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| 2. |
- Gustavsen, Alice, et al.
(författare)
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Effect on mother and child of eculizumab given before caesarean section in a patient with severe antiphospholipid syndrome
- 2017
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Ingår i: Medicine. - 0025-7974. ; 96:11
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Tidskriftsartikel (refereegranskat)abstract
- Rationale: Antiphospholipid syndrome (APS) in pregnancy may trigger the life-threatening catastrophic antiphospholipid syndrome (CAPS). Complement activation is implicated in the pathogenesis, and inhibition of complement factor C5 is suggested as an additional treatment option. Patient concerns, diagnosis and interventions: We present a pregnant patient treated with the C5-inhibitor eculizumab due to high risk of developing devastating APS-related complications. The complement inhibitory effects of the treatment were examined both in the patient and the premature infant. Outcomes: Complement activity in the mother recovered considerably faster than anticipated; however, no new thrombosis or CAPS developed during the last week of pregnancy or postpartum. Blood sampling from the umbilical vein and artery, and from the infant after delivery showed low complement activity; however, only 0.3% of the eculizumab concentration detected in the mother, consistent with low placental passage of eculizumab. Lessons: The data underscore the importance of close monitoring of complement inhibition and individualizing dosage regimens in pregnant patients receiving eculizumab. We document how traditional functional complement activity tests cannot assess the effect of eculizumab in premature infants due to the very low levels of complement factors detected in this infant born in gestational week 33. Only trace amounts of eculizumab passed the placenta. In conclusion, complement C5 inhibition might be a safe candidate treatment option for APS during pregnancy and delivery, and additionally, enables prolongation of pregnancy with important weeks.
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| 3. |
- Nilsson, Per H., 1980-, et al.
(författare)
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Eculizumab-C5 complexes express a C5a neoepitope in vivo : Consequences for interpretation of patient complement analyses
- 2017
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Ingår i: Molecular Immunology. - : Elsevier. - 0161-5890 .- 1872-9142. ; 89, s. 111-114
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Tidskriftsartikel (refereegranskat)abstract
- The complement system has obtained renewed clinical focus due to increasing number of patients treated with eculizumab, a monoclonal antibody inhibiting cleavage of C5 into C5a and C5b. The FDA approved indications are paroxysmal nocturnal haemoglobinuria and atypical haemolytic uremic syndrome, but many other diseases are candidates for complement inhibition. It has been postulated that eculizumab does not inhibit C5a formation in vivo, in contrast to what would be expected since it blocks C5 cleavage. We recently revealed that this finding was due to a false positive reaction in a C5a assay. In the present study, we identified expression of a neoepitope which was exposed on C5 after binding to eculizumab in vivo. By size exclusion chromatography of patient serum obtained before and after infusion of eculizumab, we document that the neoepitope was exposed in the fractions containing the eculizumab-C5 complexes, being positive in this actual C5a assay and negative in others. Furthermore, we confirmed that it was the eculizumab-C5 complexes that were detected in the C5a assay by adding an anti-IgG4 antibody as detection antibody. Competitive inhibition by anti-C5 antibodies localized the epitope to the C5a moiety of C5. Finally, acidification of C5, known to alter C5 conformation, induced a neoepitope reacting identical to the one we explored, in the C5a assays. These data are important for interpretation of complement analyses in patients treated with eculizumab.
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- Nymo, Stig, et al.
(författare)
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Human Endothelial Cell Activation by Escherichia coli and Staphylococcus aureus Is Mediated by TNF and IL-1 beta Secondarily to Activation of C5 and CD14 in Whole Blood
- 2016
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 196:5, s. 2293-2299
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Tidskriftsartikel (refereegranskat)abstract
- Endothelial cells (EC) play a central role in inflammation. E-selectin and ICAM-1 expression are essential for leukocyte recruitment and are good markers of EC activation. Most studies of EC activation are done in vitro using isolated mediators. The aim of the present study was to examine the relative importance of pattern recognition systems and downstream mediators in bacteria-induced EC activation in a physiological relevant human model, using EC incubated with whole blood. HUVEC were incubated with human whole blood. Escherichia coli-and Staphylococcus aureus-induced EC activation was measured by E-selectin and ICAM-1 expression using flow cytometry. The mAb 18D11 was used to neutralize CD14, and the lipid A analog eritoran was used to block TLR4/MD2. C5 cleavage was inhibited using eculizumab, and C5aR1 was blocked by an antagonist. Infliximab and canakinumab were used to neutralize TNF and IL-1 beta. The EC were minimally activated when bacteria were incubated in serum, whereas a substantial EC activation was seen when the bacteria were incubated in whole blood. E. coli-induced activation was largely CD14-dependent, whereas S. aureus mainly caused a C5aR1-mediated response. Combined CD14 and C5 inhibition reduced E-selectin and ICAM-1 expression by 96 and 98% for E. coli and by 70 and 75% for S. aureus. Finally, the EC activation by both bacteria was completely abolished by combined inhibition of TNF and IL-1 beta. E. coli and S. aureus activated EC in a CD14- and C5-dependent manner with subsequent leukocyte secretion of TNF and IL-1 beta mediating the effect.
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