation. Serum creatinine and calculated creatinine clearance did not change significantly, and weight/height ratio decreased from 20.0% +/- 7.1% to 12.5% +/- 6.5% (P < .005) during deflazacort therapy. Total cholesterol was reduced by 15.9% (from 233 +/- 15 mg/dL to 196 +/- 13 mg/dL, P < .01), LDL cholesterol by 25.5% (from 153 +/- 14 mg/dL to 114 +/- 12 mg/dL, P < .01), and TC/HDL cholesterol ratio by 28.3% (from 5.3 +/- 0.4 to 3.8 +/- 0.4, P < .01), whereas HDL cholesterol increased 18% (from 45 +/- 2 mg/dL to 53 +/- 2 mg/dL) and apolipoprotein A by 8.3% (from 122 +/- 5 mg/dL to 132 +/- 5 mg/dL, P < .05) during deflazacort therapy. Our data suggest that substituting deflazacort for maintenance methylprednisone therapy leads to an improvement in the lipoprotein profile of children after renal transplantation.

The fibrinogen prothrombin time-derived method is not useful in patients anticoagulated with low molecular weight heparins or rivaroxaban

Essentials Fibrinogen prothrombin time‐derived (FIBPT‐d) behavior in anticoagulated patients is under studied. FIBPT‐d method overestimates fibrinogen in rivaroxaban and low molecular weight heparin samples. Unfractionated heparin and dabigatran samples showed similar bias to the control group. Rabbit brain and human recombinant thromboplastin behavior was different in rivaroxaban samples.