[Molecular genetics of the thalassemias in Argentina]. / Genética molecular de las talasemias en Argentina.

PURPOSE: Was to establish the molecular genetics of thalassemias in Argentina. PATIENTS AND METHODS: Genomic DNA was amplified by PCR and six point mutations in the beta-globin gene were investigated by Dot Blot hybridization using oligonucleotide probes. The most frequent alpha-thalassemia deletions were studied by Southern Blotting. Patients were distributed in 4 groups: a) 109 beta-thalassemic carriers; b) 15 thalassemia major patients; c) 2 thalassemia intermedia patients and d) 14 probable alpha-thalassemic carriers. RESULTS: The distribution of mutated alleles in the group a) was: IVS-1 nt 1: 13.76%, IVS-1 nt 6: 7.34%, IVS-1 nt 110: 23.85%, codon 39: 39.45%, IVS-2 nt 1: 3.68% e IVS-2 nt 745: 1.83%, 10.01% could not be determined with the probes used; in the group b) the allelic distribution was similar and the compound genetic genotype were predominant related to homocygous ones; in the group c): we confirmed the presence of one beta-thalassemia mutation and a alpha gene triplication (alpha alpha alpha) in the 2 patients studied. The alpha-thalassemia character was confirmed in 8 patients of the group d) (6 had -alpha 3,7/alpha alpha genotype and 2,-alpha 3,7/-alpha 3,7 genotype). CONCLUSIONS: This study indicates that the analysis of 6 mutations in the beta-globin gene and the alpha-globin gene deletions are an effective strategy to identify thalassemias in Argentina.

High-dose intravenous immunoglobulin in non-ABO transfusion incompatibility.

The administration of intravenous immunoglobulin (IVIG) in immune and autoimmune diseases led us to use this agent to ameliorate or prevent the consequences of non-ABO incompatible transfusions in patients who need this form of therapy. IVIG (400 mg/kg/day) was infused within 24 h of transfusion in 5 patients with: (1) intestinal angiodysplasia, gastrointestinal bleeding, and anti-Kpb; (2) paroxysmal nocturnal hemoglobinuria, anti-c, anti E, anti Fyb, anti-K and autoantibodies; (3) lymphoma and autoimmune hemolytic anemia (AIHA); (4) systemic lupus erythematosus (SLE), AIHA, and anti-D, and (5) SLE and AHIA. A sustained increase in hematocrit was noted and no transfusion reaction developed in any of the cases. A single dose of pretransfusion IVIG may therefore be a useful therapeutic alternative in patients for whom no compatible blood is available. Patients with severe anemia, allo- and autoantibodies, either showing hemolysis in their pathophysiology or not, cause a serious problem in any transfusion center, especially when dealing with emergencies. In order to reduce the risks of incompatible transfusions, different modalities have previously been attempted, all with poor results. In 1989 we reported the successful use of pretransfusional high-dose intravenous immunoglobulin (IVIG) in a patient with gastrointestinal bleeding and anti-Kpb. The transfusion of incompatible red blood cells improved the anemia and allowed the exploratory laparotomy to take place. A protocol was then developed based on this case administering pretransfusion IVIG in high doses for patients for whom no compatible blood (non-ABO) is available.

[Myelodysplastic syndrome: experience of the Study and Treatment of Bone Marrow Failure Group]. / Sindromes mielodisplásticos: experiencia del Grupo de Estudio y Tratamiento de las Insuficiencias Medulares (GETIM).

Myelodysplastic syndromes (SMD) were studied in 58 patients (37 men, 21 women; mean age 61 years, range 18-81) who were grouped according to FAB criteria (Table 1). None of them showed a secondary SMD to medullary toxic agents or cytostatic treatments although 5 presented concomitant neoplastic disease. Morphologic alterations in peripheral blood smears and bone marrow were registered by 3 hematologists working independently. The intracellular and extracellular iron deposits were evaluated in every case with Perls; peroxidase activity was determined in 16 patients and intraleucocitary alkaline phosphatase reaction was carried out in 17 patients. Twenty five patients (43%) had refractory anemia (RA); 10 (17%) sideroblastic anemia; 13 (25%) refractory anemia with excess of blasts (AREB); 3 (5%) AREB in transformation (AREB-T) and 7 myelomonocytic leukemia (LMMC). Clinical manifestations at diagnosis are described in Table 2. In the observation period there were cases of anemia requiring transfusion, bacterial infections, muco-cutaneous hemorrhage and hemorrhagic episodes in the central nervous system. In the bone marrow smears the cellularity was normal or increased in 53 cases and diminished in only 3. The degree of dysplastic characteristics (erythroid, granulocytic and megakaryocytic) ranged from low to severe. It was low in most of AR, being the erythroid population the most affected in AS and the granulocytic one in AREB and AREB-T. Patients with LMMC showed similar characteristics to those with myeloproliferative syndromes and the differential diagnosis were sometimes difficult, accounting for their separate inclusion in Table 4. Out of 23 patients, 5 presented clonal pathology detected in cytogenetic studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Sindromes mielodisplásticos: experiencia del Grupo de Estudio y Tratamiento de las Insuficiencias Medulares (GETIM). / [Myelodysplastic syndrome: experience of the Study and Treatment of Bone Marrow Failure Group]

Myelodysplastic syndromes (SMD) were studied in 58 patients (37 men, 21 women; mean age 61 years, range 18-81) who were grouped according to FAB criteria (Table 1). None of them showed a secondary SMD to medullary toxic agents or cytostatic treatments although 5 presented concomitant neoplastic disease. Morphologic alterations in peripheral blood smears and bone marrow were registered by 3 hematologists working independently. The intracellular and extracellular iron deposits were evaluated in every case with Perls; peroxidase activity was determined in 16 patients and intraleucocitary alkaline phosphatase reaction was carried out in 17 patients. Twenty five patients (43

) had refractory anemia (RA); 10 (17

) sideroblastic anemia; 13 (25

) refractory anemia with excess of blasts (AREB); 3 (5

) AREB in transformation (AREB-T) and 7 myelomonocytic leukemia (LMMC). Clinical manifestations at diagnosis are described in Table 2. In the observation period there were cases of anemia requiring transfusion, bacterial infections, muco-cutaneous hemorrhage and hemorrhagic episodes in the central nervous system. In the bone marrow smears the cellularity was normal or increased in 53 cases and diminished in only 3. The degree of dysplastic characteristics (erythroid, granulocytic and megakaryocytic) ranged from low to severe. It was low in most of AR, being the erythroid population the most affected in AS and the granulocytic one in AREB and AREB-T. Patients with LMMC showed similar characteristics to those with myeloproliferative syndromes and the differential diagnosis were sometimes difficult, accounting for their separate inclusion in Table 4. Out of 23 patients, 5 presented clonal pathology detected in cytogenetic studies.(ABSTRACT TRUNCATED AT 250 WORDS)