| 1. |
- Nilsson Ekdahl, Kristina, et al.
(författare)
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An improved method to study complement receptor-mediated function of the fixed macrophage system in vivo
- 1991
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Ingår i: Vox Sanguinis. - : Wiley. - 0042-9007 .- 1423-0410. ; 61:1, s. 47-52
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Tidskriftsartikel (refereegranskat)abstract
- A method to coat unsensitized erythrocytes with fragments of C3 and C4 using autologous serum, in order to study complement receptor-dependent function of the fixed macrophage system, is presented. After incubation with serum under optimal conditions, at least 90% of the cells had C3b/iC3b deposited on the surface, with an average of 20 × 103 molecules per cell. Elimination of the coated cells by the fixed macrophage system was studied in 12 normal subjects. With a dose of 4.5 × 108 red cells injected, 75% of the cells were eliminated with a half-life of approximately 2.4 ± 0.3 min (n = 7). In subjects receiving ten times more cells, there was a rapid decrease in the amount of C3-coated cells, reaching a nadir with 85% remaining for 4–6 min, after which there was a gradual release of cells for another 20 min (n = 5). In absolute numbers, 3 × 108 of labeled cells were eliminated regardless of the dose injected. The coating procedure presented here is simple, does not introduce heterologous blood components and makes it possible to control the amount and the degree of fragmentation of the C3 and C4 deposited on the erythrocyte surface.
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| 2. |
- Gong, J, et al.
(författare)
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Complement killing of Yersinia enterocolitica and retention of the bacteria by leucocyte removal filters.
- 1994
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Ingår i: Vox Sanguinis. - 0042-9007 .- 1423-0410. ; 66:3, s. 166-170
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Tidskriftsartikel (refereegranskat)abstract
- We report studies on the complement sensitivity of four strains of Yersinia enterocolitica, serotypes O:3, O:9, O:5.27, and O:20, isolated from blood units involved in transfusion fatalities. Complement in fresh CPD plasma killed Y. enterocolitica within 4 h at 22 degrees C in 100% of the experiments. The bactericidal action was serotype and complement activation pathway dependent. Both classic and alternate pathways seemed to be active, but the latter to a lesser degree. When the classic pathway was blocked by chelation of Ca2+ no complete killing was obtained. Complement did not enhance or condition Yersinia for leucocyte filter retention. Direct removal of Yersinia by filtration was also related to serotype; all strains were reduced by filtration in heat-inactivated plasma, and all except serotype O:5.27 were reduced in Ca(2+)-chelated plasma. Our findings may explain why plasma products and platelet concentrates are rarely involved in Yersinia sepsis related to transfusion.
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| 3. |
- Nilsson, B, et al.
(författare)
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A simplified assay for the specific diagnosis of paroxysmal nocturnal hemoglobinuria : detection of DAF(CD55)- and HRF20(CD59)- erythrocytes in microtyping cards.
- 1993
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Ingår i: Vox Sanguinis. - 0042-9007 .- 1423-0410. ; 64:1, s. 43-46
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Tidskriftsartikel (refereegranskat)abstract
- Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disease that is caused by a monoclonal stem cell defect. The affected cells lack the carbohydrate linkage between phosphatidylinositol and a group of membrane proteins of which three protect the cell against complement lysis. The absence of these three proteins, DAF(CD55), C8BP and HRF20(CD59), makes cells from the erythropoiesis, thrombopoiesis and myelopoiesis extensively sensitive to complement attack and affected patients suffer from intravascular hemolysis, thrombosis and increased susceptibility to infections. In this study we describe a swift and specific assay for the detection of CD55- and CD59- erythrocytes, which is suitable for screening of possible PNH patients.
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| 4. |
- Blomberg, L, et al.
(författare)
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Improved removal of anti-A and anti-B antibodies from plasma using blood-group-active haptens
- 1993
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Ingår i: Vox Sanguinis. - 1423-0410. ; 65:2, s. 126-135
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Tidskriftsartikel (refereegranskat)abstract
- Highly efficient anti-blood group A and B immunoadsorbents for extracorporeal treatment were developed by immobilizing A and B trisaccharide and A tetrasaccharide haptens on Sepharose 4FF and Fractogel TSK using three different methods. The adsorption of the IgG and IgM anti-A antibodies was essentially the same regardless of the A hapten used or the method of oligosaccharide coupling. The adsorption of IgM anti-A was found to be more sensitive than IgG anti-A to changes in column flow rate. The binding of both the IgM and IgG antibodies was slightly lower at 37 degrees C than at 22 degrees C. An anti-A/anti-B adsorbent column potentially suitable for treatment of patients was prepared. A column switching system resulted in a more efficient adsorption of antibodies. Hapten leakage from the column was very low. No nonspecific adsorption of plasma proteins to the column (other than traces of albumin) could be detected.
