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Biomedical subjects

M C Novaretti

Publications and source records attributed to M C Novaretti.

4 recordsLinked to original sources

Immunohematological findings in myelodysplastic syndrome.

BACKGROUND: Few immunohematological studies have been done in myelodysplastic syndrome (MDS). METHODS: Twenty-nine MDS patients were retrospectively evaluated with a direct antiglobulin test (DAT), antibody screening, serum electrophoresis and immunoelectrophoresis. Clinical and laboratory studies (hemoglobin level, reticulocyte count, DHL, total and indirect bilirubin) were done simultaneously, as well as the French-American-British subtype and bone marrow biopsy findings. RESULTS: Alloantibodies were demonstrated in 17 patients (58.6%), autoantibodies in 10 (34.4%) patients and cold agglutinin in 18 (62%) patients. DAT was mediated by only IgG in 8 patients (80%), by IgG and C3 in 1 patient (10%) and by IgG, IgA and C3 in 1 (10%) patient. No hemolytic disease occurred in patients with autoantibodies. Increased serum gammaglobulin was observed in 16 (54.4%) patients. There was no correlation between the incidence of allo-/autoantibodies and the gammaglobulin level (p = 0.937) and the presence of lymphocyte infiltrates in bone marrow biopsies (p = 0.156). No significant difference was observed when the incidence of autoantibodies and number of red blood cell transfusions were compared (p = 0.334). Patients with refractory anemia and refractory anemia with ringed sideroblasts subtypes had a higher incidence of allo-/autoantibodies than other MDS subtypes (p = 0.03). CONCLUSION: Patients with MDS, in particular refractory anemia and refractory anemia with ringed sideroblasts have a high incidence of allo- and autoantibodies, probably related to intrinsic immune disorder, without clinical or laboratory hemolysis.

Adult↗

Comparison of tube and gel techniques for antibody identification.

There are several methods for antibody detection and each technique has advantages and limitations. We compared the performance of the tube (polyethylene glycol-indirect antiglobulin test [PEG-IAT]) and gel test technique for antibody identification. From January to May 1999, we performed antibody screening tests by gel and tube techniques on 10,123 random blood samples submitted to our reference laboratory. Six hundred and twenty-eight (6.2%) reactive samples were tested for antibody specificity by both methods. One hundred and ninety-six were reactive only by gel: 25 anti-D, 33 anti-C, 76 anti-E, 13 anti-c, 5 anti-e, 18 anti-K, 7 anti-Jka, 2 anti-Dia, 3 anti-S, 8 combination Rh antibodies (1 with anti- K), and 6 other antibody specificities. Two samples were reactive only by PEG-IAT: 1 anti-K and 1 anti-Dia. Four hundred and thirty were positive by the two methods: 156 anti-D, 9 anti-C, 68 anti-E, 15 anti-c, 6 anti-e, 61 anti-K, 12 anti-Jka, 17 anti-Dia, 5 anti-S, 73 combination Rh antibodies (2 with anti-K), and 8 other antibody specificities. Based on this study, the gel test is more sensitive (p <.01) than the tube test for identifying potentially clinically significant antibodies.

Journal Article↗

K phenotyping using a PK-7200 automated analyzer.

K (Kell) is one of the most immunogenic of the red blood cell (RBC) antigens. In order to select K- RBC units, we developed K phenotyping on the Olympus PK-7200 equipment to save labor, time, and costs. The Olympus PK-7200 is fully automated equipment used primarily for blood typing and syphilis screening. We tested 3,587 blood donor samples in EDTA using a commercial anti-K serum diluted in HP Hemagen Power Solution(1:40). The equipment was set to prepare a 1.7% RBC suspension in bromelain and to dispense 25 microL of the mixture (diluted serum and HP Hemagen Power Solution) in terraced microplates. After mixing, the microplates were incubated for 1 hour at 30 degrees C. Reading was performed by a C.C.D. camera and the results were automatically transferred to the mainframe computer. We found 185 K+ blood samples and 3,402 K- samples. Four samples, K+ by the PK-7200, were confirmed as K- by tube test. The use of bromelain with the PK-7200 may have caused the falsely positive tests. The Olympus PK-7200, used for K phenotyping, saves labor time and costs. It also reduces handling and thus promotes less contamination risk for laboratory personnel.

Journal Article↗

[Blood component transfusion in full-term and premature new born infants].

BACKGROUND: Blood transfusion requirements for preterm infants are greater than for newborn ones. We compare blood transfusion requirements for newborn and premature infants and their pathology: clinical or surgical; hemorrhagic accidents and survival. METHODS: 48 newborns classified in 2 groups: 26 newborn and 22 preterm infants received 251 units of blood components: 177 units of red cell concentrates, 36 of platelet concentrates, 30 of fresh frozen plasma and 8 of total blood in a 186 days period. We analyzed total requirements of components in each group and daily, under a live-infant/day rate until 120 days. RESULTS: The all-components median requirements were 7.31 units for premature and 3.46 for newborn infants. Daily requirements analyzes reveal that requirements were greater before 60th day of life (d.l.) on clinical patients and after 86th d.l. may be caused by surgical acts. Hemorrhagic accidents happen on premature with less than 60,000 platelets/mm3. The survival wave by number of transfusions, until 186 d.l., show an inversely proportional trend between the number of transfusions done and the hope of life. CONCLUSIONS: Blood requirements for preterm infants are greater than for term ones. Those requirements are related to their pathology. Prophylatic platelet transfusions may reduce hemorrhagic accidents then red blood cell transfusions in preterm infants group. The number of transfusions over 10 is a surrogate marker of bad prognosis for both groups up to 120 d.l.

Blood Component Transfusion↗