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N Duedari

Publications and source records attributed to N Duedari.

At least 37 records · Page 2Linked to original sources
PubMed1993

[Value of filariopheresis in the treatment of Loa loa filariasis].

To prevent the side effects as encephalitis, related with diethylcarbamazine treatment in loiasis, an exchange blood transfusion was proposed. To avoid the disadvantage of this heavy technique, the authors are proposing filariopheresis to trap the microfilariae using cytapheresis technique and filtration. They obtained a medium 75 p. cent microfilariae extraction: 55-70 p. cent by cytapheresis and 5-20 p. cent by filtration. The number of blood cells must be supervised as an important decrease of the platelets may occur temporary. This simple and not expensive technique is efficient, but diethylcarbamazine treatment must be instituted very quickly after filariopheresis session. Furthermore, the millions of microfilariae collected can provide useful antigen for immuno-parasitological tests.

Adult↗
PubMed1992

Frequency of the polymorphonuclear neutrophil Fc gamma receptor III deficiency in the French population and its involvement in the development of neonatal alloimmune neutropenia.

We report the case of a healthy woman (K.M.) who, after multiple pregnancies, developed an antibody directed against a nonpolymorphic region of the polymorphonuclear neutrophil (PMN) Fc gamma receptor III (FcRIII-CD16), which caused transient neonatal alloimmune neutropenia (NAIN). The antigenic target of the antibody was determined by an immunoprecipitation procedure and by phenotyping the mother's PMN. These latter did not react with monoclonal CD16 or polyclonal and monoclonal NA1 and NA2 antibodies, demonstrating the absence of PMN-FcRIII and, consequently, the NA-null phenotype. We also determined the frequency of the NA-null phenotype in a healthy, white population. Among 3,377 random blood donors, only four (in addition to K.M.) were PMN-FcRIII-deficient. These five individuals were healthy and only one (K.M.) presented an allo-CD16 antibody. The gene frequency of the NA-null phenotype was calculated as 0.0274 +/- 0.0059. We conclude that PMN-FcRIII deficiency is a rare phenomenon that can lead to CD16 alloimmunization and thus cause NAIN.

Antigens, CD↗
PubMed1992

Platelet alloimmunization after multiple transfusions: a prospective study of 50 patients.

Fifty polytransfused patients were prospectively studied to determine the frequency of post-transfusion alloimmunization and its influence on the response to platelet transfusion. Platelet- and HLA-specific antibodies were detected by means of the standard and antiglobulin-augmented lymphocytotoxicity techniques (LCT), the platelet suspension indirect immunofluorescence test (PSIIFT), and monoclonal antibody immobilization of platelet antigens (MAIPA). HLA antibodies were detected in 13 patients (26%) (IgM = 6; IgG = 6; IgM + IgG = 1). The standard LCT was positive in 12 of these 13 patients. Complement-independent HLA antibodies, only detectable in the PSIIFT and the antiglobulin-augmented LCT, were documented in two patients and were associated with poor post-transfusion platelet recovery in the patient who could be evaluated. All the HLA antibodies were detected in the PSIIFT, while only four were detected in the MAIPA. Platelet-specific alloantibodies were found in two patients by means of PSIIFT or MAIPA and may have led to poor post-transfusion platelet recovery in one patient. Platelet autoantibodies were detected in two patients but were not associated with platelet refractoriness. Paraformaldehyde-dependent platelet antibodies were detected in 11 patients but were not associated with platelet refractoriness.

Adolescent↗
PubMed1991

Brb, a platelet alloantigen involved in neonatal alloimmune thrombocytopenia.

Serum from a pregnant woman with the May-Hegglin anomaly contained a platelet-specific antibody. The serum reacted in the platelet indirect immunofluorescence test (PIIFT) with 97.6% of random donor platelets and those of the father but not with the mother's own platelets. This antibody induced a moderate thrombocytopenia in the infant that responded to infusion of intravenous immunoglobulin concentrates. The platelet phenotypes were PLA1+, Baka+, Bra+/Brb- for the mother, PLA1+, Baka+, Bra-/Brb+ for the father, and PLA1+, Bra+/Brb+ for the neonate. Analysis of the maternal serum with an immunoassay based on monoclonal antibody immobilization of platelet antigens (MAIPA) and immunoprecipitation techniques demonstrated the absence of antibodies directed against HLA class I antigens and that the antigen recognized was located on the platelet-GpIa/IIa complex. This antigen was present on 113/115 random donor platelets, in 7 of the 7 unrelated May-Hegglin platelets, and only absent in 3/24 Bra+ individuals, including the mother. No platelet-specific antibody was present in the serum of the 7 unrelated May-Hegglin subjects. The antigen recognized by this platelet-specific antibody thus meets the criteria defining the antithetic allele of Bra, i.e. the Brb alloantigen.

