Guillermo Conte L

Frecuencia y características de la resistencia a aspirina en pacientes cardiovasculares chilenos

Background: Studies performed in Anglo-Saxon countries show that 5% of patients are resistant to the antiplatelet effects of aspirin. Aim: To assess the prevalence of aspirin resistance in a sample of Chilean cardiovascular patients and its association with clinical and laboratory characteristics. Patients and Methods: Ninety nine patients (30 women, 63±10 years) treated for stable cardiovascular diseases with aspirin 100325 mg/day were studied. Clinical and basic coagulation variables were assessed. Platelet aggregation was studied with platelet rich plasma using three different agonists in an optical aggregometer. Aspirin resistance was defined as an aggregation >20% with arachidonic acid and an aggregation >70% with ADP or collagen. Results: Eleven patients (11.11%, 95% CI= 4.95-17.27%) complied with both criteria and were classified as aspirin resistant. Current smoking was more common in aspirin resistant patients (63.6 vs 29.6%, p=0.039). Conclusions: Aspirin resistance was found in a significant proportion of cardiovascular patients and was more common among current smokers (Rev Med Chile 2005; 133: 409-17). (Key Words: Aspirin; Cardiovascular diseases; Platelet aggregation inhibitors)

Valor pronóstico del nuevo sistema de etapificación internacional en mieloma múltiple. Comparación con el sistema de Durie-Salmon

Information of 81 patients aged 38 to90 years (43 women) was retrieved. According D&S system 11% were in stage I, 12% in stage II and73% in stage III. According to ISS, 34% were in stage I, 35% in stage II and 31% in stage III. Medianof survival of all patients was 32 months. Both staging systems had a prognostic value. However,median survival for the three stages of the ISS system was significantly different (67, 29 and 14months in stages I, II and III, respectively, p =0.02). Patients in advanced stages II and III of the ISS,had a higher frequency of anemia, hypercalcemia, renal failure and hypoalbuminemia. In stages IIand III of ISS the presence of renal failure was associated with a non significantly different lowersurvival.

Mieloma múltiple en Chile: Características clínicas y sobrevida

Mortality rate records are the only data available in Chile about the prognosis of patients with multiple myeloma (MM). Aim To characterize clinical features, survival rate and factors related to mortality in cases with MM treated in six large medical centers in Chile. Material and Method: Retrospective analysis of demographic data, clinical features and survival rate records of patients with MM, collected between 1998 and 2002. Survival curves were generated and a multivariate analysis of factors associated to early mortality was carried out. Results: Data from 245patients aged 38 to 95years (129 women) was collected. Fifty two percent had an IgG myeloma, 25% had and IgA and 6.1% had light chains myeloma. According to Durie and Salmon staging system, 8,2% were in Stage 112.6% in Stage II, 60.5% in Stage III and in 18.8% the information about staging was not available. Fifty percent had an hemoglobin level below 10 g/dL, 30% had a serum creatinine over 2 mg/dL and 28% had a serum calcium level over 10.5 mg/dL. Median survival was 33 months. Twenty percent of patients died within the first six months after diagnosis (early mortality). Predictive factors for early mortality were male sex, thrombocytopenia, anemia, renal failure, hypercalcemia, a beta2-microglobulin >5.5 mg/L and a serum albumin level <3.5 g/dL. There was a correlation between the number of bad prognosis factors present and the probability of early mortality. Conclusions: This group of Chilean patients with MM presented a short survival time, and 20% died within the first six months after diagnosis. More than a half of cases were diagnosed at an advanced stage (Durie and Salmon Stage III). Several factors were associated to early mortality, two of which (beta 2-microglobulin and serum albumin), are included in the new International Staging System for MM

HEMOFILIA ADQUIRIDA TRATADA CON ANTI-CD20, UN ANTICUERPO ANTI LINFOCITO B.

We report a 54-year-old male presenting with a history or recurrent nose bleeds and ecchymoses. The coagulation study showed a prolonged partial thromboplastin time, a factor VIII of 8% and a high inhibitor titer (193 Bethesda units). A diagnosis of acquired hemophilia A was reached. The patient was initially treated with cyclophosphamide for seven months without response. Therefore rituximab in doses of 375 mglm²/week for four weeks was started. After starting treatment, the patient had a hematoma in the psoas muscle with a concomitant factor VIII of less than 5%, that was treated with local measures. Thereafter, a progressive reduction in inhibitor titers was observed, until its disappearance at five months of treatment. Factor VIII levels normalized and the patient has not experienced abnormal bleeding episodes. The patient remains in remission after 67 months of follow up. Rituximab, a chimeric monoclonal antibody against the protein CD 20 is an effective treatment in acquired hemophilia A.

