Mónica Aixalá

Leukoagglutinins in patients with hemophilia

Anti-leukocyte antibodies may occur in hemophilic patients as a consequence of replacement therapy with blood derivates. In this report we describe the presence of leukoagglutinins (LA) in serum of HIV-infected hemophiliacs (HIV + He) and their absence in HIV-negative patients (HIV-He). LA activity was recovered in IgG fractions from HIV + He, in the polyethylene glycol (PEG) precipitates from these sera, and in some cases in the supernatant fractions of PEG precipitates. Although the amount of PEG precipitates corresponding to circulating immune complexes (CIC) was higher in HIV + He than in HIV-He and normals, there was no direct relationship between CIC levels and LA. LA reacted both with autologous and with allogeneic polymorphonuclear leukocytes (PMN). In contrast to PMN isolated from HIV-He, HIV + He PMN had membrane associated IgG. In HIV + He, LA activity was more frequently observed in patients with more advanced stages of HIV infection than in asymptomatic individuals. Our results suggest that LA activity could be one of the manifestations of autoreactivity associated with progressing HIV infection in patients with hemophilia.

Anti-polymorphonuclear neutrophil antibodies in patients with leukopenia or neutropenia

Introduction:  Immune humoral neutropenia (Np) could be the consequence of anti‐polymorphonuclear neutrophil (PMN) antibodies, circulating immune complexes (CIC) and/or antibodies against myeloid precursors. Granulocyte immunofluorescence test (GIFT) and a leukoagglutination technique (LAGT) assays are recommended for its diagnosis.

Pilot study of homocysteine and cysteine in patients with thrombosis in different vascular sites. Epidemiology and response to folate.

Hyperhomocysteinemia is a risk factor for arterial and venous thrombosis. However, lowering homocysteine (Hcy) with vitamins not only failed to improve outcomes but also may lead to recurrent events. Our objectives were to evaluate Hcy and cysteine (Cys) levels in patients with thrombosis in different vascular sites, and their response to folate. One hundred and sixty four consecutive patients with thrombosis (42.1% arterial (AT), 36% venous (VT), 4.9% both venous and arterial thrombosis (AVT) and 17% unusual site (UST)) were included. Hcy and Cys were highest in patients with AVT and UST (p=0.0006). Ninety-three patients were treated, 70% were followed-up. Hcy levels normalized after therapy in all patients. Cys levels tended to vary after therapy according to the site of thrombosis. We observed a significant correlation between folate and Hcy (r: 0.48; p=0.005) among homozygous for MTHFR. A significant inverse relation was observed between Hcy and folate among homozygous and heterozygous (r: 0.462, p=0.007 and r: 0.267; p=0.04, respectively). No correlation was observed between folate and Cys. In conclusion, our observations suggest that Hcy and Cys might be implicated in thrombosis in different vascular sites, and respond differently to folate.

Paroxysmal nocturnal haemoglobinuria. Experience over a 10 years period

Paroxysmal nocturnal hemoglobinuria (PNH) is a hemolytic, clonal and acquired disorder of the hematopoietic stem cell with a deficiency of all glycophosphatidyl‐inositol (GPI) linked proteins. The aim of this retrospective study was to analyse haematological and biochemical data from 152 patients referred to our laboratory for diagnosis of PNH by flow cytometry (FC).

Prevalence of Anemia and Occult Blood Losses in the Long-Term Follow-Up of Cardiac Mechanic Valve Patients Treated with a Combination of Low-Dose Aspirin Plus Low-Intensity Acenocoumarin

Mechanic replacement of cardiac prostheses requires lifelong and high-intensity oral anticoagulant treatment. The addition of aspirin to coumarin treatment has resulted in more effective thromboembolic prevention, though it also led to increased (digestive) bleeding. Aspiriri enhanced the risk of apparent or occult gastrointestinal bleeding in a dose-dependent fashion. The combined use of low-dose aspirin/low-intensity coumarins might offer a safer approach. We prospectively evaluated the prevalence of anemia markers in 127 prosthesic valve patients, receiving two treatment modalities: Group A comprised 62 patients who received 100 mg acetylsalicylic acid (ASA) added to acenocoumarin [international normatized ratio (INR) 2.5-3.5]. Group B comprised 65 patients receiving acenocoumarin alone (INR, 3.5-4.5). We found no significant differences in the mean values for the blood markers of anemia or for the presence of blood losses in urine and feces. The addition of low-dose ASA to less intense chronic anticoagulation does not increase the risk of developing anemia. Key Words: Anticoagulants—Aspirin—Coumarins—Gastrointestinal hemorrhage—Heart valve prosthesis.