Adult↗
PubMed1991

A simple, efficient washing procedure for cryopreserved human hematopoietic stem cells prior to reinfusion.

We describe our experience with a washing procedure used on cryopreserved, thawed bone marrow (BM) and peripheral blood stem cell (PBSC) grafts prior to autologous transplantation in 50 and 12 patients respectively. The procedure consists of a stepwise dilution with 2% human serum albumin and centrifugation performed either manually or using a blood cell processor (Cobe 2991). In vitro studies showed mean recoveries of 80.8% for BM nucleated cells and 73.9% for BM hematopoietic progenitors (CFU-GM). The corresponding recoveries for PBSC were 89.1 and 93.9%. After 4 h storage at +20 degrees C of the manipulated grafts, no significant loss of CFU-GM was observed. We conclude that the technique is simple and efficient for washing large numbers of hematopoietic stem cells. This method may avoid the clinical complications often arising with unwashed grafts.

Blood Cells↗
PubMed1990

[Post-transfusion purpura. An unknown cause of acute immune thrombocytopenia. 4 new cases].

Post-transfusion purpura is characterized by the occurrence of acute immune thrombocytopenia 5 to 10 days after transfusion of platelet-containing blood products in subjects who had been alloimmunized to specific platelet antigens. Four cases are reported here. Three of these 4 patients, who had a rare PLA1 platelet phenotype, had developed, during a previous sensitization (pregnancy n = 2, transfusion n = 1), an allo antibody directed against PLA1 antigen. The fourth patient presented a specific anti-PLA2 antibody. Thrombocytopenia (platelet count between 4 and 40 x 10(9)/1) appeared 1 to 12 days after the responsible transfusion and showed as haematomas (n = 3) or haemoptysis (n = 1). One patient was asymptomatic and remained untreated. The remaining 3 patients received corticosteroids orally associated, in one case, with infusions of human immunoglobulin concentrates. Thrombocytopenia was corrected within 5 to 13 days. In such cases, whenever another blood transfusion is necessary, a preventive treatment with perfectly platelet-free blood products is mandatory. Platelet depletion by freezing-thawing of red cell concentrates is probably not always sufficient, since recurrence was observed with such a product in one of our patients. The exact cause of immune destruction of autologous platelet remains a mystery.

Adult↗
PubMed1989

Immunochemical analysis of platelet autoantibodies in HIV-related thrombocytopenic purpura: a study of 68 patients.

Serum antiplatelet IgG and platelet-associated IgG (PAIgG) were studied in 68 AIDS-free human immunodeficiency virus (HIV)-infected patients with severe immunologic thrombocytopenic purpura (ITP), for the presence of platelet autoantibodies. Serum IgG with antiplatelet activity was found in 72% of the sera. However, the presence of autoantibodies against platelet surface glycoproteins was not found in these sera by means of Western blot and immunoprecipitation procedures. Nevertheless, an immunoblot immunoassay and an indirect immunofluorescence test against semi-permeabilized platelets demonstrated the presence of antibodies in the patient sera, that reacted with intracytoplasmic platelet components, and which might participate in the elimination of platelet fragments. Direct immunofluorescence tests demonstrated an increased amount of PAIgG in 75% of the patients; the bound antibodies could be eluted with ether in 44% of the cases. These eluates were found to bind to normal platelets but not to Glanzmann type I platelets. Finally, immunoprecipitation procedures demonstrated the presence of platelet autoantibodies in six of the 35 eluates studied. These antibodies recognized GPIIb in two cases, GPIIIa in one case, and an unidentified platelet protein of 150 kDa in the three other cases. The discrepancy between sera and platelet eluates was interpreted as being due to the low titre of the antibodies and to their dilution in polyclonal hypergammaglobulinaemia. The present study provides direct evidence that isolated ITP in some HIV-positive patients is due to the presence of platelet autoantibodies. These results, however, do not exclude either direct or indirect involvement of HIV in the platelet destruction.

Autoantibodies↗
PubMed1989

Hemopoietic reconstitution after repeated autologous transplantation with mafosfamide-purged marrow.

