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- Elbagir, Sahwa, et al.
(author)
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Elevated IgA antiphospholipid antibodies in healthy pregnant women in Sudan but not Sweden, without corresponding increase in IgA anti-β2 glycoprotein I domain 1 antibodies
- 2020
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In: Lupus. - : SAGE Publications. - 0961-2033 .- 1477-0962. ; 29:5, s. 463-473
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Journal article (peer-reviewed)abstract
- Objective: The role of antiphospholipid antibodies (aPL) during apparently normal pregnancy is still unclear. IgA aPL are prevalent in populations of African origin. Our aim was to measure all isotypes of anticardiolipin (anti-CL) and anti–β2 glycoprotein I (anti-β2GPI) in healthy pregnant and non-pregnant women of different ethnicities.Methods: Healthy Sudanese pregnant women (n = 165; 53 sampled shortly after delivery), 96 age-matched Sudanese female controls and 42 healthy pregnant and 249 non-pregnant Swedish women were included. IgA/G/M anti-CL and anti-β2GPI were tested at one time point only with two independent assays in Sudanese and serially in pregnant Swedes. IgA anti-β2GPI domain 1 and as controls IgA/G/M rheumatoid factor (RF), IgG anti–cyclic citrullinated peptide 2 (anti-CCP2) and anti–thyroid peroxidase (anti-TPO) were investigated in Sudanese females.Results: Pregnant Sudanese women had significantly higher median levels of IgA anti-CL, IgA anti-β2GPI (p < 0.0001 for both antibodies using two assays) and IgM anti-β2GPI (both assays; p < 0.0001 and 0.008) compared with non-pregnant Sudanese. IgA anti-CL and anti-β2GPI occurrence was increased among Sudanese pregnant women compared with national controls. No corresponding increase during pregnancy was found for IgA anti-β2GPI domain 1 antibodies. Both IgG anti-CL and IgG control autoantibodies decreased during and directly after pregnancy among Sudanese. Serially followed Swedish women showed no changes in IgA aPL, whereas IgG/M anti-CL decreased.Conclusions: IgA aPL are increased in Sudanese but not in Swedish women, without corresponding increase in IgA domain 1. Whether due to ethnicity and/or environmental influences the occurrence of IgA aPL during Sudanese pregnancies, and its clinical significance, is yet to be determined.
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- Elbagir, Sahwa, et al.
(author)
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High IgA anti-phospholipid autoantibodies in healthy Sudanese explains the increased prevalence among Sudanese compared to Swedish systemic lupus erythematosus patients
- 2020
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In: Lupus. - : Sage Publications. - 0961-2033 .- 1477-0962. ; 29:11, s. 1412-1422
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Journal article (peer-reviewed)abstract
- Objectives: IgA antiphospholipid antibodies (aPL) are prevalent in systemic lupus erythematosus (SLE) patients of African American, Afro-Caribbean and South African origin. Nevertheless, data from North Africa are lacking, and most studies use manufacturer-suggested cut-offs based on Caucasian controls. Therefore, we compared aPL isotypes in Sudanese and Swedish SLE patients using nation-based cut-offs.Methods: Consecutive SLE patients and age- and sex-matched controls from Sudan (N = 115/106) and Sweden (N = 340/318) were included. All patients fulfilled the 1982 American College of Rheumatology SLE classification criteria. Antiphospholipid syndrome-related events were obtained from patients' records. IgA/G/M anticardiolipin and anti-β2 glycoprotein I (β2GPI) were analysed with two independent assays. IgA anti-β2GPI domain 1 (D1) was also investigated. Manufacturers' cut-offs and the 95th and 99th percentile cut-offs based on national controls were used.Results: Sudanese patients and controls had higher levels and were more often positive for IgA aPL than Swedes when using manufacturers' cut-offs. In contrast, using national cut-offs, the increase in IgA aPL among Sudanese patients was lost. Occurrence of IgA anti-D1 did not differ between the countries. Venous thromboses were less common among Sudanese patients and did not associate with aPL. No clinical associations were observed with IgA anti-β2GPI in Sudanese patients. Thromboses in Swedes were associated with IgG/M aPL. Fetal loss was associated with aPL in both cohorts.Conclusions: IgA anti-β2GPI prevalence was higher among Sudanese compared to Swedish patients when manufacturers' cut-offs were used. This situation was reversed when applying national cut-offs. Anti-D1 was not increased in Sudanese patients. Previous studies on populations of African origin, which demonstrate a high prevalence of IgA aPL positivity, should be re-evaluated using a similar cut-off approach.
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