Proteína S libre en embarazadas normales: comparación entre dos métodos

Background: Pregnancy is a physiological hypercoagulable state with an increased incidence of thromboembolic phenomena. There is an increase in the concentrations of most clotting factors, a decrease in concentration of some of the natural anticoagulants and reduced fibrinolytic activity. Changes in PS levels have also been reported. Aim: To establish referral range values of functional PS and free PS antigen, during the second (2 nd T) and third trimester (3 rd T) of normal gestation. Patients and methods: Forty one normal pregnant women were included in our study, 20 during the 2 nd T (22-24 weeks) and 21 during the 3 rd T (29-38 weeks). Functional PS was measured by a clot based test and free PS antigen by ELISA. Results: Free PS Antigen was 65.8±18.3% during the 2 nd T and 62.3±16.5% during the 3 rd T. The figures for normal controls were 106±6.5%. Functional PS was 43.8±13.3 and 25.9±14.6% during the 2 nd T and 3 rd T, respectively. The figures for normal controls were 97±24% (p <0.001 compared with pregnant women). Free PS antigen did not change from the 2 nd to the 3 rd T (p=NS), however functional PS fell significantly from the 2 nd to the 3 rd T (p <0.001) and was significantly lower than free PS antigen in both trimesters (p <0.001). Conclusions: Pregnancy is associated to a decrease in PS. This abnormality is more pronounced for functional PS than free PS antigen and functional PS falls progressively during pregnancy. These assays should not be used to screen for PS deficiency during pregnancy because they could lead to a misdiagnosis (Rev Med Chile 2005; 133: 633-8). (Key Words: Pregnancy trimesters; Protein S; Protein S deficiency)

Determinación de factores trombofílicos en pacientes con trombosis venosas retinianas

BACKGROUND Thrombophilia is an alteration of hemostasis that increases the risk to venous or arterial thrombosis. This condition may be the underlying cause of retinal vein thrombosis. AIM To study the presence of thrombophilia in patients with retinal vein thrombosis. PATIENTS AND METHODS Prospective study of 55 patients aged 22 to 86 years, with retinal vein thrombosis (central or branch). Antithrombin III, coagulant protein C, functional protein S, resistance to activated C protein, homocysteine, prothrombin G20210A gene, lupus anticoagulant and anticardiolipin antibodies were measured in all. RESULTS Seventeen patients had thrombophilic markers (antiphospholipid syndrome in seven, hyperhomocysteinemia in six and resistance to protein C in three). Of these 17 patients, 53% had high blood pressure, 35% an abnormal serum lipid profile and 23% a personal history of thrombosis. The thrombosis was central in 12 (ischemic in four) and of a branch in five (ischemic in two). CONCLUSIONS Thrombophilic markers must be assessed in patients with retinal vein thrombosis.

Intoxicación aguda con metotrexato usado con fines abortivos: descripción de 2 casos

Acute intoxication with methotrexate, used as an abortive, has not been described in Chile. We report two female patients, aged 15 and 24 years old, who presented with mucositis, erythrodermia, pancytopenia, and elevation of hepatic enzymes. Plasma methotrexate levels confirmed the clinical diagnosis and both patients were treated with high leucovorin doses and management of associated complications. In one patient, pregnancy continued, giving birth to a newborn with cranial, face and limb malformations. The second patient had a late rescue with leucovorin and was discharged with a persistent sensory motor neuropathy. Considering the severity of complications and that patients may deny its use, when there is reasonable clinical suspicion of methotrexate intoxication, leucovorin treatment should be started.

La genética como factor pronóstico y terapéutico en el mieloma múltiple

The search for prognostic factors in multiple myeloma has identified the genetic profile of the tumor as the main determinant of patient survival and response to treatment. There is an association between a dismal prognosis and the presence of t(4:14) translocations or 17p deletion, determined by fluorescent in situ hybridization (FISH) or the detection of chromosome 13 deletion using conventional cytogenetic techniques. These alterations define a subpopulation that comprises 25% of patients with a bad prognosis even if they are treated with high dose chemotherapy These patients should be early derived to more specific therapies. In the other hand, the other 75% of patients without a genetic risk factor, have a higher probability of success with conventional treatment.

SÍNDROME ANTIFOSFOLÍPIDOS Y TROMBOCITOPENIA MATERNA EN GEMELAR BICORIÓNICO CON RESTRICCIÓN FETAL GRAVE

SUMMARY We report a clinical case of antiphospholipid syndrome with previous fetal death and extended anticoagulant treatment. At a second gestation (bichorionic twins) an early selective restriction of one fetus was developed which stopped growth on week 25. After a treated maternal thrombocytopenia we proceed with an elective premature delivery by cesarean section on week 28. Both twins (860 and 406 grams each) survived the neonatal period. We discuss the ethiopatogenic probable mechanisms and singular aspects of circulatory adaptation of twin B in a very complex case and management.

Púrpura de Schönlein-Henoch grave en un paciente con mieloma múltiple

A Multiple Myeloma (MM), IgG-l stage III-A was diagnosed in a 41-year-old-man. After VAD cycles IgG decreased from 7.5 to 2.4 g/dL. were mobilized with cyclophosphamide and 10 µg/Kg G-CSF. Three days after the collection of peripheral stem cell, the patient had fever, nausea, vomiting, liquid stools, shoulder and knee arthralgia and dehydration. Upper GI endoscopy showed esophageal candidiasis and ulcerative necrotic lesions both in stomach and duodenum; the biopsy confirmed necrosis. Simultaneously, the appearance of purpura with maculopapular lesions of diverse sizes appeared in the feet progressing to the limbs and trunk. Hematuria and proteinuria were also observed. Skin biopsy showed leukocytoclastic vasculitis. Renal biopsy showed focal and segmental glomerulonephritis. Serum ANCA, cryoglobulins, anti-HCV and RF were negative, and serum monoclonal IgG was 1290 mg/dL. Daily treatment with iv methylprednisolone pulses for 3 days improved skin lesions and digestive involvement. Macroscopic hematuria and proteinuria improved after two months of steroid treatment (Rev Med Chile 2000; 128: 1255-60)