| 1. |
- Dezfouli, Mahya, et al.
(författare)
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Newborn Screening for Presymptomatic Diagnosis of Complement and Phagocyte Deficiencies
- 2020
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Ingår i: Frontiers in Immunology. - : FRONTIERS MEDIA SA. - 1664-3224. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- The clinical outcomes of primary immunodeficiencies (PIDs) are greatly improved by accurate diagnosis early in life. However, it is not common to consider PIDs before the manifestation of severe clinical symptoms. Including PIDs in the nation-wide newborn screening programs will potentially improve survival and provide better disease management and preventive care in PID patients. This calls for the detection of disease biomarkers in blood and the use of dried blood spot samples, which is a part of routine newborn screening programs worldwide. Here, we developed a newborn screening method based on multiplex protein profiling for parallel diagnosis of 22 innate immunodeficiencies affecting the complement system and respiratory burst function in phagocytosis. The proposed method uses a small fraction of eluted blood from dried blood spots and is applicable for population-scale performance. The diagnosis method is validated through a retrospective screening of immunodeficient patient samples. This diagnostic approach can pave the way for an earlier, more comprehensive and accurate diagnosis of complement and phagocytic disorders, which ultimately lead to a healthy and active life for the PID patients.
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| 2. |
- Grosso, Giorgia, et al.
(författare)
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The Complex Relationship between C4b-Binding Protein, Warfarin, and Antiphospholipid Antibodies
- 2021
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Ingår i: Thrombosis and Haemostasis. - : Georg Thieme Verlag KG. - 0340-6245 .- 2567-689X. ; 121:10, s. 1299-1309
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Tidskriftsartikel (refereegranskat)abstract
- Background Low levels of total C4b-binding protein (C4BPt), a circulating inhibitor of the classical/lectin complement pathways, were observed in patients with antiphospholipid antibodies (aPLs) and during warfarin treatment. Objectives To investigate the associations between aPL and C4BPt in patients with persistently positive (++) aPL, with/without clinical manifestations and systemic lupus erythematosus (SLE), and in controls. Furthermore, we explored the impact of anticoagulation on C4BPt and in relation to complement activation. Methods In a cross-sectional design we investigated defined subgroups: primary (p) antiphospholipid syndrome (APS, N =67), aPL++ individuals without clinical manifestations (aPL carriers, N =15), SLE-aPL++ ( N =118, among them, secondary [s] APS, N =56), aPL negative (-) SLE (SLE-aPL-, N =291), and 322 controls. Clinical characteristics, including treatment, were tabulated. C4BPt was determined with a magnetic bead method. Complement proteins (C1q, C2, C3, C4, C3a, C3dg, sC5b-9, factor I [FI]) were measured. A mediation analysis was performed to decompose the total effect of aPL++ on C4BPt into the direct and indirect effects of aPL++ through warfarin. Results Overall, C4BPt is 20% decreased in aPL++ patients, regardless of SLE, APS, clinical manifestations, and aPL profile. C4BPt levels associate positively with complement proteins C1q, C2, C3, and C4, and negatively with complement activation product C3dg. In the SLE group, warfarin treatment contributes to approximately half of the C4BPt reduction (9%) Conclusion Both aPLs and warfarin are associated with C4BPt reduction. Complement activation in aPL++ patients may partly be explained by impaired inhibition through depressed C4BPt levels. Further studies are needed to understand the clinical implications.
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| 3. |
- Lundtoft, Christian, et al.
(författare)
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Combined genetic deficiencies of the classical complement pathway are strongly associated with both systemic lupus erythematosus and primary Sjögren's syndrome
- 2022
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Ingår i: Arthritis & Rheumatology. - : Wiley. - 2326-5205 .- 2326-5191. ; 74:11, s. 1842-1850
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveComplete genetic deficiency of the complement component C2 is a strong risk factor for monogenic systemic lupus erythematosus (SLE), but whether heterozygous C2 deficiency adds to the risk of SLE or primary Sjögren's syndrome (pSS) has not been studied systematically. Here we investigated heterozygous C2 deficiency and C4 copy number variation in relation to clinical manifestations in SLE and pSS.MethodsThe presence of the common 28-bp C2 deletion rs9332736 and C4 copy number variation was examined in Scandinavian patients diagnosed with SLE (n=958) or pSS (n=911), and 2,262 controls using DNA sequencing. Plasma concentration of complement proteins and classical complement function was analysed in a subgroup of patients.ResultsHeterozygous C2 deficiency – when present in combination with a low C4A copy number – substantially increased the risk of SLE (OR=10.2, CI95%: 3.5-37.0) and pSS (OR=13.0, CI95%: 4.5-48.4) when compared to individuals with two C4A copies and normal C2. For patients heterozygous for rs9332736 with one C4A copy, the median age of diagnosis was 7 years and 12 years earlier in SLE and pSS, respectively. Reduced plasma C2 (p=2x10-9) and impaired function of the classical complement pathway (p=0.03) was detected in SLE patients with heterozygous C2 deficiency. Finally, we describe a pSS patient with homozygous C2 deficiency.ConclusionWe demonstrate that the combination of partial deficiencies of C2 and C4A in the classical complement pathway is a strong risk factor for SLE and pSS. Our results emphasise the central role of the complement system in the pathogenesis of both diseases.
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