Twenty-nine children (median age: 41 months) with advanced solid tumors received, as consolidation therapy, two consecutive courses of high-dose chemotherapy (HDC) followed by mafosfamide-purged autologous marrow transplantation (ABMT) with a 3- to 4-month interval between each course. The malignancies were neuroblastoma (n = 22), Ewing's sarcoma (n = 5) and rhabdomyosarcoma (n = 2). Patients received a preparatory regimen consisting of combined high-dose melphalan before each ABMT, with the exception of five patients who received busulfan and cyclophosphamide before the second ABMT. Prior to HDC, bone marrow sufficient for two transplantations was harvested in remission, treated with mafosfamide (50 micrograms/ml) and cryopreserved. Following incubation with the drug, a consistent inhibition (greater than 99%) of granulocyte and macrophage colony-forming units was observed. Despite the elimination of measurable hematopoietic progenitors, all patients underwent engraftment within a similar period of time after the first and the second ABMT. However, peripheral leukocyte and granulocyte recovery was delayed (median 26 and 28 days, respectively, after the first graft; median 27 and 28 days after the second graft). No difference was observed in the bacterial infections following the first and second ABMT. One patient died after the second transplant with diffuse aspergillosis. Recovery to 50 x 10(9) platelets/l occurred after a median 42 days (range 19-71) after the first ABMT and 43 days (range 14-110) after the second. Two patients died of recurrent disease before attaining a normal platelet level. One patient remained thrombocytopenic and died from visceral failure at day 200. These results demonstrate the feasibility of repeated ABMT with mafosfamide-treated marrow.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Early immunization against platelet glycoprotein IIIa in a newborn Glanzmann type I patient.

Alloimmunization against platelet glycoprotein IIb and/or IIIa is a complication rarely observed during the evolution of type I Glanzmann's thrombasthenic patients. The occurrence of such alloantibodies is usually due to repeated blood transfusion and greatly complicates the treatment of these patients since they prevent effective platelet transfusion and might, theoretically, cause posttransfusion purpura. We describe the case of a newborn thrombasthenic patient who developed an IgG platelet allo-antibody 1 month after birth. The diagnosis of Glanzmann's thrombasthenia was complicated by the rare platelet phenotype (PLA1-negative PLA2-positive) of the healthy mother, which was probably heterozygous for the abnormal thrombasthenic gene. Immunofluorescence and immunoblotting techniques demonstrated that the patient antibody was principally directed against the platelet glycoprotein IIIa. Surprisingly, this patient had only received four blood transfusions (fresh frozen plasma on days 1 and 2, and standard red blood cell concentrates on days 5 and 6) before the discovery of the antibody, suggesting prior in utero sensitization. This study emphasizes the need for early diagnosis of the disease. Thrombasthenic patients should be transfused with deleukocyted platelet-free blood products.

Blood Platelet Disorders↗
PubMed1988

[Changes in serum lipids and lipoproteins in 3 cases of heterozygous familial hypercholesterolemia treated by LDL apheresis on dextran sulfate-cellulose columns].

Three patients with heterozygote type IIa hyperlipoproteinemia were treated by specific LDL apheresis with a dextran sulfate-cellulose column every two weeks. Each apheresis resulted in a fall in total cholesterolemia of about 50 p. 100 with a parallel fall in apoprotein B. The average drop of 15 p. 100 in HDL-cholesterol appeared to be due to the hemodilution induced at the end of apheresis. After two months, cholesterol and apoprotein B concentrations before removal were 15 p. 100 lower than baseline values. Treatment was well tolerated. These findings appear encouraging for the treatment of heterozygote forms of familial hyperlipoproteinemia resistant to chemotherapy.

Adult↗
PubMed1987

Persistent remission of adult chronic autoimmune thrombocytopenic purpura after treatment with high-dose intravenous immunoglobulin.

Transient efficacy of high-dose intravenous immunoglobulin infusions (HDI) is widely demonstrated in autoimmune thrombocytopenic purpura (AITP). A trial involving repeated injections of HDI was conducted in two adult patients with chronic AITP in order to evaluate their long-term efficacy in refractory forms and their ability to obviate splenectomy. Both patients received 2 g/kg body weight of polyvalent intact intravenous immunoglobulin followed by seven and eight boosters (0.8 to 1.2 g/kg body weight) when the platelet count decreased. It was found that the injections could be spaced progressively. The platelet count remained normal 200 and 800 days after the end of the treatment. The demonstration of the possible long-term efficacy of repeated injections of intravenous immunoglobulin encourages us to recommend this safe therapy for patients with chronic AITP.

Adult↗
PubMed1987

Effects of irradiation on human platelets stored at 20 degrees C.

The morphologic and functional properties of platelets after irradiation with 2500 rads and storage, in first-generation containers, for 48 h in a liquid phase at 20 degrees C with continuous horizontal agitation have been analyzed and compared with a control group of the same platelets which were not irradiated. The preservation technique induced changes in the morphology and aggregation stimulated by ADP and collagen. However, no significant differences were found between the irradiated and non-irradiated groups. Irradiation is not a conditioning factor to add to the hazards of preserving platelets in a liquid phase.

Adenosine Diphosphate↗