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| 5. |
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| 6. |
- Shev, S, et al.
(författare)
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Second-generation hepatitis C Elisa antibody tests confirmed by the four-antigen recombinant immunoblot assay correlate well with hepatitis C viremia and chronic liver disease in Swedish blood donors
- 1993
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Ingår i: Vox Sanguinis. - 1423-0410. ; 65:1, s. 32-37
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Tidskriftsartikel (refereegranskat)abstract
- Seventy-three Swedish blood donors (52 men, 21 women; median age 36 years) repeatedly reactive for hepatitis C antibodies (anti-HCV C-100-3) were tested with a second-generation (2nd-gen) anti-HCV Elisa and a 4-band recombinant immunoblot assay (RIBA 2). These results were correlated to serum alanine aminotransferase (S-ALAT), liver morphology and viremia as detected by 'nested' polymerase chain reaction (PCR) based on primers from a 5'-noncoding sequence of the HCV genome. Thirty-five of 46 (76%) donors with positive 2nd-gen Elisa tests confirmed by RIBA 2 were PCR positive whereof 27 had histological findings compatible with chronic persistent hepatitis (CPH) and 7 had chronic active hepatitis (CAH). Ten of 56 (18%) 2nd-gen Elisa-positive donors were RIBA 2 negative (or indeterminate) and none of these had chronic hepatitis nor were PCR positive. Seventeen of 73 (23%) donors were 1st-gen Elisa positive but 2nd-gen Elisa negative. All of these were PCR negative and only 1 (6%) had chronic hepatitis (CPH). An elevated S-ALAT level (reference < 0.7 mu kat/l) was found in 26 2nd-gen Elisa and RIBA 2-positive donors of which 18 had CPH and 7 had CAH and all 25 were PCR positive. A normal S-ALAT level was found in 9 of 34 (26%) donors with chronic hepatitis (all had CPH) and positive PCR. We have found that blood donors with positive 2nd-gen anti-HCV Elisa tests confirmed by RIBA-2 and especially with a concomitant elevated S-ALAT are highly likely to be viremic as demonstrated by PCR and to have chronic hepatitis.
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| 7. |
- Widell, Anders, et al.
(författare)
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Antibody to hepatitis-C-virus-related proteins in sera from alanine-aminotransferase-screened blood donors and prospectively studied recipients
- 1991
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Ingår i: Vox Sanguinis. - 1423-0410. ; 60:1, s. 28-33
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Tidskriftsartikel (refereegranskat)abstract
- A prospective study of posttransfusion non-A, non-B hepatitis was conducted in Malmo, Sweden, in 1984-1985, in which donors were alanine aminotransferase (ALT) screened but not ALT selected. Among 741 patients studied at 0, 6, and 12 weeks after transfusion, 13 developed non-A, non-B hepatitis, and these were further followed up. Stored sera from the 13 hepatitis patients and their 123 donors were tested for anti-hepatitis C virus (HCV) by ELISA and if positive, analyzed by recombinant immunoblot assay (RIBA). All ALT-elevated blood units (n = 301) and a similar number of ALT-normal units were also tested. Only 4/13 patients with non-A, non-B hepatitis seroconverted to anti-HCV, all with ALT peaks greater than 10 times the upper normal. All seroconversions occurred within 5 months after transfusion and could be confirmed by RIBA. Hepatitis C in recipients occurred both after transfusion of blood that was strongly positive, weakly positive, and/or negative for anti-HCV by ELISA. In donors grouped by ALT levels, the anti-HCV prevalence varied between 0.4 (normal ALT) and 14% (ALT elevated greater than or equal to 2 times). Of the total of 9 donor units positive by ELISA, only 5 were confirmed by RIBA. Of the 5 recipients of the RIBA-positive blood units, 3 went into hepatitis, 1 remained normal at 10.5 weeks, and 1 showed a slight, transient ALT elevation at week 12. The recipients of ELISA-positive but RIBA-negative blood remained healthy.
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